Driving wheel axle material

[Tim V]

Precision Araldite, not 5 minute. The thread is a good idea, or you could make some plastic tubes which were a smooth fit inside the tube, bored out for the rod. Then assemble the axle with its open end up, the lower end pushed into a blob of blue tac with the bush. You can then soak the rod etc with the Araldite, and it will sit there without leaking out. Push more araldite into the open end. Leave for 24 hours in a warm place, before attempting to cut the tube. If the space inside is filled properly with set Araldite, it won't collapse.

[Paul Townsend]

Anyone got experience of that combination for any gauge?

I think you know the answer to that Paul, so we're all applauding you as volunteer trailblazer. Imagine the cross-pieces below split with copperclad bridges, and it could be some sort of way forward:

Oooh, outside CSBs!
Interesting...BG with not so wide as usual frames would allow for this.
Sandwich frames might hide the bits.....

[Paul Townsend]

Biggest difficulty I see is combining CSBs with Split frames....extra insulation issues arise 8-{
Anyone got experience of that combination for any gauge?

Paul, I don’t understand where these insulation issues arise.

My preferred stretcher material would be PCB with copper facing on both sides, so that both can receive solder fillets to unite the stretcher with the frame on each side.

I don't disagree with any of this.
The classic way of splitting frames that you describe is valid for CSBs with no obvious extra difficulties.

However, as a non-classicist ( hated Latin) I have been using other ways of insulating the chassis bits. Some ideas (from 2mm bods I think) use very thin DS PCB as an insulating plate over the hornblock slots. Thus chassis is not live but bearings and HBlox are. This is what I had in mind in saying CSBs tricky! I will need to arrange the CSB support HR knobs to be insulated too. Exactoscale and Maygib have offered plastic HBlock bits too.

As there are so many cats to skin, each loco needs its own approach and an armoury of options on the bench helps!

[Paul Townsend]

<snips>
Can I ask, when using the tube and rod from Eileen's, how you cut the tube after assembling it onto the rod?

I didnt!
Like Bill, I cut the tube to length before inserting wire and araldite. Sawed with piercing saw and ground to finish.

method of working with a (modified) George Watts quartering jig)

Tell us more, please.

The red colouring on the wheels by the way is the remnants of some jewellers rouge I have been using to polish the treads. It works a treat but is a sod to clean off.

I have read in another context that our driving wheel often have poor finish so had wondered about trying that but mislaid the roundtuit.
Are you doing it because you were advised to or because you have tested and found proven benefits?

[Paul Townsend]

It's best to cut the tube before assembling the axles. Also it is a good idea to make the inner rod slightly shorter than the axles, so if you have to trim the axle lengths your are only cutting the tube. You have to do this if you harden the rods, since there is no easy way of trimming them.

Yes but..... doesn't that negate the whole point of making split axles this way? By having a "perfect" concentric tube and then cutting it once it is mounted on its rod (sorry, no smut intended) then the two halves will remain concentric. The moment that the tube is cut into halves and then assembled then however good the jig is that is used to hold it all together then innacuracies can occur. Doing it that way is no better/different than using solid parts cut with male and female halves a la Branchlines.

Look forward to your contribution Paul when you have caught up with some shut eye. I assume it is still Fresher's Week.

Bryan

I reckon Bill meant as I do:
cut the tube to length before assembling insides. The insulating cut comes later.

[Paul Townsend]

Davey Tees description is what I do too.

I had considered final grind to length after wheels on but the ethics of grinding araldite seemed a bad idea!

I await to hear more about the modified GW quartering tool method from Hollybeau.

Next issue.....
Last year I started pinning wheels to axles and now have a technique that often (!) seems Ok with solid axles. However I have not yet tried it with tube-splits.
Thoughts anyone?

Brain only partly restored

[hollybeau]

Gosh - a thread that is snoozing for nearly a year but when poked takes on a life of its own. Where to start?

