Making square holes and square shafts.

[02jcole]

Hello all,

I am in the process of making some steam fittings and wonder what is the best way of creating the square on the spindle and a matching square hole in the handwheel Any tips.

James.

[Tel]

These spindles/handwheels will be pretty small? 'bout the easiest way to make the spindle is to file it while it's mounted in the lathe, using one jaw as a datum.

Conventional wisdon sez you use a broach for the square holes, but, they are expensive and won't get enough use to justify the cost. Instead, drill your core hole a little oversize and force a piece of HSS tool steel thru' it - you might 'ave to taper the end of the HSS a bit. You can make internal hexs the same way using a chopped off allen key.

Do it in the vise, with the workpiece backed up by a suitable bush that will let the 'former' come thru' enough to do a good job.

Having said all that - it is sometimes better just to run a thread on the spindle & thread the handwheel, then hold it all in place with a good locknut.

[waggy]

James,

As Tel advises, thread the spindle and wheel.

Secure with Loctite threadlock and a locknut. Won't ever move in normal use.

Waggy.

[steam4ian]

G'day Waggy,

You can lead a horse to drink;
But you can't make it water!

Regards,
Ian

[stevep]

Lawrie Lawrence's method, which I have used many times with complete success, is to broach the square hole in the handwheel in the lathe.

Having drilled and parted off a handwheel blank. hold it so that it rests against the chuck jaws, and put a square needle file in the tailstock, and then push it through using the tailstock handwheel.

To remove, open the jaws and put the blank on the inside, and just undo the tailstock handwheel.

You may have to do this a couple of times to complete the hole.

Incidentally, a good wheeze for handwheels is to get seven pieces of brass tube - I think I used 5/32". Tie them in a bundle (6 around the outside and one in the middle) and silver solder the lot together. Part off slices, and a few minutes work with a needfile gives a very reasonable representation of a cast wheel.

Steve

[Old Biker]

If you don't mind a bit of toolmaking, broaches are not that difficult to make, just a bit fiddly. The small one is 1/8" square for loco hand wheels. Incidentally the hand wheel is for a loco that was started in 1974 is still just a rolling chassis.

Mark

[spurley]

Hi Mark

These broaches look good, are they made from silver steel or gauge plate? Probably either would do I imagine? Are they filed up and then hardened once the teeth are sharp? Then do you use them by hand or in the lathe tailstock? I suppose they could be used in a drill press if the chuck is locked and the quill shaft is operated up and down?

Wow loads of questions!

Incidently Steve, who is Lawrie Laurence please? (just for interest as you mentioned him). I like your idea for the 'built up' job, might well give that a go at some stage.

Cheers

Brian

[steammadman]

old biker is a man after my own heart, why buy when you can make.

silver steel will make a damn good broach.
look around for some square stock , used to be on the market),
i've had mine in stock about 40 years.
however, cut or file teeth on 1 ,orbetter still 2 faces,make sure
you get em sharp, then very gently push your "broach" through
, hand wheel, turn the broach through 90 deg,and repeat , gently ,
using your tail stock, with the embryo hand wheel held in the chuck
and the "broach" held in the tailstock chuck, NOT MUCH PROJECTING.

i used this wheeze at least 50 years ago with succes.

REMEMBER SOFTLY SOFTLY CATCHES MONKEY

[GWRdriver]

Something worth consdering I don't believe anyone has pointed out which can simplify the job, rarely are miniature wheel holes broached fully square. As often as not the hole is drilled round and oversize so the broach needs only put four healthy nicks in the diameter at the rquired ACF dimensions.

[Boadicea]

spurley said:

who is Lawrie Laurence please? (just for interest as you mentioned him).
Cheers
Brian

Reckon Lawrie Lawrence = Curly Lawrence = LBSC = Model Steam Engineering Icon.

[alanstepney]

Reckon Lawrie Lawrence = Curly Lawrence = LBSC

Wrong one.

Whilst Curly was indeed LBSC, Lawrie was a contributor to ME, for a time one of the editorial staff, and member of Bournemouth SME.
His main "fame" is probably his series on Injectors, and how to make them. A series that should be required reading for anyone interested in them.

Oh, and neither was related to the "other" Lawrences, DH, or TE.

[spurley]

That's why I asked the question!

[Old Biker]

Brian
The broaches are either filed or milled taper /square . I have cut the teeth variously by filing or milling, both equally tedious. The teeth are 'almost' sharpened before hardening then touched up with a fine oil stone. With silver steel or gauge plate I find that quenching from cherry red into old cooking oil (windows open in w/shop as it stinks a bit !)is plenty hard enough, even then I have broken the odd one !.
The smaller broaches can be pushed through from the Myford tail stock but in the larger sizes this is a bit hard on a 3 1/2 inch lathe so I really use the broaches for sizing, removing most of the material with a file as I did here.


Mark

[albertsell]

Gentlemen,
I must have made more than 30 hand wheels, all with a square hole made using needle files in not much more thn 5 minutes each/square.Much easier,quicker and cheaper than making a broach.
Bye Albert.