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Delage 15-S-8 Grand Prix (1/8)


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@Pouln welcome to the thread and thank you for your suggestion. Following your remark I changed the term 'rotating disk' to 'spindle'. I tried to keep the use of terminology as limited as possible (=to those parts that are actually applied / actuated).

 

I think I will use more terminology, such as headstock, along the way, possibly in small print for those who are interested in that. The main text (=summaries of what's to follow) can be made in large print and the details in small print. What do you think of that idea?

 

 

6a. Milling machine

A milling machine can be compared to a vertical drilling machine. In the latter, a drill chuck or collet chuck can be mounted, which in its turn holds a drill bit. The workpiece is firmly clamped onto the drilling machine's bed. Then the drilling bit is moved downwards by pulling a lever. This way a hole is drilled in the workpiece. 

 

In what aspect is a milling machine different? The big difference is that with a drilling machine it's only possible to remove metal in the direction of the drill. For example a handheld drilling machine is used to drill a hole in the wall, a vertical drilling machine is used to drill a hole in the workpiece. You can only drill round holes; the drill bit has only one cutting face. 

 

On the other hand, a milling bit is not only sharp on one side, but also on its sides. Try to see it as a three-dimensional knife that -whatever direction you're moving it to- will cut anywhere. It's sharp on all sides. Using a milling machine you can not only drill a hole (downward) but you can also cut metal sidewards. Compare with engraving letters... this can be seen as 'miniature milling'. 

32154410314_b64668c83a_b.jpg

While milling, the milling head will always stay in the same lateral position (it can only be lowered or raised), but the workpiece is moved. Usually a milling machine features a table with two hand wheels, one to move the workpiece to the left or to the right, the other to move the work piece to the front or to the back. 

 

In my workshop situation the milling machine is attached to the lathe, so that there is no need for a separate bed with hand wheels. Instead, the tool holder of the lathe is used (photo 5a, part 'b'). A disadvantage of this is that each time I'll want to change between lathe and milling machine, the tool holders will have to be replaced by the (small) milling machine bed. There are also advantages: this construction is less expensive than two separate machines. More importantly for me, it saves a lot of space. I live in an apartment in Amsterdam and simply don't have the space for a separate milling machine of reasonable size. There are more advantages, but these are the most important ones. 

6b. Collets

32873577311_63a5606bc7_b.jpg
 

In a lathe, collets are used to mount workpieces. On the other hand in a milling machine, (different) collets are used to mount milling bits. The system is similar to that of a multitool (Dremel for example). 

6c. Milling bits

32844134472_c63483045b_b.jpg

On this photo you can see the regular milling bits (2 to 10 millimeters). As mentioned, milling bits can be considered as drill bits that can remove metal not only downwards but also sidewards. 

6d. Micro-milling bits and corner bit

32957666676_234fc59f32_b.jpg

To remove small bits of metal, small milling bits are required. On the photo you see bits with diameters from 0,3mm. to 1mm. My dentist has promised me to collect used specimens (that can still be useful for cutting soft aluminium). 

 

In the top of the photo you see a diagonal cutter. 

6e. Vise with parallels

32873580791_eaece73bf1_b.jpg

These are two different tools that can be used together. The workpiece can be clamped in the vise. The vise itself can be mounted on the milling table. 

 

My finger points to so-called 'parallels'. These are twin pieces of equally tall metal. The workpiece can be put on top of them before the vise is closed. That way, the workpiece is raised horizontally. In my Proxxon set there are seven pairs of parallels, each a different size. 

6f. Precision prisms and clamps


32154403484_cb7f26a042_b.jpg

The clamps do what their name implies: they secure a workpiece to the mill's bed. The precision prisms have the same function, be it for round workpieces such as cylinders. On the photo one of both prisms can be seen. The workpiece is clamped, on the one side, by one prism; and on the other side by the other prism. 

6g. Dividing head 

32999363945_9875bb4c44_b.jpg

As discussed in paragraph 3, the dividing head is used to rotate the workpiece and to divide it into segments. If six sides of a nut need to be cut, the workpiece is mounted onto the dividing head. One side of the cylinder is milled. Next, the dividing head is turned 60 degrees to the right and the next side is milled. Then again the workpiece is turned 60 degrees to the right and the next side is milled, et cetera. I explained this more clearly here. A dividing head is a requirement for accurate drilling of holes for wheel spokes. 

 

The dividing head can be mounted horizontally or vertically on the milling bed. On the dividing head a regular chuck or collet chuck can be fixed, holding the workpiece. 

Edited by Roy vd M.
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Great posts regarding rather complex tools. I support the idea of at least mentioning the right name of the pieces. If someone without further knowledge wants to follow along or invest(igate) he has the right search terms on hand.

 

Did I miss it? Or did you not tell what huuuuge set you got to play with? This looks like a rather complete bundle i am very interested in.

 

Thank you for posting so detailed. I am sure this is a big help for many around without related training.

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@Schwarz-Brot OK I will mention the right names of the pieces (if mistakes are made I hope the experienced machinists will correct me) in the respective posts. 

 

The set of tools as described is unfortunately not available as a package. It was chosen after consulting @vontrips who kindly helped me on this matter; more tools were purchased after reading manuals, instructive books and studying videos. 

