Back to back checking

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I wonder how many of us check the back-to-back measurements of our models - even on brand new RTR offerings.

Some time ago, with kit building in mind, I bought a B to B gauge and put it in a drawer awaiting the "kit building" day.

I'm still awaiting that day but was frustrated by a locomotive that was constantly derailing the front bogie so, as almost a last resort, I pulled out the gauge.

Having checked the loco and, as a double check, several other pieces of stock, some of the measurements were so far adrift that I was convinced I'd bought the wrong gauge !  Most needed a considerable easing out - that refers both to where they were out and the percentage of stock requiring adjustment.  I really was sure I'd got the wrong gauge !  Maybe millimeters are smaller in China ……………………..

I know checking this has always been a recommendation but I'd always rather poo-poo'd the idea thinking it was just for the ultra-finescale boys.

I would urge you all obtain a gauge and check your stock - you may well be in for a shock !!

'Petermac
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Hi Peter,

Essential piece of kit. And not just for wagons, coaches and the like. As points have got more fine scale (especially the frog gaps) those tolerances on older locomotives can be problematic, especially Hornby models. I had an interesting conversation with them regarding their tolerances several years ago after I found a brand new GWR Castle model was routinely derailing on some hand built points (not mine, I wasn't into building them then) where everything else was running through. Way under acceptable limits. That's when I got another essential bit of kit - a wheel puller. Which created another problem of the motion gear then fouling the body after the wheels were correctly gauged because the width across the pistons was under scale. Which then meant widening the piston assembly….

All rolling stock gets checked on a regular basis. Helps to set the wheels at a tight fit or just slightly under, otherwise the rim can hit the frog nose.

Decent micrometer, back-to-back, wheel puller, and some Loctite or plastic compatible CA to keep the wheels where they should be after adjustment. 

Nigel

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I agree with Peter and Nigel …..for me it is also an essential item in my tool box
First thing I grab after a derailment……its astonishing how often wagons and carriages are under gauge. Dapol are particularly bad although I have had problems with new Hornby coaches.

The other useful tool (which I also bought from DCC Concepts) is a plastic gauge reamer…..inserted in place of a sticking wheel set….a few turns……and hey presto another free wheeling wagon. Not something for fine gauge modellers perhaps but perfect for a coarse gauge operator like me!:lol:

Cheers

John

Last edit: by John Dew


John
Granby III
Lenz DCC,RR&Co Gold V10 A4 Windows 10
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Hi Peter,

John's right, reamers are also very useful (or the end of a conical drill bit), but it's amazing what a set of brass bearings does to the running. Often needs a reamer to open up the hole. Old second hand stock with wobbly wheels due to time-worn holes often benefits from a set of pin-points.

Nigel

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Thanks Guys,

very useful /  helpful tips there.

 An axle reamer will be added to my Hattons Trunk, can this be used to open out axle holes to accept brass bearings?

Colin

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I am guessing you would have to specify that…..mine just gets rid of the imperfections in the plastic Bearing and ensures it is the correct depth
Cheers

John

John
Granby III
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[user=2170]Colin W[/user] wrote:
Thanks Guys,

very useful /  helpful tips there.

 An axle reamer will be added to my Hattons Trunk, can this be used to open out axle holes to accept brass bearings?

Colin

Hi Colin,

These reamers are meant more for cleaning out and taking a very thin layer of plastic off. They do not have an aggressive blade. A fresh drill bit with an angled point (60° if you can find one) works better. Just cut to the length required,  wrap some tape around for grip. That said, most existing holes just need a blob of thick solvent glue in the existing hole, leave it to sit for 15-20 seconds to soften the plastic, and the bearing can be pressed in with some flat ended pliers. If too much is removed some slivers of styrene can be solvent welded in around the bearing.

Nigel

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[user=1632]BCDR[/user] wrote:
…………………………………………………………………. If too much is removed some slivers of styrene can be solvent welded in around the bearing.

Nigel
Whilst taking the utmost care that your brass bearing remains perfectly centered otherwise your wagon will waddle along the track looking like a creature from outer space.   :roll: :roll:

'Petermac
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Hi Peter,

Never found this to be an issue. It's not as if new holes are being drilled. Reaming or drilling is self centered. It's also worthwhile polishing the axle ends with #1000 grit. I used the Dremel.

Adjusting the back to back is more of an issue. Has to be done equally on both sides. One reason why the micrometer is required. Really accurate centering needs the gear/wheel puller. I calibrated mine, so many turns per mm

Nigel

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I was referring to the bit about filling in around an over large hole Nigel .....

'Petermac
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Hi Peter,

If by accident or over enthusiasm too much is removed solvent weld some styrene in. I use Tamiya thick glue. I have had to do this with some old Dapol models that had run for so long the holes were oblong.

More serious is not getting the wheels centered after adustment. A wagon going down the track with the body at an angle looks decidedly odd. And will be a bad runner.

Nigel



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Thanks again everyone, most helpful.

 First job today here on a cold wet winter's day is to check the smooth running of all my stock on track and points. Should keep me out of mischief and away from doing the vacuuming  :twisted:

I know that a few wagons could do with better wheels but as the majority are new, running has been very good with just the odd one which I'm sure needs attention.

I think some of the newer "speedbore" type tip drill bits are cut at a much steeper angle that the traditional so may be a good starting point to insert bearings. Trouble is the bits are too long, shortening might be a challenge.
 

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Interesting topic, Thanks Peter.

I have issues with a Vitrains class 37 shorting out on a couple of sets of points so this has spurred me into digging out the b to b gauge to check.

Gary
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