Romford or Markits wheels not quartering correctly?

[Captain Kernow]

I may be coming at the from the wrong direction, but I was wondering if anyone had had any experience of Romford or Markits driving wheels not quartering correctly, once the wheels have been secured on the axle?

 

I am aware of some wheels not fitting onto the axle end without a little fettling, but what about the self-quartering side of things?

 

Many thanks.

 

[RexAshton]

They really don't have a choice in the matter. What problems are you having?

[polybear]

If the wheels are fitting the axles ok then presumably any quartering issues must be due to either incorrect machining of the square ends of the axles, or the square holes in the wheels.

[Izzy]

When you say quartering, do you mean that they aren’t producing an exact 90degree difference, or that they are all - how many are involved - giving differing results?
 

If the latter then it is a problem but, if the former, and they are say, 87 or 93 degrees, and all matching, then that in itself isn’t a real problem. They should still work quite okay. The actual quartering doesn’t have to be absolute, just the same for all particular wheelsets used. If it’s one particular wheel type/size it might be the casting batch die positions moved slightly. All supposition of course.

 

Izzy

 

[hayfield]

Could it be that its a case of unmatched wheels, as they now do prototype wheels and either new and old styles have got mixed up

[Captain Kernow]

OK, here is the background to this tale and an update.

 

I have been building a NuCast Partners (designed by Justin Newitt) chassis for my old Cotswold 16XX body kit, which I have been building concurrently.

 

One of the features of the etched coupling rods provided in the chassis kit is the fact that the etched crankpin holes, at approx 1.5mm diameter, are really too big for standard Markits crankpins, which measure up at 1mm diameter. Too much slop, really, but to begin with, having found the basic chassis, once constructed, rolled along very nicely under finger power, I decided to leave things as they were.

 

Once I fitted the motor and gearbox, however, there was an annoying hesitation in forward gear, which I just couldn't get to the bottom of. I bushed the crankpin holes on the driven axle, but that didn't make any difference, nor did any other adjustments.

 

In the end, I had managed to tweak both rods and chassis too much, with the result that I couldn't be sure where the (continuing) problem lay.

 

I have a second 16XX kit, which was intended to go under one of the new Rapido 16XXs and be built in P4.

 

In order to eliminate all other possible causes of the problem (too much slop in the hornblocks or crankpin holes or imprecise locating of hornblocks, for example), I decided to use the second chassis and build it rigid, in OO, for this loco. The first chassis will be dismantled in due course and re-used for the P4 loco.

 

I bought an Avonside Chassis Pro jig a couple of years ago and hadn't used it hitherto, the first 16XX chassis having been built on my older Hobby Holidays jig. Whilst there's nothing fundamentally wrong with the Hobby Holidays jig, when I read and watched the instructions for the Avonside jig, I was immediately much impressed with the greater precision and ease of use that it offered.

 

I build the second 16XX chassis yesterday afternoon, using the Avonside jig.

 

All axle holes were lined up and matched with the new coupling rods, which I had already put together and bushed with some 1.1 mm I/D, 1.5mm O/D tube from Eileens.

 

Everything matched up precisely and the whole chassis went together nice and square, with no hint of any unevenness when stood on it's wheels on a flat piece of glass.

 

With a nice, smooth fit between coupling rods and crankpins and minimal slop and no hornblocks to worry about, I could see no reason for the chassis not to run smoothly first time.

 

But it didn't.

 

Further investigations revealed that the leading two wheelsets, with the front halves of the articulated rods on, ran nice and smoothly, but the centre and rear wheelsets, with their respective coupling rod halves on, did not.

 

But they didn't bind where you might expect. Thanks to the precision of the Avonside jig, there was no binding when either side was 90 degrees from the vertical, rather it was when it was about 20 to 25 degrees from the vertical.

 

I swapped the front and rear wheelsets over, being careful to keep each corresponding wheel on the same side.

 

This time, the rear two axles and corresponding rods went round nice and smoothly, whereas the leading two (the now leading axle was previously the rear axle), did not and started binding in the usual places.

