Thread: Arbor hole in Saw Plate

Worth a try, of course, the saw plate will be hardened to some degree, but I'd think it's probably more like spring temper hardness, rather than cutting edge hard... You could try a small file and see how hard it is around the hole, if the file skates off, I'd say you'll probably have to grind it. A bit of carefull work with a dremel?

The other thing you could try is to heat the area you want to drill to bright red with a map torch and then cool slowly to anneal it then try and ream it to 7/8"

Regards
Ray

Thats going to take a few reamers.

Originally Posted by RayG

Worth a try, of course, the saw plate will be hardened to some degree, but I'd think it's probably more like spring temper hardness, rather than cutting edge hard... You could try a small file and see how hard it is around the hole, if the file skates off, I'd say you'll probably have to grind it. A bit of carefull work with a dremel?

The other thing you could try is to heat the area you want to drill to bright red with a map torch and then cool slowly to anneal it then try and ream it to 7/8"

Regards
Ray

Personally i would not heat it, too much chance of it going "wobbly" as the inside expands with nowhere to go radially. Most blade blanks these days are far from hard (at least all the ones i have cut up were soft) It doesnt even really matter if you are a bit out, as soon as you wear the tips a bit the blade will re-balance itself. Just so long as its no so bad you can't use it!

I would send it back at their expense as it is NOT as advertised!!!!!!
Kryn

Originally Posted by Ueee

Personally i would not heat it, too much chance of it going "wobbly" as the inside expands with nowhere to go radially. Most blade blanks these days are far from hard (at least all the ones i have cut up were soft) It doesnt even really matter if you are a bit out, as soon as you wear the tips a bit the blade will re-balance itself. Just so long as its no so bad you can't use it!

Hi Ewan,
Yes, that's a good point, heating the center would most likely buckle the thing.. ( I withdraw that dumb advice ) The last circular saw blade I cut up was to make riving knives for the table saw, and as I recall the material wasn't all that hard.

Regards
Ray

Your local saw doctor, mine quoted $28 to resize a wood blade which wasn't worth it for my crap blades

Originally Posted by Ratbag

but thought an imperial step-drill could resize it to the required 7/8" while retaining concentricity. Is this achievable with a carefully setup 1000w AEG in a bench stand on a vey low speed with plenty of Trefolex?

I have a step-drill that was used for exactly that. Though I have no idea how the saw was set up.

Stuart

Is it possible to make a new arbour to suit the 20mm blade? Maybe you could even machine the existing to 20mm and then if you need to use the 22.23 blades in the future you can use a spacer. Maybe you will find the 20mm bore is more common and you can just keep purchasing these in the future?

Hi

A possible method is to buy a conical shaped grinding stone ... you can get them . I've enlarged holes by using a drill and the stone , the conical shaped stone tends to self centre in the hole and it enlarges the hole .


http://www.ebay.co.uk/itm/AXOLITE-CO...item564be10d60

Mike

Originally Posted by KBs PensNmore

I would send it back at their expense as it is NOT as advertised!!!!!!
Kryn

HI,
My thoughts Exactly.

Originally Posted by morrisman

Hi

A possible method is to buy a conical shaped grinding stone ... you can get them . I've enlarged holes by using a drill and the stone , the conical shaped stone tends to self centre in the hole and it enlarges the hole .



AXOLITE CONICAL SLIP STONE | eBay

Mike

I would go this way as well. I have several tapered grind stones that would easily do that job. You would have to take it slowly so you didn;t put a step in the stone.

You could also just use a plain cylindrical diamond burr and run it around the hole in a regular fashion and check it with a vernier for roundness.

If you try and drill out the centre there is a chance it could pull off centre.

Rob

Could the method of using a tapered stone and achieveing a parallel bore be descrbed.

Originally Posted by pipeclay

Could the method of using a tapered stone and achieveing a parallel bore be descrbed.

You won't get a parallel bore this way, but it won't matter as the taper will be slight.

As the blade is clamped between centre discs a knife edge on the blade centre would be enought just to lightly centre it.

All the load is taken on the clamping discs.

If you want a perfect job you can easily grind the tapered disc centre out to the correct outside circumference, and then drill out the taper section on the press.

It's highly unlikely you would get any runout with the drill this way.

Rob.

we are only talking 1.1 mm approx all the way round the outside of the hole. If the blade is not real hard, I'd be carefully marking it out and filing it with a 1/2 round file. you could probably do it in under 10 minutes.
bollie7