G3 Track and wheel standards

geoff_nicholls

Western Thunderer
Surely the problem with the proposed standard does not lie with Slaters, but with the rest of the G3 modelling crowd? slaters produce wheels to the current standard measurements, if we all said we preferred a different standard they would produce wheels to that one. It makes no difference to their machinery, the tolerances are the same, aren't they? the problem is the migration from old to new. Would that mean tearing up and throwing away existing track? And if new track were needed, could existing wheels cope with it.
The earlier post says we would need to replace track, well I've just replaced £400 of GRS track with £300 of Cliff Barker(a simpler layout) and would need to pay someone to upgrade the latter to the new standard. And then there's the cost of converting stock.
The tapered axle is a very different problem, because it means extra work in the manufacture of the axle, and therefore extra cost. I would have thought someone could earn himself some beer money offering a tapering service, tapering existing Slaters axles.

One final question, but an important one, what are the minimum curves for the new standard? I've upgraded from 8' to 3m. Could I get a 4F with the new back-to-back round 3m curves?

I think you should go ahead with your new standard, but you need to build a small layout to take to exhibitions to show everyone how much better it looks and build from there. That's what the EM, P4, and S7 guys did.
 

Mike W

Western Thunderer
Good point Geoff. I wonder if Slaters would provide 50 axles to somebody so it could be on an exchange basis.

Indeed Mark does list Gauge 3 3ft 1in split spoke wagon wheels, but at £42 for a set of four raw castings and no axles, that's almost as much as the Spur 2 ones and a lot more work.

Also I note Mark conveniently gives us the real tyre width as 5.6mm and G3 standard 6.8mm. Sorry, but that's probably good enough for me.

Mike
 

jamiepage

Western Thunderer
Likewise, I think. The 6.8mm wheel width plus flanges reduced to the G3 standard for sprung axles, (or 1.5mm actually- why not?) is OK for me. That brings it pretty close to unklian's modded wheelset, which looked very good.
Especially with proper axles, dished wheel rear faces etc.
The back to back is a discrepancy I shall live with, I think. Unless thinner flanges would allow an increase in B-B (59mm?) whilst maintaining compatibility with current standard. That's where I need to sit down and think it through a bit.
 

Mike W

Western Thunderer
Talking of turning Slaters axles, I ordered 100 axles of wheels today and a few spare axles to experiment with. Unfortunately they are out of stock of all G3 wagon wheels - awaiting axles! Grrrrr!

Mike
 

unklian

Western Thunderer
Geoff, I never said there was anything wrong with Slaters wheels, and as you rightly say they are nothing to do with the standards set they are just made to suit . I like them very much and I don't mind turning them to suit my needs. They also happen to work very well with the existing standards. Where did I say anything about anyone having to replace their track ? My point in opening this thread was to ask if anyone had considered better standards than the existing Gauge 3 Society ones . If you really wanted to change, apart from altering wheels, you would only have to change parts of your points. Also the radius of curve your 4F will traverse is dependent on the side play in its chassis and nothing to do with back to back dimension. May I ask why you changed from GRS to Cliff Barker track ?
The problem I personally have with the G3 Society standards is the recommended 6.8mm wide wheel passing over 3.5mm check rail gaps. This produces problems with wheels falling into the central frog gap (up to potentially 7mm wide) when you have point frogs with larger angles than 1:8 or so. The recommended way around this is to fill in the check gap so that the flanges bottom out and carry the wheels through the gap. This means of course that all your wheels must have exactly the same depth flanges for this to work. The other way is to have much wider wheels, at least 8mm . Neither method is prototypical ( unless you model trams !) or very finescale.
But of course you are right, the only way to prove this is to build a layout to finer standards, and of course I am doing this, albeit slowly. Steam in the garden has been a priority this summer !
Mike and Jamie, you will find if you look at the dimensions in my first post, that maximum scale width of tyre is 6.63mm, so all the existing standards are very close in this respect anyway. If however you increase the back to back you may well need to increase the over checks dimension on your track. This will however have the advantage of making the check gaps smaller .
 
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unklian

Western Thunderer
Talking of turning Slaters axles, I ordered 100 axles of wheels today and a few spare axles to experiment with. Unfortunately they are out of stock of all G3 wagon wheels - awaiting axles! Grrrrr!

Mike

So perhaps you should just buy the wheels and use the discount towards getting a batch of tapered axles turned to fit them on ... ?
Only kidding Ian

PS I would prefer insulated wheels , it keeps my options open, I remember the bad old days when everyone was converting from 3 to 2 rail ... !
 
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jamiepage

Western Thunderer
Yes, I get that, I think. So 6.8mm wide wheels are not terribly compatible with G3 track standards? Darn it.

Are you intending to adopt the Spur II standards? Inside or out? I do find this all rather interesting, even though I have a blind spot when it comes to understanding wheel/ track inter relationships.
 

