Sciencemadness Discussion Board

Combining multiple saw blades to make 1/2 - 3/4" width cutting width - possible?

RogueRose - 14-5-2016 at 17:10

This is a theoretical custmom setup where a specific width needs to be cut in boards at a specific depth. The table saw can accomidate the width of many blades together and has height adjustment.

I know a router can be used for something similar, but that isn't an option for this application.

If I stacked 4-8 blades together to get correct width and put them on the drive axel, would that be a problem? I think drilling a few holes (3-6) through the stack and bolting them together so all the teeth are aligned would be workable.

So once the blades are stacked and bolted together, is there any reason why this setup wouldn't work assuming the motor had enough power to cut the material?

Given that all the blades are identical and there isn't R/L stagger between blades allowing them to lie flat, should all the teeth be aligned together?

If there is R/L stagger (say blade is 4mm and each tooth is off-set 1mm R or L, alternating, would staggering the teeth every other blade work as well (so each blade is turned 1/2 distance to next blade so they don't push against each other if stacked directly against each other).

dado set

CharlieA - 14-5-2016 at 17:47

What you need is an 8" dado set with the same size mounting hole as the arbor on your saw. For example: http://www.lowes.com/pd_75071-281-1811865_0__?productId=3712...

If this is a one-shot deal you may be able to find a cheaper "wobble type" dado, but this is not recommended for frequent use. If the groove is one you need to cut a lot of, always the same size, you could try using router bit, if the size you need is available and you have a router.

Buying a bunch of saw blades, as you mentioned, is probably not cheaper (bolting them together wouldn't be necessary). With a dado set, you can set the width you desire within 0.001".

Happy woodworking, from a frustrated woodworker!
Charlie

Dr.Bob - 14-5-2016 at 17:48

This is how a dado blade works, most have two normal circular blades and then some simpler blades between them, often with only a few teeth each. You don't need to bolt them together, if they are simply held in together tightly with the normal nut to hold the blade.

Normally, you stagger the blades, which allows the blades to sit tightly together.

BromicAcid - 14-5-2016 at 17:57

You could always use a single blade and just adjust the fence fractionally between cuts to do multiple passes. I guess technically you could put multiple blades on your drive axle but I would be very reluctant to try to bolt them together due to the potential for the bolts to off-balance the blades which is always a scary occurrence. I think if you tightened them down enough the compressive force would be enough to get the blades to spin together and you wouldn't need to bolt them but it's not an ideal solution. As mentioned above a dado would be preferable. Then again you could use the blade to cut each side of your grove then go in with a chisel.

Fulmen - 14-5-2016 at 18:27

Should work. I agree that bolting them would be a bad idea, not only can they be a PITA to machine but they would get imbalanced for sure. Teeth alignment shouldn't be an issue, if anything a staggered setup should give a smoother cutting action.

XeonTheMGPony - 14-5-2016 at 20:54

As others said it works, but needs a slower feed rate and tends to ruff cut, use max cuation and safety, best safest option is a router.

diddi - 14-5-2016 at 23:07

get a router an attach it to your saw bench so you have a fence to guide everything properly

Bert - 15-5-2016 at 04:40

Describe the cross section of the groove you want to cut, and the finish requirement-

Stacked or wobble Dado would be my choice from the rather limited description of what you are trying to do.

Eosin Y again - 15-5-2016 at 04:51

The dado blade would work better than a number bolted together.

Bert, an explanation please? U2U me.

BromicAcid - 15-5-2016 at 05:52

Quote: Originally posted by diddi  
get a router an attach it to your saw bench so you have a fence to guide everything properly


I would say this depends, the original poster did not mention the type of wood or the depth of the cut. A hard wood like maple and a deep cut (>1/8") at 3/4" width is going to tax a router to do in one pass which of course means multiple passes. Then it comes down to the tolerance that the OP wants, when I have a long sheet of wood and need multiple passes it turns into a pain in the butt to try to either shim the wood up while traveling or lifting it by hand as it's fed along the fence which can cause issues. My own router table only will work on things 18" or less from the edge, if RogueRose is trying to put these cuts somewhere in the middle section of a 4x8 sheet of plywood* then they would be out of luck in my setup using a router.

What I am saying is that it is an option, as is the dado but either one has positives and negatives. Personally for me, I prefer the table saw for a deep precision groove.

* = Usually try to put things into international units but on this post I was putting things in inches because I am used to that for woodworking, weird how the brain compatmentalizes. Anyway, the plywood is 4 x 8 feet in size, is that the international standard? Are sheets of plywood in Europe 1.22 x 2.44 meters?

ELRIC - 15-5-2016 at 07:32

According to Wikipedia, yes, that is a standard size in most of Europe, along with

10 ft. X 5 ft. I found that to be kinda odd myself. Has anyone here ever seen any

plywood that size? I sure haven't, and can say with a high % of certainty that I have

handled more plywood than anyone on the forum ;)


And, I second the dado blade

[Edited on 15-5-2016 by ELRIC]

[Edited on 15-5-2016 by ELRIC]

CharlieA - 16-5-2016 at 05:55

If you have just 1 or 2 dados to cut, I'd go with Bromic's suggestion to use the single saw blade and just readjust the fence. Of course, you can always go the old fashioned way with chisels!:)