Bloody Mary 1/8 Scale

[nick]

On 8/14/2023 at 4:38 AM, Jo NZ said:

After an absence,  due to an MX-5 wedding present, I've got back to BM. Producing the Mazda logos for the wheels and steering wheel on the MX-5 gave me a lot more confidence in using canvas to replicate emblems and logos. I've returned to the front tyre and added the sidewall detail. Probably the most time consuming activity was finding a font with a flat top 3 and a 9 with a bottom curve for the size marker! The letters are produced in F360 with the text function, extruded onto the sidewall and then cut to height with a rounded profile.

I'm still not sure how to print the tyre - now I have lettering on the sidewall I can't support it there. I was looking at extending some of the tread blocks and extruding them to a curved support. Any ideas?

 

 

 

Sorry late to the party here, what the font is your friend:-  https://www.myfonts.com/pages/whatthefont

Just paste an image of the font you're trying to match and away you go.

 

Have fun.

 

I've been putting off printing tyres due to support issues like you. My current plan is to split them along the tread, effectively into two halves. especially if they have a non-zig-zag bit of tread like these.

 

Why?

1. they print fast because they have little height.

2. the detail on the walls will be sharp and accurate because it's being printed in the optimum orientation

3. it should be possible to print a latching setup to join the two halves, hidden internally.

4. they will print directly on the plate, which means they will be round and true, and there won't be any scaring.

 

That said, I haven't done it yet. I've just finished about a 5-litre long battle with my Saturns getting the lift speeds and distances dialled in. They' ve been unreliable since day one and this is the problem I now know.

 

Also for logos etc. I always go to illustrator first and produce a nice clean vector from my source jpgs . Pull this into fusion as an svg and away you go, you can just scale, rotate etc, then extrude straight away. You don't want to be messing about trying to do graphics/fonts/logos etc in fusion it's just too hard. Horses for courses etc. Yes it's another step, but much easier. You start to  build a bit of a library up too of re-useable assets - Bosch, Lucas, Magnetti Marelli etc, etc

 

Nick

 

[Jo NZ]

Thanks Nick.

 I tried whatthefont but got bogged down in the multiple questions, not many of which apply to numerals. I'll try again!

I printed two tyres using Siraya tenacious obsidian black - a flexible resin. Here's a comparison with one printed in Elegoo ABS like grey...

 

 

 

A few problems:

It's translucent. I could probably get over this by painting inside the tyre  black.

It's printed 1.3mm larger than the Elegoo print (which is the right size). The resin is very flexible, I'm wondering if the weight of resin has elongated the tyre as it's printing.

 

Nick, I thought that your idea of printing half the tyre flat on the print plate was a good one - but unfortunately the tyre diameter is too big for the Mars 2pro.

 

Possible solutions

Make the tyre solid (uses lots of resin!) which hopefully would be rigid enough to stop the distortion.

Print in black Elegoo resin

Print the current tyre in the resin I used for the first effort, ages ago, which was resione F69. This is not so flexible and definitely blacker.

 

Each print takes 5 1/2 hours, which means the experiments are a bit long winded.

 

All suggestions gratefully received.....

[nick]

3 hours ago, Jo NZ said:

Thanks Nick.

 I tried whatthefont but got bogged down in the multiple questions, not many of which apply to numerals. I'll try again!

There aren’t any questions? Just roughly crop a jpg image of the font you’re looking for to just the word you want, upload or drag drop it onto the page I gave you, done. 
 

if your flexible tyre is just oversize and regular, and otherwise OK, scale your print down in chitubox to 9x.xx% using the 1.3mm vs the diameter. Ie diameter / diameter+1.3mm = scale factor
 

use an infill pattern if you don’t want it fully solid, lychee is probably better at this than chitubox but chitubox will still do it. 
 

Or alternatively, I’m not convinced about the rings you’re printing inside the wheel to be honest. Can’t you print it hollow and put something inside it like a a silicon/vinyl/rubber tube of about the right diameter cut to length and bent into a torus? Or even print a solid torus in standard resin if the new resin is flexible enough to go over it? Two halves of expanded polystyrene packing foam cut to shape would also work etc, etc 

 

Finally, I’ve just got a Saturn 3 Ultra and it’s very good, as well as being big enough to print your tyres. I bought it because I’ve concluded the Saturn 2 I’ve had for a year is basically landfill. I’ve wasted about 5x its cost in resin trying to get it to print reliably and still failed. The 3 does appear to work a lot better (so far) just sayin. Generally be cautious of big printers in my experience, I’ve concluded they’re probably quite good at printing big mini figures produced by others, which is what most people seem to want them for, but if you want to print bigger, still accurate parts like we do, or worse larger quantities of smaller parts, it’s a minefield. I naively thought a Saturn/Jupiter is just a bigger Mars 2 pro, how wrong I was. 
 

drop me a pm if you’re interested, it’s a long story!

