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John Stevenson
07-12-2011, 04:36 PM
Only applies to the older straight sided splines and also only if the tooth width is a common one.

Got this in today.

http://www.stevenson-engineers.co.uk/files/straight_spline1.jpg

Some DC drive motor of some description and the motor has no front bearing, it relies on the pinion in the gearbox to keep it all in line.

Well this one whilst not looking bad has some bag in it, I reckon a new armature or pinion on it's own will reduce the wear to acceptable limits but not going to happen as no one knows who made these.

Well the pinion is going to cost a load so make a new insert for the motor to fit the worn splines. Quick measure up and I reckon they were 1/8" originally but now just a tad over 3mm so thinking if I make a new guide bush for the 3mm keyway broach and pop a hole in the bush 1/10 of a turn round from the keyway I can cut one and use the bush to index round ?

http://www.stevenson-engineers.co.uk/files/straight_spline2.jpg


So three cuts per spline and 10 splines later this was tapped onto the pinion and after tapping it on and off in various position it was a bang on fit.

http://www.stevenson-engineers.co.uk/files/straight_spline3.jpg


Bored the armature out and shrunk the new sleeve into position, seemed long winded but it was quicker than making a new slotting tool and setting the slotter up to do just this one bush, about 2 1/2 hours start to finish.

form_change
07-12-2011, 04:43 PM
Nice one John.
What size press (tonnage) are you using to cut those splines with?

Michael

macona
07-12-2011, 04:57 PM
Should be able to do that with a generic smaller arbor press. I did some 8mm last week into steel with an arbor press. Not fun.

John Stevenson
07-12-2011, 04:58 PM
Only a crappy Marlco hand press, bought it a while ago with a load of broaches but it's horrible.

http://www.stevenson-engineers.co.uk/files/marlcopress1.jpg

The handles at the front get in the way of what you are broaching and swinging these handle whilst facing them isn't natural.

I have another press outside that's a ratchet press and the handle is to the side and you pull it down, far more natural, but it's a big bugger.

This one is OK up to 1/4" but after that you know you are using it

Alistair Hosie
07-12-2011, 05:06 PM
Stop grumbling John it's green how can it be horrible ? Anyway next time you and Gerty come over or up to civilized land for tea pop in and let me have it.
I mean the machine not a punch in the nose:D Alistair

bborr01
07-12-2011, 05:24 PM
Pretty neat setup John.

How did you position the hole for the pin?

Brian

motorworks
07-12-2011, 05:25 PM
Shut the front door...that's great !!
:)

John Stevenson
07-12-2011, 05:44 PM
Pretty neat setup John.

How did you position the hole for the pin?

Brian

The POS Bridgy has a stepper driven 6" Hoffman dividing head one one end of the table al the while si it's a doddle to put the bush in this, mill the broach groove then tell the table to move 60 degrees and pop a hole in.
it uses the Division master controller and is so easy to use.

tyrone shewlaces
07-12-2011, 05:47 PM
Diabolical cunning!

TexasTurnado
07-12-2011, 05:51 PM
The POS Bridgy has a stepper driven 6" Hoffman dividing head one one end of the table al the while si it's a doddle to put the bush in this, mill the broach groove then tell the table to move 60 degrees and pop a hole in.
it uses the Division master controller and is so easy to use.

Good one, Sir John! Very clever thinking of putting a pin in the broach bushing...

gary hart
07-12-2011, 05:59 PM
Slick, gotta remember that one.

ahidley
07-12-2011, 06:48 PM
Awsome, The simple things DO IMPRESS me!! Of course I'm a simpleton!! :)

tyrone shewlaces
07-12-2011, 07:22 PM
... The simple things DO IMPRESS me!! Of course I'm a simpleton!! :)

Me too. So I guess I impress myself every day.;)

I ain't afraid o' dyin',
but I sure am gonna miss myself.

lazlo
07-12-2011, 07:42 PM
Got this in today.

Some DC drive motor of some description and the motor has no front bearing, it relies on the pinion in the gearbox to keep it all in line.

John, that's an interesting motor. What did it come from? It looks like the spline is designed to provide axial movement for the drive motor??

Mcostello
07-12-2011, 09:35 PM
Darnit, John is there no end of your ideas! Great job!

Zahnrad Kopf
07-12-2011, 09:55 PM
... so thinking if I make a new guide bush for the 3mm keyway broach and pop a hole in the bush 1/10 of a turn round from the keyway I can cut one and use the bush to index round ?

http://www.stevenson-engineers.co.uk/files/straight_spline2.jpg


So three cuts per spline and 10 splines later this was tapped onto the pinion and after tapping it on and off in various position it was a bang on fit.

John, that's really good thinking. Really, spot on.

dp
07-13-2011, 02:10 AM
A one-off, but a damn good on-off. Well done, John.

pgp001
07-13-2011, 02:57 AM
John

That's a good solution alright, but I am afraid to have to inform you that just like many things in this world it ain't new.

My late father did exactly the same thing to produce the six splines on his model Burrell traction engine crankshaft gears about twenty years ago.

I guess he had probably seen it somewhere else as well.

At work they like to call it "Re-inventing the wheel"
Come on now John................Must try harder. (just kidding)

Phil

John Stevenson
07-13-2011, 03:14 AM
Yes I know it's not new Phil because I used it about the same time as your father to put 2 keyways in AJS 7R timing gears at 90 degrees to one another by milling a woodruff keyway in a standard bush.

Nothing is really new in this game unless it's materials or electronics.

I can proudly remember inventing the cat head steady with no outside help at all, only problem was I was 100 years too late :rolleyes:

Often time it just needs a gee up to get ideas floating around again with the current crop of users.

.RC.
07-13-2011, 05:48 AM
Very nice work.... BUT OMG did anyone else see it..... I am sure I saw a bit of concrete on the floor of one of the pics... :D