Method of making split axles with tube: DaveyTee has the description spot on. However, the problem I was trying to explain (and apologies if I caused the confusion) is to suggest (nay state) that the tube and rod specifically mentioned by, and ordered "on our behalf", by Derek Russan of Eileen's Emporium (see bottom of page 1 of this thread) do not work together as there is not enough clearance between the two to use thread or plastic and, as I have reported above, cutting through afterwards merely causes the stainless steel outer to deform onto the steel inner (not matter how careful I am) and thereby shorting out the lot and rendering it useless. The problem can be overcome I would suggest by either a) cutting the tube into its component parts and to the correct lengths before assembling (thereby allowing cleaning up of the cut edges but also ruining the simple perfection of the "one tube" method) or b) using the tube with a thinner rod, or c) using the rod with a thinner walled tube. Of these options I prefer the latter as the strength is obviously in the rod, not the tube (since that gets cut in half etc). However, that being so it means all the efforts by Derek to find us the "right material" have been to no avail. I mean no criticism of Derek by these observations and I am sure he meant well in tracking these materials down. They do need to come with this "health warning" however. I hope that is clear.

Paul's split frames: I have heard of this method of using thin, twin-sided copper cladding to isolate the hornblock from the frame before but am far from convinced that the extra complication is worth it for such little reward (presumably a dead chassis is seen as an advantage when it comes to fitting the body or using across-the-frames outside cylinders). However, this method negates one of the advantages of split frames, namely that it doesn't matter if a brake block touches a wheel in the "normal" arrangement . Furthermore, there is precious little room even in P4 between the frames and reducing this even further with the PCB may make fitting gearboxes difficult and by moving the bearings inwards will make the model less stable (OK not by much but I am sure you get my point). Of course if you do have the luxury of modelling the braod gauge then these objections (more like concerns for you Paul) may disappear.

Modified Watts quartering jig. I knew when I mentioned it this might come back to bite me in the proverbial. Let me be clear I think the Watts jig is excellent and the best tool I have found for quartering wheels. However, and it probably comes down to my ham-fistedness I always feel I need seven pairs of hands to hold everything when I am putting the parts into the jig. I also have a concern that when the wheels are in the act of being pushed onto their axles the pressure falls onto the front hub of the wheels. These are rarely flat or parallel and the small surface area allows them, in my mind to "rock" when the axle is inserted. I cannot count the number of times I have taken a pair of wheels out of the jig to find the wheels are perfectly quartered but the wheels wobble on the axle. My modification arises from my experiments with the Gibson brass wheels (and no I am not going to tell you all about them : you will have to wait for the Snooze article). However, I have found that by gluing (superglue) small lengths of square section brass across the face of the jig (both sides, and one each side of and equidistant from the axle hole) the wheel rim, and not the boss, takes the force and keeps the wheel in the correct alignment. My second modification is to gently ream out the axle holes in the jig with an 1/8" reamer such that the axles are a tight fit inside it (remove the spigot, spring and grub screw first!). Then by using overlong axles (which have a good taper on them) and by setting back the sprung loaded pins by say 2mm each side from the face of the jig the axle enters the wheel held on the spigot and then passes through into the body of the jig in a very accurate way. The projecting axles are easily cut off and cleaned up later. To date I have only assembled three pairs of (brass-centred) wheels in this manner but each one is absolutely wobble free and the quartering is spot on (chassis ran first time without binding despite no slop whatsover in the rods/crankpins). On the basis that a drawing or photo is worth a thousand words here is a quick sketch:

Watts jig0001.pdf

and finally Esther (and given that the subject of this thread is "Driving wheel axle material" ). I have noticed (or it may be my imagination) that running stainless steel (tube) in brass bearings/ hornblocks does not allow the wheels to spin as freely as say using mild steel axles in the same combination. I have gently "lapped" the axles in with a mix of brasso and thin oil as advocated by that master modeller Steve Duckworth, washed everyting out and then lightly oiled the result but somehow there just seems to be more friction with the stainless steel. I don't know if we have a resident metallurgist amongst our ranks who can comment on this observation but if the problem persists it may persuade me to abandon stainless steel tube altogether.

