Re: that jigsaw :-(

[LRod]

>Why is it that jigsaw blades always seem to flex sideways in the cut? I just >had to make many cutouts in to the edge of some 9" boards, too wide to get >under the radial arm on edge. >The cuts perpendicular to the grain are fine, but once I swing the jigsaw round >and try to make the longitudinal cut, the blade always bends to one side, >resulting in a cut that is not at 90 degrees to the surface of the board. >Even more infuriating, it seems it always bends outwards at the bottom of the >cut, never mind which direction I cut in - so it's not the way the table of the >jigsaw is set, because then the deviation would be constant. > >I've more or less had this problem with every jigsaw I've owned (on the third >right now) and a friend of mine says he has the same happen to him.

With what brand(s) of jigsaw are you having this problem?

[Leon]

I recommend a better brand blade for starters. Bosch are great, DeWalt are bad. If that corrects the problem good. If not look into Bosch or Milwaukee.

[Peter Huebner]

That's what I have at the moment - Bosch. Also some very narrow DeWalt for tight corners, way overpriced they were too. It's the others I was mostly having the trouble with though. Just ran out of Metabo blades. I also have some Swiss ones, can't remember the brand.

-P.

[Peter Huebner]

Current saw is a Bosch (I'd describe it as upper mid-level; it's not a really expensive model, but the best of the next bracket down). Previously I had an AEG (blew a winding) and before that a wee Metabo (needle bearing meltdown). My friend who also has this trouble of the blade not staying straight in the cut has one of the really expensive pro-Metabos (he's a chippie).

-P.

[Jay Pique]

With a Bosch jigsaw and Bosch blades you've got a pretty good combo toolwise. One of the ww'ing rags had an article on jigsaw technique recently that really helped me out with my cutting. After just changing my grip I was able to cut much cleaner and tighter radii than before - using the same blade and saw. (Disclaimer: I'm using the

1590EVSK which is the latest offering from Bosch).

JP

[JacQ]

Peter Huebner wrote in news: [e-mail]:

i've had the same problem with my bosch, a sharp saw blade does help a bit though. Not so long ago i got the festool jigsaw (trion PS 300 EQ,

, and i have to say that the extra guide bushes do help a lot. Mind the sticker shock though ! (Actually for us europeans it is not so bad, all other power tool brands are hideously expensive over here compared to the us price, so often a festool is not that much more expensive) Also, the festool plunging circular saws and guide rails are really excellent, you can put your board on a sheet of styrofoam on your table, mark out the cuts and make them in place; really beats a table saw for large boards !

[Toller]

Okay, what magazine and issue? I have the same problem as the OP. I thought trading up from a craftsman to a Bosch would solve my problem, but apparently it is rather than the tool.

[nailshooter41]

Pete:

I feel like the odd man out here, but in my experience it isn't always a function of going to buy a better blade to fix this. My personal experience over the years has been this:

If you are cutting something thicker than 1/4", blade quality matters a lot. The correct blade ((tpi), the correct width of blade, and the sharpness of the blade matter as much as the device that pulls it up and down.

Overheating of the blade (causing distortion) due to a dull blade, pushing the blade too hard (blade duil causing heat, etc. as above), and the incorrect blade (why use a 18 tpi low kerf to cut pine?) and speed of the machine contribute much more than anything to the quality of the cut.

If you get a pretty good quality blade (I like the Bosch for reliability and durability) and a machine (I like the Bosch here again, but the tool mags prefer DeWalt), and pick the right blades and cut at the right speeds (higher tool speed and you push the machine slower) you should reduce your problem by a huge amount.

About the only time this is a problem for me anymore is when I push the machine too hard because I am impatient. Guaranteed I will have a bevel cut.

Robert

[Wood Butcher]

As you have this problem with every jigsaw, that points to operator technique. If you put any sideways force on the blade as you turn then the blade will behave as you describe. Try a few practice cuts with a good blade and pay special attention to not applying any side force during the cut and I'll bet you see a noticeable improvement. Just for grins, get an old blade and make some cuts where you are pushing sideways and see the difference. Even a straight line cut will wander all over hell and creation. Hope this helps.

Art

[Prometheus]

Happens to every jigsaw I've every used except the Bosch. I don't know what kind of super-voodoo they put into those things, but they're the only one that is worth a dime.