 

Here a list of everything (be sure to make a good deal if you intend to purchase multiple items...) :

 

LATHE

- Proxxon 24400 PD 400 lathe

- Proxxon 24402 splash guard and chip collecting tray

- Proxxon 24410 independent 4 claw chuck

- Proxxon 24417 parting off tool with tool holder

- Proxxon 24419 collet chuck with collets

- Proxxon 24412 mounting disk 

- Proxxon 24550 cutting tool set

- Proxxon 24552 threading set

- Proxxon 24062 radii cutting tool

- Proxxon 24630 center drills

- Proxxon 24414 center arrangement

- Proxxon 24406 traveling steady

- Proxxon 24082 threading arrangement

- Vogel 241101 dial (not yet described)

- Vogel 250302 tool post (not yet described)

 

Milling machine

- Proxxon 24104 milling and drilling machine

- Proxxon 24144 set of collets

- Proxxon 24421 dividing head

- Proxxon 24140 fine feed (not yet described)

- Proxxon 24257 clamps

- Proxxon 24610 milling bits 2-5mm.

- Proxxon 24620 milling bits 6-10mm.

- Proxxon 24255 machine vise

- Proxxon 24262 precision prisms

- Proxxon 24266 parallels

- VHM micro milling bit 0,6mm.

- Corner milling bit 90 degrees, 10mm. diameter

- VHM micro drilling bit 1,0mm. 

- VHM micro drilling bit 0,3mm. 

- Glanze 777103 10mm. set of indexable turning tools

- Glanze 777450 (I think is the UK serial) 10 mm. set of indexable parting, contouring and threading tools

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4 hours ago, Schwarz-Brot said:

Wow, you really went kind of all-in. Pretty complete allround package for a beginner. Don't even want to ask what you paid.

 

Probably two arms except the right hand, usefull to hit the keyboard :)

 

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There are plenty of reasons not to mention the total amount. By many it's considered not done, at least here in the Netherlands. It could be considered as bragging. It could be considered as hautain. It could lead to envy. But mainly, it's not done to talk about things like that. 

 

On the other hand, the question we're talking about is exactly the same question I had before I had painstakingly gathering all the information (when I was still deciding whether to opt for Proxxon or a Chinese lathe or a good second-hand lathe such as an Unimat 3). Nobody could tell me exactly how much this (indeed) complete package would cost. There are so many variables... I wanted a PD 400 but could just as well have bought a 230 or 250. For my situation a 400 was better... it can house the heavy dividing head (with many dividing configurations) to give one example. 

 

Also I don't see the added value of the 'PM me and I'll tell you the amount'-principle. It isn't logical to me. And by the way, based on the above serial numbers you could just Google everything, add the prices and deduct a discount. So I'll simply tell you, for the sake of educated information that is one of the purposes of this topic; the total amount of all the above was, for me, 5.180 euro including VAT and shipping costs. 

Edited by Roy vd M.
Painstakingly, not painfully...
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Sounds like a pretty good deal for what you got. It's obvious this couldn't be exactly cheap.

 

Didn't know you "don't do" talking about money things in the Netherlands. Feels kind of strange, considering you're a direct neighbour to Germany. But good to know. Bragging, envy... We're all grown ups. In the end it is the way you talk that determines how it's interpreted. No worries, mate.

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Roy, for me, the price you pay is a reasonable investment if it brings you endless hours of joy over a lifetime.

 

Amsterdam is a beautiful city. I go there for a few days almost every May for work.

 

Regards,

Jeremy

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I for one respect that you wanted to avoid being seen as 'bragging' etc., but also glad you did reveal the cost which, for what you have shown seems very reasonable.

Do I 'envy' you...too right I do....will I sulk about it....no bloody way.....life's too short for that crap....I genuinely hope you get a lot of enjoyment out of it....and share your experiences with it with us.

 

Regards

 

Ron

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@Schwarz-Brot, @Jnkm13 and @silver911, thanks for the replies guys. I am glad to read your opinions and agree with you. 

 

To further specify, I estimate that lathe and accessories cost approximately 3.500 euro and milling machine plus accessories approximately 1.700 euro. Seeing that I paid approximately 1.900 euro for the lathe, that leaves 1.600 for accessories. Those who are looking for purchasing a lathe should therefore be aware of an added cost of at least 85% the price of the lathe if you want to go for the full package. I say 'at least' because this particular lathe was relatively expensive. While you can find a lathe with similar specifications for half that price, I would doubt you'll find that the accessories will also be half the price. Hence 'at least' the added 85%. 

 

The milling machine is a different story. Having an independent similar milling machine plus splash guard and chip collecting tray would have cost me approximately 300-350 euro extra (taken into account a discount). Here the price of the accessories is approximately 150% the price of the milling machine. That is mainly due to the price tag on the dividing head. 

 

More questions or remarks about this subject are always welcome, in the thread or per PM. 

 

@Jnkm13 I'm not so fond of all aspects of the Netherlands but I can say I'm quite proud of Amsterdam which is, indeed, a very nice city with generally nice people and lots of things to do. 

 

19 hours ago, silver911 said:

life's too short for that crap....

 

My thought exactly!

 

7. The most important missing link between me and starting the build is the uncertainty regarding exact measurements. As mentioned before, Mr Daniel Cabart had told me at Rétromobile that no blueprints have survived. Although I had brought along my tapeline to the exhibition, in the end I decided against using it because it felt very awkward and out-of-place there. Revs Institute has kindly agreed to take some key measurements when the car will be back in Florida. 

