Thread: Old Atkins grinder

Originally Posted by BobL

A long belt runs between 2 two speed pulleys that when combined produces pulley ratios are rather odd, 1.1 for one pair and 1.4 for the other.

The 1.1 x 2850 = ~3000 RPM (thats OK) t'd the other would be near 4000 RPM, seems rather high.

There is a sign on the spindle cover that says to only use the higher speed when the wheels wear down to less than 8"

Not so odd. I have a similar arrangement for the J&S (in fact, it has 3 belt positions). It would have been done to ensure that grinding could be done at the optimum speed for longer. With direct drive bench grinders it is no longer possible (unless there is a VFD in the system) but I would guess that wheels are relatively cheaper now anyway.

Michael

Originally Posted by Michael G

Not so odd. I have a similar arrangement for the J&S (in fact, it has 3 belt positions). It would have been done to ensure that grinding could be done at the optimum speed for longer. With direct drive bench grinders it is no longer possible (unless there is a VFD in the system) but I would guess that wheels are relatively cheaper now anyway.

Michael

Sure, I understand the reason but then I would have though the ratio between the two pairs of pulley would be 1.25, Instead it is, . . . . . . . 1.27 ? ! ?
That's not what I got the first time I did that division.

So not odd at all - I must be losing it.

They are my favourite grinder. Spent many hours finishing forgings on them.
At Strathfield M.S. I'm custodian of a similar Hebco. Soon should get a set of spanners for the rest adjustments, to hang beside it.
The switch (original) is an odd thing.
I'd be curious to know what the bearing size is, to plan for replacements.
cheers,
Andrew.

Pulled the while thing apart today. It sure is bult like a battleship.

Before I pulled the motor out I ran it on a VFD - only in Y mode but it runs nice and smootly.
The large ball bearings look clean but I will repack them when I put it all back together.

Except for the water bath and a couple of spots nearby on the frame the rest of the rust is just surface rust. Even the rough casting inside the frame shaped up pretty well with a few passes with a a wire wheel on an angle grinder. I was going to use electrolysis on the rust but I think I might just give everything a coat with phosphoric acid. Might use electrolysis on the water bath though.

I've got the motor out on the bench and will open it up in the next day or so to see if can be converted to ∆.

I've converted the motor to ∆ and derusted and painted most of the rest.

Most of the bolt heads were rusty. After I took the rust off which a wire wheel, here is how I held them while they got spray painted

I managed to do a bit more on the grinder in the last few days.

Just pottering along with a bit of electrolysis on the badly corroded cooling tank.

Here is how it started out.


Unbolted the tank from the grinder and knocked the loose stuff off with a hammer and gave it a once over with a wire wheel where I could get at it.


12 hours in the electrolysis tank, 2.5A
The pink is almost certainly lead oxide primer.


Couple of coats of paint - Im not planning on refilling it with water - will just use it as a handy place to put stuff.

Just a reminder of how it started out.


Now almost refurbished.
The casting is fairly rough so I did not see the point in to fancy a paint job so it's only handprinted to keep the rust at bay.
I put back the two grey wheels that were originally on it but I think I might replace one with a wire wheel.


Bit of a closer up view.


Controls
Fwd/Stop
Speed up to 60Hz
2 Emergency stops for extra safety - Nah there was a hole on the Plate and decided to fill it with something.


Internals.
Will fit some dust covered over the switchgear
Std 1.5kw HY VFD


Back view with 240V ventilation fan,

Looks good, there's a sense of satisfaction in giving a fine quality machine like that another lease on life.

Ray

Hi there BobL,
Great old machine you have restored there. Must have quite a long history. Trying to recall when the Atkins WA name was last seen. Could have been mid or late 1960's when they became Atkins Carlyle, and more recently were swallowed by Blackwoods. The whole machine may have been made in WA for Atkins at the time, as they bought in a lot of re-branded goods from local firms, and may have had some engineering capacity of their own. Did the motor happen to be an AEC or other Perth built brand? Just curious. Look after the old gal. Regards,
Combustor.

Thanks guys.

The grinder came from a school pre-vocational centre. I reckon the wheels on it are probably the originals.

The Grinder itself is almost certainly a rebrand.
Underneath the Atkins label, the other label says "Universal Grinders, York St Sydney"
The motor is a HEBCO made by H.E.Brehaut in Mont Albert, Victoria.
It's at seriously beefy motor being at least twice the weight of a modern cast iron 1HP motor.
The star point was the easiest to find and there was heaps of room inside it compared to any of the motors I have converted

The motor (sans wheels) runs fine up to at least 90Hz (not that I ever intend using that fast)
I've set the pulleys to the low gear and limited the frequency to 60Hz for the moment.

One thing I will do is move the VFD panel to a transparent box on the front of the grinder.

OK it's done.
I added a dust cover to the back of the switch gear and moved the VFD front panel to the front of the grinder base.
Not the ideal position, a bit low down, but there was very little usable real estate left on the front