 

you’re getting close though and your tyre looks good to me, plus you’re saving me a load of time and resin! 👍😜

[Jo NZ]

Nick - I followed your advice, removed the rings, downsized it, and then increased the wall thickness...

 

Now, I used to be a development manager. How many times have I told developers (mechanical, electronic and software) to ONLY change one thing at a time? What did I do... 

 

So the next print was undersize. Increasing the wall thickness of the tyre from 1.3 to 2.6mm gave the resin enough rigidity to stop it stretching. After that disaster I printed another tyre at the standard % reduction (12.5%) and of course it's spot on.

 

I haven't tried an infilll pattern in lychee, I went through a stage of hollowing out anything large in chitubox, including my first attempt at tyres.  Nearly every one has leaked over a period of time. The uncured resin seems to work it's way to the surface and leave a sticky mess. The flexible resin was even worse, the tyre increased in size after a couple of days and then split.  I've tried multiple drain holes too, without much success.

 

Here are the tyres - the thin one, the thickened and reduced size one (11.12%), and at last the correct one, with a rim fitted just to prove it.

 

 

 

All the pimply bits on the middle tyre are the remains of the supports that I didn't bother to clean off.  They sand off really easily. Using the chitubox supports also worked, although I did remove or move any supports that were on the text or in the grooves in the tread pattern.

 

 

 

[nick]

That last one looks great to me. So you’ve cracked it then by the looks of it? Excellent. Are going for an ‘inner tube’ of some kind or are they stiff enough with the new thicker walls? 
 

to really throw a spanner in the works, my other idea was to print three-part moulds - a centre with a hump to create the void where the inner goes and two outers keyed to the centre for the walls/tread. Then just pour silicon into it with single pour and vent holes on the top. Easy to make in fusion just put your tyre model inside a big cylinder use combine cut, then split body. This is how I make dies for Louvers etc and it works well. 

[Jo NZ]

The tyres work fine on the rims, with no filler inside.

 

I've put the tyres and magneto on Cults3d, as free stl files, if anyone wants them. They're drawn 1/1 so will scale to any size.

[Jo NZ]

A little bit more progress. The hub knock-offs are quite intricate.  The photos I have show some of the outlines, but not well enough to copy from. Luckily I came across this

 

 

..which is a match for the spinners.

 

I used that photo as a canvas, and eventually got to here

 

 

 

The engraving can just be seen at 1/8 scale.

 

I did try photographing them, but my old Canon G7 can't bring itself to focus...

 

Now all I have to do is knock them about and simulate peeling chrome plate.

 

[Jo NZ]

I've gone back to the engines, because a lot of the build involves lining up with bits of them - or clearing them with the bonnet.

First step was to get some decent 3d prints of the cylinder barrels and heads. The barrels weren't too difficult, using standard chitubox supports on the head face, but deleting those on the fins. The edges of the fins try to warp downwards (as it's printed) but these were acceptable. The heads were more difficult. I tried several style of chitubox support but the fins always curled over. eventually I made my own supports, but still had deformation around the cutouts for the pushrods. The final version looks like this - I continued the support across the pushrod slots and it stopped the warping

 

 

 

 

The supports are thinned at the head face to make them easier to remove. Note that I set the supports on the head/fin joint.

 

The front engine...

 

 

 

I found some suitable diameter springs in my collection if recycled printer and cd drive parts (I generally only keep the springs and small screws, possibly bits of rod as well). The rockers had been drawn long ago.

 

Here is Engine no.1 assembled and temporarily in the frame. i've left the carbs off as the are very easy to knock

 

 

 

 

There's a wire (hose!) going into the oil catch tank. this appears to be wedged between the cylinder and the body work

 

Very easy to draw, just a profile rotated around an axis.

 

 

 

 

And there's that very nasty exposed chain drive...

 

Next time I'll shorten the rockers so the pushrods are parallel.

