Choosing the right (pegas) blade

[kstano83]

I have been using Proxon blades on my scroll saw because it´s what I can get locally. 99% of my work are puzzles of 20mm (3/4") thickness. No. 3 and 5 are my sizes to go for. I usually cut one at the time, but when I go for quantity, I do stacked cutting.

I got a Pegas starter blade pack with my scroll saw but I used them too soon to be able to distinguish how different each blade cuts.
I was lucky to find the pack (in my messy garage) with only 3 blades in it. It was modified geometry no. 3. I instantly put it in my scroll saw and the puzzles I made with it were the smoothest and cleanest pieces I have ever made. It was like cutting through butter. It even lasted at least twice as long as the Prxxon blades. I was sold on it and wanted to get dozens of them.

Later ,"time for stacked cutting". I put two 20mm pieces of beech wood together. Made my first cuts and snapped the blade. I thought the one was too dull from previous cutting. I put in a new one and it broke within a minute. The same happened with the last one.

Any suggestions? Is the blade not suitable for such thickness? Or is beech wood that much harder than maple or oak? (Woods I´ve never had troubles doing stacked cutting with).

Also, even after making a straight line I was not able to pull the wood back due to wood dust building up behind the blade. After I finish a cut, the built up dust is so hard and stuck that the only way to remove it from a work piece is with a hoover or even and sand it off. Having dust collection attached or not made no difference. It has never been that bad with Proxxon blades. Why is that?

 

[MJOriginals]

Hi kstano

When im cutting puzzle patterns at 20mm thick i never stack cut them, 40mm overall thickness can be hard work if the wood has got any real strength and to ensure accuracy of the cuts particularly when cutting tightish curves I find that you have to cut so slowly that it ends up taking longer than cutting two seperately and i dont seem to get the accuracy i want
If im cutting a fairly easy cutting wood say lime, pine or meranti, i tend to use a pegas No5 R code 90.429 for 20mm thick, if its really detailed i might use the 3R code 90.428 but if you do go down to that you got to accept breakage of the blade as a 5 is recommended up to about 10mm and the 3 even less. If the wood is harder to cut eg cherry elm or similar then i tend to favour olsen PGT blades either 5RG or 7RG but these are more difficult to turn tight .

If i was cutting 40mm id use a 9RG olsen PGT, but tight curves can be a hassel with these.

So you dont get stuck due to sawdust packing benhind i found the only way to guarentee that is to keep working back every little while, i cut about 25mm forward and then work the blade back along the cut backwards if its a cut i have got to keep open but that doesnt always work.
Also you could try the blade lub stick from olsen (always hobbies do it)

hope this helps

Martyn

 

[MJOriginals]

Hi kstano

Just had a thought www.scrollsawer.com has a good guide to blade selection plus a downloadable PDF call "never fail blade chart"
Which gives good advice on blades to use for any particular circumstances
Hope this helps
Martyn

 

[kstano83]

To be honest, some of the puzzles I make stacked are pretty simple, that´s why I was surprised why it was happening. I have seen several "choosing the best blade" articles but I try to gain that knowledge by my experience rather than try what others say (not that they may be wrong). Probably the best thing to do is to go through several types of pegas blades again and see what type and size suites me best.

 

[kstano83]

I got a package today. Super skip no. 0.2 and 1, some spiral blades and one pack of other blades to try out. I even got a tiny pack of Haribo gummy bears as a treat. :mrgreen: