bending blades

[Marcellarius]

Hi y'all,

I'm doing a project with stacked beech plywood, four layers of about 5/16" (+/- 3,2cm)
what's a bit new to me is that the blades will not do a quick turn but bend very much. (up to at least 50 or 60 degrees)
so it's almost impossible to make small corners. Image: Blue line normal cut, red line bend cut
I saw oak or merbau but had never had this much bending on a blade.
I tried both Flying Dutchman UR and TC #3 and #5.
#5 has less bending, but due to the small pattern I can't use #7 
the tension of the blade is good.
could this be due to the fact that the beech ply is very hard and has layers of glue?

does anyone recognize this problem?

[Mainewoods]

could this be due to the fact that the beech ply is very hard and has layers of glue?

Absolutely Marcel.  I'm no expert, but that's what my limited experience has taught me =if you can't make the turn, your blade's too small.  That's assuming you're trying to make the turn as slow as possible to give the blade a chance to make and clear the cut.  Is there waste on either side of the line?  Sorry I'm not offering any real help here, hopefully someone gives you a more viable solution!  Good luck!

[scrollgirl]

I think that you are trying to cut too much at a time.  Beech is very hard wood and you are really pushing things by trying to do four layers.  How about trying to do two at a time?  That way you can still use the smaller blades you need for your pattern and be able to follow the lines.  I think that it is just too much for those size of blades.  Just my thoughts . . .

Good luck and let us know, Sheila

[newfie]

I'm with Sheila think your trying to cut to much at one time.your cutting 4 layers of 5/16 at a time that's about 1-1/4" thick. i would reduce layers and try that.

[Marcellarius]

Thanks for your response.
I thought about the thickness, but didn't tried 1 layer. (will do in a minute)
The thing is that I'm making a project with 2 coasters in a coaster holder.
it's a wedding gift and the design includes their name and date.
the first and last will be mounted as the holder, the two in the middle are the actually coasters.
when the coasters are in the holder you should be able to see right true.
when sawing this "non staked" the result wont be good enough to my standards for this project.....

dilemma: smooth/straight/slow vs sloppy/rough/quick

I now try to work around it by making wide curves (as possible) and do the corners from both sides, but that's a lot of extra work and in the small parts almost impossible.

thanks again, I'll show you the project when finished.


 

[dgman]

Hey Marcel, In addition to the above, You might try to increase the tension on the blade.

[Marcellarius]

@Dan: I think the tension is good, I'm afraid that if I do more the blade might brake.
@Mainwoods: I guess you're right that the blade is to small regarding to the thickness of the 4 layers.

when I look at the ratio/proportion blade vs teeth on a #3 and #5 UR/TC the teeth are in "minority".
I just did one layer and the curves are real sharp and no bending of the blade.....

so 4 layers is over the top I think....
....at least if you want to scroll out each part in one piece. 

[bettyswood]

It might save you time if you cut 1 or 2 instead of 4 because you will not spend time fighting it while you are cutting.  Are you using packing tape?  Sometimes that makes the cutting a little easier too. 

[Marcellarius]

yes I used tape. the first part ( were I think a 4 layer cut is necessary) is finished.
for the next effect I do a 2 layer cut, this will be much easier!

everyone: thank you for helping.

[tux_linux]

multiple layers of wood are much harder than a single wood of same thickness.

I know your problem - but I also do not have a real solution. I would go with Sheila, cut one at a time - and do it real accurate...

regards
Torsten