Mike W

Western Thunderer
May I suggest somebody has a quick chat with Ken Cottle about this? He checked over the revised standards before they settled on the narrower wheels which in fact were already being made by Slaters, so the Society really just acknowledged the fact that most people used them anyway, so either had to change the standards to accept them or allow most members to ignore the standards. Ken, of course, is also very familiar indeed with fine standards in the smaller scales. I think Jamie has known him for a long time?

Mike
 

Mike W

Western Thunderer
Returning to the subject of this thread, I have never turned Gauge 3 wheels myself. This is partly lack of confidence, although I used to do it in 7mm many years ago when I was younger. I don't mind doing decorative things, but wheels have to be dead right. So, I'd be interested to hear whether anyone uses a form tool. Back in the 1970s my father used a form tool for 4mm to what he described as "Manchester standards", but even then, on a Unimat3, you couldn't just wind it in and cut the whole profile, it was a gauge as much as a tool. I did something similar in 7mm, using a Slaters tyre cut to give an edge which I then used to cut a crude form tool.

Personally, the availability of such a tool in Gauge 3 (maybe to unklian's standards) would give me the confidence to have a go. Anyone else have a view? or suggestion?

Mike
 

jamiepage

Western Thunderer
Mike,
No I haven't used a form tool, although I don't have an aversion to them at all. In fact, they must be the best way of ensuring a standard shape, and I would buy one if available.
I use a mandrel. Basically, first skim off back and bore through. Then on a mandrel to turn each one to overall flange and tyre diameters with a 'square' flange. Then resetting the topslide to 3 deg. and fitting an angled tool so the final cut (at 3 deg.) also profiles the flange front face. Round off to finish. A form tool would do these last two jobs very well of course.
I have a couple of old, rubbish, wheel castings if you'd like something to practice on?
 

Mike W

Western Thunderer
Thanks Jamie, but I'd better get my house move done first and kit out the new workshop. In the Spring maybe. Thanks.
 

jamiepage

Western Thunderer
Ian,
In the original post, you pointed out the washers behind your modded wheels. Can I just check please, what you were increasing the B-B to?
Oh, and did it work?
Thank you.
I'm doodling around B-B of 58.6 max, flange thickness 1.3-1.4 at the moment, but I find nothing instinctive about this track/wheel relationship business unfortunately. I can confuse myself far too easily to be entirely healthy.
Jamie
 

unklian

Western Thunderer
Hello Jamie,
I made my back to back as much as 60mm, but generally 59mm. This will not I am afraid work with G3S track standards !
However to go back to your G3 forum thread your calculation that D + 1F must be less than B + 1C is absolutely correct and fundamental. The reason that finer wheel standards don't work with the G3S standards is because of this. Once you increase the back to back to compensate for thinner flanges, you have to increase the over checks dimension B to stop the flanges hitting the crossing nose. It really is that simple, I would take Cabbage/Ralph's over scientific pronouncements with a pinch of salt if I were you. I am not sure why he has to defend the G3S standards so vehemently, they certainly weren't worked out very scientifically.
If you go back to the table of dimensions I added to my first post it is all there. I gave the prototype dimensions with their tolerances, those scaled to 1:22.6 and then the three sets of model standards. As I hope you can see the only standards my wheels are truly compatible with are the Spur II ones. For the time being as my outdoor track is all Barker 64.5mm gauge widened and on a continuous curve I get away with all wheel standards. But when I get to make some more points I will have to make a decision. The one point I have made for my indoor layout is to Spur II and with Spur II wheel sets works a treat .
 

jamiepage

Western Thunderer
Ian,
Thanks very much indeed.
Although I am starting to get a grip of this track/ wheel thing, I'm becoming more and more drawn to Spur II to be honest.
Rather reminiscent of what happened when my O modelling morphed into S7 now I think about it, and on reflection I'm getting less convinced there is a particular need to strive for compatibility with the G3S standards. The Spur II standards are very comprehensively laid out.
I was grateful to Ralph actually for the time he spent on the maths, and certainly impressed by it, it did help.
The more general outbreak of defensiveness for the status quo was noticeable though; it did rather stretch a point (in my opinion) to read someone arguing against the point of tolerances in track/ wheel standards, and it didn't in general come over as terribly 'welcoming' to anything 'new'. It would have been nice to have seen a more reasoned discussion of Jon's original suggestion, but there we are. Each to their own I guess.
Anyway, thanks again Ian. I'll hack away at a Slaters wheelset tomorrow.
Jamie
 
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Oz7mm

Western Thunderer
Malcolm Fisher at Peartree is always on the lookout for things to batch produce. Perhaps he could be approached to make tapered axles.

However at present he is not geared up for spoked wheels but when I went over to see him he was thinking about how he might do them.

John
 

jamiepage

Western Thunderer
John,
Thank you very much. That reminds me actually, I did contact him before but it was just before Telford so I promised to follow it up after. Then forgot until you've just reminded me, so I'll start again.
Jamie
 

Mike W

Western Thunderer
Malcolm is excellent at this sort of thing, but don't you dare ask him now - I'm waiting for 500 Gauge 3 wagon buffers and don't want him diverted onto other things!

Mike
 
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