Is this table saw lathe jig safe?

15

I recently saw a video on how to build a jig for turning stock on a table saw. It seemed unsafe to me, as the motorized jig was advancing stock sideways into the rotating saw blade.

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This seems like a very useful technique, but I'm primarily concerned about the safety aspects of it. Although from what I understand, cove cutting using a table saw is a generally accepted practice, which seems fairly similar.

Doresoom

Posted 2015-03-17T17:52:47.897

Reputation: 3 118

I would disagree, but brought it up in Meta.

– FreeMan – 2015-03-17T19:02:53.950

4I've also wondered about the safety of this jig, but I would feel a lot more comfortable with it if it had a polycarbonate shield covering the entire top (just in case the spindle explodes) and if there were solid, dedicated hand grips well outside the blade's path. – rob – 2015-03-18T15:18:58.003

The roughly-equivalent jig for a router is safer and more versatile. – keshlam – 2016-05-14T18:10:33.747

1Not sure if this is entirely on topic, since I suppose the safety aspects of it may be a little subjective. Although potential answers could provide definitive reasons why it's unsafe. – Doresoom – 2015-03-17T17:54:18.383

Answers

11

I think the word 'safe' here might be relative. Just like modern cars are safe, when driven on the road, and obeying traffic laws. I think in this case the answer is a profound NO.

Table saws are 'safe' when used for cutting wood that is against the table, and the stop, preferably using push sticks and a riving knife. I see none of those things going on here.

I've seen lots of people do things not as the tools was intended without getting hurt, but most of those same people have stories about nearly losing a finger, or having a piece of lumber being tossed across the workshop. Why take that risk, when there is a perfectly good tool designed to turn wood?

BrownRedHawk

Posted 2015-03-17T17:52:47.897

Reputation: 1 636

1Excellent point about the workpiece being suspended above the table. Something I hadn't considered. – Doresoom – 2015-03-17T18:56:22.473

Also, even though the piece is turning relatively slow compared to the saw blade, you're not using the intended direction of the saw's tooth to make the cut against the wood. Even cutting coping on a table saw is rough on the blade, now imagine how rough this must be. – BrownRedHawk – 2015-03-17T18:58:22.667

3lateral stress on the saw blade (for which it is not designed) plus a material that has knots and possible internal stresses (i.e. branches) plus the above mentioned - it doesn't leave me feeling warm and fuzzy – ewm – 2015-03-18T14:10:13.227

9

I think my biggest concern is that I don't have a good feel for how this system will behave. When I'm about to perform some action with a power tool, it's very deliberate, and I've thought through the type of bad outcomes that might result. For example (not a complete list by any stretch)

  • Table saw: Kick back
  • Miter saw: blade binding
  • Band saw: blade breaks and spools out across the table
  • Drill press: bit binds, spins work piece
  • etc.

Knowing this, I can anticipate problems and mitigate them. I place my body a certain way with respect to the tool, I hold the piece or tool in a certain way, use additional clamps, finger boards, etc. as appropriate.

I just don't have a good feel for how this thing is going to behave when something goes wrong, or even which ways it could go wrong. It looks like it works very well, but I'd be damn careful with it.

CoAstroGeek

Posted 2015-03-17T17:52:47.897

Reputation: 336

2

Well, aside from the addition of the cordless drill to turn the stock, how is this different from cutting cove with a tablesaw? That's a time honored technique where the stock is pushed on a vector against the side of the blade.

I think the devil is in the build. The strength of the same jig design will always be dependent upon materials, fit, build and technique in use. The user in this case is careful to make several low degree passes before he gets to the product he desires - that also mirrors the technique for making cove.

I might also quibble over the ergonomics: I think the critiques made here are spot on because I also would like to see features that move the woodworker's hands further away from the blade, but then I didn't see his hands anywhere near the blade, so maybe I'm wrong.

If the jig is built well and used with the caution we should always employ, it seems very practicable.

KRS

Posted 2015-03-17T17:52:47.897

Reputation: 21