I think that is enough for one post!

Bryan

[Paul Townsend]

<much snipping>
Method of making split axles with tube: DaveyTee has the description spot on. However, the problem I was trying to explain (and apologies if I caused the confusion) is to suggest (nay state) that the tube and rod specifically mentioned by, and ordered "on our behalf", by Derek Russan of Eileen's Emporium (see bottom of page 1 of this thread) do not work together as there is not enough clearance between the two to use thread or plastic and, as I have reported above,

I used Dereks and others SS tube with a different inner rod which is smaller so never had this problem. Source of rod was jewellers pivot steel, vailable at ME exhibitions and mail order in assorte sizes. The material is hard, straight and blackened (oooh porn filter!)

Agreed re Stainless Steel in bearings is a pain but useable.

When I was learning wheel pinning last year I wanted a supply of 1/8" ground mild steel rod to use (as easier to drill than the readily available silver steel); apparently no longer available. Many ME suppliers do 1/4" up but I can't find any smaller in Imperial size. Not all my locos are split axled.

Perfect axle material would be ground mild steel tube. I wish!

Paul's split frames: I have heard of this method of using thin, twin-sided copper cladding to isolate the hornblock from the frame before but am far from convinced that the extra complication is worth it for such little reward (presumably a dead chassis is seen as an advantage when it comes to fitting the body or using across-the-frames outside cylinders). However, this method negates one of the advantages of split frames, namely that it doesn't matter if a brake block touches a wheel in the "normal" arrangement . Furthermore, there is precious little room even in P4 between the frames and reducing this even further with the PCB may make fitting gearboxes difficult and by moving the bearings inwards will make the model less stable (OK not by much but I am sure you get my point). Of course if you do have the luxury of modelling the braod gauge then these objections (more like concerns for you Paul) may disappear.

Horses for courses! I have used both techniques giving live or dead frames.
Bonus for lovers of Victorian locos in any gauge..brakes non-existent or few and often just wooden blocks.

Modified Watts quartering jig.

Ta for that full explanation, points mostly agreed.
Our very own Steamraiser showed me a similar but less well engineered mod which worked for me too. I will upgrade to your version!

I think that is enough for one post!

Bryan

Nonsense , keep it coming 8-}}

[Russ Elliott]

When I was learning wheel pinning last year I wanted a supply of 1/8" ground mild steel rod to use (as easier to drill than the readily available silver steel); apparently no longer available.

Try Folkestone Engineering. He's friendly and knows his stuff. I've only bought the silver steel, an excellent surface finish, and it was spot on 0.125". (The 2mm stock was excellent as well, none of the 1.94 rubbish.) But I'm a bit confused, Paul - what's the difference between ground mild and silver - just the drillability?

[Paul Townsend]

When I was learning wheel pinning last year I wanted a supply of 1/8" ground mild steel rod to use (as easier to drill than the readily available silver steel); apparently no longer available.

Try Folkestone Engineering. He's friendly and knows his stuff. I've only bought the silver steel, an excellent surface finish, and it was spot on 0.125". (The 2mm stock was excellent as well, none of the 1.94 rubbish.) But I'm a bit confused, Paul - what's the difference between ground mild and silver - just the drillability?

Thats the issue for me.
I had trouble drilling .5mm holes at 45degrees in SiSteel axles even with a jig to Tim Venton's design.
MS is softer and has less additives to enable hardening for tools and Mild steel machines more easily in general.

SiSt is carbon 0.95–1.25, manganese 0.25–0.45, chromium 0.35–0.45, silicon 0.40 max.[1] In the annealed state is has a hardness of 27 HRC. It can be hardened to 64 HRC.