 

So what I did was indicate the measurements most important to me, in a scale drawings seen hereunder. Several of these drawings can be found online (see opening post) and some more are in my collection (can't share them due to copyright), each made by another artist, and all are quite different from one another so I have no clue as to which one is correct. My plan is to pick one (probably the one hereunder) and amend it in accordance with the measurements. There are 26 measurements in total.

 

Here a description, which refers to the images. Horizontal: pink. Vertical: purple. 

32398105543_116478f1db_b.jpg 

A: From rear wheel center to end of car.

B: Tyre diameter.

C: From rear wheel center to front wheel center.

D: Horizontal distance from rear bonnet end to the front wheel center. 

E: Horizontal distance from front bonnet end to the front wheel center. 

Note: combination of D and E should be slightly shorter than the length of the bonnet, because the bonnet is slightly sloped.

F: Front wheel center to front of frame.

G: ‘Vertical' tail line (from bend to bend).

H: From floor to top tail line bend.

I: From floor to top of body, behind cockpit. 

J: From floor to bottom of frame.

K: From floor to top of fairing (without glass screen). 

L: From floor to top of cowl. 

M: From floor to top of radiator housing.

N: Width of grille, inclusive of border strip.

O: Width of radiator housing, at the front.

P: Width of radiator housing, at the rear.

Q: Width of the combined bonnets, at their rear.

R: Width of the body, at rear of fairing.

S: Track gauge.

T: Width of the body, at rear axle. 

U: Thickness of tyre.

32368626014_16abbd7455_b.jpg 

V: From front of gear house to rear end of cam cover. 

W: From front of compressor house to rear end of cam cover.

X: Width of compressor house.

Y: From left cam cover to right cam cover.

Z: Height of compressor. 

Edited by Roy vd M.
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Well, first, congratulations for your material! A dream... 

Second, what a great project! I do love your research, all my wishes for this challenge.

And keep in mind "the best is the enemy of good". Without the complete real car in your workshop, without drawings, 

you will have to make compromises, approximations, this is inevitable!

Do not be discouraged, go ahead!

Good luck sir!    

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@Roy vd M. - cool bits of kit. As the others say. Hope you get to play with them soon.

 

One thought on your measurements, I'd echo  @PROPELLER's "best is the enemy..." comment, before noting that wheels are a nightmare. From the stuff we did on the 806, loads of parameters are probably required just for the tyres. Keeping it simple, rather than a try to characterise the things in immense detail, it might be useful to have the axle heights and ground clearance loaded and unloaded. That with tyre diameter should give some idea what is happening when you try and scale things.

 

Regards

 

nick

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  • 2 weeks later...

@Pouln The car should be back in a few weeks; there's no rush as I'm having a very busy time at work :)

 

@PROPELLER Thank you for your kind reply. As will be seen throughout this thread, there will be quite a bit of 'borrowing' (=immaterial thievery) from your own artistic achievements, mainly here. I'm glad you are interested in my build, so that perhaps along the way you might be willing to answer some of my questions.

 

I agree, also with @NickD, that I will eventually have to make compromises. Fortunately I am in contact with the owner of the best surviving automobile of the lot, chassis #1, but still then I'll sometimes have to let it go, as Elsa would say. 

 

Regarding the wheels... yes they can be a nightmare, especially if we're not sure about the different sizes used. The Delage used different sizes, for one; so we can't know for sure that it was much different with the Fiat. Perhaps we have been comparing 30 inch tyres on the one photo with 27 inch tyres on the other... I don't intend to try doing 'a better job' than Revs Institute did. Once exception, to make the car as close to the 1927 situation as possible, is that I'd like to replicate the original spark plugs as seen on the drawing from 1927. 

 

Hopefully there are people who can help me with this. 

 

The spark plugs currently installed in the 15-S-8 engines, look like this:

 

Chassis #1:

33349613001_095ea6474a_k.jpg

 

Chassis #3:
33436870316_ae39f5ddb0_b.jpg

 

Chassis #5:
33349612231_83330cc563_k.jpg

The isolators on these spark plus have very simple shapes (easily turnable on the lathe), they are nothing more than a cylinder with five grooves in it. But on the 1927 drawing it looks quite different: 

33349856701_bbea3010fc.jpg

My question is, what material do you guys think the spark plug parts are made (referring to letters a-i in the above drawing)? 

 

By the way the first parts have been completed. I will write an elaborate update shortly. 

 

I look forward to your opinions as regards the spark plugs... 

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@CrazyCrank The real cars don't appear to have the original spark plugs. Those spark plugs are probably not made anymore. The spark plug on the photo and the one in the original drawing seem to be similar; I can't spot any integral difference. Anyway I was looking to find what colors what parts of the spark plug most probably would have had; and now I know :)


For quick readers the main text is printed large. The details are always in small print.



8. For the cooling liquid coupling I started parting off a bit of brass rod. The cutting tool for parting has to be perfectly perpendicular to the workpiece.

If the cutting tool is even a little bit off-set, the cutting will be slightly tapered. Setting the parting tool is done by moving the tool holder all the way to the left, so that the tool is aligned along the collet holding chuck (of course the lathe is turned off!). This way the tool is aligned nicely. The gold-coloured part is the actual cutting tool. When it has lost its sharpness, that cutting bit can be replaced.  

33330370061_9b052d6059_k.jpg

9. The correct height of the cutting tool is determined by using the tailstock's center.

The center is attached to the tailstock, on the utmost right side of the lathe. See here, photo 5a. The center is seen on photo 5g. Because the end of the center is at the exact vertical center of the workpiece, and during parting off the exact center has to be used, the center is used to determine the height of the parting tool. I do that by turning a small wheel on top of the tool holder. First the wheel is turned to the desired height, then the counterwheel is fastened and lastly the tool holder is fixed. 