 

Given that the centre wheelset was a constant, this could only mean a problem with what was now the leading wheelset, previously the trailing wheelset.

 

Closer examination and comparison with the other wheelsets showed that the wheels weren't quartered to exactly the same degree as the other two wheelsets.

 

I swapped the wheelsets round again and put what had become the 'defective' set back in the rear axle bearings and the problem transferred back to the rear two wheelsets again.

 

To put the matter right, I would either have to replace the defective wheelset (and hope that the replacement matched the two good sets) or somehow contrive to twist the defective wheelset back to match the two good ones, not so easy with Markits steel axles and metal wheel centres.

 

I found an old Markits axle in my spares box and filed the corners off the 'square' part of the axle end and re-fitted it to the wheel and re-assembled the chassis.

 

Amazingly, all worked well now, both in '2-4-0' and '0-6-0' mode.

 

Although I have tightened the defective wheel on the axle as much as possible, I now have to decide whether to keep it as it is and hope it never comes loose, or order a new wheelset (or more probably, a complete set of wheels and axles, in the hope of consistency).

 

At least I've got to the bottom of the problem, which I am convinced was also responsible for the original problem with the first chassis.

 

Although many of us like the idea of self-quartering driving wheels, there is perhaps something to be said for the 'press-on and quarter yourself' type, as sold by Alan Gibson and Ultrascale.

 

[Re6/6]

When the 'CP²' jig first came out I built a chassis for a Cl 14 Constructeon kit and the end result was perfect. I can highly recommend this jig.

 

Liking the idea of self-quartering driving wheels I recently purchased a set of P4 Markits axles with the intention of turning down the backs of the flanges of some Romfords on the lathe. Maybe not now!

[Michael Edge]

Are they new axles? I have had faulty ones in the distant past, with the quarters not machined accurately - this was long before the Markits era though.

[DCB]

I would suggest that you get a good few axles and a few spare wheels and mix and match until you find 3 sets where the crank pins actually are at 90 degrees.  Don't file the axles they will come loose soon enough with out filing off the corners.   Then again you could just fix the loose wheel to the rounded axle with industrial strength Super glue.   With most products it is the oldest / earliest which were the most accurate and accuracy degrades as the tooling ages.  Usually the binding seems to be in the 30 to 60 degree area relative to vertical if the quartering is out and at 0 or 90 degrees when the rods are the right length.  Getting some later Romfords correct to gauge was difficult enough without quartering issues.

[Captain Kernow]

1 hour ago, Michael Edge said:

Are they new axles? I have had faulty ones in the distant past, with the quarters not machined accurately - this was long before the Markits era though.

Mike,

 

Both the axles and wheels were bought in 2016.

 

52 minutes ago, DavidCBroad said:

I would suggest that you get a good few axles and a few spare wheels and mix and match until you find 3 sets where the crank pins actually are at 90 degrees.  Don't file the axles they will come loose soon enough with out filing off the corners.   Then again you could just fix the loose wheel to the rounded axle with industrial strength Super glue.   With most products it is the oldest / earliest which were the most accurate and accuracy degrades as the tooling ages.  Usually the binding seems to be in the 30 to 60 degree area relative to vertical if the quartering is out and at 0 or 90 degrees when the rods are the right length.  Getting some later Romfords correct to gauge was difficult enough without quartering issues.

David,

 

i'm not proposing to keep the filed down axle, it was really to test my theory. I've ordered some new wheels and axles now and I will be doing exactly as you describe.

 

[cctransuk]

28 minutes ago, Captain Kernow said:

Mike,

 

Both the axles and wheels were bought in 2016.

 

David,

 

i'm not proposing to keep the filed down axle, it was really to test my theory. I've ordered some new wheels and axles now and I will be doing exactly as you describe.

 

 

I find that, nowadays, the square holes in Markits wheels are usually too small to fit onto the square end of the axle as bought.

