Easy Removable Splitter for your Table Saw

[Wayne Davy]

After assembling my new KS-12 Table Saw, I had two problems with the stock Splitter. Firstly, it is next to impossible to align it perfectly with the blade. Secondly, its height/design did not allow my Overhead Guard to function correctly. This is due to the stock ones height which is needed to support the stock Guard. So to solve both these problems, I designed and made a new Splitter as well as changing the mounting assembly at the back of the Saw.

For the new Splitter, I took a piece of plate Aluminium that I had and cut out a new, lower height Knife. To allow my Overhead Guard to lower down, I cut a 'V' in the Knife. I also fashioned it to be as close as possible to the blade when it is fully raised and also cut the front in an arc to match the Saw blade. I also cut some mounting slots in the back section.

For the mounting assembly, I simply lay the existing mounting blocks on their side giving me a level surface. Then I took a piece of 11mm thick angle Aluminium (70 x 55) and cut it to size. I then cut some slots for adjustment as well as drilled 2 initial holes to bolt the Splitter to.

I bolted the lot together and then did the tricky bit. After aligning the Splitter perfectly to the blade, I removed the whole unit but leaving the Splitter part in place on the angle block. I then to the lot to the Drill Press and drilled a third hole through both the Splitter and the Alum Angle. I disassembled the lot and changed the two bolts to become alignment pings bolted to the Alum. Angle and then got a third longer bolt with two nuts and a Tri-Knob. This has become my quick release mechanism and it works a treat.

So, what do you all think??

[Bob Willson]

Now I'll have to make one for myself. Well done Wayne. A great idea

[ozwinner]

Now Wayne, you know there is a vacancy for jig maker, are you putting you hand up? :rolleyes:


Al

[Wayne Davy]

Al,

No, I am not looking to replace Sturdee. Actually, I have been making Jigs/Tools/Improvements for ages (do a search).

Cheers,

[ozwinner]

I know!!! I was just fool'n.


Al

[Wayne Davy]

Bob,

Thanks mate. I have another improvement I have been thinking about in that I will make another longer, lower height Splitter that matches up to closer to the blade for general use. This one is set for the max 12" Blade height (about 110mm cut) which I wont be using all that often. I will probably make one to match the blade at, say, 40-50mm cut which I use more frequently.

Of course, I must then remember to change Splitters if I raise the blade right up. (but I think that will be very obvious).

[Wayne Davy]

I would have liked to have made one like in this link but the 12" blade in my saw takes up to much space. Anyway, check this out for another great idea
http://www.jdwoodworking.com/tools/02tool_splitter.htm

[derekcohen]

Wayne

First of all, well done on a creative idea. It is certainly a MUCH better alternative to no splitter when sawing without a blade guard, as we have to at times.

Secondly, you may recall a relatively recent thread on this topic, one in which we hashed out a few needs, but no one actually built anything. I did have a few ideas that I was keen to put into practice, but got waylaid (as we all do :rolleyes: ) and have yet to construct the thing.

The splitter link you supply is NOT a good design. It is NOT a riving knife. The definition of a RK is that it follows the curve of the blade. As it does so it maintains the same distance from the blade. The splitter in the link will increase its distance to the blade as the blade is lowered. This will increase the likelihood of Kickback.

So while you are in an inventive mood I'd like to see you going into "second phase" with a Riving Knife. The basic need is that the Riving Knife is capable of rising-and-falling with the blade as well as tilting as the blade tilts. Your design, unfortunately, only caters to the latter. But we do have a model for the KS-12, a tablesaw we share. I have included below a picture from the manual of the optional Riving Knife, one that was never offered in Oz. It does call for a different arbour, and this is where the inventiveness is required - what do you fabricate to attach the following?

Regards from Perth

Derek

[Wayne Davy]

Derek,

You are totally correct (as usual) and, as you were posting the above, I was busy editing my posts changing "Riving Knife" to "Splitter". I was posting in a hurry (SHMBO was calling) and I just started typing "Riving Knife". I think I did this as my old saw had a proper Riving Knife.

Anyway, yes, that design looks great. Shame they don't offer it as an option on ours and all other saws of our type. I did have a look at the arbor arm in the saw and was tying to think of an easy way to fit a proper Riving Knife but could not come up with anything easy/quick. So I decided the Splitter mod above was the best bet for the time being (way better than the stock one which I could not get aligned anywhere near straight with the blade).

The main problem with our Saws is the 12" blade - it just does not leave much space at the back of the blade to the edge of the insert hole. Actually, I just measured it and it is 25mm at full blade height - not much space for a Riving Knife. I guess the answer would be to change down to a 10" blade and then have heaps of room but I am not to happy about that option. Is that design for the KS-12 or is it for a 10" saw? I shall give it some thought in anycase.

[Dean]

Nice work again Wayne.
Whats that ZC Insert made out of? Looks like Melamine from the photo?

[Wayne Davy]

Dean,

You are correct, its Melamine coated MDF (not chipboard) - works fine but I do want to make one from UHMW plastic sometime.

