Need help with stack cutting

[anewscroller]

I have been having a terrible time lately with stack cutting. I can stack two 1/4" baltic birch and generally get decent results, but no more than that. I tried 4 and got 4 pieces of firewood. I have been able to cut 1" stock in the past, so I'm a little baffled. I admit that I tend to use the smallest blade I can get away with when doing fretwork whether I'm stack cutting or not.
I just finished 2 pieces of 1/4" oak and while they look ok overall, I can see every miscut and I can tell which piece was on the bottom by slightly smaller cuts in some areas.
I keep my blade square and tensioned (until it comes loose in the middle of cutting)
I"m currently using a Craftsman 18", hoping Santa brings me an EX-16.
Thanks in advance for any advice

[fredfret]

When Stack cutting you really need to use the blade you would for the same thickness of thick stock. I use one size larger than I would use if I were cutting a single layer. Example: 1" stock #5 blade, 1/4" stock #3. For fine detail I never stack more than 2 layers and I will go down 1 size in blade size from a #3 to a #1. The distortion in reduced the thinner the stock.
Fredfret
Wichita, Ks

[sawdust11703]

anewscroller, you have the wrong theory on blade size selection. You should always use the BIGGEST blade that you can get away with to cut what you need to cut. Not the other way around. The bigger the blade, the more mileage you can get off that one blade. Now getting to your problem, if your blade is square to the table with proper tension, I will almost bet you that at times you are pushing the wood too hard through the blade causing it to bend and cut at an angle. Thats why the cut areas on your pieces don't match up in certain areas. You will have much more of a tenency to do that using thicker wood or when the blade is getting dull or using a small blade in thick wood. Even experienced scrollers have a tendency to do that from time to time. A lot of times you don't even realize you're doing it. To be honest, I personally feel stack cutting over 1/2 inch is too much and certainly over 3/4 inch. When people stack cut, they are usually stack cutting wood which is 1/8" or thinner and probably only stack it about 1/2" high or so. Only a few times have I ever stack cut 1/4" and when I did it was only to cut 2 items.

[Rolf]

I agree with Sawdust, I do lots of stack cutting mostly 1/16 ply 6 up about 1/2 inch. My work requires that I use a 2/0 blade so going beyond the 1/2 inch ends up being counter productive. Another issue is when cutting that thick, besides pushing sideways, you need to allow the blade to "catch up" before making a turn. Take a piece of scrap push hard, stop, then see how much the blade continues to cut. I was demonstrating that at our recent wood show.

[anewscroller]

Thank you all so much. I need to be patient and not try to do too much at a time.
I do get in a hurry sometimes. So much to do, so little time.

[Forester21]

You mentioned cutting baltic birch. Usually that means plywood? Which means you are also cutting layers of glue that will really dull your blades quickly.

I stack cut 3 layers of 1/4 inch wood all the time without problems. Both solid woods and plywoods. I like to use a number 5 blade.

Check your table top to make sure it is level too....

T

[Okie]

Yesterday I cut my first stack. It was 2 - 1/4" pieces of Poplar. I cut a xmas orniment and was fairly pleased with the results. I used a 2/0 new spiral fd blade to cut the inside pieces and a #3 fd to cut the outside. I also cut two more of a different pattern today with about the same results.

[anewscroller]

Last nite I did a stack using 2 1/4" pieces of baltic birch ply, #1 R blade and took my time. I was very pleased. Thanks all for the advice.

[sullyscroller]

I have cut 4 - 1/4 red oak plys at once but you have to use at least a # 5 blade and go slower than usual, give the blades time to cut. Also try the flying dutchman ultra reverse blades, they cut like butter and no fuzzies.

sully

[Kepy]

I have found that 3 in a stack of 1/4" and 4 or 5 in 1/8" is the optimum. More than that and it slows you down too much.

[marshall]

I've had great results in cutting 5 with the 1/8" BB Plywood , I use a no. 3 and 5 and they do great - just remember you can't rush when cutting for this is when things don't turn out good . Always remember slow is better - you can always stop and take a break and come back too it ---Good Luck .............MB