Puzzling Dilemma!

[CptChaos]

Greetings All,

I am brand new to this forum. I have been playing with my scroll saw for a few months now and am enjoying my self thoroughly. I have discovered that I really enjoy making various puzzles. From simple flat, block puzzles to puzzles similar to the works of Judy & Dave Peterson. I enjoy the Dinosaurs and Medieval patterns especially. I also am trying my hand at Puzzle boxes. (I have a few photos if anyone is interested)
My dilemmas is this:
When sawing the thicker puzzles, say out of 3/4 inch or more stock, my pieces seem to be off slightly. Enough so that they can be separated in one direction but not the other. It is like my saw tabletop is not at a true 90 degrees. I have checked and rechecked using all the suggested ways in the scroll saw books. It is a true 90 degrees. I have a feeling that it is my technique. I am not trying to force the wood through the saw but I sometimes catch myself, in a turn, moving the blade to the side. I did have some success by moving my table 1/2 a degree off of 90. This helped on a few pieces but I feel it is still a technique problem. I fully admit that I'm a "Newbie" and that this could be a common "Newbie" mistake.
Any constructive suggestions would be greatly appreciated.

Thank you for your time!

Sean Pound
Aurora, CO

[BobD (Archive)]

Sean,
It is a technique problem--and one that I'm guilty of as well! I just cut Judy's Dolphin puzzle out of purpleheart this weekend, and it is one of the first that I didn't have to sand between the pieces so they will come apart both ways!

If you apply ANY pressure to the sides, your blade will bow. Your blade is already bowing slightly as you press on the blade, and this is compounded when you turn a corner (like one of the lobes in Judy's puzzles).

It comes down to slowing WAY down. Let your saw keep up with you. Use the biggest blade you can to keep up with your saw ( I used a #7 skip tooth for the puzzle I just cut, it makes for a bit wider kerf, but that was a sacrifice I was willing to take).

Just take your time when you are cutting. Here's a for instance: Take a piece of scrap and try to cut a straight line. Go forward about 1" and stop. you will see that as you stop, your saw blade will spring ahead anywhere from 1/32" to 1/16". That shows how much faster you were pushing than the saw was cutting...

It's all about practicing...

Another thing that could be a problem is if your blade isn't tensioned enough. I keep my blade as tight as I can without it slipping out of my blade holders when I'm cutting a puzzle. It may break prematurely, but it keeps me from sanding lobes and sockets.

Hope this helps!

Bob Duncan
Scroll Saw Woodworking & Crafts (gotta get in the habit of writing the new name)

[Rick-H]

90 Degree

Not sure how your are checking for the 90 degree, but I use a different method with good results. In the scrap of the wood you are going to use cut out a test 1" square, just freehand cut it, it does not have to be anywhere near perfect, just a general 4 corners. The part cut should come out the top or the bottom easily. Adjust the table until tyou can cut that square out and get it to come out either way. Don't worry about what the bevel guage is on the table. Don't worry about if a square on the table against the blade is perfect. You have the table set to where when you cut you are getting square cuts on the wood.
Another thing is when you cut always try to keep the save piece on the same side of the blade. I keep my save part to the right side. Even cutting puzzles where both sides are save as you cut think in terms of the right side it the save part. We still unconsciously try to keep the blade pushed against the line. As we cut there is a tendency to keep the wood pushed up against the blade causing a slight bow. In setting the table in the above manor you have compensated for that pushing and bow.
Another thing I do a lot is while cutting keep feeding the wood but just release the side pressure. Keep your fingers on the wood to hold it down yet, but let the pressure go on the sides of the wood. Many times you will see the wood jump back under the blade where you have been putting the side pressure on it trying to keep the blade against the line. The more practice you have the less you will see the wood jump back. But I still find many times when I cut and release the wood still comes back some. If nothing else watching it jump back makes you more conscious of how much side pressure you are putting on the cut.
This has worked for me, and you might give it a try and see if it helps.

[3_M]

Hi Sean,

Welcome to the forum.