 

I invariably have to remove, with a square needle file, a little of the casting taper in the holes to get an accurate fit onto the axles. I am careful NOT to file the square hole towards the front face of the wheel; just in the first millimetre or so from the back face of the wheel.

 

If the wheel is 'pulled' onto the axle by tightening the fixing nut, without clearing the casting taper, the square hole can be 'trimmed' slightly off its correct orientation by the cutting action of the square steel axle into the softer mazac wheel.

 

The wheel should fit onto the axle - without any need to press or force it - before assembly, if quartering is to be accurate.

 

John Isherwood.

[Michael Edge]

2 hours ago, Captain Kernow said:

Mike,

 

Both the axles and wheels were bought in 2016.

 

David,

 

i'm not proposing to keep the filed down axle, it was really to test my theory. I've ordered some new wheels and axles now and I will be doing exactly as you describe.

 

They should be OK, I've had no trouble with anything made as late as that, must be something else.

[mike morley]

I have a Bachmann Ivatt Mogul that I converted to EM with a set of Markits wheels some time around 2016.  I never could get it to run properly and frequently found myself suspecting the quartering, but always dismissed the idea.  I eventually gave up and put the loco to one side, but your experiences will prompt me to look again.  Thank you.

[hayfield]

17 hours ago, Captain Kernow said:

Mike,

 

Both the axles and wheels were bought in 2016.

 

 

 

16 hours ago, cctransuk said:

 

I find that, nowadays, the square holes in Markits wheels are usually too small to fit onto the square end of the axle as bought.

 

 

 

14 hours ago, Michael Edge said:

They should be OK, I've had no trouble with anything made as late as that, must be something else.

 

 

Thank you all for this information, something I should take note of as I have many sets of Romford wheels I have picked up over the years.

 

Since changing to EM gauge I do tend to buy new axles, but if I am having issues in the future you all have given me an insight to issues I have never considered before. Thank you 

[Barclay]

This is very interesting as I've been having terrible trouble with a 00 gauge chassis for a Great Eastern J17 that I'm building for a friend - to the extent that it's now back in bits as I simply could not isolate the problem and the only option is to basically build it again from the frames up, with new hornblocks.

 

I don't normally use Markits wheels and on encountering a hesitance have always been able to tweak it out by adjusting the quartering. With these wheels I took it for granted. I set hornblocks with London Road Models alignment jig axles and have never got it wrong before......

 

I think that if I get time at the weekend I will check the wheels' quartering with the GW models wheel press, or otherwise make something up to check they are all the same. 

 

 

Just a thought - the axles are very old ones that I took out of a kit that I converted to EM - food for thought?

Edited August 12, 2020 by Barclay

[Captain Kernow]

Thanks to all who have commented on this. I'm now awaiting the arrival of some replacement wheels, from which I will select one to replace the problem wheel.

 

It's interesting that the problems some have reported getting wheels to fit on the square axle ends seem to be quite recent. I don't recall ever having this problem, say, 15 - 20 years ago.

 

It's worthy of note that the recent problems I have experienced have been with new items, not older ones that have been in the spares box for years.

 

[cctransuk]

53 minutes ago, Captain Kernow said:

It's interesting that the problems some have reported getting wheels to fit on the square axle ends seem to be quite recent. I don't recall ever having this problem, say, 15 - 20 years ago.

 

It's worthy of note that the recent problems I have experienced have been with new items, not older ones that have been in the spares box for years.

 

My experience too - could it be wear in the moulds for the mazak wheel centres?

 

John Isherwood.

[St Enodoc]

I wonder whether one of the crankpins hasn't quite got the right throw (can't really think why though) or the crankpin hole is not exactly perpendicular to the wheel?

 

Even more off the wall - is the axle on the offending wheelset bent or twisted? You could check that by changing the wheels but not the axles.

Edited August 12, 2020 by St Enodoc

[Captain Kernow]

4 hours ago, St Enodoc said:

I wonder whether one of the crankpins hasn't quite got the right throw (can't really think why though) or the crankpin hole is not exactly perpendicular to the wheel?