MS has less additives and wouldn't harden:
mild steel contains 0.16–0.29% carbon; making it malleable and ductile, but it cannot be hardened by heat treatment, has a relatively low tensile strength, but it is cheap and malleable; surface hardness can be increased through carburizing.

Acknowledgements to Wikepedia for facts injection!

[Paul Townsend]

When I was learning wheel pinning last year I wanted a supply of 1/8" ground mild steel rod to use (as easier to drill than the readily available silver steel); apparently no longer available.

Try Folkestone Engineering. He's friendly and knows his stuff. I've only bought the silver steel, an excellent surface finish, and it was spot on 0.125". (The 2mm stock was excellent as well, none of the 1.94 rubbish.)

Tried him again just now...same as other suppliers...he does 1/8" Si Steel but no ground finish MS in that size.
Ta anyway.

[Alan Turner]

You can use ground steel dowles. example here: http://www.boneham.co.uk/shop/product/i ... dowel_pins

regards

Alan

[Russ Elliott]

Just a thought, Paul - I wonder if the Stapletons have got some old Sharman 1/8" stock? (It might be ancient enough to be mild steel?)

[grovenor-2685]

You can use ground steel dowles. example here: http://www.boneham.co.uk/shop/product/i ... dowel_pins

Well yes but the catalogue says

Engineers steel dowel pins are precision hardened and ground parallel pins

the hardening will not help make them easy to drill.
Regards
Keith

[Alan Turner]

You could always anneal them but you might have to hope that they won’t distort in the process.

However silver steel is only ground tool steel.

Alan

[allanferguson]

Gosh - a thread that is snoozing for nearly a year but when poked takes on a life of its own. Where to start?

Modified Watts quartering jig. I knew when I mentioned it this might come back to bite me in the proverbial. Let me be clear I think the Watts jig is excellent and the best tool I have found for quartering wheels. However, and it probably comes down to my ham-fistedness I always feel I need seven pairs of hands to hold everything when I am putting the parts into the jig. I also have a concern that when the wheels are in the act of being pushed onto their axles the pressure falls onto the front hub of the wheels. These are rarely flat or parallel and the small surface area allows them, in my mind to "rock" when the axle is inserted. I cannot count the number of times I have taken a pair of wheels out of the jig to find the wheels are perfectly quartered but the wheels wobble on the axle. My modification arises from my experiments with the Gibson brass wheels (and no I am not going to tell you all about them : you will have to wait for the Snooze article). However, I have found that by gluing (superglue) small lengths of square section brass across the face of the jig (both sides, and one each side of and equidistant from the axle hole) the wheel rim, and not the boss, takes the force and keeps the wheel in the correct alignment. My second modification is to gently ream out the axle holes in the jig with an 1/8" reamer such that the axles are a tight fit inside it (remove the spigot, spring and grub screw first!). Then by using overlong axles (which have a good taper on them) and by setting back the sprung loaded pins by say 2mm each side from the face of the jig the axle enters the wheel held on the spigot and then passes through into the body of the jig in a very accurate way. The projecting axles are easily cut off and cleaned up later. To date I have only assembled three pairs of (brass-centred) wheels in this manner but each one is absolutely wobble free and the quartering is spot on (chassis ran first time without binding despite no slop whatsover in the rods/crankpins). On the basis that a drawing or photo is worth a thousand words here is a quick sketch:

Watts jig0001.pdf

Bryan

I have had concerns about wobbly wheels when using the GW quartering jig (a most excellent tool), but I have worried about applying pressure to the rims rather than the hub, because of the risk of the spokes distorting, perhaps permanently, particularly with larger wheels. I do remember breaking the spokes on a Studiolith wheel many years ago in this way. Equally I've never been happy with the technique advised (I think) by Mike Sharman when his wheels first became available of "gently" pulling the wheel into line. Does anyone have any views / experience?

I feel this should mabe be a separate thread, but I'm not sure how to achieve that while linking in here. Can a moderator advise?

Allan F

[grovenor-2685]

I feel this should mabe be a separate thread, but I'm not sure how to achieve that while linking in here. Can a moderator advise?

