Making a table saw from Wickes grinder

Hi. I have part of a Wickes bench grinder to hand. Motor is rated at 250W, and 2950 RPM. The spindle diameters are 12.5 mm. I would probably need a circular saw at least 160 mm in diameter. Spindle centres stand about 130 mm from bottom of the base.

Would it be suitable as the motor drive for a table saw to cut thin sheets, like wood and aluminium? Thanks.

Edited By Richard Rogalewski on 23/04/2015 14:06:12

Edited By Richard Rogalewski on 23/04/2015 14:06:39

i would not build a bench grinder using that motor, the answer is NO

I see no reason why not, a motor is a motor after all.

It looks to have decent cheek plates but they could always be replaced and the top speed is well within what a 160mm saw blade safely travels at. My main concert is whether 250W is sufficient for you needs without over loading it. Depends on what you mean by thin sheets.

I have a tiny table saw of about this power that I use for cutting laminate, alloy and thin brass sheet for the engraving machines.

That motor is one third of a horse power it will not have the power to cut

I reckon that will be a nice machine for cutting thin acrylic brass & weaker aluminium alloys. It won't be as fast as a full power table saw, but will have more grunt than some cordless 6" saws on the market at the moment. Go for it.

The only slight reservation I have is that some saw blades run at 6000 rpm -ish, so this may be a bit slow. I doubt if it'll be worth putting in gearing/belt to go faster.

Have you considered mounting it on the underside of your bench (inverted or on a pivoting angle bracket) so it's not in the way? Could then either raise it up or just have a small permanent protrusion on the top of the bench.

Regards,

Richard

the 165mm cordless circ saws tend to run around 3250-3750rpm so you are not too far off and a bit slower is probably better for matal anyway.

Wattage may just be OK for thin makerial, as a comparrison a DW cordless has a 460w motor but I doubt thin brass and Ali would load it as much as say a 40mm hardwood worktop which they whizz through.

Get as thin a kerf blade as possible as this will compensate for the lower power.

J

A saw bench blade and spindle are put under a heavy load, my saw bench has 3 ball bearings and is belt driven from a 2HP single phase double ended spindle, the other end drives the planer table. I also say 'No' to its use.

Clive

Only if you apply a heavy load. The OP did state thin wood and light alloy and mine cuts that fine on 180W

Proxon make a very nice saw bench that must be all of one watt, don't see anyone slagging these off ?

I reckon it would be ok on a smaller blade, having said that I made a very useful topslide grinder for my lathe using a similar motor.

The the only thing I found I had to do was add a cooling fan as the motor was not meant for continuous use.

It runs quite happily for an hour or more now spinning a 8 x 1/4 white wheel, shown here grinding the main bearing jiournals for the R & B.

Hi. I'm particularly interested in cutting 3mm thick aluminium. Nice if I could do that with a thin blade. I would not want the blade to stick proud more than about 10mm. Also, maybe I could do dc injection to retard motor?

I'm not sure about obtaining a blade with a bore of 12.5 mm. Not looked, maybe they exist.

P.S. I'm trying to identify a s utable blade that is okay with aluminium.

I think I'm going to have to put a collar on the spindle to increase the diameter to 20mm.

Edited By Richard Rogalewski on 23/04/2015 18:46:30

Edited By Richard Rogalewski on 23/04/2015 19:14:28

John, I did mention the Planer which is quite a load, I run a 320 mm blade as well.

Clive

Blade

Just watch yourself as it probably has a couple of degrees negative rake

Edited By JasonB on 23/04/2015 20:06:16

My only concern is that these do run quite hot as they don't have a cooling fan.

Try to avoid repeated starts or extended use (a bit of a 'caught both ways' there).

Neil

Cured that easily Neil, no problem with long runs.

By the time you get a table mounted above the motor, you will have lost most of the usable depth of cut. It is preferable for the saw teeth to be cutting downwards as opposed to near horizontal when operating at a "shallow" depth of cut. As others have said, there is not much power available for that size of blade.

It's my understanding that saw blades should protrude just enough to cut the material thickness and no more.

Best to check though because this is fact for wood, I'm not sure as for metal.

PS: I cut aluminium on my cheapo bandsaw with a fine metal tooth blade not much help as to your question but I think I would keep it as a grinder.

Edited By Jesse Hancock 1 on 23/04/2015 21:11:42

I did a drawing. For a 165mm dia. blade: If the blade was proud of the table by 10mm at the maximum height, at the cutting point, the teeth would be coming in at an angle of appx 30 degrees to the table. There must be something on the internet about these matters. I'm assuming cutting is on downward movement into the table.

Edited By Richard Rogalewski on 23/04/2015 21:39:28

You really want the bottom of the gullet level with the top of your work as a general rule, more so with the slight negative rake of the blade I linked to. So probably about 15mm  projection from the table for your 3mm plate.

A riving knife behind the blade to support the crown guard not only does the obvious job of protecting the blade but should the work try and lift mid cut the bolt where the guard pivots will also limit the amount of lift and save the work getting thrown up at you, the riving knife itself will also help stop the work closing onto teh blade which can happen with metal as well as wood.

Richard, I did change my link to a 160mm blade which is about half teh price of teh 165mm one.

Edited By JasonB on 24/04/2015 07:51:12

Richard,

I think you may be needlessly imposing a large diameter blade ...

Have a look at this design

O.K. you would need to make a spindle, but you could then use small diameter blades from the portable trimsaws.

MichaelG.

Edited By Michael Gilligan on 24/04/2015 09:09:35