Riving knife for Wadkin table saw

[brewdexta]

I have a surfeit of table saws, I currently have 4! Two really old ones awaiting renovation, a Wadkin AGS12 that I am using, and a Wadkin AGS10 that I've converted to single phase to sell.

Problem is that the riving knife that came with it was for an AGS12, which is fortunate as I needed one for mine, but it does leave a space between the table and the blade guard that needs filling

New they are about 85 quid plus VAT and delivery, and there's not much to them. I'm having difficulty getting a bit of springy steel, mild steel it too bendy, to make one.

The pic below shows what it should look like, I've added dimensions gleaned from threads on other sites. I've looked through my stock of steel and I've nothing the right dimensions and type, and I've looked on ebay, can't seem to find the right material and thickness.

It can vary a little, so 2.5mm would probably be fine, it depends on the blade used. The idea is that its wider than the blade to stop the blade being pinched, but less than the kerf so the timber doesn't get wedged on the riving knife. The original is 2.4mm.

I've looked at old stihl saw blades, too thin, but the right kind of material, all my other stuff is far too thick or mild steel. Anybody got any suggestions for donor material? I may be able to get a big old blade off a rip saw if I look around I guess, it may mean a trip to a scrap yard, not many good ones about now

Cheers
Andy

 

[julianf]

I can't answer your actual questions, but I have an ags10 knife here (that I need) if you need any measurements from it.

 

[brewdexta]

I can't answer your actual questions, but I have an ags10 knife here (that I need) if you need any measurements from it.

If you could confirm the dimensions that would be great, and a pic would be a bonus

There have been a few changes in design over the years so there may be a few differences.

Cheers
Andy

 

[bigegg]

i've got a few circular saw blades here.
if i have one the correct thickness, you are welcome to it.

 

[bigegg]

ps.
would a piece of 2.4mm plexiglass work?
or even plywood?

 

[brewdexta]

It would be a bit flimsy at 2.5mm thick with an alloy blade guard sat on top. An old blade may well do it, especially as the dimensions I have cover 10 to 12" saws, and mines 10" so can probably be shorter. Anything around 2.5mm would do it unless Julian's measurements prove otherwise.

 

[frank horton]

think I'd try a piece of st/steel seems a bit tougher than sheet m/steel....
on my wadkin Q? spindle moulder I made some springy plates from heavy brass sheet...
these kept the wood tight against the back stop...
mind the cost of brass may almost equal the cost of the correct part...
the only sort of thin material of the type u require easily found would be from the working end of a decent builders shovel....cheap to buy and bin the rest...would need a bend to flatten it perhaps...
do it cold unless u can re-temper....
just an idea

 

[brewdexta]

That's a possibility, I'll have a walk through my farmer neighbours yard

 

[zzr1200]

Brew, l have a piece of 316 stainless (14g/2mm) that I could cut to your size/shape at work as my plasma cutter is here. If your down Sheffield way give me a call or pm.

I could try and find/get a bit of 2,4mm if you want....

zzr

 

[brewdexta]

Thanks!

I think 2mm will be less than the width of the blade so too thin.

When I get back home from London I'm going to have another look around the area and see if I can spot something suitable first.

Neighbouring farm is first port of call...

Cheers
Andy

 

[zzr1200]

Brew, I presume your in Basvagas, I'm on way down to Essex tomorrow, back up Monday.

I'll try and get over to Twiggs in Matlock next week if you can't find a suitable bit of stainless..if you want me to.

Do you still have my phone number???

 

[Bladevane]

How about getting a used saw blade and get a friendly forum user to cut out the riving knife on his/her CNC plasma machine?

 

[brewdexta]

Brew, I presume your in Basvagas, I'm on way down to Essex tomorrow, back up Monday.

I'll try and get over to Twiggs in Matlock next week if you can't find a suitable bit of stainless..if you want me to.

Do you still have my phone number???

I was in the city, I only go to Bas Vegas when absolutely necessary On my way home now. Don't worry about the SS, I have a couple of local leads now, but thanks for offering!

 

[brewdexta]

How about getting a used saw blade and get a friendly forum user to cut out the riving knife on his/her CNC plasma machine?

