Allchin Differential Lubrication

[stephen goodbodyParticipant @stephengoodbody77352]

Hi all,

I'm new to this forum and so apologize if I'm repeating an often-asked question, but does anyone have any guidance with respect to lubricating the differential gears on an Allchin traction engine?

The engine is the Bill Hughes design doubled-up to 3 inch scale, and the specific questions are:

1. Do you lubricate the differential?

2. If so, how? (short of removing the rear wheel and stripping the unit down)

3. Is it best to use grease or oil?

The engine is not hard worked but it does get used every few weeks through the summer and clocks up perhaps 20 miles a year.

Thanks to all,

Steve Goodbody

[stephen goodbodyParticipant @stephengoodbody77352]

[JasonBModerator @jasonb]

1. Yes

2. Really depends on how the model has been built, my Fowler has a couple of small access covers in the gear covers, it may be these were left of teh 1.5" design but could have been added to a larger scale engine as there would have been a way to do it on the full size.

3. Some people like grease but it can also collect dust and ash which makes a nice grinding paste, others oil which will drain off and carry the dirt with it. something between the two which you may be able to squirt in would be motorbike chain lube.

Again I'm not sure what allowance has been made on yours for lubricating the diff centre as you will also want to keep that oiled, mine has an oil box and pipe to get oil where it is needed

[Chris Evans 6Participant @chrisevans6]

In my ancient motorcycle gearboxes and also an old 36" Ransomes lawn mower (which has a diff in the rear roller) I use semi liquid grease. Usually known as type "O" widely available for lorry chassis lube systems. This for me is the best of both worlds as is does not leak out as easily as a heavy oil. Patience when filling is required. Maybe you could drill and tap for a grease nipple say 1/8 BSP and give the odd squirt before running ?

[stephen goodbodyParticipant @stephengoodbody77352]

Many thanks for the replies Jason and Chris,

Focusing on question 2, and specifically the Bill Hughes Allchin design, I would greatly like to hear from anyone who has built and runs one of these engines and to find out how they lubricate the differential pinions (aka compensating center).

The drawings show oil holes for the pinion shafts, these appear to be lubricated through the two driving pin holes in the wheel hub. However I can see no way of getting oil to the pinion gears themselves short of blindly squirting it into the gap between the winding drum and the toothed driving plate.

Any help is greatly appreciated.

Best regards,

Steve

[Paul LousickParticipant @paullousick59116]

Hi Steve,

The compensating centre should be lubricated and as stated above, oil will run thru and would need regular application which is how the drip lubricators work and grease + dust makes a grinding paste. However the diff gears on the full size traction engine which I drive uses grease. Built in 1926 and travels hundreds of miles each year and still going strong, often on dirt roads.

The drawings for my Ruston show holes in the casting for oiling the pinion shaft (from oil which is in the cavity behind the winding drum) the and a pipe for transferring oil to the axle. (someone on the TractionTalk web site may have a better answer for your Alchin)

I have modified the design, replacing the screw which locks the pinion gear shaft with a long grease nipple. This now lubricates the gears and axle from a common point while locking the shaft.

Edited By Paul Lousick on 10/10/2016 23:47:42

[JasonBModerator @jasonb]

You might want to ask the same question on Traction Talk forum (model engine section) as there are a few there with Allchins of various sizes.

My Fowler has a similar arrangement to Pauls in 2" scale. It may well be that these finer details were left off teh 1.5" design and as I said if it has just been doubled up then they will be missing.

[GoCreateParticipant @gocreate]

Hi Stephen

I've built the Allchin in 3 inch scale. When driving the differential gears only rotate against one another when cornering and the rotational speeds are very slow. With this in mind, right or wrong, this is what I did.

I made my gear pinions from steel, to provide a good bearing I lined them with a cast iron bush and used silver steel pins, I coated the pins in dry film moly disulphide lubricant. On reflection an oilite bush could have been a better choice.

I also coated the gear teeth in dry film moly disulphide lubricant so no grease or oil is used.

I have only recently finished the engine and won't be steaming until next spring, so at present i can't give any feed back on this method.

Hope this helps.

Nigel

[Paul LousickParticipant @paullousick59116]

Nigel,

I did not think of using moly to lubricate the gear teeth on a model engine. And as you have said they only rotate when cornering. What are other peoples comments with using it ?

Paul.

[stephen goodbodyParticipant @stephengoodbody77352]

Thanks once again to all who've replied.

Jason – I wasn't aware of Traction Talk and will indeed post the same question there. I've registered but don't yet have the permissions needed to access the forum or post a thread.

NIgel – it sounds like you saw the 'problem' (if it is one) in advance. Based on your own engine, do you think it's feasible that simply squirting oil into the annular gap between the winding drum and the toothed driving plate will stand a chance of getting at least some onto a bevel gear or a pinions such that it would then be spread to the other gears as the differential rotates?

To anyone else reading this who has first-hand experience of the Bill Hughes design, I would very much like to hear your approach to lubricating the Allchin differential.

Best regards

Steve

[GoCreateParticipant @gocreate]

Hi Steve

I don't think squirting oil though the annular gap mentioned would be very effective in getting the oil where it's needed. Chain saw oil is tacky, this could be used on assembly and should keep the surfaces wetted, then don't worry about it, re-lubricate once a year or so.

I will be using chainsaw oil on my main exposed drive gears, because it's tacky it shouldn't fling around to much or run off to quickly.

Nigel

[Gordon WParticipant @gordonw]

Don't forget that some, or most, chainsaw oil is bio-degradable now, so might not be best for a job like this. Motorbike chain oil would be my choice.

[stephen goodbodyParticipant @stephengoodbody77352]

Hello Jason,

As previously mentioned, I've registered for Traction Talk but have been unable obtain the permissions needed to post or reply to a thread on any of topic sections. I've tried several times contacting the forum owner, using the contact details provided by the website, but have unfortunately had absolutely no response or reply.

Do you happen to know if the Traction Talk forum has closed to new members? If not, can you (or anyone) perhaps recommend or suggest what the issue may be?

Thanks in advance for any help or suggestions,

Steve

[JasonBModerator @jasonb]

David can be a bit irratic as to when he gets round to adding new members, I have sent him a message which has worked in the past when others have been waiting for approval.

It will be worth the wait.

J

[stephen goodbodyParticipant @stephengoodbody77352]

That's very kind of you – thanks Jason.

Best regards

Steve

[JasonBModerator @jasonb]

Just had an e-mail from Traction Talk owner, you should have access now.

J

[Clive HartlandParticipant @clivehartland94829]

Dry powder lubrication is not as good as a grease, I have seen a test report regarding using dry powder and then grease in the same set up and they found that the grease was superior for lubrication. This was a cylinder and ram and the two figures given were totally different. They recommend using grease.

Clive

[Ian S CParticipant @iansc]

There is a PTFE/Teflon dry spray lubricant, can't remember the name.

Ian S C

[stephen goodbodyParticipant @stephengoodbody77352]

Many thanks once again.

Jason, it does indeed look like I know have access to the Traction Talk forum, your help is very much appreciated.

Best regards
Steve

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