Wright writes.....

[jrg1]

Mick that J27 is looking great. I had to double take as the J26 I have been building on and off looks very similar and in a similar state... even down to the blocks of wood! 

 

Tony, the Gibson wheel issues from what I have seen and experienced. They are a good wheel if treated with a simple proceedure to assemble them. It is just a shame that they are supplied with out a instruction leaflet. 

 

The method that I have used over the years is not too involved and has varied over the years. My first P4 loco was a J72 pererverance chassis with Gibson wheels 20 years ago. 

 

The method that I have used is:-

1 buy all wheels required in 1 batch not mixing production runs

2 inspect wheels for moulding pips and remove.

3 check crankpin hole is similar on all wheels 

4 relieve the axle hole by slightly countersinking the hole Say about 0.1mm removing the  90 degree edge to 45 degrees and very slight. 

5 rebate the back of the crank pin hole to allow the crank pin to screw all the home and be at or below the surface level

6 screw crank pin into the hole, back off 2mm then apply superglue to thread and screw fully home. Some times I find that the screw is not 90 degrees to the face of the wheel (generally pointing towards the centre) gently bend square

7 Check axle for burs to end and remove. 

8 run wet and dry to the corner of the axle ease the end to enter the wheel

9 start the axle into one wheel check it is square. 

10 install bearings/ gears washers etc onto axle

11 start second wheel on axle/ then check the assembly in a GW wheel press.

(11a if you dont' have a wheel press, hand quarter the wheels and place square in a vice, and tighten keeping all the wheels square and the axle. Use a square to check by eye!) 

12 adjust the quartering if required 

 

Here is where the kit building/ adjusting etc takes normal procedures. I have found that if the wheels are quartered by eye a handy pair of tools is 2x 150mm long hardwood square blocks with 2 prongs of 1.5mm nails sticking out can adjust gently by twisting a single wheel to adjust the quartering to be handy. One tool on each side of the loco. This allows for very small adjustments to be made

 

The one thing to try not to do is take the wheels on and off, and definitely not mix up wheels and axles. I generally get away with no more than 2 reassemblies!

 

This works for me. No doubt others will chip in with what they do! 

Agree-I would however suggest that the first axle is set up and quartered complete, and then axle 2 assembled and adjusted until true with number 1, then axle 3, and so on.  I have an old Hamblings wheel press for this

[grob1234]

Hello,

 

I wonder if somebody more knowledgeable than me is able to help?

 

I'm finishing off the chassis for my LRM J69. The wheels spin freely independently. The connecting rods and wheels are bind free when no drive is attached. The gearbox is free running when not connected to the drive gear (runs better backwards than forwards, but I guess this is always the case!) The gearbox and drive wheel are free running when connected. So, basically, everything is free running on its own, however when the motor, gearbox and drive gear are connected and the connecting rods are added, the whole thing is far less free running. So, I suspect an issue with the con rods. I'm loathe to open up the holes in the con rods further, the problem I have is not really knowing how much 'slop' is acceptable. I don't want to open up the holes too much, though my gut instinct is that this might solve the problem... any top tips would be greatly appreciated!

 

EDIT: Heres a little video to show you what I mean:

 

https://youtu.be/p8OhbOD4vrs

Edited February 16, 2016 by grob1234

[AndyID]

Hello,

 

I wonder if somebody more knowledgeable than me is able to help?

 

I'm finishing off the chassis for my LRM J69. The wheels spin freely independently. The connecting rods and wheels are bind free when no drive is attached. The gearbox is free running when not connected to the drive gear (runs better backwards than forwards, but I guess this is always the case!) The gearbox and drive wheel are free running when connected. So, basically, everything is free running on its own, however when the motor, gearbox and drive gear are connected and the connecting rods are added, the whole thing is far less free running. So, I suspect an issue with the con rods. I'm loathe to open up the holes in the con rods further, the problem I have is not really knowing how much 'slop' is acceptable. I don't want to open up the holes too much, though my gut instinct is that this might solve the problem... any top tips would be greatly appreciated!

 

EDIT: Heres a little video to show you what I mean:

 

https://youtu.be/p8OhbOD4vrs

 

From your video, it looks like the center driver on the right hand side is not square on the axle. You can see how the flange on that wheel has a distinct wobble as the chassis travels along the track.

 

That has the effect of making the crank throws unequal and that tends to lock the mechanism at various points during a revolution. In the video the gear driven wheel starts to rotate, then it jams. You might not be able to detect this problem when you remove the motor and push the chassis along the track because when you do that, the wheels are really being synchronized by the rails rather than by the coupling rods.

