Is kickback an issue with miniature tablesaws? (100-250W)

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charangohabsburg
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Is kickback an issue with miniature tablesaws? (100-250W)

Post by charangohabsburg » Fri Sep 12, 2014 6:05 am

Not that I would need a small tablesaw, but for some cuts it would be nice to have one...

I own an old Emco Unimat which I can convert into 1001 different "stationary" dwarf power tools. It has a splitter at about 30mm behind the blade, so I assume this is not really thought to prevent kickback but rather to simply hold the blade guard.

Would it be smart to keep this item in museum condition instead of using it or am I overestimating the danger of kickback on such a small saw? (90mm diameter blade, 100 Watt motor).

I have no intentions of tweaking the saw because adjusting it is a hassle, so it would not be worth the modification effort. But maybe I would look for another miniature tablesaw that would be safer to use, or at least would be worth a modification.

Any thoughts on this?
Markus

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by Allen » Fri Sep 12, 2014 6:12 am

Kick back is caused by a fence that isn't set up correctly, and wood that starts to pinch the blade as tension is released during the cut. So you're splitter is taking care of one, and the fence should be adjustable.

You can also add feather boards to hold down the work piece for added safety.

As well, with such a small blade, you aren't going to have the tip speed of a larger saw.
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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by charangohabsburg » Fri Sep 12, 2014 9:17 am

Thank you Allen.
The fence of my saw is not adjustable but it is absolutely square to the groove in the table where it runs in, but I have to set the whole table right in order this groove will be square to the blade... You guess what kind of pioneering hobbyist piece of machinery this was 40 years ago.

I had a look at the numbers and it turns out that the linear speed of my saw's blade teeth is about five times slower than that of a 10" table saw (recommended speed for my saw is only 1600 rpm). Five times less speed means 25 times less kinetic energy in a piece of wood of the same size being kicked back in a perfect manner. So I think I'll give it a shot. :)
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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by simso » Fri Sep 12, 2014 9:21 am

Any kickback is dangerous, regardless of the saw power, IMO less powerful items become more dangerous because we push them to the limit and have a tendency to get careless because we get frustrated with them.

But yes you can get kickback on a small saw, and yes it can still take your fingers off.
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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by Kamusur » Fri Sep 12, 2014 9:54 am

Did some calcs concerning a mates Casadei combo machine fitted with a 12inch blade and if he gave me the correct axle speed the tip of the teeth travel at about 160mph and i would hate to be hit in the eye with even an insect at that speed.
So far Ive only managed to launch 1/2 a sheet of ply back a metre or so......
Obviously a lot more power than Marcus is mentioning but still a timely reminder.." take care everyone.

Steve

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by kiwigeo » Fri Sep 12, 2014 11:31 am

I thought I had the balls to run a piece of MDF through my 10" table saw with the splitter off. Afterwards I still had balls but they were &&&^^%%ng sore balls!!! Dumbest thing Ive done for a while....

:shock:
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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by Kim » Fri Sep 12, 2014 3:47 pm

kiwigeo wrote:I thought I had the balls to run a piece of MDF through my 10" table saw with the splitter off. Afterwards I still had balls but they were &&&^^%%ng sore balls!!! Dumbest thing Ive done for a while....

:shock:
Maybe best to opt for castration Marty...that'll fixit for ya... B.T.W. If you go ahead with the idea you would of course become known as "The eunuch with the Unisaw" :D

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by Strings » Fri Sep 12, 2014 4:43 pm

my advice is never EVER use a table saw without a riving knife.
personal experience about ten years ago... my boss had taken the knife off to kerf some mdf for a job as the knife sat higher than the blade and didn't put it back on. the following day i saw the knife wasn't in but used the saw anyway thinking that with my experience i would be fine. anyhoo... was pulling the carriage back when my pinky or the material touched the blade and my hand ended on top of a 96 tooth saw blade at 4000rpm.. luckily the extraction guard was sitting high so i was able to lift my hand off the blade instantly screaming the F word and cradling my hand ..It is the worst feeling to look at your fingers and try to move them but not have them move. there is more to the saga but in summary flip flop ring, middle and index finger severed on an angle thru the primary knuckle but the nice doctor put them back on although one of them is crooked.... can post a pic if you like but its a bit gruesome
just to share :wink:

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by demonx » Fri Sep 12, 2014 4:52 pm

Strings wrote:my advice is never EVER use a table saw without a riving knife.
Something I've never taken off my table saw and don't plan to. It is there for a reason!

Even with this I have had the odd kickback, if you use something often enough it'll happen eventually, but it's best not to help it happen.