You want to start a new topic just click on the relevant forum title, ie 'Chassis and suspensions' in this case, in the header bar, then click 'new topic'. Once you have started it you can copy and paste from here to there if you want to quote something.
I can split the topic if needed, ie to move some existing posts, which post would you think has diverged to that extent?
Keith 'l j

[hollybeau]

I have had concerns about wobbly wheels when using the GW quartering jig (a most excellent tool), but I have worried about applying pressure to the rims rather than the hub, because of the risk of the spokes distorting, perhaps permanently, particularly with larger wheels. I do remember breaking the spokes on a Studiolith wheel many years ago in this way

If the wheel breaks I would suggest that the axle is too large for the hole (or vice verce) and too much force is having to be applied to insert one in t'other. If the axles are a tight fit or simply won't even enter the wheel I use a tapered reamer, from the back only, gently removing a little at a time until the axle will go in about half the depth with a (hand push) fit. Of course if you are using (the superior!) brass wheels they are stronger and you don't have this problem. I suspect that one of the causes of post fit wobbliness is forcing axles into the plastic. The latter is capable of deforning and then once out of the jig the pressures are released and hence the wobble.
I set the thickness of the strips of brass in my modification to just a smidge (engineering term) over the gap between the wheel hub and the face of the jig. In this way when the axle is pushed in any deformity is limited by the hub coming up against the jig face. I hope that is clear.

Just going back to mild steel v's silver steel etc what are 6" nails made of? If they are MS and are wider in girth than 1/8" then can they not be turned down to the correct size in the lathe? I haven't tried it and this is just a random thought so I am dodging under the table from the innevitable bullets as I write.

Bryan

[allanferguson]

I set the thickness of the strips of brass in my modification to just a smidge (engineering term) over the gap between the wheel hub and the face of the jig. In this way when the axle is pushed in any deformity is limited by the hub coming up against the jig face. I hope that is clear.

Just going back to mild steel v's silver steel etc what are 6" nails made of? If they are MS and are wider in girth than 1/8" then can they not be turned down to the correct size in the lathe? I haven't tried it and this is just a random thought so I am dodging under the table from the innevitable bullets as I write.

Bryan

That's a very clear exposition. I've actually been using plasticard spacers under the wheel, but just a smidge thinner than the gap. I'll try a thicker piece of plastic. I also note your comments re tapering of axle ends, and using overlong axles. I haven't aspired to brass wheel centres, and I would worry about cutting axles to length in a plastic wheel. I do taper off a little of the axle ends, but I don't want to reduce the grip of the wheel on the axle. Incidentally, I've found that many axles supplied with wheels seem to be a fraction short, and I've in some cases made up replacement axles to a measured length.

Do be careful about mentioning the use of a lathe on here! I got into trouble for this in another thread!

Allan F

[Will L]

... I suspect that one of the causes of post fit wobbliness is forcing axles into the plastic. ..

Mike Ainsworth and I were discussing this today while doing an impromptu GW wheel press demo as part of manning the society stand at Manchester. We are both happy users of unmodified GW presses who don't suffer from wobbly results. What we both do is chamfer the ends of the axle before pressing on the wheels. From experience I can tell you that If you don't do this, then the edge of the axle will shave plastic off the inside of one side of the axle hole. You shouldn't then be too surprised to find you have a wobbly wheel.

The set of wheels used to do the demo has been pressed on on numerous occasions. The axle is well chamfered and the wheels still go on wobble free.

..If the axles are a tight fit or simply won't even enter the wheel I use a tapered reamer, from the back only, gently removing a little at a time until the axle will go in about half the depth with a (hand push) fit. ..