 

The best thing might be to make sure all the wheels are running true without the coupling rods before you do anything else.

[Michael Edge]

Agree-I would however suggest that the first axle is set up and quartered complete, and then axle 2 assembled and adjusted until true with number 1, then axle 3, and so on.  I have an old Hamblings wheel press for this

I would agree with that and the post that it is commenting on but I must repeat (for the umpteenth time) that the tyres do not come off Gibson wheels. They used to certainly but since Colin Seymour took over this problem has been eradicated. However I don't use the Gibson crankpin system (or any of the other currently fashionable loose bush systems), I drill and tap the wheels 10BA and screw in (with some Loctite) an old fashioned Romford (Hamblings to older modellers) crankpin. This leaves a plain 1mm diameter pin, the rods are secured with a slice of 1mm i.d. tube. The loose bush systems are engineering nonsense, a full size crankpin is a plain round pin, the rod bushes are pressed in to the rods, a loose bush merely adds another layer of slop to the system and the securing nut serves to lock the slop in a different position in each wheel. This is most evident in Slater's 7mm wheels - tightening the retaining nuts moves every crankpin bush off centre at random angles. If you really must have threaded retaining nuts then the only commercial one that worked properly was K's, these had plain crankpins moulded into the wheels with a threaded portion for a 14BA nut at the end. These nuts are much thicker than the full size ones though and can cause great difficulty where clearances are tight, even in 00 gauge let alone EM or P4.

[grob1234]

From your video, it looks like the center driver on the right hand side is not square on the axle. You can see how the flange on that wheel has a distinct wobble as the chassis travels along the track.

 

That has the effect of making the crank throws unequal and that tends to lock the mechanism at various points during a revolution. In the video the gear driven wheel starts to rotate, then it jams. You might not be able to detect this problem when you remove the motor and push the chassis along the track because when you do that, the wheels are really being synchronized by the rails rather than by the coupling rods.

 

The best thing might be to make sure all the wheels are running true without the coupling rods before you do anything else.

Hello Andy,

 

Thank you for your observations. I've had another go at it, and its running reasonably smoothly. I think part of the problem may be my failure to get a truly square chassis. First attempt, so I know looking back I made a few mistakes. I've had to open up the bearings a little too much to compensate for the non square chassis, which is resulting in the center wheels not rotating perpendicular to the frame. When the body is on, the effect is not to bad, and it runs very slowly if required. I think what I'll do is continue with it for now, and at the very worst case I can purchase a new chassis, and use a jig to aid construction, tail firmly between my legs for not taking care in the 1st place! 

[Horsetan]

..... I have no wish to denigrate any manufacturer's products, but I cannot get on with friction-fit driving wheels. No sets I've used have ever run true, the tyres have come off and the wheels have shifted on their axles under power. I managed to get motor/gearbox running sweetly, but the way forward is for the guy to chuck the dud wheels away and replace them with Markits. That way it'll run very well I'm sure. 

 

Does anyone else have issues with friction-fit drivers? The reason I ask is that I've frequently observed kit-built locos where the builders are extremely happy with them. Several such locos have been through my hands to sell on (not all with friction-fit drivers, to be fair). A definition of 'happy' is very different from mine. Locos which wobble, whine, grind, have tight-spots, are jerky, derail at the slightest track transgression and won't haul their own weight....

Generations of P4 builders have got on perfectly well with friction-fit, for whom it's the only way to go. I've rarely had problems with them. Rolling stock wheels and drop-in conversion sets are invariably friction-fit.

 

Markits will never cater for 18.83, so the "replace with Markits" remark is about as useful for us as a chocolate teapot.

 

I can't help but detect yet another subliminal knocking of P4 builders here, for whom friction-fit is the only way to go. Next you'll be telling everyone that P4 doesn't work.

[cctransuk]

I can't help but detect yet another subliminal knocking of P4 builders here, for whom friction-fit is the only way to go. Next you'll be telling everyone that P4 doesn't work.

 

You must have a subliminal knocking detector as sensitive as a seismometer, then!

 

Where was P4 even alluded to?

 

Why would it be impossible to produce P4 wheels with a Markits-style axle? (Nothing was said about the likelihood of Markits producing them itself).

 

Why do some P4 advocates perceive knocking even when no denigration has taken place?

 

But - if the cap fits !! (.... and that is denigratory).

 

Please - can P4 modellers just get on with it, without feeling the need to proselytise or accuse us heathens of blasphemy all of the time?

 

Regards,

John Isherwood.