33417802276_45bbd84d44_k.jpg

10. The required turning speed is 1.400 revs. 

The diameter of the workpiece is 5 millimeter. It's brass, so that the cutting speed should be 70 to 100 meters per minute (see the text above the table). For parting I use a speed of 1/3 the cutting speed, so approximately 28 meters per minute. According to the table that's closest to 1.400 revs.

32644114003_5596a1bfd4_k.jpg

11. The correct drive/driven wheel ratio is chosen and set.

In the housing of the drive system three combinations of pulleys can be chosen: from small to large (=acceleration), from neutral to neutral and from large to small (deceleration). The greatest speeds (1.400 and 2.800 revs) are gained from small to large. After the belt is chosen and set, a switch on the lathe headstock lets you choose between low or high gearing. Switch setting 'I' is 1.400 revs, setting 'II' is 2.800 revs. In total this lathe therefore has six speeds (2x3). 

32644110013_41771b599d_k.jpg

12. Workpiece and cutting tool are lubricated with cutting fluid. 

For this I use Multicut Soluble Oil (Chronos), applied with a brush.

32644107263_d70c5497c3_k.jpg

13. Parting off in action.

32615113624_f4cd4e124f_k.jpg

14. The result: the unusable bit was cut off.

32615104954_67d8728757_k.jpg

15. Next, turning off (not to be confused with parting off).  

Turning off is the process of removing 'a layer of metal' off of the rod, by scraping along its length with a cutting tool. Regarding the hereunder photo: later I found out that I was using the wrong cutting tool (the one on the photo is not perpendicular to the workpiece).

32644115873_8fdeda22bc_k.jpg

16. The largest diameter has to be 4,9mm., according to the drawing. Therefore the workpiece is turned along its full length of 4,9mm.

33459553135_1fead0b758_k.jpg

17. The next diameter to be turned is 4,35mm. That diameter has to be turned from the face up to and until 1,69mm. from the start of the workpiece.

As can be seen, for turning the 1,69mm. I use the handwheel. First I position the cutting tool to the start of the workpiece (=on the lathe: the right end). Then I set the handwheel to zero. Next it's a matter of turning on the lathe, rotating the handwheel one full rotation and then adding another 0,69 millimeter. That latter position you can see on the picture. I'll take off bits of metal until the remaining diameter is 4,35mm. For that I also use a handwheel. Mind that if 0,4mm. has to be cut off of the diameter, the handwheel has to be moved only 0,2mm. The reason: 0,2mm. is cut off on both sides of the workpiece simultaneously. In total that's 0,4mm. 

33417817136_7087f5f236_k.jpg

18. This is what it looks like (using the wrong cutting tool by the way).

33302587862_01c582559c_k.jpg

19. Each processing step is started from position zero. On the next photo, both handwheels are seen set to zero. 

It's important, in this respect, to mind the clearance between gear wheels and semi-screws relative to one another. Therefore it is always a good idea, when measuring or positioning, to turn the wheel in one direction only (=the direction in which you're going to cut or measure).

33330364261_f16c121b6b_k.jpg

20. Here four diameters were turned: 4,9mm.; 4,35mm.; 3,5mm.; and 2,9mm. See paragraph 16.

32644115273_f731484534_k.jpg

21. Next, boring the face of the workpiece, approximately 0,2mm. deep.

32615116674_a21d5f044b_k.jpg

22. Here I made a mistake: with the side of the cutting tool I unfortunately removed part of the raised edge.

33302594022_9c6ec231f2_k.jpg

23. So I started over. This time I used the correct cutting tool. Hence the result looks nicer: 

33417808326_8c55aa3429_k.jpg

24. After the top half of the workpiece was finalized (lathe-wise), it was time to treat the lower parts. 

33417817586_a87e543995_k.jpg

25. The cutting tools are quite wide for working in tight spots. Therefore I decided to grind a new cutting tool. 

The table grinding machine is a Metabo 150. The raw tool bits can be found for sale online. To prevent annealing of the hardened steel I never ground for longer than max. 3, 4 seconds. After each mini-session I dipped the tool in a bath of water. After half an hour I got myself a pointy tool.  

32615118294_49777e68cf_k.jpg

26. You can see how much pointier 'my own' cutting tool is than the standard. 

32644111483_38b0f3cb21_k.jpg

27. It works!

33417807536_ff2209368f_k.jpg

28. The new cutter in action: 
 

 


29. The interim result, before milling.

33417816056_680da6b745_k.jpg

30. The 1mm.-milling bit is positioned along the workpiece with a lot of cautiousness. 

The workpiece was put on the dividing disk, collet holder and all in place. Because I measure all distances from the beginning of the workpiece, I first check the position of the milling bit. A tenth of a millimeter too far to the left, the milling bit will inevitably break off. This happened twice already... a pity because the buggers are not cheap. 

33417804226_8406ca3641_k.jpg

31. The Z-axis is also set to zero when starting milling. 

33330376211_931a1660d8_k.jpg

32. Each time the dividing disk is rotated 60 degrees, the disk is fastened with a socket wrench. 

If I didn't, the milling could generate a bit of shaking and there would be undesired clearance. 

32615110244_c5dbd8f0cf_k.jpg

33. According to this diagram, for each of the six sides the dividing disk has to make 6 full rotations plus 28/42th part of one rotation. 

I therefore install the disk with 42 holes. Using a pencil I mark holes 28 and 14. The first of six (five, really) parts is done by making six full rotations and adding 28/42th of a rotation, so using hole #28 of the disk. The second side: six full rotations and continuing to hole #14. The third: six full rotations and continuing to hole #42. The fourth: 6x, hole 28. Fifth: 6x, hole 14. Sixth: 6x, hole 42. That's the starting position. Alternatively I could have picked disk 39, 36, 33 or 27 (in which case I should have used different holes). The reason why these disk could also have been used is simple: the numbers are divisible by three. 

32615101254_58dba410a6_k.jpg

34. The depth of one side can be calculated, using the following drawing. 

If one side is 100, the maximum width is 200. The distance between two opposing sides is 175.

33307636692_fd128010ec_k.jpg

35. Here we go... exciting! 

32615100674_935e5dba89_k.jpg

36. Milling with a broken mill bit.. not ideal after all. 

If I had known I wouldn't have done it of course. But I found out that milling bits characteristics are quite similar to drill bits.


33417808836_99a008ab22_k.jpg

37. The hole for the horizontal cooling liquid pipe: milling with a 3mm.-milling bit. 

33417801996_2c177c5577_k.jpg

38. After that the horizontal pipe was turned: next, checking if it fits.
It's not a good idea to start the lathe now... 

32615112684_f7c0823e36_k.jpg

39. Because a broken milling bit was used on the lower hexagonal, (in daylight) the result appeared to be a bit rough. A folded sanding paper can (just) be shoved in. That way the flaw can be corrected rather easily. 

32644108473_047c8c135d_k.jpg

40. The face gets a slight enhancement by a drilling bit in the tailstock of the lathe.

33417816456_51c2236b81_k.jpg

41. My own pointy cutting tool isn't that pointy to reach the tightest of spots. For that I used a 0,3mm. milling bit plus the dividing disk. 

The first 0,3mm. milling bit broke upon me studying its shape too intensively. Or well, in reality, when determining the starting position, I turned one of the hand wheels in the wrong direction. Even if it was one tenth of a millimeter or so, the milling bit broke off instantly. A sad end to a never used milling bit. Fortunately I had a spare. The dividing disk was rotated slowly while the mill dit its job. I didn't expect it to work, but it did! 

33302596382_5f30339c84_k.jpg

42. Here a video of this milling task. 
 

 

43. Using a 3,3mm. drill bit the previously milled hole is enlarged.

I had misinterpreted the drawing. The 3mm. I saw on the drawing represented the narrower diameter of the pipe.

33417802996_03a4517fb4_k.jpg

44. End photos and video of this part of the build:

33302585272_69243930c9_k.jpg

33330374251_e9c2c763ce_k.jpg

33417803506_ff739a4719_k.jpg

33417821816_94aecf093c_k.jpg
 


What's left is to solder this part and electroplate it(nickel); then it will be finalized.

Total build time: 8h. 
Total measurement study: 20h.

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I don't think you need oil or cooling liquid with your lathe and milling machine. This can enhance the surface quality but isn't exactly necessary with the light work you do with these machines. It only makes a mess of the workplace.

 

Also, there's nothing like the right or wrong tool with milling machines and lathes. A tool can do the job or it cannot. If it works it is right. Sure, there are always tools that work better than others, because they are designed exactly for that special task. But it is not always necessary to get that special tool. In my training we did most of the work on lathes with the exchangeable bits you showed above. They can do mostly everything but parting and undercuts.

If the surface quality is poor feed slower.

 

Sanding can be done on the lathe! Just rotate at low speeds and bring the sanding paper to the desired surface. This is very handy, but be careful. It is no good idea to get your hands too close to the chuck!

 

Do you have to align your tools every time? No quick exchange tool holder available for this machine? If you can get one, I would highly recommend to get it. Spares a lot of time and iirc you can set the tool to defined angles using those holders.

 

Good job and nice to see detailed pictures of all the steps involved. I am sure this helps many beginners quite a lot.

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Roy, thanks for this very detailed report. As swartz-brot said, it will help many along.

Final pictures and movie show the parts stuck in green stuff.

It looks like the material one uses to put flowers in. Is that it?

Do you use that to hold it while soldering and does it withstand the high temperatures for silver soldering?

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Agree with the above, cutting/lubricating oil will just make your machine, which is a micro lathe and being used on soft material, a oily mess in no time.Just take your time parting off and you should be ok

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On 3/18/2017 at 4:56 AM, parryj said:

Following this with great interest. Love the excellent detailed write ups for each step. I'm learning along with you.

 

Much more learning along to be done then, in this post I'll describe some more mental processes (a nice term for correcting errors).

 

On 3/18/2017 at 4:26 PM, Schwarz-Brot said:

I don't think you need oil or cooling liquid with your lathe and milling machine. This can enhance the surface quality but isn't exactly necessary with the light work you do with these machines. It only makes a mess of the workplace.

 

On 3/18/2017 at 5:16 PM, colin said:

Agree with the above, cutting/lubricating oil will just make your machine, which is a micro lathe and being used on soft material, a oily mess in no time.Just take your time parting off and you should be ok

 

Thank you guys, I have left out this step in the hereunder steps and that seems to work fine. In future attempts I'll only use it when I think it will be necessary (cutting steel for example) or when it may be useful to achieve a smoother surface. 

 

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Also, there's nothing like the right or wrong tool with milling machines and lathes. A tool can do the job or it cannot. If it works it is right. Sure, there are always tools that work better than others, because they are designed exactly for that special task. But it is not always necessary to get that special tool. In my training we did most of the work on lathes with the exchangeable bits you showed above. They can do mostly everything but parting and undercuts.

If the surface quality is poor feed slower.

 

Good advice as well, thank you. Per PM I also got the advice to use a specific left-cutting tool. That was also a useful heads-up. Great tips everyone.

 

Quote

Do you have to align your tools every time? No quick exchange tool holder available for this machine? If you can get one, I would highly recommend to get it. Spares a lot of time and iirc you can set the tool to defined angles using those holders.

 

Unfortunately no quick exchange tool holder exists (ready-made) for this Proxxon machine as far as I'm aware. It's not too bad though, I have three tool holders that can be individually fixed in height. And the indexable tools all have the same height... that's a nice feat. Still I'll probably check out some (general purpose?) quick exchange systems, perhaps there's one I can use on my lathe. 

 

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Good job and nice to see detailed pictures of all the steps involved. I am sure this helps many beginners quite a lot.

 

Thanks. It might help beginners because I'll describe the things I don't do correctly as well as the end results after several attempts. That might lead to a better understanding of the practical problems one could encounter. 

 

On 3/18/2017 at 5:07 PM, Pouln said:

Roy, thanks for this very detailed report. As swartz-brot said, it will help many along.

Final pictures and movie show the parts stuck in green stuff.

It looks like the material one uses to put flowers in. Is that it?

Do you use that to hold it while soldering and does it withstand the high temperatures for silver soldering?

 

Thanks Poul. It's indeed the same material to put flowers and Christmas decorations in. I have never silver soldered before (that will be one of several 'new experiences' to be described in t his thread) but I don't think I'll try it on this stuff. I expect it would burn / pulverize immediately. 

 

On 3/18/2017 at 5:16 PM, colin said:
On 3/19/2017 at 0:08 AM, sharknose156 said:

Very well done and thank you for taking such length and time to explain your work.

 

Thanks Sam, it's my pleasure. And it also helps in directing my thoughts and trying to fetch solutions I must say. At one point when I was describing my method I found out -simply by describing it- that I made a mistake. 

 

 

 

44. I chose to follow the difficult path and try to replicate the original spark plugs. See here the drawing. 

Whereas the currently installed spark plugs would not be very difficult to make, about as complex as the previous cooling liquid coupling, making the authentic spark plugs will be a much more demanding task.

 

The green markings on the drawing 'inside' the spark plug, are the diameters of the several 'rings parts' of spark plugs. For example, the top piece has a diameter of 0,6mm. The 'disk' underneath has a diameter of 1,2mm. The large hex has a maximal diameter of 3,2mm. et cetera. This is all scale-true, so everything is 12 times larger in reality. Or so I thought at the time...  

The green markings to the left of the spark plugs are the distances, measured from the plug's top. For example, the start of the first 'disk' on top (1,2mm. in diameter) is at 0,45mm. from the top. The end of the visible part of the spark plug is at 5,37mm. 

 

The blue dotted lines are just guidelines, used to mark positions and to measure in an easy way. There are more horizontal guidelines than markings, because sometimes the cutting tool has to start or end at a different position, because of the shape of the cutting tool. For example take a look at position 3,68mm. There are two horizontal guidelines. The lower line runs parallel to the top of the largest hex; the top line is the position where the cutting tool should be positioned, if I went further down the cutting tool would damage the hex. Using another cutting tool, the intermediary length is turned off. 

 

The purple markings are not important here, these were used for measuring the cooling ilquid coupling-part. 

33327186312_00cb030a4e_b.jpg

45. Five different cutting tools will be used (among which 'my own'), the cutting tools will have to moved to several positions and at the 20th step the cross-slide will have to be rotated to 84 degrees, in order to turn off a taper. 

In the hereunder overview the names of the cutting tools are coloured. If anyone needs a translation I'll be happy to provide it, although this is not the step plan I'll eventually use.

 

This will be a useful exercise in working consistently, because these spark plugs will have to be made in eight specimens. Of course they will have to look as identical as possible. In total there are 22 steps to make one spark plug (in this schedule). I am excited to execute this step plan. Hopefully it's correct...  32669062843_951d8c93ba_b.jpg
62. A few hours later. The step plan doesn't seam to leave the battleground quite intact.

33107868510_16e3ce71cd_b.jpg

63. The first result.

32648379964_05dc6f6462_b.jpg

64. I decided to keep the spark plug attached to its 'sprue' for awhile. On the hereunder cropped image you can see its contours. Apologies for the bad picture quality, but the part is very small (3mm. x 5mm.) and it shines quite a bit, so that it's not easy to photograph well. 

On the next photo the part is 19 times as large as in reality.  


32678035893_a7b966daff.jpg

65. And a vid. 
 

 

68. But life is not always kind (even in micro-scale). One of the most entertaining aspects of my topics seems to be, looking at them as if I were an outsider, to read about my errors. Aren't we all ramp tourists to a certain extent? :D Well, the errors are about to be described!

 

I started work on my second spark plug, hoping to get them similar in shape. 

Diameters are not so difficult... this should be 3,20 millimeter in diameter which is spot on in this example, but I'll also accept 3 or 4 hundreds of a millimeter off.

33477531126_4bdfff123c_b.jpg

69. The hand wheel receives some graffiti as well.

32674593004_a12cac51c9_b.jpg

70. See here the two spark plugs. They don't match at all and the large hex was way too thin... I tried to correct it by using pliers (pressing force) but it had little use. 

 

How is this possible? Well I found out that in my step plan I didn't take into account the gear wheel clearance of the lathe. 

If I move the cross slide 3,0mm. to the left, according to the handwheel, that will be in fact 3 millimeters if the gear wheels are in the correct position. However if I will then turn the handwheel in the other direction, again 3,0mm., the cutting tool was in reality moved only 2,9mm. That's caused by the clearance of the gear wheels driving the cross slide. Therefore it's very important, in each single step of the step plan, to decide where to start the cut... from the left side or from the right side. That's what went wrong here. 

33518535645_e20f7a8a53_b.jpg

71. I changed the step plan integrally. Different cutting tools, strict turning directions, fewer cutting tool changes, calculations of cuts that will speed up the process. In the first step plan there were 14 tool changes, now only 2. Rather than 5 cutting tools used, the new step plan only uses two, each on one tool holder so that i won't have to change them all the time. Also I won't have to reestablish the zero (cutting starting point). It will save a lot of time, the accuracy level will improve and more detail will become visible. All too good to be true? It seems to be but still... I have faith in this new step plan. 

33389871851_3a81465e77_b.jpg

72. I USED to have faith in the new step plan. A lathe is absolutely merciless and at step 9 I had written down some wrong values. A reminder to always stay aware and keep thinking!! Now I can start over, again :)

I thought I had to turn off 0,2mm. three times so i started the first cut... and that appeared to be 0,05mm. too far right away. Turns out (no pun) that I copied a bit of text to a non-corresponding step...

32703762783_8fb06314e2_b.jpg

But hey I'll patiently start over smile.gif. And I still have a bit of faith in the new step plan, no worries.... laugh.gif

73. ... although also this time the step plan didn't survive all cutting activities.  

33520973705_c1e57cf68e_b.jpg

74. But this time there were fortunately no mistakes in turning, providing a result that is clearly better than the first specimen. All details are now distinguishable and the proportions are in correspondence with the drawing. Consistently taking into account the gear clearance pays off and provides a feeling of increased assuredness. 

32706117873_88f7479ca3_b.jpg

Milling the hexes yet has to be done; I decided to put that on hold until I'd have finalized a second spark plug specimen. As they are now, they can be ideally compared to one another.

75. The markings om my 'used' version of Drawing 6 will probably become more clear if I'll show the intended results per processed step. The position of the spark plug (on its side) is equal to its position in the lathe as long as it's mounted there. I left out those steps that don't influence the spark plug visually.

Step 2: turning diameter of 3,2mm., from 0 to 12,5mm. 
32683264734_d2742e6ee1.jpg

Step 3: facing, determining right hand zero (=for turning from right to left).
33398258671_93d0a03b1f.jpg

Step 4: turning diameter 2,5mm., from 0 to 3,68mm.
32683264584_949d461fc3.jpg

Step 6: turning diameter 1,8mm., from 0 to 3,12mm.
33398258601_a2aa8af652.jpg

Step 9: turning diameter 1,5mm., from 1,8 to 3,12mm.
32683264474_68933db3f8.jpg

Step 10: cutting 0,1mm. groove, top (=right hand side) of large hex.  
33398258511_2511bf6971.jpg

Step 11: cutting 0,1mm. groove, 2,29mm. distance. 
32683264314_08ca502abe.jpg

Step 12: cutting 0,1mm. groove; 1,9mm. distance.
33398258421_ae5f5baaf7.jpg

Step 13: turning diameter 2,7mm., from 4,54mm. to 7,5mm. 
32683264164_95292df522.jpg

Step 14: turning diameter 1,9mm., from 5,5mm. to 12,5mm. 
33398258311_7f597a5fae.jpg

Step 15: cutting off edges of top large hex and top small hex.
32683264094_d32a48bc3f.jpg

Step 16: turning diameter 1,2mm., from 0mm. to 1,01mm.
33398258211_d48fd43bce.jpg

Step 17: cutting 0,1mm. groove, at 0,94mm. distance.
32683263934_a4113c6748.jpg

Step 18: turning diameter 0,6mm., from 0mm. to 0,45mm. 
33143220710_4593f80086.jpg

Step 20: turning a taper of 84 degrees from top of small hex, distance of 0,53mm.
33369851362_b71ba86087.jpg

Step 21: milling small hex. 
33143220460_d1a2ed2733.jpg

Step 22: milling large hex.
32683263674_ee9aa36782.jpg

End result: 
33143220290_cd851e84cc.jpg

Again my own end result, before milling the hexes:

33143835440_54341f0231.jpg

76. On video it looks like this:

 

77. To my eyes these match reasonably. A single minor error (the top part of the spark plug isn't equal). I'm not sure how this could have happened and which one of both would be correct. But well it doesn't matter that much anyway, the reason for which I'll explain now.

33530312525_37000655af_c.jpg
 

It came to my attention that the spark plugs should not be 3,2 in max. diameter, but approximately 2,4mm. This mistake was made by misinterpreting Drawing 6 (see opening post). That drawing says how tall, long and wide the engine is... but it does not say where all those ends are (=from where to where the measurements have to be made). Anyway, no worries, I'll start over.  

 

This time I will try something different. The new spark plugs will be that small and my home-made cutting tool is that sharp, that it's probably possible to turn the spark plugs using only that home-made cutting tool. It will then have to be repositioned twice.

