Replacing a splitter with a riving knife

[Oaktree11]

Hi all. Continuing the saga of my new/old table saw, it has a splitter not a riving knife. It is hateful. Now I have the saw all cleaned and in pieces seems the ideal time to rectify this and fortunately, I found a YouTube vid of someone doing just that to what appears to be a similar saw. See here:

The issue is that because of the nature of the rise and fall mechanism this riving knife will only come into play when the blade height is 40 or 50mm. I suppose it’s not that big an issue really.
A pic of my saw is attached and you will see it’s nearly identical to the one in the video.
I would appreciate any comments about this and whether you think it’s worthwhile.
thanks John

 

[Orraloon]

Its better than running without a splitter or knife. My saw is an oldish Delta with a splitter that also holds the guard and it is a pain having to take it off and on again. I do take the time to put it back every time but life would be so much easier with a rise and fall knife. As there is a bit of blade height above the knife at the lower end just be sure there is enough knife height for the workpiece being cut. For shallow trenching cuts (non through cuts) kickback would be unlikely and you would be doing it with no knife or splitter with the old setup. I take it you will be making up an overhead arm arrangement to hang a blade guard from.
I have sometimes pondered how it could be done so thanks for the video. If I ever have it all apart I may be tempted to give it a go.
Regards
John

 

[Oaktree11]

Its better than running without a splitter or knife. My saw is an oldish Delta with a splitter that also holds the guard and it is a pain having to take it off and on again. I do take the time to put it back every time but life would be so much easier with a rise and fall knife. As there is a bit of blade height above the knife at the lower end just be sure there is enough knife height for the workpiece being cut. For shallow trenching cuts (non through cuts) kickback would be unlikely and you would be doing it with no knife or splitter with the old setup. I take it you will be making up an overhead arm arrangement to hang a blade guard from.
I have sometimes pondered how it could be done so thanks for the video. If I ever have it all apart I may be tempted to give it a go.
Regards
John

Well, I agree with what you say. Yes I will deal with the blade guard later but that’s easy compare to the riving knife!
I have made a start and it looks ok. I have mocked up a prototype in cardboard. Bear in mind in the pics and vid that the saw is upside down. I will have to reshape the riving knife (it’s too high) but overall it looks good.
the plate that the riving knife will bolt to will be in 8mm plate. Need to find some…
also ignore the cardboard stiffeners on the back!
not sure if the vid will load - sorry

 

[Oaktree11]

Ok. I have. Moved on and made a ply template. I thicknessed it down to 6mm and I reckon that’s about right for the steel. I have glued it on and it works really well. Now to get some 6mm plate.

 

[Oaktree11]

More progress. I am loosely following the video. I am using 6mm plate. It’s plenty thick and stiff enough and leaves about a 1mm gap between it and the blade. I can space the riving knife appropriately.
I cut the clearance hole for the arbor then cut the shape out. I was going to go all 8mm set screws but after I put the first in I was worried about weakening the casting so I opted for 6mm for the other(s). I may just fit one as shown.With the 8mm and 6mm tight this is rock solid. I don’t think I will use the third one. It hardly a highly stressed item. I will threadlock the bolts though. i would be interested in what others think.
Next step is to design the riving knife. I am waiting for some 2mm plate. Thicker than the blade body but less than the kerf.

sorry, I have messed the photos up and there are lots of repeats - I am going to leave it unless I make it worse…
Mod Edit- images tidied up.

John

 

[TominDales]

Looking at the video, I wonder if you could shape the knife to curve more round the blade so that the knife would appear at or close to 0mm thinckness as I feel there is still a kickback risk with thinner wood. The knife would then be proud of the saw for thicker boards which would make through housings impossible - if you use the saw for housings. You could potentially have two holes, one for thin an done for thick boards? Just a thought.

 

[Oaktree11]

Looking at the video, I wonder if you could shape the knife to curve more round the blade so that the knife would appear at or close to 0mm thinckness as I feel there is still a kickback risk with thinner wood. The knife would then be proud of the saw for thicker boards which would make through housings impossible - if you use the saw for housings. You could potentially have two holes, one for thin an done for thick boards? Just a thought.

Yes, I am going to experiment with some cardboard/wooden mock-ups before I cut steel! I will try different lengths etc. I can’t quite get my head around it with the saw upside down! I can assemble the saw fully now. I have put two threaded holes in the end of the carrier now to mount the riving knife on so it will be easy to change.

 

[TominDales]

Its worth a try. Table saws scare me, so I'd vote for a good riving knife. As for a guard. I've suspended one from the ceiling rafters, it works pretty well as long as you dont move the saw. Alternatively you need to put a post on the corner of the TS and hand a guard from that. I've seen some quite good pictures on the net of Us guys making them. They like to use their TS for all sorts of cuts we wouldn't do in the UK, that need a guard that is easy to move out of the way.
I wish I had a TS of the quality of the one you have pitutured. I scrape by with a cheap Eihell that I've spent far too much time truing and strengthening up.

 

[heimlaga]

There is a chap in Sweden who developed a very good riving knife with paralelogram movement for the Wadkin Bursgreen 10" AGS. Maybe something could be made along those lines.

 

[Oaktree11]

There is a chap in Sweden who developed a very good riving knife with paralelogram movement for the Wadkin Bursgreen 10" AGS. Maybe something could be made along those lines.

now that is a good thought, thank you Heimlaga. I will try to find some more information on that. Any idea where to look?
john

 

[Oaktree11]

Update! I found the site I think you are referring to here: Verktyg, Maskiner & Fordon
all in Swedish but will persevere! Thank you again for the hint. John

now that is a good thought, thank you Heimlaga. I will try to find some more information on that. Any idea where to look?
john

 

[heimlaga]

Update! I found the site I think you are referring to here: Verktyg, Maskiner & Fordon
all in Swedish but will persevere! Thank you again for the hint. John

Aye there it is.
Send the inventor a message if you have questions to ask. If I remember correctly he is fluent in English.

 

[Oaktree11]

There is another video here with the same idea. It’s beautiful but I thinks it’s beyond my skill level to produce though I would consider having one made.
I now have the 2mm plate for the simple riving knife. I think I can live with the blade being higher than normal on thinner material to get the benefit of the riving knife.

 

[Oaktree11]

There is another video here with the same idea. It’s beautiful but I thinks it’s beyond my skill level to produce though I would consider having one made.
I now have the 2mm plate for the simple riving knife. I think I can live with the blade being higher than normal on thinner material to get the benefit of the riving knife.

 

[Oaktree11]

Ok well I have made the riving knife and it works really well. Clearly, it does not come into effect unless the blade height is about 35mm but that’s not an issue for me. Won’t affect cutting rebates and I will remove it when/if I fit a dado stack which this arbor will take. Still needs tidying but it’s nearly there
John
not sure if the vid will work - it doesnt for me

 

[Orraloon]

Congratulations on getting it working. Not seeing the video but a couple of picks would do.
Regards
John

 

[Oaktree11]

Congratulations on getting it working. Not seeing the video but a couple of picks would do.
Regards
John

Thank you … sorry about the vid, I will try again and post some pics later this morning!

 

[Oaktree11]

Just going to try the vid again

 

[Orraloon]

Only getting the sound track. Think its winding the blade up and a background dog barking.
Perhaps put it on youtube and put up the link.
Regards
John

 

[Oaktree11]

Only getting the sound track. Think its winding the blade up and a background dog barking.
Perhaps put it on youtube and put up the link.
Regards
John

Damn, this time the vid worked fir me but obviously not for others…thought I had cracked it! I will post some pics! Thanks for letting me know. John