[trw1089]

I would agree with that and the post that it is commenting on but I must repeat (for the umpteenth time) that the tyres do not come off Gibson wheels. They used to certainly but since Colin Seymour took over this problem has been eradicated. However I don't use the Gibson crankpin system (or any of the other currently fashionable loose bush systems), I drill and tap the wheels 10BA and screw in (with some Loctite) an old fashioned Romford (Hamblings to older modellers) crankpin. This leaves a plain 1mm diameter pin, the rods are secured with a slice of 1mm i.d. tube. The loose bush systems are engineering nonsense, a full size crankpin is a plain round pin, the rod bushes are pressed in to the rods, a loose bush merely adds another layer of slop to the system and the securing nut serves to lock the slop in a different position in each wheel. This is most evident in Slater's 7mm wheels - tightening the retaining nuts moves every crankpin bush off centre at random angles. If you really must have threaded retaining nuts then the only commercial one that worked properly was K's, these had plain crankpins moulded into the wheels with a threaded portion for a 14BA nut at the end

Hi Mike

 

Great tips there, but I can assure you that I got the wheels from Colin and the tyres certainly did come off after the first time I disassembled the wheels and motion.

 

I think Doug's tips are probably the best way forward if using them, or take the route that Tony suggests and stick with Markits/Romfords.

 

Cheers

Tony

[Mark Forrest]

The suggestion of issues with friction fit wheels has prevented me from modelling steam locos in the past. Reading around on the subject I find there are those who have no problem with them and others who swear they are inferior and can never work. For my chosen gauge I have two options; learn to get along with friction fit wheels, or stick to modelling diesels.

 

Every time the subject comes up on this thread I find myself learning something new. Last time it was the method for pinning them to the axle, this time it's Doug's helpful checklist of how to assemble and Mike's thoughts on crankpins. I'm hopeful that by following this advice I can build models which benefit from the finer profile wheels in the Gibson range, rather than being put off by a limited range of Romfords in EM and no real alternative in P4.

[billbedford]

I've never got on with friction fit drivers largely for the reasons already stated. I also like to get a running chassis then strip it down for a final clean and paint. Whereas Markits will stand up to any amount of assembly and reassembly I always feel that with friction fit drivers, once on best left alone.

 

Can you remind me which railways used demountable wheels?

[Focalplane]

I understand that the quartering discussion has slowly translated into a more general discussion about 4mm scale wheels.  I have only used Romford/Markits wheels over the years and never really liked them, first because of the slotted nut, second the far from even surface of the hub at the rear of the wheel, requiring what I consider to be risky fettling of an expensive item, and third the Romford screwdriver which always seems to go missing when I need it.

 

I doubt if I have ever had such a wheel set that, when put together, rolled evenly down the track with no wobbling.

 

Fast forward to Slater's 7mm wheel sets and, apart from the incredibly soft allen key they sell, all goes well every time.  I countersink the rear of the crankpin hole, then screw in the crank pin, check it is straight and then apply loctite.

[billbedford]

You must have a subliminal knocking detector as sensitive as a seismometer, then!

 

Where was P4 even alluded to?

 

Why would it be impossible to produce P4 wheels with a Markits-style axle? (Nothing was said about the likelihood of Markits producing them itself).

 

Why do some P4 advocates perceive knocking even when no denigration has taken place?

 

 

Sometimes whats not said is as important as what is said....

[MJI]

I went to all the trouble of sourcing an "o" with an umlaut from Word's bank of additional text symbols, and what does RMWeb do to it in my original post? Turns it into a question mark! GRRRRRR!!!

 

Strange how all the Motorhead fans are getting older now.

 

Then I think about all the people I know who were fans of NWOBHM, big fans in teens and twenties.

 

Alll now in their 50s

[billbedford]

I just love the way that people sure that everyone knows they use Romford wheels by leaving the slots in the nuts in plain view.

 

Didn't someone once make a quip about things below the footplate being essentially invisible?

Edited February 17, 2016 by billbedford

[KalKat]

One trick with Romford/Markits is to wipe a little Plastiscene into the hub. If you need to access the nut again, the screwdriver will work through it.

 

 

Emma

[gr.king]

Somebody involved in this debate is bound to be clever enough to tell me why Slaters and others don't offer black plastikard sheet any thinner than 0.015" when Slaters offer 0.010" white and competitors still offer 0.005" white. Confirmed answers would be infinitely more useful than theories or speculation....

 

Ten "thou" black attacked repeatedly with standard hole punch would produce enough permanently black Romford type wheel nut covers for a modelling lifetime. The thinner sheet would be useful for loads of other things too. Having to resort to thin white sheet (short of patiently rubbing down black sheet instead) isn't a good alternative if you don't want white edges to appear as the paint finish wears down.

