Delrin Chain Disaster !!!!!!!!!

A little while ago I had some friends round to run some trains, Graham B wanted to see one of my JLTRT 37s running. When I went to pick it up and put it on the track the delrin chain from 1 bogie fell off.
The loco was powered on both bogies so it still ran, but on close examination of the chain this is what I found.



Some paint has got on the chain, I can't remember how and it looks like halfords acrylic primer, but it has corroded the links if you enlarge the photo and look carefully at the links on the left you will see that the ends of the links have melted away.

So is it the paint or has something else go on the chain and has now gone ? Has anyone any ideas ?

In future I will be making sure that no paint gets on the delrin chain.

Richard

As a fan of the Delrin Chain system, this is a very valuable warning.

Thanks..... Steve.

Out of interest how tight did you have the chain Richard?
I have had similar which I put down to grease from the old RJH style worm and gear spraying everywhere on several of my 1980s Dave Parkin MMP locos.

My method these days is to make the chassis up, test fit the wheels then remove, paint & weather chassis wheels
Once hard I build up the bogie avoiding spraying issues.

Cliff

The chain isn't tight, I fit the chain fairly loose and then add a tension-er but still with a bit of slop, it doesn't work if they are too tight.

I'm not sure where the paint came from as normally I don't fit the chain until all the painting (but not weathering) has been done, if it had been dirty brown paint that would have been from weathering but grey primer, I have no idea how it go there and all my other locos are paint free.

I do wonder though if it is a bit oil from the gearbox that has got on the chain.

Richard

Probably specialist oil or grease.

I remember Simplex derailleur gears in the late 60's being made of Delrin and it's pretty impervious to most things, even cycle lubricants.

Has anyone tried miniature stainless steel roller chain instead of delrin? The smallest I have found on line has a pitch of 3.747mm and is 5.3mm wide, so a bit bigger but could probably still fit. It might be more suitable for G1.

Overseer said:

Has anyone tried miniature stainless steel roller chain instead of delrin? The smallest I have found on line has a pitch of 3.747mm and is 5.3mm wide, so a bit bigger but could probably still fit. It might be more suitable for G1.

Click to expand...

If its wider than Delrin then it could potentially be a problem, there isn't much room for a gearbox and delrin cog and usually the cog needs filing down a bit to make it fit.

It sounds interesting though, have you got a link for it ?

Richard

Richard,
A quick look makes me think that the damage is indeed mineral oil. What lubricant have you used in the gearbox?
Steph

Steph

It would be one of those that is sold by the model railway trade one that looks a bit like a pen and the other a syringe.

Richard

Aah, yes. I know the stuff if it's the one in a clear pen-shaped thing with a black cap? It is a mineral oil and not a particularly good one.
In most of our models a plastic-compatible synthetic is the way to go. For gears it helps if it's thixotropic as it stays on the teeth of the gears.

If really is worth investing in the Hob-E-Lube pack. From memory it's about £12 and includes various grades of quality lubricants. Including the powdered graphite that's the only recommended lubrication for Delrin chain drive (if it's necessary at all).

Steph

Is Delrin supposed to be self-lubricating? I can imagine a scenario where dirt build-up causes a sticky motion when joints move, and lubricant being applied with a view that this will lubricate the rubbing surfaces. Whereas maybe a good clean in an ultrasonic bath would do a lot more good?

Yes, it is self-lubricating, but under high loads a dusting of graphite is recommended to reduce wear.
Steph

Steph Dale said:

In most of our models a plastic-compatible synthetic is the way to go. For gears it helps if it's thixotropic as it stays on the teeth of the gears.

Click to expand...

Steph, please recommend a suitable product... maybe even with a photo. Thank you, Graham

Graham,
I use the Hob-E-Lube 'Gear Lube' on any/all model gears. It's good stuff and thankfully comes in small quantities. You might find suitable lubricants listed as 'Anti-slinging' rather than 'Thixotropic'; it's the same property...
Steph

richard carr said:

If its wider than Delrin then it could potentially be a problem, there isn't much room for a gearbox and delrin cog and usually the cog needs filing down a bit to make it fit.

It sounds interesting though, have you got a link for it ?

Richard

Click to expand...

This site has quite a bit of information on various size chains etc. http://www.smallparts.com.au/store/...el/chainrollermetalsimplexstainlesssteel/A/1/
I haven't actually seen the miniature chains but they look to be high quality.

Interesting, but at about £30 per 7.5" length it would have to be very good. It looks like the sprockets are about £3 ea and need their bores machining; they're also a touch large.
Oh, and efficiency will be hopeless if you don't get the pitch centres right; they need treating pretty much in the same way you would gears. I'd be very interested to see someone having a go with it though.

As an alternative M&M are currently offering toothed belt drives.

For the simplicity and cost I think I'd stick with the Delrin option - just don't oil it...!

Steph

Steph Dale said:

Interesting, but at about £30 per 7.5" length it would have to be very good. It looks like the sprockets are about £3 ea and need their bores machining; they're also a touch large.

Click to expand...

Although for a Sentinel it might provide an authentic sound without the additional cost of a sound chip!

Reminds me of the summer I was sixteen.

In those days you left school after your "O" levels, or stayed on, if you were going into VIth form. The last four weeks of term were going to be my swansong, having been a bit of a nuisance during my five years at grammar school, I had been "asked" to move to the local VIth form college....so I was going to have a field day in my last month at grammar school.

Sadly, my dad, a local secondary-modern deputy-head, had other ideas, so he took me and stranded me at my grandparents' in Cleethorpes...with the full blessing of the head at the grammar!!!

I spent my days working on the Lincolnshire Coast Light Railway, which ran from the end of North Sea Lane, along Anthony's Bank to the Fitties holiday camp. Summer 1968.

There were a couple of Simplex chain driven diesels working, and one of my jobs was to cycle along the track to a stranded loco and put the chain back on.... One was called Paul, the other Nocton.

Happy days.

Amazing number of teenaged girls stayed at that camp too.......