[Peter Huebner]

Trying to figure this out is where I am at. I didn't maybe make the point very explicitly clear in my original post: one time I am cutting clockwise and the other time I am cutting anticlockwise relative to my body and both times the blade flexes towards me at the bottom of the cut (3/4 inch depth on this last job). So I figured it was either something inherent in the tool, woodgrain, or my technique. With the latter two much more likely than the first.

Sideways pressure is probably unavoidable as you are making a rounded first cut towards/into a corner of the cutout - but I am sure I was not exerting sideways pressure on the reverse straight cut.

In the end I swapped blades for each cut - used a very narrow (new) blade to cut the curve in towards the left corner, and a very sharp brandnew blade for the reverse straight cut back into the other corner. Still the flexing happened somewhat through. Not to mention it's a pain in the arse to do it this way if you have 72 cutouts to make (fortunately in groups of 6 so I didn't have too many blade swaps).

thx for your suggestions - will pay more attention to this next time

-P.

[Peter Huebner]

With you all the way, Robert. I did notice that giving the machine more time to make its cut and using the hightest speed in the cut improves things out of sight. (see my reply to Wood Butcher for more on what I did and tried - still without getting a result to my entire satisfaction).

Bent/distorted blade is not the issue here, I was cutting clockwise and anticlockwise relative to my body position and both times the bottom of the cut was bevelled towards me *each* time. So the blade flexed left once, right the other time. There must be something else at work here.

I was using superclean cut blades cutting 3/4in macrocarpa this time - not out of the way I would have thought.

-P.

[Jay Pique]

Shopnotes Vol. 15 Issue 86 - March/April 2006

JIGSAW SECRETS For Flawless Cuts

In a nutshell they say to turn off the orbital cutting action, use a

20tpi blade with points that stick straight out (a straight-cutting style versus an up-cutting style blade). The biggest tip that worked for me was turning the saw from the front. "Grip the saw directly above the blade when cutting curves. Take it slow, and let the blade do the work." You use only one hand, and sort of let the saw pull itself along.

JP

[lwasserm]

I have a Milwaukee (actually AEG) and if a Bosch is a dime the Milwaukke is worth 15 cents.

[Wood Butcher]

With the problem showing up on both CW & CCW cuts I'm more convnced it is sideways pressure causing the problem. The bottom if the cut flexes toward you as you push the saw away from you.

** It's not unavoidable, but it does take a bit of practice to avoid it. Line your body up directly over the top of the saw so you can exert downward pressure as you push(or pull) the saw in the direction of the cut. If you are not directly over the saw it is too easy for the downward pressure to be translated into some sideways force which is hard to feel. Practice on some MDF, it has no grain, until you get the hang of it. Be patient. If I managed to do it so can you. BTW I'm using HF blades in my 25 year old Crapsman jigsaw.

***You should use the widest blade you can for your minimun cut radius. Too narrow a blade is hard to keep going straight on the non curving parts. I had a chart of blade widths vs minimum cut radii but I can't seem find it. Google failed me too. Anybody else have this or a link to one?

Art

[CW]

With the symptoms you describe, it is technique, no doubt about it. You are exerting sideways pressure toward the outside of the radius.

[Leon]

And yet, :~) he is using a Bosch.

I use a Milwaukee and really don't have a problem unless I cause it. Just like thin kerf blades on a TS if you use thin jig saw blades they will be more likely to flex and not cut true with out proper technique.

[Leon]

Just a thought, if you are going through this many saws, and all you have listed have very good reputations, perhaps you are using the wrong tool for the job at hand. I really kinda sounds like you may be pushing the tools too hard.

[Prometheus]

Couldn't argue that- I never used the Milwaukee jigsaw, but their other stuff is nice.

[Prometheus]

I caught that after I posted it, but I'll stick by it- more or less. As noted, I've never had occasion to use the Milwaukee. I've used a couple dozen oddballs, mostly Black and Decker and Skil, with a DeWalt and Craftsman or two in the mix there and the first time I laid hands on a Bosch, it was so much nicer than the others, I just stopped looking.

Now I've got to find someone who's got one of those and see for myself. It never ends, does it?

:)