I am working on a small layout / test track, which I plan to re-use my old peco points (live frog, 1990 vintage).
I have been fettling them up for re-use and they seem to work okay, except with Roco locomotives, where the flanges are deeper and the Roco locomotives very clearly bump as they go through.
I have come across two schools of thought about solutions:
- Deepen the web between the check and running rails, or;
- Spin the Roco wheels and reduce the depth of the flanges (Nick Welch mentions this one in Festiniog Odyssey)
I'm leaning towards the fixing the flanges (but I don't have a lathe so this could be tricky) as this is the source of the problem, rather than potentially create another one by fiddling with the points (and there are more of them).
Has anyone tried resolving this one and what would you recommend please?
Thanks
Tony Deighan
I would first check the back to back measurement on the wheels. It should be 7.5mm. If it's less the wheels will bump over the checkrails of the point. If it's more the wheels may climb the frog. It's a common problem. I'm not sure if Roco flanges are deeper but I haven't noticed.
As Ted said once the back to back is correct have a close look at where the loco is actually riding up in the point.
You have to be careful when working on points with files as it is easy to file off too much.
If it is the start of the plastic check rail where the loco is ridding up it is possible to ease the angle of the start of the check rail. But do not increase it all the way along.
If it is at the point of the V of the frog then it is possible to widen the gauge of the V by filling one side, but do not make the frog any deeper.
There is another problem that the post 1980 Roco locos get when they ware out the axel slots in the chassis and the axels start to twist in the chassis when power is applied making the wheels sit at the wrong angle to the track. If this is what is happening the loco may well run through points fine in one curved direction but jump up in the other.
The way to test this is to turn the rear wheels slightly by hand and watch the front axel to see if it twists in the frame.
But as I said this is only with the post 1980 chassis with the spring drive that looks like this for the steam loco:
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fi663.photobucket.com%2Falbums%2Fuu358%2FM-e-l-l-o-w%2FRoco1980Chassis.jpg&hash=b0b7d0f45ff363dc908ddd1cc7b6fdcbc38f3051)
or like this for the diesel loco:
(https://forum.009society.com/proxy.php?request=http%3A%2F%2Fi663.photobucket.com%2Falbums%2Fuu358%2FM-e-l-l-o-w%2FRocoHOe0-6-0Diesel.jpg&hash=7e31be0ab4f03c22ced984e3d1fc369b6df33b4e)
(Diesels made before 2005 do not have the extra resistors and capacitor.)
It is possible to fix the problem by packing out the axel slots, but the best thing to do is sell the loco and get a new one!
Brian Meldon
I have cured this problem by running the loco and using a Dremel sanding tool to reduce flange depth.
Quote from: tedp on March 06, 2012, 21:41
I would first check the back to back measurement on the wheels. It should be 7.5mm. If it's less the wheels will bump over the checkrails of the point. If it's more the wheels may climb the frog. It's a common problem. I'm not sure if Roco flanges are deeper but I haven't noticed.
I second this. I've got this problem with one of my Minitrix locos where the back-to-back on the rear axle is miles out and the loco rides up on a frog. Haven't worked out how to get the thing back into place yet... sigh...
--
Rod
Quote from: tat2drod on March 07, 2012, 10:59....... I've got this problem with one of my Minitrix locos where the back-to-back on the rear axle is miles out and the loco rides up on a frog. Haven't worked out how to get the thing back into place yet... sigh...
Rod
One wheel on the Minitrix chassis, the one without the gear, has a plastic centre and these have been known to become lose on the axel. If it is a good fit careful application of leverage between the chassis block and the wheel centre (not the wheel edge) with a small watchmakers screwdriver will widen the gauge.
If it is too wide then remove the axel and use a small vice with jaw protectors to slowly push the wheels together. Again on the Minitrix chassis the wheel without the gear will move. If it is the rear axel there is still enough room to do this provided the rods are correctly quartered. The two crank pins can just sit on top of the vice jaws with the centre of the wheel in the jaws.
Hopefully the central spur gear wheel would have been positioned correctly from new and has not moved so it will not need adjusting. But if it does and it is the plastic type with a central brass insert on the axel it is very easy to snap the plastic.
Brian Meldon
Twist in an axle may contribute to the problem of the Roco chassis but it would have to twist quite a lot to cause such a problem. On a Minitrix 0-6-0 the back to back problem is usually due to the insulated wheel moving. I have seen the same happen several times. Using a small vice to press the wheel in, as Brian says, is the answer.
Okey dokey guys, thanks for the answers. I'll have a shufty later on.
--
Rod
Quote from: tedp on March 07, 2012, 11:34
Twist in an axle may contribute to the problem of the Roco chassis but it would have to twist quite a lot to cause such a problem.
We have worn some Roco 1980
I have three Roco locomotives, two diesels and one steam locomotive. They all must be pretty ancient as they don't have the spring drive but do have some kind of suppressor, not that it works, many complaints from the TV viewers when I had them running yesterday - "which nostril did you want that shoved up" was mentioned at one point.
I think I'm going to run with John's advice and modify the loco, mainly because I just know that changing the points will mean I make a complete cod's of it. What I thought would work would be to cover the motor etc in masking tape to stop the filings getting in, hold it in a vice and then use various grades of files and polishing sticks to produce something rather more scale.
Useful advice on how to fettle up points and back-to back measurements etc.
Best regards
Tony
Do they have the word ATLAS on the chassis and plastic gears down one side of the chassis?
If so they are the first type of chassis fitted these locos and you are fortunate to have some that actually still work! Quite often the wheel centres were made off centre making the wheels wobble the axels are also plastic and the spur gear (that the motor worm drives) often manage to strip them selves. You should not expect these chassis to work for that long before they die!
There is however a third type of chassis that has ROCO on the underside and gears down the centre of the chassis block. These are the second type used before 1980 and were an improvement on the 1st.
Brian Meldon
Thanks Brian
They are the first type with Atlas down the side - I'm doomed then! The oldest one has been an indifferent runner for some time and I thought I had sorted that out.
I'll do a "do minimum" job on them to get them working and then pray. I was hoping to use the steam locomotive chassis under something British, but I guess it's probably best to concentrate on other motive power.
So it's building the Parkside Dundas F&B 0-4-0T then - a post on what the boiler backhead looked like will soon follow...
Thanks
Tony
Tony
Not necessarily.
Sure, check the back to backs... essential with all rolling stock
If the wheels are still firm, introduce very carefully a tiny amount of high penetration superglue. This can work wonders. If you sand of the flanges, do a tiny bit at a time. Do not let the wheels get hot.
Thanks John,
The back-to-back measurement seems to be fine and I have had two of the three locos running through Peco points with no problems this evening.
I'll certainly follow up on the superglue angle, one of the diesel chassis sits underneath the first kit locomotive I ever built, a Meridian Kerr Stuart and I would hate to see it grounded.
Many thanks for your help
Tony