[Wayne Davy]

Derek,

Where did you get that parts picture from?? Maybe we could do a bulk order for the parts. I know there are others who have the KS-12 that would probably be interested (depending on cost of course).

[Wayne Davy]

Derek,

I just had another look inside the Saw with the blade fully raised and the gap from the back of the blade to the rear trunnion is only 10mm - much to small for a riving knife I feel. Your thoughts??

[Vasco]

Thank's Wayne for sharing. That is a problem I have been having and now you have given me a fix for it. Only problem is, now I have to make one. :( Your'e not taking orders are you? :D
Regards Vasco

[derekcohen]

Wayne

The parts picture comes from the manual that came with my saw.

I measured the free area at the rear of the 12" blade at exactly 20mm. Allowing for a 5mm distance between blade and Riving Knife, that means the Riving Knife can only be 15mm wide. While that seems really skinny, theoretically I think it could work since the aim is simply to keep the kerf open. Doing so practically, however, is another matter.

One option is to use a 10" blade. But the tablesaw is best set up with a 12" blade since it then can spin at greater speed and this gives greater power. I have used both 10" and 12" blades for years quite happily, so I don't think that too much is lost with a 10" blade. Alternatively, use a 12" blade but do not extend it fully.

It would be ideal to find a solution based on the picture of the Riving Knife I posted earlier. Ideas of others include:

http://www.woodcentral.com/cgi-bin/readarticle.pl?dir=powertools&file=articles_234.shtml

These are more in line with your modification. One that is closer to my goal is:

http://benchmark.20m.com/tools/HammerB3/B3RivingKnife/hammerb3_rivingknife.html

Regards from Perth

Derek

[Wayne Davy]

Derek,

A Riving Knife is definitely the ultimate and I may have thought of a way to do it with the 12" blade rather than going down to a 10". As I mentioned above, the biggest problem is the 10-11mm gap under the table from the blade to the trunnion. This is rather small and is where the mounting block would be but a steel one should have enough strength. I think I will try a mock up in alum as it is easy to work with. If I can get something that works, I'll look at getting a metalwork mate to help fabricate the mount block in steel.

[Wayne Davy]

Thank's Wayne for sharing. That is a problem I have been having and now you have given me a fix for it. Only problem is, now I have to make one. :( Your'e not taking orders are you? :D
Regards Vasco
Vasco,

All you need to make is the Angle Bracket with two slots for adjustment and the holes to mount the stock Splitter/Blade Cover. I had to make a new Splitter as the stock one was too high and interferred with my custom Overhead Blade Guard/Dust Port. I take it you dont have one so you should retain the stock Guard. The angle bracket is the easiest to make but, if you don't like working with metal/alum., take you Splitter to a metalwork shop and I'm sure they would make one up from some steel angle real quick. Should not cost much - (probably way less than the just the postage from Bris to WA for one I could make)

Cheers,

[Vasco]

Wayne,
thank's for the advice, I think that is what I will do for now. I do intend making a saw gaurd like yours when I get some spare time. I saw yours a few months ago and thought that it would be a good mod to make.

this is a mod I made to my on off switch. I find the original is too small and too far to reach especially when you are trying to hold onto a piece of wood after cutting while trying to reach for the switch. I bought the Triton switch from Carbatec they have it as a stock item. Conveniently the KS12 has a couple of bolt holes in the right spot. I find this a much safer way to switch the saw off. I was using a foot switch originally however I found that I would often double click the switch by mistake so swapped over to this method.
Regards Vasco.

[Wayne Davy]

Vasco,

Yes, moving the switch is something I want to do as well. I'm actually going to swap the Magnetic NVR Switch from my Cyclone Motor over to the Table Saw and put the standard switch from the TS on the Cyclone. Make life a lot easier for both machines. Currently, I have to reach up to the Blower Switch to turn on the Cyclone which is quite a pain. Changing the switches will allow me to position the standard switch in a more convenient position.

[DPB]

Thanks, Vasco.

That will be my next improvement to my table saw.

[DPB]

Wayne, did you look at this one?

http://www.rockler.com/findit.cfm?page=10889&sid=AFD15

[journeyman Mick]

I've got no splitter or guard on my TS at all (bought 2ndhand at auction) and was wondering if one of you gents could take some photos of the back of your saw to show how they mount. I've got a generic 12" TS which has "Mao Shan" cast into the rear trunnion. Thanks in advance.

Mick

[Wayne Davy]

Mick,

Download the Grizzly Contractors Saw manual (any one) and you will get a full parts diagram showing all the bits as well as some good pictures of the mount.

This is a direct link:
http://images.grizzly.com/grizzlycom/manuals/g1022prom.pdf?

Cheers,

[Wayne Davy]

Wayne, did you look at this one?

http://www.rockler.com/findit.cfm?page=10889&sid=AFD15
DPB,

Yep mate, I did. Those type are even worse as they don't even tilt with the blade.

[journeyman Mick]

Thanks Wayne!

Mick

[Bob Willson]

I was just thinking. OUCH!

Is there any reason why a splitter has to be longer than it is thick? I mean, the saw blade is 3.2 mm thick, whu do we need a splitter that is 25mm long? Wouldn't a 3.2 mm post do just as well?