 

A summary of the step plan: 

 

1. Turning from right all the way to the left, whereby I will follow the contours (left side of the cutting side is perpendicular to the work piece). 

2. Again turning from right all the way to the left, to get a smoother finish. I'll use exactly the same profile plan as at step 1. 

3. Turning from left all the way to the right (right side of the cutting side is perpendicular to the workpiece). 

4. Again turning from left all the way to the right

5. Cutting the tapered bit (current step 20). 

 

So far for the theory... now only to be executed in practice. If it works I'll get an even more accurate and uniform end result. 

 

I tested this a bit already and it looks like it's feasible... only the tiny diameter at the spark plug's top end (0,4mm.) will have to be cut after the larger diameter (0,8mm.) in order to prevent the top bit from being thrown into space and beyond. 

78. I secured the cross slide (that's usually unnecessary) and checked the clearance of the handwheel. It appears to be, approximately, 0,13mm. That's an average, because the clearance will differ depending on how I'll use that handwheel, depth of cut, feed etc. 

 


80. All of a sudden I had a sensation of 'eureka' and I realized how to accurately measure the size of the spark plugs... I know the diameter of one cilinder (55,8mm.) and I also know the diameter of the spark plug's thread (18mm.) and the aperture (8mm.). I only did not realize that I could use these data. Now I do. I've since then measured several drawings and end up with maximum spark plug diameters between 2,4mm. and 2,5mm. That would mean that a spark plug key of approximately 26mm. would fit.

 

A question to you guys: does anyone of you happens to have any idea of that size (spark plug key of 26mm.) was used on spark plugs of around 1925-198? 

 

Anyway the spark plug will be approximately 75% the size of the already finished specimens. 

33447800371_85318fe500_b.jpg

 

 

Total build time: 18h.  
Total measurements study: 26h.  

Edited by Roy vd M.
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Well, Rob. It is a learning experience (not only for you).

If you forget to think about the way the turning of the handles is transferred to the movement of the supports, you're in for a surprise.

Some of my handwheels do not have any free movement, but the main support and the cross support do.

What I always do to take out that clearance (if there is space to move) is turn  in the opposit direction and then back). If you do that the gears will have enough space to catch.

 

You are to be commended for the amount of time you spend to figure out the measurements, prepare drawings and fabricating, rethinking, redoing and above all, taking pictures and explaining to us by means of this forum what you are doing.

Kudos for that!

 

But, you found out that measuring from one point does help solve it. That's why construction drawings always measure from one single point.

 

By the way, below is a link to an introduction of the lathe. It gives the proper (UK english) terminology for the parts of the lathe. 

http://www.mini-lathe.com/Mini_lathe/Introduction/introduction.htm

The apron is actually the vertical part (the face) of the support.

Here they call it the carriage, cross-slide and compound. I'm sure our friends at the other side of the Atlantic have their own terminology for it.

In dutch I would say support, dwars- of kruisslede and bovenslede of beitelslede).

 

From the pictures I gather that you have a quick exchange toolholder. You just don't know that you have it.:D

You can buy some more of the actual cutting toolholders and then you will not have to set proper tool height anymore.

Edited by Pouln
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Roy, is the positioning done via a ballscrew spindle? There shouldn't be that much backlash then, I think. But look into your machines specifications. Should be listed there how much (little) is guaranteed. I don't know the machine, so I cannot tell. But there might be ways to adjust that. Apart from that it is for sure a good idea to only cut in one direction. Backlash can never be completely avoided, just minimized.

I would suggest cutting the hex surface immediately after the lathe work without taking the piece out of the chuck. Set an endstop if you can on the milling axis to always get back to the same depth. This way you get the same hex on every piece (immediately after being worked on the lathe before taking it out of the chuck is the only moment in time when it is all perfectly aligned!). If you take out your working piece and replace it in the chuck it will never be aligned well, introducing angle errors that can be quite hefty.

This is the reason for never starting with a piece of the final diameter - you have to turn over the whole piece one time to get all surfaces perfectly parallel to the rotation axis. As I said - this only stays aligned as long as the part is not taken out of the chuck.

 

When milling the hex it might be a good idea to utilize the tailstock to support the work piece. Since you need a guide hole to do so I would suggest the following workflow:

 

1. turn over the whole piece to get the surfaces even and parallel

2. drill a guide hole

3. turn your part as before, but leave enough excess for the guide hole to be cut away later

4. support the part via tailstock and mill the hex surface

5. cut away the excess piece with the guide hole

6. cut off the final piece

 

Another thing: If you don't already know how - you should get used to standard ways of indicating measurements in drawings. There's a reason engineers do so. I am sure you can work your system out, but for anyone else it is pretty hard. I then would work from those drawings instead of the written step plans (or combine the two). - Engineering drawings usually make it pretty obvious what needs to be done to achieve the result your after. Since you already have the drawings it is not a big deal - just print the area of interest and write down the measurements by hand. Having a drawing makes it much more easy to imagine the next steps while working on the parts.

 

An alternative to getting several identical parts would obviously be casting. If you don't intend to use the bare metal this may be a simple solution. On the other hand it should be possible to get pretty accurate parts with a consistent work flow.

 

Nice write-up as always. Thank you for sharing.

 

 

Edit: I second @Pouln: His tip for taking out the backlash was so normal for me, I didn't even think of it! Good advice.

Edited by Schwarz-Brot
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