The rockers are a nightmare to assemble. The bolts holding them to the head are 0.5mm hex head rivets from MFH. They are cast, so I drilled out the holes to 0.6mm to compensate....

 

It's going to get some serious weathering, the rockers and springs in particular need to look very oily.

 

On to engine no. 2!

 

 

 

 

 

[stevehnz]

That is looking everso smart. 👍 

Steve.

[dnl42]

This is just amazing work! Everything from the digital modeling to the phsycial realization. 

[Jo NZ]

Thanks guys

While I am girding my loins to assemble the second engine, I modelled a few more bits  from the dashboard.

 

 

This is a pump handle. As it's connected to the fuel system I'm guessing that it's for fuel pressurisation - there's no mechanical or electrical pump anywhere.

I've only modelled the handle as I can use brass rod for the shaft.

 

 

 

There are assorted bits on the dash...

 

 

Fuel gauge (and I've just realised that it tells you when you've pumped enough), two switches (magnetos?) - they look like 1920s light switches, two pump things that fit into the oil tank, and a tap which connects to the fuel system - a bleed valve?

 

I've already modelled the back of the fuel gauge - the gauge itself and the face remain to be worked out...

 

Replica vintage light switches are 50mm diameter by 40mm high, so that gave me a reference.

 

 

I can use brass for the plungers on the oil feeds (?). Here's the rest

 

 

And the tap

 

It's not quite fully detailed, but in 1/8 scale it's only 6mm long, so I'm happy with it!

 

I still need to find a way to make the stamping on the dash for "FRONT and REAR" (twice). They look like 1/4" characters in full size, so I'm looking for a stamping set with 0.75mm letters.....

[nick]

On 1/11/2024 at 3:40 AM, Jo NZ said:

 

 

I still need to find a way to make the stamping on the dash for "FRONT and REAR" (twice). They look like 1/4" characters in full size, so I'm looking for a stamping set with 0.75mm letters.....

This is looking great. I’ve had some success CNC machining my Bentley Dashboard and my machine is also capable of engraving pretty well to, so if you want to knock up a fusion drawing of the panel I’ll have a go at cutting one out of ali and engraving it for you if you like (don’t forget my friend what-the-font? For matching the lettering!) I’m not sure I can engrave small enough, but happy to try. Also how thick is the ali - I’ve got most small sizes. 

 

 

 

i got pretty handy at drawing the faces in illustrator too for making decals, so if you have a square on shot of the dials I don’t mind knocking some decals up too,it’s quite time consuming learning how to do it I found!

 

the good news is that all weights next to nothing and will fit in an envelope. 
 

Nick

 

 

[Jo NZ]

Thanks Nick, I'll PM you.

 

[dnl42]

On 1/10/2024 at 11:12 PM, nick said:

This is looking great. I’ve had some success CNC machining my Bentley Dashboard and my machine is also capable of engraving pretty well to, so if you want to knock up a fusion drawing of the panel I’ll have a go at cutting one out of ali and engraving it for you if you like (don’t forget my friend what-the-font? For matching the lettering!) I’m not sure I can engrave small enough, but happy to try. Also how thick is the ali - I’ve got most small sizes. 

 

That looks extrodinary! Without the clamp and pen, you could have said it's the 1:1 prototype. 

[nick]

Here's the first attempts:-

 

 

This is pretty near to the limits of what I can do with this machine I think, I've had to use single line fonts (don't ask) but hopefully they are close enough to what you want? I'm going to have one last go with 0.1mm V bit and two passes ay 0.06mm to get 0.12mm depth, the issue is, the deeper the engraver the wider the stroke becomes and you end up displacing a lot of material that doesn't clear neatly.

 

Stay tuned, it's useful for me as I'm learning a lot about engraving I didn't know before 

 

Nick

 

[Jo NZ]

Wow! that was quick!  Looking good....

[nick]

OK learnt a lot! I’ve got some engraver bits arriving tomorrow, I think I can get a finer line with these over the v bits I’ve been using so far. 

[nick]

I think I've finally cracked it now:-

 

 

I got hold of some EXTREMELY pointy V bits, but it took me a while to figure out the feed and plunge rates to stop them immediately snapping as they didn't have any data sheets

 

 

Once I figured that out, they last quite well and cut nice thin lines. All this stuff is quite small for our readers!

 

 

Looking at the photos, rather than real life, I think I can maybe be get the lettering thiner at the expense of depth, so I may have one last go with a more shallow cut.

