Bearing boxes for ball race

[Paul McDonoughParticipant @paulmcdonough43628]

Dear all, I am looking to make a set of powered bogies for an ‘diesel’ electric loco and I would like to use out board ball races mounted in bearing boxes, likely fixed. The shaft size will be 10mm and the outside diameter of the ball races 22mm.

Given that I have to make I bunch of these i am wonder if there is a sensible way to make the 22mm blind flat bottomed hole in mild steel without having to bore each one?

would multiple drill sizes finishing with a 2 flute flat bladed 22mm mill be a reasonable approach?

I will have to take it very steady as I think 22mm will be on the limit of the capability of my little mill.

i do have a boring head but it’s going to be a right pain making a dozen of these, plus the failed ones!

alternative ideas would be welcomed

 

 

[Peter Cook 6Participant @petercook6]

Depending on the stock being used, I think I would be tempted to make them on the lathe rather than the mill. Drill, as you suggest, most of the material out, then a boring bar in the tool holder will be far easier to take the last cut to 22mm and the “facing” cuts to get the bottom of the hole flat.

Assuming square (or rectangular) stock, once the first piece is set up in a four jaw chuck and  clocked centrally, if you only loosen two jaws to remove the finished item you should be able to slot the next piece of stock into place.

[DiogenesParticipant @diogenes]

Have you done a test to establish whether that leaves them at the right size for a good fit?

I’d probably ‘rough’ them all (say to 21.5) by any expedient means, and then ‘finish’ them to final size one after another, preferably on a fixture plate or jig.

– I’d be looking to do them in the lathe for first choice too.

[Paul McDonoughParticipant @paulmcdonough43628]

Yes the 22mm dia 2 flute mill was a bit tongue in cheek, I guess I’m fishing for ideas to help take the pain out of making them!

Agreed, if I’m going to bore them, which it looks like I am, then the lathe would be the place to do this, probably with round stock and accept the final profile.

i did wonder if the use of needle bearings might reduce the pain, by reducing the material needed to be removed and may be finish with a reamer?

just trying to reduce the repetition

 

[BazyleParticipant @bazyle]

Tube if right size with end cap soldered on. If square or rectangle can make tube from two bits of angle iron welded or silver soldered. End cap can be soft solder.

Oilite bearings might be enough if not aiming to be a club passenger hauler.

[Bazyle]

On Bazyle Said:

Tube if right size with end cap soldered on. If square or rectangle can make tube from two bits of angle iron welded or silver soldered. End cap can be soft solder.

Oilite bearings might be enough if not aiming to be a club passenger hauler.

Cheers, yes I did wonder about fabrication, could resort to oilite would certainly be compact

[Nigel Graham 2Participant @nigelgraham2]

Better than fabrication in that way, would be to through-bore the block and screw a thin retaining-plate to the back. Or, it there is room, make the block slightly thicker and give that extension an internal groove for a circlip to engage the outer ring of the bearing.

Since needing a batch and they having to be identical, I would be tempted to make a simple fixture to bolt to the faceplate so the blocks all locate against rigid datum faces much wider than a chuck-jaw tip.

Using a four-jaw chuck risks the “fixed” jaws moving very slightly from one iteration to the next.

Mark each block’s datum corner, e.g. by a centre-punch dot on the “front” face, to ensure equality of assembly even if the bores are a thou’ or two off-centre (as long as the error is constant). One assembly the dots need face in the same direction across the bogie, of course.

[Paul McDonoughParticipant @paulmcdonough43628]

Thanks for the ideas Nigel, I have to confess, setting up jigs an rigs for ‘mass production’ makes me cringe but I fear it does make sense once I have established a solution which I like the look of.

i might compromise the looks to accommodate chunky ball races, they have given me comfort that I’m using the best engineered solution avoiding nagging doubts about my home made bearings dragging or ‘going oval’

might just have to accept that some things are worth making properly again and again!