Well, I did measure the crank throw and it's the same on all wheels.

 

The crankpin hole was not noticeably out of the perpendicular, either.

4 hours ago, St Enodoc said:

Even more off the wall - is the axle on the offending wheelset bent or twisted? You could check that by changing the wheels but not the axles.

I could look into that.

 

What is clear, though, was that once I had filed sufficient off the square ends of the 'sacrificial' axle, enough to twist the wheel round by a few degrees, the binding problem went away.

 

[cctransuk]

32 minutes ago, Captain Kernow said:

Well, I did measure the crank throw and it's the same on all wheels.

 

The crankpin hole was not noticeably out of the perpendicular, either.

I could look into that.

 

What is clear, though, was that once I had filed sufficient off the square ends of the 'sacrificial' axle, enough to twist the wheel round by a few degrees, the binding problem went away.

 

 

Which accords with my view that these problems arise from an overly tight fit between wheel and axle; forcing the wheel onto the axle can disturb the correct orientation of one to the other.

 

By careful filing the back edge of the square hole, I try to achieve the kind of fit that I used to experience with these wheels as-bought - the wheel should fit the axle without the need for any pressure, but with no rotational play.

 

John Isherwood.

[Izzy]

The problems with Romford wheels not fitting well on the axles is age old. I can remember having it when I first started ‘finescaling’ Tri-ang chassis in the mid-60’s. Mostly it was the axles not being machine finished properly, they needed dressing on the edges and especially the rear shoulder otherwise they seated out of true and wobbled badly. But the wheel castings could also have the holes not formed well. If you struck lucky and got both issues it was a right old game. Sounds like not a lot has changed. Slaters 7mm ones are by comparison a different story entirely of course, in another league, but then they have the benefit of being for a larger scale, of different design, and costing a bit more. But worth it for the ease of use. Shame the Romfords aren’t the same. Perhaps they are sometimes and it’s still down to Lady Luck.

 

Izzy

[cctransuk]

2 minutes ago, Izzy said:

Mostly it was the axles not being machine finished properly, they needed dressing on the edges and especially the rear shoulder otherwise they seated out of true and wobbled badly. But the wheel castings could also have the holes not formed well.

 

..... but nothing that a little close inspection and a touch of a needle file won't cure. I still swear by them, and wouldn't use press-fit / self quartering wheels.

 

John Isherwood.

[melmerby]

On 11/08/2020 at 15:38, cctransuk said:

 

I find that, nowadays, the square holes in Markits wheels are usually too small to fit onto the square end of the axle as bought.

 

 

 

John Isherwood.

I have some 00 5' 8" Markits wheels and they are a perfect fit, tight yes but they do go home to the shoulder.

 

EDIT

Looks like I'll have to buy some more as I've just managed to damage one with a cutting disc

Edited August 12, 2020 by melmerby

[Captain Kernow]

12 minutes ago, cctransuk said:

Which accords with my view that these problems arise from an overly tight fit between wheel and axle; forcing the wheel onto the axle can disturb the correct orientation of one to the other.

 

By careful filing the back edge of the square hole, I try to achieve the kind of fit that I used to experience with these wheels as-bought - the wheel should fit the axle without the need for any pressure, but with no rotational play.

Completely agree and is also in accord with my own experience.

 

I have built quite a few chassis, where I have used a small, square section needle file, which, with care, can remove material from all four sides of the wheel at the same time.

 

This is the first chassis where something has gone wrong.

 

[Captain Kernow]

The theory has been confirmed.

 

New Markits wheels arrived today, thanks to the most efficient offices of Wizard Models and one set has replaced the problematic ones.

 

The wheels were a good, tight fit on the axle ends and didn't require any fettling, prior to being attached.

 

The wheelset appears to be quartered correctly and more importantly, is consistent with the quartering on the other wheels. Most important of all, the chassis rolls along nice and smoothly.