 

Nick

[nick]

OK that's it now, I've engraved this at 0.06mm depth and I'm pretty confident that the font stroke width is just the width of the tool tip, 0.1mm so that's as fine as it will go, you can see it's slightly better than the earlier version at the bottom of the shot.

 

 

Hope that will be good enough? I don't think you're going to get down to the this size and stroke width with punches to be honest. 

 

Nick

[klubman01]

1 hour ago, nick said:

OK that's it now, I've engraved this at 0.06mm depth and I'm pretty confident that the font stroke width is just the width of the tool tip, 0.1mm so that's as fine as it will go, you can see it's slightly better than the earlier version at the bottom of the shot.

 

 

Hope that will be good enough? I don't think you're going to get down to the this size and stroke width with punches to be honest. 

 

Nick

That looks really good.  Impressive workmanship.

Trevor

[nick]

OK they’re in the post! Let me know how you get on

20 hours ago, nick said:

OK that's it now, I've engraved this at 0.06mm depth and I'm pretty confident that the font stroke width is just the width of the tool tip, 0.1mm so that's as fine as it will go, you can see it's slightly better than the earlier version at the bottom of the shot.

 

 

Hope that will be good enough? I don't think you're going to get down to the this size and stroke width with punches to be honest. 

 

Nick

OK they’re in the post, let me know how you get on. 
 

Nick

[Jo NZ]

Awesome, Nick! In the meantime I had better finish the bits for the dash...

 

The only part to do is the fuel gauge

(Incidentally I love the fixings. Two hex head, one countersunk slotted and a hole...)

 

 

 

I drew up the gauge face in fusion 360 and cut it to show the lettering

 

 

And looked at lots of fancy programs to recolour and add detail. Most of them are so complex they would take weeks to learn (e.g. GIMP) (I'm still looking for a simple photo editor to replace Picasa 3....)

 

Guess where I ended up? Microsoft Paint....

So the finished dial looks like

 

 

 The outlining that has appeared isn't present when it's printed. Also this is 6mm across in 1/8 scale so only readable with a magnifying glass.

 

 

I've also drawn the gauge holder

 

 

Which fits behind the panel

 

I've printed the gauge onto photo paper through Word (you can size the image in mm so it prints correctly).  Now for the gauge itself...

[nick]

Wow you made that hard for yourself! I get why you drew it in fusion (if you dont have illustrator) so you did the hard bit. Add the colour in fusion - just extrude the lettering in white, then the background in black add a scale, say a line 5cm long or something known next to the gauge face, then go to file, capture image set a custom resolution in Inches rather than pixels and print the thing with windows photos using the resize option if required, measure your 5cm bar on the physical print and scale accordingly using resize.

 

You've gone from a nice fully scalable vector in fusion via ms Paint, to MS word which is really bad at handling images faithfully.

 

I suspect you might need to make the white lettering/markings wider than they actually are - at this scale the bleed from black to white is enough to lose it, so I end up making everything fat and it looks right when printed.

 

I just work in illustrator in the first place which I know isn't for everyone, and certainly isn't quick and easy to learn, but it's very good at stuff like this, especially if you're doing a lot of it.

 

 

Have fun!

 

Nick

[Jo NZ]

Coincidentally I also drew up the Rev counter for the Birkin Bentley

Time to have another look at it. Bigger script and wider lines...

[Jo NZ]

The dashboards arrived from Nick, and I have to say that the engraving is brilliant!

 

Unfortunately they have suffered in the post...

 

 

I'm not sure what did it, but they are curved in two directions - pretty difficult to do

 

luckily, with some gentle flattening in a vice, and then a rubber hammer and surface plate, they can be recovered. I flattened the worst one first

 

 

 

I drew the plate intentionally 5mm larger all round, so I'd got some fiddle room to get it in the right place on the dash hoop

 

 

 

Looking good! I was looking through my photos for more detail when I came across this

 

 

 

Notice how the dash hoop goes down the side of the chassis? I'd never noticed it before, and made the hoop to sit on top of the chassis.      Bugger.

 

So next is to build a new dash hoop out of laminated strips of wood. I still have the jig that I used to make the first one, so a slight modification will correct it. I'm off to my LMS tomorrow to get thin strip hardwood.  Luckily he supplies boat modellers so always has a good selection...

 - and then I can use the second dash plate....