[derekcohen]

Bob

A splitter does not need to be "longer than it is thick". There is no "recipe", per se, as far as I am aware. The job of the splitter to to keep the kerf open and thereby prevent the timber being cut from binding on itself. In other words, to prevent the kickback that occurs when binding takes place. There are different ways to achieve this, some better, some worse. But basically we are just tring the keep the kerf open, and this may not occur if the splitter is too low, too skinny, or too far from the blade (the latter is the argument for a riving knife).

Regards from Perth

Derek

[bitingmidge]

October 2001 FWW had "Methods of work" snip on making a splitter out of a broken drill bit, together with a justification for it. The whole thing is quite a small file size, attached picture gives the gist.

As always the quality of he attachement is pooey, because I'm trying to keep the file size to a minimum.

If you want more/better send me a PM!

Cheers,

P

[Bob Willson]

Been working on our avatar have we biting? Just a touch too much gold there for a little midge isn't it? :)

[MrFixIt]

Hi Wayne
Dean,

You are correct, its Melamine coated MDF (not chipboard) - works fine but I do want to make one from UHMW plastic sometime.

Why?

[Wayne Davy]

Hi Wayne

Why?
Why not!! :D


Seriously, the reason is that it will be way more solid. After cutting out the areas under the insert to fit on the insert supports, the mdf one is a bit thin in places. It will probably last for quite a while but I have some UHMW the right size so I will cut one out sometime. This stuff is really strong and will probably last for years and years I think.

Cheers,

[MrFixIt]

Hi
Seriously, the reason is that it will be way more solid. After cutting out the areas under the insert to fit on the insert supports, the mdf one is a bit thin in places. It will probably last for quite a while but I have some UHMW the right size so I will cut one out sometime. This stuff is really strong and will probably last for years and years I think. Cheers,
I guess those reasons are good enough :D

I would have thought though, that even the "thinner parts" of the mdf insert would still be strong enough, after all there is usually not much (if any) weight on the insert inself.

[Wayne Davy]

All (particularly Derek),

Ok, I have giving this some thought and after looking around inside the KS-12, I think I have a possible way of mounting a proper Riving Knife to the Arbor support arm. Check out the attached (badly drawn) pic's. The first pic shows the stock Trunnions and Arbor support arm so that you can see what is behind my modification shown in the second pic.

Questions - Comments (good, bad or otherwise - only way to learn)

[bitingmidge]

Been working on our avatar have we biting? Just a touch too much gold there for a little midge isn't it?

Just my personal one-day protest against flashing avatars!!
:D :D :D

P

[derekcohen]

Wayne

That is excellent!

The one addition I would make would be to design for an adjustable riving knife, both in the vertical and horizontal planes. This will enable the unit to be set more accurately (in line with the blade, and at the correct height, distance).

Other factors to consider: (1) thickness of steel (preferred over aluminium) is same thickness as blade (2) how to attach the unit to the Arbor support (I had developed a very similar concept to yours, and where I got stuck was my unhappiness with drilling and tapping the iron Arbor).

Regards from Perth

Derek

[Wayne Davy]

Derek,

Thanks! I was the same - did not want to go drilling into the Arbor arm hence the bracket that goes around the arbor arm. This will be made a tight, slightly undersize fit so that some bolts will pull it in tight onto the Arbor Arm. I really feel it will be quite solid if its done right.

Yes, I do intend to make the Riving Knife a separate component to the plate and also make it fully adjustable - no point doing all this if it cannot be aligned perfectly to the blade.

I am going to make up a prototype in Alum. over the coming weeks (I hope) and see how it goes. Once I get that right, I'll look at what needs to be make from steel. Actually, I am thinking that if I put a brace bar on the back of the support plate, aluminium may be fine. Just have to see I guess.

[Wayne Davy]

Thought I might expand out the design idea a bit.

The Support Plate will be quite large - 150mm high and about 300mm long. The reason for this is the very small gap from the blade to the rear Tunnion which is only 10 to 11mm. Making the plate large should give it lots of rigidity as well as giving me some 'meat' to attach the actual Riving Knife. Also, the Support Plate needs to have a 'kink' in the end to get around a raised area on the cast rear tunnion and also bring the support into rough alignment with the blade. I am also going to put a square tube brace on the back of the Support Plate to help stiffen it (now, now, no rude comments guys).

As for the Riving Knife, it will also be quite long and tapered with the bottom section only about 8mm wide but increasing as clearance to the blade allows. Something like 20mm at the top of the insert and about 70 mm at the top. To make this nice and ridgid, I intend to thicken up the slender section under the table with several pieces forming a metal sandwich which will be bolted to the Support plate.

Now, owing to the small clearance, making the Riving Knife section fully adjustable in/out, up/down and tilt is now the main challenge. I am actually thinking of making some of the adjustments back at the Arbor support connection but I'm not sure yet. The goal will be to make the thing so that any adjustment needed is only minor.

That's all I can think of at the moment (comments, ideas please)

[Bob Willson]

Just my personal one-day protest against flashing avatars!! Wot? Youse doesn't want me to change MY avatar does youse? :cool: