Driving wheel axle material

[Paul Townsend]

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

That US ground mild steel is what i have been looking for over a year!
TVM for link.

None of the UK suppliers that you list or others I have tried carry GROUND MS, only the drawn stuff which is not accurate eneough for axles.

I too hope Eileens will import some so have asked Derek so to do.

[45609]

None of the UK suppliers that you list or others I have tried carry GROUND MS.

The Steel Express page I used as a link to show equivalent specs did.....

http://www.steelexpress.co.uk/engineeri ... dprecision

[billbedford]

only the drawn stuff which is not accurate eneough for axles.

Really??????
Given the way that most frames are designed and built I would think a few micron +- on the axles were the least of people's problems. But then, P4 builders do like their hair shirts.

[Russ Elliott]

Quite right, Bill, a few microns either way is not the issue. What is of issue is a value a hundred or a thousand times that.

Generally, anything 0.1235" or less will be useless IMO. It might suit a tight Sharman wheel bore, but an Ultrascale bore will not grip that sufficiently. And let's remember part of the subtext of this thread is to try to avoid pinning of wheels if we can get away without needing to do so. Such a diameter will tend to rattle around inside a 1/8" bearing bore, whose actual dimension will vary wildly between production batches, depending on the state of the drill. Moreover, any grubscrew-fitting worm wheel on that kind of diameter will become eccentric, which is bad news for load-sensitive transmissions with small coreless motors, as users of Portescap drives will confirm.

Metal to metal interference fits, as with metal-centred wheels, are typically 0.00025".

Although 'bright drawn' may be closer to what we want, ideally 0.124+", its diameter can't be guaranteed unless the stockist checks it. (Which is Paul's point.)

Needless to say, axle alignment jig material diameter needs to be good, but most homebrews will probably user silver steel for this purpose, with its better tolerance. Frame, crankpin throw and crankpin bush errors will inherently be present, so the last thing we want to tempt fate with is by using a subsize jig alignment diameter.

But then, P4 builders do like their hair shirts.

And often for sound engineering reasons.

[grovenor-2685]

The Steel Express page I used as a link to show equivalent specs did.....

But appears to be only from 1/4" dia upwards.
Keith

[45609]

time to get my eyes tested.

[billbedford]

Quite right, Bill, a few microns either way is not the issue. What is of issue is a value a hundred or a thousand times that.

Generally, anything 0.1235" or less will be useless IMO. It might suit a tight Sharman wheel bore, but an Ultrascale bore will not grip that sufficiently. And let's remember part of the subtext of this thread is to try to avoid pinning of wheels if we can get away without needing to do so.

Maybe we should not lose sight of the reason that people want to to pin the wheel in the first place, and that is that the bores on moulded plastic wheels are too tight to hold a glue film. Any attempt to use glue to prevent the wheel moving on the axle will be bound to fail because the glue will be wiped out of the joint as the wheel is pressed onto the axle. The answer, AIUI, would either to make to the wheel bores a loose fit so that there was room for the glue to form a film around the axle, or to cut a series of 'pockets' with a burr around the parts of axle covered by the wheels. Obviously, in the latter case, a glue that did not require air to go off would be required.

But then, P4 builders do like their hair shirts.

And often for sound engineering reasons.

I often think that any sound engineering solution would likely begin 'If I were you I wouldn't start from here...'

[Will L]

Maybe we should not lose sight of the reason that people want to to pin the wheel in the first place, and that is that the bores on moulded plastic wheels are too tight to hold a glue film. Any attempt to use glue to prevent the wheel moving on the axle will be bound to fail because the glue will be wiped out of the joint as the wheel is pressed onto the axle. The answer, AIUI, would either to make to the wheel bores a loose fit so that there was room for the glue to form a film around the axle, or to cut a series of 'pockets' with a burr around the parts of axle covered by the wheels. Obviously, in the latter case, a glue that did not require air to go off would be required.

Actually, in my experience of Gibson wheels, I find if is possible to get a glue film in. You start by putting a chamfer on both axle ends, which you should do in any event so you don't scrape a layer of plastic out of the axle hole on the way through, then you put the loctite in the axle hole rather than on the axle end, then you will get a functional glue layer. If the joint really is so tight that no glue layer forms most of the way through, it will form in the space left by the axle end chamfer. The only down side is that you will find there is a tendency to glue the sprung axle studs on your GW press down their holes.

