How easy is it to correct RTR loco back-to-backs?

[Chamby]

Your advice please.

 

I have just purchased a nice Bachmann model steam loco but when giving it a test run, it rises up off the rails when passing through the check-rails on some points. It’s particularly bad with the new Peco bullhead points, though it also ‘sticks’ when passing through Code 100 streamline check rails.

 

The back-to-back measurement of the six driving wheels appears to be out (too close together).

 

How easy is this for me to fix myself? (Given that I don’t have any back to back gauges or associated tools).

 

Or should I send it back for replacement? (supplier is Hattons) and if so, is this a known/common problem with the Fairburn tank?

 

Thanks in anticipation,

 

Phil.

[crompton 33]

The back to back gauge is one of the main tools you need . Not just for loco's coaches/trucks as well . You can get them from here good price as well. http://www.petersspares.com/markits-m38-4b2bgoor-backtoback-oo-gauge-145mm-with-gear-recess.ir

[gordon s]

I would invest in a GW wheel puller and a B2B gauge.  There's some more info here.  They used to be around £20, so a lot cheaper than wrecking a loco.

 

http://www.rmweb.co.uk/community/index.php?/topic/19209-gw-models-wheel-press-and-quartering-jig/page-3

 

Apologies, this may only be about the wheel press/quartering jig.

 

Try this link....

 

http://philsworkbench.blogspot.co.uk/2016/10/mtk-motor-bogie.html

Edited December 12, 2017 by gordon s

[Il Grifone]

It depends on the model. Some are easy, others a right bu^^er. That said I would be reluctant to touch the back to back without the appropriate measuring instrument to set it correctly (a gauge or better a vernier/digital caliper). (The correct setting depends on the track and thickness of the flanges.)

 

I would ring Hattons and ask their advice. Tampering with the model could affect the guarantee.

Edited December 12, 2017 by Il Grifone

[Oldddudders]

It depends on the model. 

 

I concur. Being at the hamfisted end of the modelling spectrum I have nevertheless managed to successfully re-gauge more than one Hornby Bulleid light pacific by inserting a small screwdriver twixt driving wheel and frame. Since one is only looking to gain less than 1 mm, gentle persuasion works well. For non-driven axles I have found equally gentle twisting of opposing wheels on the axle can be effective. My reference tool for correct B2Bs is an NMRA gauge, one of the most useful tools I own. 

[Bernard Lamb]

Before you start on any drastic action I would check that things like the sand pipes are not fouling the track and causing the problem.

I had a problem with mine and a bit of bending cured things for a while. They then worked loose again so I cut a couple of mm from them. Now runs very well.

Bernard

[34theletterbetweenB&D]

Regauging in the larger direction by gently tapping an axle end with a drift as suggested in post 2 is preferable over other techniques for minimising any risk of disturbance to the wheel seat wtth consequences to quartering or centering. Lot easier too on any loco with wheelsets retained by a keeper plate as the errant wheelset may be removed competely for treatment off loco (says he who is just too lazy and always adjusts in situ unless some other task requires the wheelsets out anyway...).

[Theakerr]

For my Bachman K3 i made a mini puller from a bit square brass section and three small bolts.  Bit fiddly but it worked very well.

[Chamby]

Thanks for all the above prompt and helpful replies. Times like this more than compensates for all the froth found elsewhere on this forum!

 

I get the impression that the axle is a push fit so with a little gentle encouragement, will have some give, which is good to know. I think it probably wise to invest in a back to back gauge, it might help sort out some of my waddling rolling stock as well!

 

The loco concerned is a Bachmann Fairburn tank, purchased new. It looks like the leading drive wheels are slightly out of gauge (too narrow) and need widening just a wee bit to avoid riding up on the check rails. It is interesting that the problem is more acute on the new Peco Bullhead points. This suggests they might be built to tighter tolerances than the rest of the streamline range?

 

I feel I’m being slowly drawn in to some of the darker arts within our hobby, thanks to this finescale bullhead track. Probably not a bad thing, though I might have thought twice if I had known this before investing in it so heavily!

 

Phil

[Dunsignalling]

I concur. Being at the hamfisted end of the modelling spectrum I have nevertheless managed to successfully re-gauge more than one Hornby Bulleid light pacific by inserting a small screwdriver twixt driving wheel and frame. Since one is only looking to gain less than 1 mm, gentle persuasion works well. For non-driven axles I have found equally gentle twisting of opposing wheels on the axle can be effective. My reference tool for correct B2Bs is an NMRA gauge, one of the most useful tools I own. 

It sounds scarily crude but it really does work. The emphasis has to be on the gentle, though; and stop twisting as soon as you feel movement.

 

I used to employ a pair of screwdrivers, fore-and-aft of the axle, but the method seems to work just as well with only one. My favourite tool for the job is an old Stanley quarter-inch carpenter's screwdriver with a nice flared tip and a flat handle.

 

The side making contact with the wheel must be up against the axle so that the pressure is applied as close to the centre as possible.

 

John

Edited December 13, 2017 by Dunsignalling

[Dunsignalling]

Your advice please.

 

I have just purchased a nice Bachmann model steam loco but when giving it a test run, it rises up off the rails when passing through the check-rails on some points. It’s particularly bad with the new Peco bullhead points, though it also ‘sticks’ when passing through Code 100 streamline check rails.

 

The back-to-back measurement of the six driving wheels appears to be out (too close together).

 

How easy is this for me to fix myself? (Given that I don’t have any back to back gauges or associated tools).

 

Or should I send it back for replacement? (supplier is Hattons) and if so, is this a known/common problem with the Fairburn tank?

 

Thanks in anticipation,

 

Phil.

Not so much common as almost universal, and not confined to any one model..

 

You will need to get a b-t-b gauge before attempting any adjustment, though.

 

John

[RexAshton]

If it's a new model get onto Hattons. If you try yourself without the right tools you may make it worse and also invalidate the manufacturer's warranty.

[John Tomlinson]

I have a GW models wheel puller, and found this to be a great aid for such a problem, along with a back to back gauge.

 

One risk is that as you move the wheel out it becomes less firm, and shifts a bit messing up the quartering. This would be a significant problem, and detrimental to the running. As said in the last post, if its actually new I'd be tempted to speak to the supplier and see if they'll change it, had it been some pre-cherished bargain from ebay I suspect my answer would have been to have a go yourself.

 

John.

[Jol Wilkinson]

I feel I’m being slowly drawn in to some of the darker arts within our hobby, thanks to this finescale bullhead track. Probably not a bad thing, though I might have thought twice if I had known this before investing in it so heavily!

Phil

Phil,

 

you are simply being introduced to the benefits of using consistent standards for wheels and track. A look at the DOGA site will show how the various dimensions relate.

 

Jol

[tender]

It is interesting that the problem is more acute on the new Peco Bullhead points. This suggests they might be built to tighter tolerances than the rest of the streamline range?

 

I feel I’m being slowly drawn in to some of the darker arts within our hobby, thanks to this finescale bullhead track. Probably not a bad thing, though I might have thought twice if I had known this before investing in it so heavily!

 

Phil

 

 

Phil,

 

you are simply being introduced to the benefits of using consistent standards for wheels and track. A look at the DOGA site will show how the various dimensions relate.

 

Jol

 

 

If you're using Peco turnouts you need the DOGA Intermediate B2B gauge, not the Finescale Gauge which is for handbuilt track using narrower (1mm) flangeway and check rail gaps.

 

IIRC the new Peco bullhead turnouts have the same flangeway and check rail gaps as their Streamline code 75 turnouts (1.2mm).

Edited December 13, 2017 by tender