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by colburge » Fri Sep 12, 2014 4:58 pm

Hey

Scares the shit out of you when it happens, and you only do it once. Same goes for the router table, damn near took my thumb off last weekend, I was lucky it only routed my thumbnail off.

Col

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by demonx » Fri Sep 12, 2014 5:05 pm

Push blocks. Buy push blocks! Plastic is cheaper than flesh.

I have a couple different types I use for the router table, band saw (when resawing) and the table saw

The one I use for the table and band saw has a 90 degree hook on it so I can continue to put pressure against the fence as well as push the timber towards the blade, but always keep my hands away

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by Kim » Fri Sep 12, 2014 5:37 pm

I use a couple of pig trotters as push blocks on all of my static machinery. Shit yeah it makes a bloody mess, but so far it appears I have them all fooled. 8)

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by colburge » Fri Sep 12, 2014 5:41 pm

I use frozen hot dogs as push sticks, they fit in my hand comfortably.

Col

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by kiwigeo » Fri Sep 12, 2014 6:01 pm

colburge wrote:I use frozen hot dogs as push sticks, they fit in my hand comfortably.

Col
I guess after you've used them they become battered hotdogs
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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by colburge » Fri Sep 12, 2014 6:16 pm

Skinless franks?

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by charangohabsburg » Sat Sep 13, 2014 11:42 am

Strings wrote:my advice is never EVER use a table saw without a riving knife.
personal experience about ten years ago...
I feel sorry what happened to you. Thanks for the reminder!

However, it was never my point to suggest to not use a riving knife or splitter.
One problem I see with my miniature saw is the distance of the splitter from the blade which I thing would be unacceptable for a bigger saw, and maybe is so for a miniature saw too.
2014_P7700_2020-1.jpg
2014_P7700_2020-1.jpg (89.25 KiB) Viewed 21934 times
In any case, as Allen pointed out the linear speed of the saw tips is considerably less on a 4" blade than on a 10" or 12" blade. On my saw, the tip velocity at the recommended low speed of 1600 RPM would be less than 30 km/h.

Last evening I was assembling that saw, and there are many details that I dislike. A proper setup which has to be done every time I would use it after having it stuffed away, takes at least 30 minutes, and every blade height adjustment (which actually is a table height adjustment) involves a new, careful table-blade alignment). :?

Oh well, maybe I'll just put the tablesaw attachment in the "museum" (the wooden storage box, that is), but I hope to do with it at least some cuts on wood this weekend.
The good news is that the mini-lathe (which the whole thing actually is) works fine.
Markus

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by graham mcdonald » Sat Sep 13, 2014 8:50 pm

With a StewMac fret slot cutting blade and a simple jig you can turn it into a all purpose fretting saw. I have a similar old table saw, and even though I only use it a few times a year, with a few slotting templates it means a few minutes work to slot a board and the rest of the time it is a useful storage for bits and pieces of wood and jigs.
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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by charangohabsburg » Sun Sep 14, 2014 2:39 am

I agree with you Graham, that this would be a good idea - if I not already had a "Jointapprentice Hobby A1" for cutting fret slots (with virtually no setup-time :D ).

My idea has been to use it for long and clean rip cuts (bindings and similar stuff) instead of cleaning up what comes out of the band saw. Today it turned out that not only it is a bit of work to set the table (fence) right in relation to the blade, but setting up the splitter in the same plane with the blade is a major pita. No wonder people remove safety devices if these don't work properly without re-designing them!
Markus

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by charangohabsburg » Sat Sep 27, 2014 5:41 am

Turns out that it's not a good idea that I have a close look at tools I never used. I start to imagine what I could do with it, figure out that the old or cheap tool I have would not do the job, and then... hmm, maybe I should start now a fund-raising campaign! :lol:
Markus

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by charangohabsburg » Thu Oct 16, 2014 11:23 am

Now tis is a nice little powerful tablesaw!


youtu.be/

It seems they not only got no kickback but also never thought about how smart it is to cut things freehand. :shock:

Unfortunately my electronics skills are not on par with the one of those going-to-be electrical engineers at the Polytechnical University Zürich (ETHZ) who built this nifty tool for replacing the old saw (scary little monster) they used for cutting up their circuit boards. You can find the whole story of their saw here.
Markus

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Re: Is kickback an issue with miniature tablesaws? (100-250W

Post by kiwigeo » Thu Oct 16, 2014 4:21 pm

"We've attached 4 Pentium-4 coolers to the IGBT and two Apple-G5-Fans that shove a lot of air (and noise) through the coolers. This is enough to dissipate 700W (continuous!). The hot-glue doesn't even melt, although this thing converts into a hairdryer :-)"

Are they building a miniature saw or a frickin' miniature nuclear reactor????

Those Swiss..... :?
Martin

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