I personally would not want to remove any plastic out of the holes, not just because of the danger of mis-centering the axle as suggested above, but also as the tighter the hole, the less likely the wheel is to move on the axle. For that reason I try hard never to mount a pair of wheels on the axle more than once. If the axle really is too big, then I think the first obvious symptom would be the hub splinting, and at that point I think a return to the manufacturer for a new wheel/axle is in order. I cant see any mechanical reason why just a tight fit should cause a wobbly wheel, unless of course, you scraped a chunk of plastic out of the hole trying to get an unchamfered axle in.

Will

[allanferguson]

I feel this should mabe be a separate thread, but I'm not sure how to achieve that while linking in here. Can a moderator advise?

I can split the topic if needed, ie to move some existing posts, which post would you think has diverged to that extent?
Keith 'l j

Well, mine, actually! But I wasn't sure what the form was when I've "invaded" someone else's thread.

Allan F

[Philip Hall]

Equally I've never been happy with the technique advised (I think) by Mike Sharman when his wheels first became available of "gently" pulling the wheel into line. Does anyone have any views / experience?

It was Mike (or Iain Rice) who expounded this technique and it works with Sharman wheels, because the tyres are locked on the the centres. For this reason it's not entirely successful with Gibson wheels, as when you tweak there is a possibility of moving the tyre, not the centre, as the tyres are a press fit onto the centre. I've often managed to do it, though. Both types are moulded from a slightly 'bendy' plastic, which may or may not be the same (anyone know on here, Iain maybe?), and which deforms slightly as the axle is pressed in. I understand the centre contracts slightly from this deformity, holding the wheel nice and firmly on the axle. This is why you must have a decent chamfer on the end of the axle, as Will so rightly says. If you don't it will almost certainly take a shave off the centre as the axle goes in. If the appearance of a slight recess around the axles is troublesome, a little filler or very thick paint will take care of it.

This technique is unnecessary with Ultrascale wheels as they are moulded of a much more rigid plastic and the axle hole is a close fit on the axle. In most cases these days I pin the axle to the wheel a la Hayes, Venton etc.

Finally, axle material. I am presently 'restoring' a Martin Finney M7 which had not been built in, shall we say, the best sort of style, and which was fitted with Sharman wheels. The axles were overlength, so I trimmed them off in the lathe and, as they were a bit loose in the wheels (I think they'd been on and off a lot of times) set to and drilled the axle ends at 45 degrees for pins. After the fourth broken drill bit it dawned on me (actually pointed out to me by someone to whom it was obvious!) that the axles were silver steel. I replaced them with mild steel and all was well. I think these wheels were original Sharman productions, so maybe Mike was using silver steel then. My mild steel axle material is very accurately ground and comes from a friend who had a little to spare; it is very close to 0.125", and I use it (and the 3mm equivalent) when making up replacement axles.

Philip

[Russ Elliott]

I think this might be ground mild steel, the only problem is it's in the States. At 4 dollars for 6 feet, it seems absurdly cheap. Perhaps the enterprising Mr Eileen's could get a few chopped up lengths in stock?

[45609]

Hello Russ

Yes indeed it is mild steel and to be precise it is AISI/SAE 12L14 which is a leaded and therefore a free machining grade. Equivalent specifcation references are listed here. They might be worth a call as Wolverhampton is a bit closer than New Jersey. Precision ground bar stock is listed lower down.

There are many other sources. A few names off the top of my head that would be worth Googling and adding to the supplier.txt if they aren't on there already.

Mallard Metals
College Engineering Supplies
Noggin End Metals
Milton Keynes Metals
Macc Model Engineers Supplies

Cheers....Morgan

[shipbadger]

To answer Phillip Hall's question about the type of plastic used in the original Alan Gibson wheels (can't comment on current production) and Mike Sharman's. I had expressed a preference to Alan that I preferred Sharman wheels as when soldering 5A fusewire to the rims the plastic did not shrink away from the rim as his sometimes did. Alan told me that it was because Mike Sharman used a type of recycled plastic which had a different composition to that which he used. Alan Gibson, always the gentleman, did offer to re-shoot the plastic centre into any rim that I returned to him.

Tony Comber