Fixing Steel Axle to Plastic Gear

Pannier Tank
Posts: 51
Joined: Sun May 02, 2010 1:11 pm

Fixing Steel Axle to Plastic Gear

Postby Pannier Tank » Wed Mar 04, 2020 9:03 am

Thinking ahead to a Dapol Class 22 Gauge conversion where I will be re-using the Plastic Gear Wheel on replacement extended Axles. The Gear Wheel is a push fit on the Axle and I am concerned that this may slip when in use. I am not too sure on what adhesive to use, Super Glue may set too quickly before the axle is in position, Araldite maybe too thick and some of the Loctite Retainers expand when applied to Steel and therefore could possibly split the Plastic Gear Wheel.

Can anyone recommend a suitable adhesive?
Regards

David

Jeremy Good
Posts: 117
Joined: Fri Feb 19, 2010 10:36 pm

Re: Fixing Steel Axle to Plastic Gear

Postby Jeremy Good » Wed Mar 04, 2020 9:21 am

David

I used Araldite on my conversion of the Dapol Class 121 DMU which used the Branchlines DMU wheels to maintain the split axle pick-ups. The conversion is on here in the Multiple Units section.

No problems with this so far...

Jeremy

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jim s-w
Posts: 1746
Joined: Wed Jul 30, 2008 5:56 pm

Re: Fixing Steel Axle to Plastic Gear

Postby jim s-w » Wed Mar 04, 2020 11:28 am

I just roughen up the axle where the gear will go by rolling a file over it. I’ve never glued a gear in place on any RTR conversions

HTH

Jim
Last edited by jim s-w on Wed Mar 04, 2020 1:07 pm, edited 1 time in total.

Enigma
Posts: 258
Joined: Tue Aug 13, 2013 2:49 pm

Re: Fixing Steel Axle to Plastic Gear

Postby Enigma » Wed Mar 04, 2020 12:06 pm

jim s-w wrote:I just toughen up the axle where the gear will go by rolling a file over it. I’ve never glued a gear in place on any RTR conversions

HTH

Jim


Just what I was going to say. Use the serrated edge of a coarse file over the location point of the gear by rolling it on a hard surface.

And once fitted - leave it there!

Philip Hall
Posts: 1354
Joined: Mon Aug 10, 2009 7:49 pm

Re: Fixing Steel Axle to Plastic Gear

Postby Philip Hall » Wed Mar 04, 2020 4:40 pm

I abrade the axle with a file, but often drill a hole through the gear into the axle at 45° and insert a nickel silver pin.

I am a bit suspicious of any kind of glue where oily plastic is involved, especially where mechanical strength is required, hence playing safe(er) with a pin.

Philip

bécasse
Posts: 20
Joined: Sun Jun 17, 2018 8:26 am

Re: Fixing Steel Axle to Plastic Gear

Postby bécasse » Wed Mar 04, 2020 9:15 pm

I would file small notches in both the axle and in the central hole in the gear wheel (so as to speak), so that the two notches will be adjacent when the gear wheel is correctly mounted on the axle. Then I would use araldite to fill the resulting mini-void when mounting the gear on the axle. Once the araldite sets, the axle and the gear wheel will be permanently fixed in position, successfully resisting both longitudinal and rotational forces. The advantage of this method is that it is very easy to do (and without any great skill), needing only a small file and some freshly mixed araldite. Even the 5-minute version of the glue will give you adequate time to ensure that the gear wheel is central on the axle before it "goes off", although my preference is usually to use the 24-hour version.

Terry Bendall
Posts: 1682
Joined: Sun Jul 27, 2008 7:46 am

Re: Fixing Steel Axle to Plastic Gear

Postby Terry Bendall » Thu Mar 05, 2020 8:08 am

I have never found it necessary to roughen the surface of the axle or use any type of adhesive and have never had any slippage of the gears. It does of course depend on the comparative size of the old and new axles.

Terry Bendall

Pannier Tank
Posts: 51
Joined: Sun May 02, 2010 1:11 pm

Re: Fixing Steel Axle to Plastic Gear

Postby Pannier Tank » Thu Mar 05, 2020 10:36 am

Thank you all for your replies which were very helpful and much appreciated. I'm probably being a bit over cautious as this is my first attempt at re-gauging a Diesel Locomotive with Split Axles.

I'll report back when the conversion is complete.
Regards

David

John Palmer
Posts: 604
Joined: Fri Jul 15, 2011 11:09 pm

Re: Fixing Steel Axle to Plastic Gear

Postby John Palmer » Thu Mar 05, 2020 12:10 pm

Don't know whether you have seen Captain Kernow's Class 22 conversion thread at https://www.scalefour.org/forum/viewtopic.php?f=21&t=2022&p=16334, but if not then it may be worth a look. If you intend to press steel stub axles into the nylon gear muff, as shown in that thread, then it looks to be a straightforward job to bore through the muff on either side of the gear after the stub axles are fitted, and then to fit a short length of rod that will mechanically lock the stub axles in place. Disclaimer: I've not seen the components 'in the flesh' or had experience of this kind of conversion, so my suggestion may be completely inappropriate. Wouldn't be the first time.

Pannier Tank
Posts: 51
Joined: Sun May 02, 2010 1:11 pm

Re: Fixing Steel Axle to Plastic Gear

Postby Pannier Tank » Thu Mar 05, 2020 4:54 pm

John Palmer wrote:Don't know whether you have seen Captain Kernow's Class 22 conversion thread


Yes I have, a very interesting thread.
Regards

David

Dave Franks
Posts: 54
Joined: Tue Apr 16, 2019 9:02 am

Re: Fixing Steel Axle to Plastic Gear

Postby Dave Franks » Fri Mar 06, 2020 12:02 pm

The problem I had with a Bachmann 4F conversion was that the supplied axles were under size by 0.05mm, not much you might say but enough that an interference fit would not hold even with roughening the axle and applying Loctite 603, it worked for a while then let go. I turned up a new axle to, iirc, 2.5mm and tried again but with the gear having been damaged by spinning on the old roughened axle this let go too. The gear had a boss on one side so that was drilled 0.5 and the axle just marked then the gear was moved along, 'easily' and the axle drilled through then the gear aligned once again and drilled right through the boss and a brass wire pushed through with some Loctite 603, obviously that has never moved since. it was fortunate I didn't have to remove the wheels as they were still firmly fixed on the new axle. The 4F regularily trundles round Wharfeside with 60 minerals (usually 30) with no bother at all. Other conversions have been okay but I did file a slight flat on the axle as I noticed the 603 seemed to fix to the plastic gear more than the steel axle? So the flat became a sort of keyway.
Clip showing the rough but successfull testing of the converted 4F and wagons:- https://www.youtube.com/watch?v=l7vNZioYlss
All wagons fitted with Gibson wheels and brass bearings.

Dave Franks


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