To see that the table is square with the blade is very easy. Just cut about 1/16" into a scrap of wood and than turn it around and try to fit it in the back of the blade. If it fits the blade is square to the table. When you cut a square or a circle and you push just a little to hard, the blade cuts with a bevel. You can not set your table that it would be square because the next time you might not push so hard into the blade.
Don't turn the speed down too much maybe 3/4 speed, a lot run the saw full speed. The blade gives a smoother cut with higher speed, with too low a speed the blade grabs the wood instead of cutting it.
Like Bob was aying, have good tension on the blade, better too much than not enough. The blade should give a nice high ping sound. Some call it a high C like in music.
Please do NOT push too hard into the blade, let the blade do the cutting. With low speed you start pushing too much and the blade start to cut with a bevel. That is the reason that you can get the puzzle apart only on one side.
If you go to this site: http://www.mikesworkshop.com/Q&A-FP.htm there are a lot of good tips for you. This is not a commercial advertising. Just try to help a new scroll sawer.

Mike M

[CanadianScroller]

Welcome aboard!

Some great advice you have been given.
The bowing happens to even the most seasoned sawyer.

I find cutting at the speed of an advancing glacier helps me. Sharp blades are a must!

[lucky788scroller]

you are all set with all that advice. Let us know how it turns out.
(no disclaimer here Hi mike!)

Dale

[CptChaos]

Thanks to all!!!!!!!

I wish to express my gratitude to all who have taken the time to respond to my posting.
I knew my problem could not be the saw, I paid too much for it to be defective.
I had the feeling it was the "nut behind the wheel"!!
I will continue to practice and am confident that my technique will improve.
Again, thank you all for your help.
I've been on automotive and motorcycle forums before and they usually treat the newbies like crap for the first few postings, ridiculing and claiming ignorance of the postee'. You usually have to wade through a load of crap before you can get the information you are looking for.
Nice to see a forum with considerate and helpful individuals. Even to the new people.

Thanks again!

Sean

[minowevie]

HI Sean. I just wont to welcome you too. You have come to a great forum. and you have started out with some advice from the top guys. We are so lucy here to have are more exsperienced and thoughtfull scrollers here. I have leared a couple things from your thread myself. so glad you are here. your new friend Evie

[Magpie]

CptChaos said, "I paid too much for it to be defective." Not necessarily true!

http://www.cnn.com/2006/AUTOS/06/14/pricey_lemon/index.html

Happy scrolling!

[CanadianScroller]

I knew my problem could not be the saw, I paid too much for it to be defective.

Just out of curiousity what kind of saw did you buy?
Have you place a straight edge across your table?
Even new saws can have imperfections.

A slight bow or crown in a table can be as frustrating as a curved neck in a guitar.
Check the table with a straight edge.

[CptChaos]

Saw Purchased.

I purchased the RBI Hark 226 model. I had seen other saws at woodcrafting shows and was very interested. My son was in a woodworking class last year and was told he would receive extra credit if he attended the Woodworking expo/convention. So I took him. I watched the demonstration of the Scroll saw again and, at the time, could financially swing the cost. So I bought it. After further review, I probably could have found a less expensive model and been just as satisfied. But Hind sight is always 20/20. No regrets. I like my saw.
And the table is level and true.

I will post some of my attempts soon.

(Scary about the 1.7 million Lemon that Magpie posted.)

Thanks,

Sean

[sheltiecarver]

Sean,
I have an RBI Hawk also - they're super for doing puzzles and 3-D cutting. They have a bit more clearance beneath the arm, so that we can (v-e-r-r-r-y) slowly cut stuff up to about 2 1/2" thick. That is, of course, a lot to ask of a scroll saw, so it is better done in a softer hardwood like basswood or birch or poplar - maybe butternut. Even then, the devilsome leaning blade can do us in - like Carl said, moving at about the speed of a melting glacier is pretty appropriate!
I doubt that you will ever really be sorry that you bought such a fine saw, although, if saws continue to advance, you may want to add another in 10 or 20 years. By then you may be teaching a grandchild to scroll!
Sandy