Actually,……… perhaps someone makes the bleedin things?

[howardbParticipant @howardb]

“Actually,……… perhaps someone makes the bleedin things?”

If you don’t want to make bearing housings, think about buying them in.

Two bolt 10 mm ID self-aligning flange bearing units. £8.48 per pair from ebay.

https://shorturl.at/ttta6

 

[noel shelleyParticipant @noelshelley55608]

Something that is rarely mentioned on here when it comes to making BIG holes is the Weldon shanked Rota Broach type of cutter. For holes in material upto 2″ thick they are quick and accurate in sizes from 11mm upto 60+mm. Using 22 mmOD 2rs bearings press fit in an open ended housing would be fine – or put a cover plate on. Oilite would be ok, though less free running. Noel.

[Paul McDonoughParticipant @paulmcdonough43628]

Thank you Noel, I had not heard of these, but they look like ‘precision’ versions of the hole saws i use on wood and other forgiving materials.

I am not beyond using goop or bearing retainer to ‘cure’ a slightly over sized hole, provided the cutter does result in a slight over sized hole.

Might even help with alignment! Sorry

 

[noel shelleyParticipant @noelshelley55608]

If you are near me (north Norfolk) PM me, I have up to 38mm and the machine to drive them, could soon do them. I would say use 21mm then bore to size or try one and see ?  Noel.

[Paul McDonoughParticipant @paulmcdonough43628]

Thank you for your kind offer Noel, I live in Bristol so it would be a bit of a trek.

im going to give this a bit more thought, but the Rota broach is a good call thank you.

[Stuart Smith 5Participant @stuartsmith5]

You could always buy them.

What about these:

https://smrengineering.co.uk/products/small-axlebox-with-10mm-bearing

or these:

https://smrengineering.co.uk/products/miniature-pillow-block-bearing-1

No connection with the company, but I have bought wheels from them.

Stuart

[ZanParticipant @zan]

I agree with Nigel,making a simple fixture for the faceplate. That’s how I did my axelboxes.
two thick plates set at right angles screwed onto a jig plate ( mine was probably  a 100 mm square of alloy 10 thick) then a small plate clamping the box in place with a pre bored clearance hole , screwed into the aligning pair and packing to  stop it tilting   Push it hard into the register then centre the jig plate with a wobbler to the centre punched centre. Mark the boxes so you know which corner is say front bottom.

if doing this for loco axel boxes, one side has to be clamped on the back, the other on the front to keep the orientation the same, probably not too important fora riding car but the location bars need a step to clear the box flanges when reversed

It was a simple task and the slide graduations (or dro) take care of the diameters and are the same after the first one is completed
my axels slid in without any form of binding, and the coupling rods were exactly the same length

I’ll see if I can find the photo later…

[Paul McDonoughParticipant @paulmcdonough43628]

They look neat, it’s nice that some makes these things. I’m a little surprised that they are machined from plastic, but I guess that’s the modern way.

less keen on the pillow bearings, they look a bit repurposed but I can see that they would work if disguised with a fake bearing box mounted in front.

so both could do the job

[Paul McDonoughParticipant @paulmcdonough43628]

Cheers zan, I can see the gearing up for a small production run is the way to go if I’m going to make em!

[Perko7Participant @perko7]

Mine were cut from a length of square aluminium-zinc alloy, the outside cleaned up in a milling machine to the correct width/height, then slices cut off, faced each side in the lathe to correct thickness, then bored right through for a light push fit and then a plate fixed across one end to form the cheeks which bear against the faces of the horns. The bearings were then inserted with a smear of Loctite. Haven’t moved in 3 years of regular use.

[Paul McDonoughParticipant @paulmcdonough43628]

Thank you Perko7 for your advice and experience

[old martParticipant @oldmart]

The lathe would be my choice in a four jaw independent chuck. A centre cutting end mill will leave a hole that is deeper at the outside, a very shallow cone.

[Author]

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