Swing grinder help

Hi all,

I inherited an Excel swing grinder in bits, my guess is it was taken apart to aid moving it, its very heavy. I have put it back together and all looks good but what I need is a manual to help set it up properly.

My main concern is the spindle head had been removed, should it be square to the table or are they at a slight angle to stop back cutting once dressed?

Any help would well received.

There was an article in ME some years ago about making a swing grinder which might help.

Excel are based at Colliery Lane, Exhall, Coventry telephone 02476 365255. Worth a call.

Robert Butler

Not the same company, same name but only started in the 80,s my machine is the original 60,s machine but thanks anyway.

Hi ega, if it's the one I'm thinking of, it was in October/ November 1997 in MEW.

Regards Nick.

If the Wheel head is not dead square it will grind a hollow. This may be only very slight, and may not be important for what you intend to use the machine for. However it is defeating the object as the machine can be made to cut perfectly, and any work coming off the machine is known to be flat. Provided the work has not been distorted during mounting it on the machine, that is.

Large ground steel tooling plates always showed signs of the back edge of the wheel cutting when I was in industry.

Regards

Gray,

Nicholas Farr:

Yes, indeed, and thanks for the correction!

I suspect that Gray has provided the answer to the OP's question.

PS For what it is worth, the article referred to describes the procedure for "squaring the spindle" (MEW 46 page 29).

Thanks for all your replies.

I spent the evening clocking the head square using the tramming method and the best I could get was 0.01mm / 0.0004" TIR over a 10 inch sweep of the machine table. I then refitted the mag chuck.

I then dressed the wheel and skimmed a 50mm dia billet in .0005" passes swinging from the right to the centre of the wheel and back to the right. It is not how I would expect it to look.

I am going to check the mag table tomorrow and see if its hollow.

P.S. how can I post pictures on here?

Thanks Graham

.

It’s a bit of a grind … but start here: **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=103028&p=1

MichaelG.

Your error over 25 mm or 1" will be so small as not worth worrying about.

Your mag chuck may well be distorting the work if it is thin. This is what I was hinting at in my earlier post. Old feeler gauges make good packing when placing work onto the Mag chuck, before engaging the magnets.

The Mag chuck should from time to time be reground, but be sure all other sources of error are eliminated first.

Wear very often takes place in the centre of the table. It is where most people tend to place the work. Operators of Surface grinders will often place parts all over the table to minimize wear and save on table regrinds.

Strips of thick rubber with an aluminium backed edge. Rather like a Tenon saw, make good cleaning aids for the table. To remove dust and coolant, but nothing beats the palm of your hand afterwards.

Regards,

T'other Gray,

Edited By Graham Meek on 03/06/2023 11:29:48

Hi ega, I remember seeing the actual machine at a Harrogate exhibition, and it had a note with it saying the construction was published in MEW. Funny how these thigs stick in ones mind.

Regards Nick.

My use of a swing grinder showed you cannot use the full width of the thicknes of the grinding wheel. When truing it I was instructed to take off more than half the contact surface leaving a narrow contact to cut and grind.. It was just a matter of truing and then taking off a bit more to leave the original truing to cut. I only ever took very small cuts to clean up jobs.

Hi Clive,

I had missed the wheel dressing technique from my notes. It is something which I have done automatically in my profession, but had totally forgot about. Thanks for bringing it up.

The larger Lumsden grinders, which work on the same principle have a powered slide which dresses the face of the wheel, or wheel segments concave. It achieves exactly the same as you suggest, but it is quicker to do.

Regards

Gray,

Clive, Graham

As only a relatively narrow band at the outside of the wheel can be used for accurate grinding why are swing grinders always fitted with such bulky wide faced wheels?

Seems silly to pay for so much grinding media that will simply be lost as dust to create clearance when truing. Especially as quite deep, narrow cup wheels are made. Is it as simple as safety? I imagine a narrower face cup wheel will be more vulnerable to major accidental damage should an over-large feed be attempted.

For many years I used a deep cup 6" white wheel with, I think, 1/2" face for my finish tool grinding and drill sharpening with a Picador swing across the wheel device. Partly because the narrow face seemed more suitable for use with the Picador but mostly because it was offered at the right price at the right time. Working only from the side made the the rest simpler too.

Clive

Clive to Clive, I think your right, ever sen one of those grinding machines where you run cylinder heads across, the wheel is very thick. I would hate to see one go bang.