I've got a plasma, cutting isn't the issue, just getting some circa 2.5mm springy plate/sheet etc. I have a couple of local leads that I will explore when I get back this evening. Probably cost me a couple of beer tokens, but I have a few crates of home brew so not an issue

 

[brewdexta]

I measured the blade thickness and the kerf this morning. The blade is 2mm thick and the kerf 2.8mm so around 2.5mm is fine. The OEM is 2.4mm. I found a bit of 2.5mm stainless sheet offcut on the bay of thieves which should do it, I will have a bit left over for other stuff too, always comes in handy

I did try earlier in the week and nothing came up at 2.5mm, seemed to be out of stock. I was going to try the local scrappy but he's an Olympic standard talker, and I've got the compressor service this morning. Another option was a spring steel 3D printer base plate, unfortunately they all seem to come in at 3mm which is too thick.


Cheers
Andy

 

[brewdexta]

After mending the casting that holds the riving knife, I got on with making the knife. The knife that came with it was the wrong one, too big, it turns out its for the next size up AGS12 model. Which is good as I needed a knife for that too. It has one but it's been cut down for sled/rebate work so you can't put a crown guard on top. Here's the wrong knife with the right crown guard, you can see where they have clumsily cut a slot for the clamp, and haven't radiused it so the clamp gets jammed.

So cut out a ply template from the cardboard one

Making sure it is slightly small to take into account the radius of the plasma cutter tip

Then cut a couple out, JulianF wanted one too and I had just enough stainless.

I got the template shown on the right of the above picture, from a woodworking forum, but I suspect the top slot is not exactly what is needed, at least on the crown guard I have. There is a notch at the back of the riving knife that fits into a pin at the back of the crown guard.

Next I need a spacer to sit between knife and the clamp. I found this piece of brass in the scrap box, almost perfect, one half already tapped M10 that will bolt to the knife, the other I tapped M8 for the clamp.

Here's the spacer set up on the new riving knife in the crown guard. The spacer may be a tad too long, but I can adjust that when I get it fitted.

Here's how it looks before getting a star knob for the clamp. I need to sharpen the knife a bit more and get a cleaner radius, but stainless is a bit of a pig to work so it's mainly grinder work.

The bolts are just M10 coach bolts with a bit welded on to enlarge the square under the head to stop them spinning in the slots. Although I ground as much of the galv off that I could, I still had a fan going and didn't hang around in the workshop between welding bolts.

to be continued

 

[brewdexta]

Here's the knife being fitted, first the bolts, as you can see there's not much head room. The bolts from AMS et al are about 30 quid including VAT each, and you need two, so coach bolts and a bit of weld are a good budget alternative.

Here's a temporary spacer being fitted to find the centre of the blade. Ideally the main spaced should be slightly on the shy side, or just enough to centre on the thinnest blade likely to be used so that shims can be added to centre on a fatter blade. In reality I doubt if anybody does that Anyway, 5mm seems to centre the knife on the existing blade so I'll find a bit of 5mm steel and cut a slot in it.

Here's the knife fitted, looks OK, next test is to see if the blade rises and falls ok

Doh!, knife too long and hits the washer of the bolt below. No big deal, it can be shortened

Which leads me to think the riving knife pattern is wrong, at least for the AGS of this age, there are quite a few versions knocking about. The one sold by AMS is the same pattern, and 85 quid. So if you bought the knife for 85 quid plus VAT, and the bolts for 29 + VAT each and the washers at 10 quid plus VAT, you would be parting with 195 quid and still be short of the nuts and would have to modify the knife

Last episode once I've cut the spacer and the cropped the knife.

cheers
Andy

 

[brewdexta]

I got around to making the spacer for the riving knife today, I had to wait for a bit of 5mm steel. Carp photo warning.

I trimmed a bit off the riving knife so it doesn't clash with the rise and fall mechanism, bolted it together and it looks OK, it isn't going to win any beauty competitions but its safe.

And with the guard on. The slots in the riving knife didn't need to be so big, unless you are using really small blades, which isn't recommended.

Just need to put the cast table top back on. Last job is to finish off the electrics then I can sell it and reclaim the space for the new bar area in the barn

Cheers
Andy

 

[mechman]

I got around to making the spacer for the riving knife today, I had to wait for a bit of 5mm steel. Carp photo warning.

View attachment 188148

I trimmed a bit off the riving knife so it doesn't clash with the rise and fall mechanism, bolted it together and it looks OK, it isn't going to win any beauty competitions but its safe.

View attachment 188149

And with the guard on. The slots in the riving knife didn't need to be so big, unless you are using really small blades, which isn't recommended.

View attachment 188150

Just need to put the cast table top back on. Last job is to finish off the electrics then I can sell it and reclaim the space for the new bar area in the barn

Cheers
Andy

Now your talking.