[Jason T]

When Chris and I built 'The Mill' for the EMGS competition, we decided early on to use Gibson wheels on all locos and stock and have had no issues. One of the reasons was aesthetics, as they make Markits/Romfords look like steamroller wheels. On a layout measuring 60" X 18", aesthetics is important....

[Arthur]

Can you remind me which railways used demountable wheels?

And you can you remind me which railways use plastic spokes. Ever tried heat shrinking a rim onto them.

 

No thought not.

[asmay2002]

Somebody involved in this debate is bound to be clever enough to tell me why Slaters and others don't offer black plastikard sheet any thinner than 0.015" when Slaters offer 0.010" white and competitors still offer 0.005" white. Confirmed answers would be infinitely more useful than theories or speculation....

 

Why not buy 0.010" black from Evergreen?

[coachmann]

I continue to buy .006" black styrene sheet. In fact it is vital for many a job and it's current use is packing up GWR pressed Steel coach bogies to the ride-height I happen to require. Ask me where I got it and it was either Alton Model Centre or else Rhuddlan Models, such is my memory!

Edited February 16, 2016 by coachmann

[gr.king]

I genuinely had no idea that the thinner black sheet was available. I've never seen any. Thanks to you both for the sources.

[Michael Edge]

Hi Mike

 

Great tips there, but I can assure you that I got the wheels from Colin and the tyres certainly did come off after the first time I disassembled the wheels and motion.

 

I think Doug's tips are probably the best way forward if using them, or take the route that Tony suggests and stick with Markits/Romfords.

 

Cheers

Tony

You must have been really unlucky then, I've used hundreds of them and not had one tyre come off a wheel from Oldham.

[Mark Forrest]

You must have been really unlucky then, I've used hundreds of them and not had one tyre come off a wheel from Oldham.

Maybe it's the way you 'old 'um?

 

(I'll get my coat...)

[wagonbasher]

Somebody involved in this debate is bound to be clever enough to tell me why Slaters and others don't offer black plastikard sheet any thinner than 0.015" when Slaters offer 0.010" white and competitors still offer 0.005" white. Confirmed answers would be infinitely more useful than theories or speculation....Ten "thou" black attacked repeatedly with standard hole punch would produce enough permanently black Romford type wheel nut covers for a modelling lifetime. The thinner sheet would be useful for loads of other things too. Having to resort to thin white sheet (short of patiently rubbing down black sheet instead) isn't a good alternative if you don't want white edges to appear as the paint finish wears down.

If everyone banned theory and speculation this threads page count wouldn't have reached double figures..

 

Andy

[DougN]

Watch out... someone is about to stand on a soap box. 

 

The quality of the current Gibson wheels and the product that Colin is now producing I believe is superior to that of 20 odd years ago. So my technique is still vaild, I have been using them in P4 all that time and I don't want to count the axles I have used. 

 

I will point out that Colin's product is still competitive compared to others, Markits are about 5.56 (checked on website) Alan Gibson 5.70 (from the website) Ultrascale 20.01 (from the website) (where's the ouch symbol!) 

 

I have had tyres come adrift along time ago. After a clean up of the plastic insert and clip the tyre back on! To make doubly sure that it never happens again the offender was wiped with locktite! This was a wagon wheel purchased second hand. I have never had a loco tyre come free! 

 

Quartering is a bit of an art. Yes I have had my failures... One is still blowing raspberries at me on the pending shelf! It will end up one day working properly. Generally with perseverance and a bit of thinking through the engineering there is solutions. Iain Rice's Chassis book has a great page or 2 on how to do it! 

 

P4 vs OO vs EM vs flower arranging. Ah.... time to get over it guys. Not starting arguments.. It is all a broad view, I can say live and let live.  I build kits to P4 but have a RTR/ RTP OO layout... nothing like sitting at my work tray building the all singing all dancing Finney V2/ Bradwell J26... while a Hornby K1 runs past with 20 wagons and the D16 the other way with 3 Hornby coachs....I have seen P4 run terribly, as much as I have seen OO really grate! So as usual, no doubt Tony would agree with me, be complimentary (or is that diplomatic?) or say nothing!

 

If you want a "look down the nose" come to Australia and state you model British..." OH yeah I had a triang... never ran.... all rubbish..." now look at this flat earth layout with almost no buildings running trains out of the latest box. To be fair alot of Aussie railways ran through not much! 

 

BRMA has changed this somewhat with some really high quality impressive layouts on the exhibition scene. 

 

Off soap box now...