Making propeller shafts using brass tube - advice please

[Quiet Mike]

I was disappointed with the fit of the propellers on my last build, the Airfix Blenheim. They were loose on the ends of the stubby little shafts, which in turn also rattled around the engine cases. I've seen several modellers on here using brass rod on their WIP threads, and it looks like a very good alternative. As a relative newcomer to the hobby, and still mainly building OOB, is there a good 'How To' idiots guide out there? I've just come back from my local model shop, but was a little overwhelmed with their selection of brass rods and tubes. (Maths is not my strong point, and I was struggling with having both metric and imperial sized rods and tubes in front of me) 

If anyone has any tips or advice, or leads on good threads explaining how to do this, I'd appreciate it. I'm keen to push my modelling skills forward, but making stuff from brass rods and styrene sheets is all new territory for me, and I'm rather wary about where to start.

 

Thanks in advance.

 

Mike.

[JWM]

A 2 mm brass tube with thin walls is a reasonable choice. You can drill out the engine with 2 mm drill, cut some 10 mm piece of brass tube (an edge of triangle file is good for cutting), press it into engine and use a bit thinner brass or plastic rode as prop shaft. Secure it from back.  For V-engines I use often a lollipop handle, which are a bit larger but they are very nice and low friction plastic (you cannot glue it, just press on front of engine) and in this case 2 mm brass can work as shaft of prop as well. You do not need to eat lollipop (they taste are awful ), just left it in water overnight and it will dissolve, then you have nice handle to play with...  

Regards

J-W

 

[Troy Smith]

On 25/09/2020 at 17:48, Quiet Mike said:

If anyone has any tips or advice, or leads on good threads explaining how to do this, I'd appreciate it. I'm keen to push my modelling skills forward, but making stuff from brass rods and styrene sheets is all new territory for me, and I'm rather wary about where to start.

 

They are cheap enough materials to play with, and learn their properties.   

 

I was given a load of brass rod and tube, but if buying, suggest getting some you have matching drill bits for, so you can drill holes.  

Mine is imperial,  but I have 'near enough' metric bits.

 

Mostly folks do this so your props can spin, but it does allow the props to be easily removed for transport, and the only tricky bit is making sure things are properly centred and straight, so use a centre punch for the initial marking.   I use a needle in a pin vice,  which is an amazingly useful tool BTW.

 

If replacing existing bits, you may want to get the same size, but a piece of brass rod, say 1mm, and a piece of tube this will fit into is all you need, though a set of telescoping microtubing is a handy thing to have for all sorts of uses

eg, guns and pitot tubes, 

I replaced the guns on a 72nd Cromwell like this,  using 0.6 mm for the main part and 0.8mm for the collars, and cut the larger tube collar by rolling the tube on a cutting matt with flat bit of a 10A scalpel blade, it cuts easily.  I flared the end with a small nail, brass is reasonably soft compared to steel, so cuts, files and drill easily.  

50621188 by losethekibble, on Flickr

 

So a micro tube set can have many other use.

 

if you get everything right they can do this.... which greatly amused my inner child...

50620037 by losethekibble, on Flickr

 

It helps alignment to allow the rod to go to the spinner tip, and you mayb need to add some plastic sheet to the inside of the nose to help mount the brass tube,  which is what matching drill bits come in handy. 

 

From memory Mike, you like bicycles,  modelling is not some closed world,   my skills were greatly improved from my youth by having done serious DIY building jobs, mostly from learning to importance of dryfitting, careful cutting and how to trim and shim to minimise filling and not make a mess in the first place,  so think laterally from bike maintenance.  tools, materials ans techniques, and you maybe surprised what can be transfer,  And a bit of practice getting the feel of a new material and your away

 

Note, re brass,   I've not explored soldering myself, but seen some fantastic work on here. 

 

On 25/09/2020 at 17:48, Quiet Mike said:

but making stuff from brass rods and styrene sheets is all new territory for me, and I'm rather wary about where to start.

If you are looking at sheet styrene, look for a multipack of thicknesses,  it usually sold in thousand of an inch, I'd suggest getting 10, 20, 30 and 40 thou, which are approx 0.25, 05., 0.75 and 1mm thick.   60 and 80 are available, but you can layer the stuff. Less commoin are 5 thou and 15 thou,  5 thou can be really useful but seems hard to get

this is a multipack

https://www.ebay.co.uk/itm/5-Assorted-Sheets-Matt-White-Plasticard-Size-A4-Mixed-Assortment-Styrene/293708736832

Supplied as follows:

0.25mm (0.010") White 1 off

0.5mm (0.020") White 1 off

0.75mm (0.030") White 1 off

1.0mm (0.040") White 1 off

1.5mm (0.060") White 1 off

 

 

The other things to get are Slaters assorted micro strip

https://www.ebay.co.uk/itm/Slaters-1001-Assorted-Microstrip-Pack-of-50-Lengths/383205922764

and it is nearly impossible to cut thin strips accurately (it tends to curl)  and if you ever want to add some detail,  say some wheel well or cockpit ribbing, or any of those things you see done, this will really help.   Tip, get some straws, blank one end, tape together, and sort the strip into the relevant sizes, as the assorted set is a mix of the ones listed here

https://slatersplastikard.com/plastikard/microstrip.php

 

and a set of Evergreen rod and Tube assortment , #217 

eg https://www.ebay.co.uk/itm/EG217-Evergreen-Plastics-Assorted-Rodding-Tubing/251789466779

 

no connection to the sellers, just to show what i mean.

These two may seem expensive, at approx £5 each,  but they are the only assorted sets available,  and they will last for ages unless you turn into a scratchbuilding maniac.

 

If you don't already have some , 

https://www.ebay.co.uk/itm/US-PRO-20pc-HSS-Metal-Micro-Mini-Small-Drill-Bit-Set-Metric-0-3mm-1-6mm-2409/301382753809

There are higher quality ones, but for plastic use I found these fine.

 

and these

https://www.ebay.co.uk/itm/NEILSEN-CT0480-4PC-PIN-VICE-DRILL-CHUCK-SET-0-4-8mm-Hobby-Mini-Dill-Chuck/233746677275

 

Note, I use one of these with a needle for a centre point, also a scriber, and for applying drops of superglue

 

Sorry, rambled off,  all the above I'd consider pretty much essential,  you mention having a hobby shop, and they should have all the above, I don't have a shop anywhere near so do shop online.

 

Any questions, ask away.

HTH

[Black Knight]

Just to mention that Trumpeter do packs of brass tube at very reasonable prices.

You get 8 tubes, of 4 different sizes, each 200 mm long. The tubes go up in tiny mm steps and there are about 8 packs covering from 0.3mm to 4 mm or so

eg, A pack, in steps might be 0.7, 0.8, 0.9, 1mm.

A pack costs between £2.50 and £4 depending where you buy it from

If you go to K&S it'll cost you about £1.50 - £2 for one tube, 250mm x 1mm

 

example; https://www.hmhobbies.co.uk/20cm-brass-pipe-set-1-03-04-05-06-trumpeter-tools.html

[Quiet Mike]

Excellent advice, thank you all! I feel well informed enough to get some suitable supplies and have a go now, I am very much obliged.