But then, P4 builders do like their hair shirts.

And often for sound engineering reasons.

Who needs a reason?

Will

[billbedford]

Loctite is not a glue. It is a retainer. Meaning it reacts with steel in the absence of air and expands slightly, making a tighter force fit. It does not react in anyway with plastic.
But apart from that. If a wheel bore is less than the axle diameter just how thick will a glue film be?

[Will L]

Loctite is not a glue. It is a retainer.Meaning it reacts with steel in the absence of air and expands slightly, making a tighter force fit. It does not react in anyway with plastic.

Ok, in those terms Loctite is not a glue, but I thought I was just quoting somebody.

... the reason that people want to to pin the wheel in the first place, and that is that the bores on moulded plastic wheels are too tight to hold a glue film.

and are we really talking about anything else other than loctite in this context?

But apart from that. If a wheel bore is less than the axle diameter just how thick will a glue film be?

Thick enough to get a noticeably better gripe. Because plastic is plastic, and the axle will go through a hole which is already smaller than the axle, it isn't asking much to force a layer of retainer or glue in there as well. At a molecular level were are talking about vanishingly small dimensions.

Actually if the axle really is that tight there shouldn't be a lot of need for either the retainer or a pin, but as I also agree with the advice I received from one Bill Bedford about arranging things so you only put the wheels on the axle once, who's to know if your need the retainer or not until after the wheels are on?

If people are putting enough stress on the wheel axle joint to brake a good tight fit, I think they should be wondering about the the running qualities of the whole chassis. I've still waiting for the day when I need to pin a wheel to an axle, though I did have to do a gear wheel once.

Will

[Horsetan]

....Any attempt to use glue to prevent the wheel moving on the axle will be bound to fail because the glue will be wiped out of the joint as the wheel is pressed onto the axle. The answer, AIUI, would either to make to the wheel bores a loose fit so that there was room for the glue to form a film around the axle....

In the same way that your 3D-printed wheels are loose enough to go askew or fall off the axle if there were no glue present I do think they would benefit from a tighter fit, even with the key-and-keyway quartering system.

AGW wheels require no glue or retainer, whilst Ultrascales require only a film of retainer. You would only put retainer around the axle tip anyway, and let the wheel centre bore spread it backwards as the wheel is pushed onto the axle. There is no wiping out of the joint.

[Russ Elliott]

Wahey!

[grovenor-2685]

Price per length? As in piece of string?
Look really hard and the small print says 8".
So it seems a reasonable price, and a fair range of diameters.
Keith

[Paul Townsend]

Wahey!

Excellent, ta for link.
Goodbye to bust .5mm drills for wheel pinning

[Tim V]

Presume you looked at my workbench thread - no broken 0.5mm drills there....

[Philip Hall]

Ultrascale are now selling the steel they use for their axles - lots of different diameters. Specifications on the website:

https://www.ultrascale.com/eshop/products/CAT013

I have had some lengths and it cuts and drills nicely and is very good dimensionally.


Philip

[Paul Townsend]

Presume you looked at my workbench thread - no broken 0.5mm drills there....

Yes, and made the 45degree cross-drilling jig to your design....BUT
I could only get Silver Steel axle material....many drills broken at break-through.
I have been trying to get ground MS in 1/8th which disappeared from known suppliers some years ago.

Just received GMS pack from Ultrascale ( unbelieveable...came within 36 hours of order )...will try again with jig soon.

[Knuckles]

This thread is scaringe somewhat. Are you saying for RTR conversions and kits I need to scratch build my own axles? I really really really do not want to do that.

Anywhere you can just buy them?

[Alan Turner]

Axles normally come with the wheels but you can buy the axles separately from Ultrascale if you wish.

Alan

[Paul Townsend]

Are you saying for RTR conversions and kits I need to scratch build my own axles?

Most bods are happy to attach wheels to supplied axles with loctite. I have built 20+ chassis that way. Only recently had a problem that triggered me into trying pinning....hence my contributions to this thread.
Please don't be frighted!