On 11 Oct 2004 11:28:29 -0700, (oddjobboy)
wrote:

Anyone had any experience of dropping a new single phase motor into
something like the old 10" Wadkin I've been offered for notalot?

A 10 AGS ?

I've got one of these.
http://codesmiths.com/shed/workshop/wadkin/

Long before I got it, someone had converted it to single phase. The
(retired) guy I bought it from had a fairly large home workshop,
filled with tools from his past commercial workshop. This was the only
machien that was vaguely usable, as he was using a static phase
converter for the others and had a lot of trouble with them.

Unfortunately the conversion was a "materials to hand" job. The motor
he'd used was _way_ underpowered and the saw was bordering on the
dangerous. So, that motor had to go.

I thought the task would be easy. It wasn't !

Getting the motor was easy - a 3HP single phase Clarke from Machine
Mart, £80 + VAT You have to buy them new because motors of this power
rating just don't show up S/H - industrial motors are 3 phase,
domestic motors aren't that powerful. If you're on Machine Mart's
mailing list, they send you invites to weekend open days (most bank
holidays) where Clarke own-brand kit is reduced by 17.5% - worth
knowing for the big stuff.

Switchgear was no problem, as I can sparkie with the best of them. A
NVR starter from Axminster and a rotary isolator switch. Machine Mart
also sell starters, but theirs have tiny buttons. As the starter has
a proper contactor inside, it's easy to extend this with extra stop
buttons. Your existing starter may well be usable, but check the
setting on the overload relay.

IMHO, a separate isolator switch is essential. It's not safe to work
on the whirling bits unless you can either shut off _two_ switches, or
unplug it.

Now the awkward bit - the pulley. The new motor is a 24mm keyed
shaft, the old pulley was a 1" shaft fitted to a 3/4" motor shaft with
a home-made adaptor sleeve. I couldn't re-use the existing pulley
without machining it out to take a bigger sleeve. I have a lathe to do
this, but it would be getting marginal on thickness for either the
sleeve or the bottom of the pulley grooves. It would also make the
change irreversible, should I screw things up.

So I bought a new pulley. That would be easy I thought....
Seems that triple pulleys are now a rarity, owing to modern belt
materials and the preference for polygroove belts in high power
applications. I considered swapping both pulleys, but couldn't easily
fit one to the old arbor.

The nearest triple pulley I could find (made by GKN) was expensive
(some tens of quid !) and wrong for both pitch between pulley grooves
and the groove profile. Seems that 40 year old pulleys were sized on
the cubit scale, and modern ones aren't exactly the same - still, it
seems to work now. A modern taper-lock bush in the pulley at least
means that I can fit any motor shaft to it in the future, without
swapping pulleys again.

Now the motor bracket. This is another job that's simple in principle,
just big and awkward. I had to re-drill four holes in the plate, to
accomodate the new motor and its new bolt location relative to the
pulley. This was done on the measure once, drill twice, curse
frequently plan. I don't quite know how I got it wrong, but I
mis-measured something. I was also drilling it on a friend's mill, 40
miles away from home....

If I knew how to strip the arbor, I'd have done that and replaced the
ancient bearings whilst I had it in bits. But it wasn't obvious
(anyone know ?), the hydraulic press is 200 miles away, and I just
couldn't be bothered. I did forge myself a nice new C spanner though,
so that I could grip the arbor nut without abusing the pin holes with
a badly-fitting rod.

Finally I had the parts. I just needed to re-assemble it (which is a
pain to do without taking the table off, but it is possible).
Amazingly it all then worked, and it even tensioned the old belts
correctly. The adjustment slots aren't generously sized.


Once finished though, the saw was transformed. No more bogging down,
even when doing full-depth rips in oak or warped blade-grabbing larch.
Well worth all the time and trouble it took.


Hope this is helpful. Post again if there's anything I can clarify.
--
Smert' spamionam