Official Luthiers Forum!

I finally got all the new jigs made (including Chris Paulick's arc cutting jig for the small bandsaw).

I still have not made pics of my version of the arc cutter, but the pics of my rosettes shows it works well. The main rosette uses bubinga, ebony, and Zip Flex Blue Paua, 0.064" along with some bwb fiber. The small, upper rosette is the same without the Zip Flex. I also used LMI White glue for the first time and loved it!

Very nice!

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Thank you Stephen. Chris's arc cutting jig as way cool.

Mike

Nice job Mike!
I'm glad the jig is working out for you. I think you'll find that it allows you to do some detailed cutting for rosettes as long as you keep the saw blade tweeked. When cutting shell just take it slow.

Thanks Chris. Not sure what you mean about tweaking the blade. I have broke three blades (two were the 1/16" blades). I am going to buy that HF blade welder. After some downtime, the wood around the blade seemed to adjust with humidity and thats when I broke the 1/8" blade. My saw is a three wheel and I am certain that makes things tougher. I will be getting one of those 2 wheel skil bandsaws (9"). Less stress on the blades. Plus the wheels are aluminum, not plastic. I will post pics of the jig later today in this thread.

I do know this, once you have it set up for a rosette, you do not want to have to take it apart because of a broken blade. That just messes everything up!

BTW, I should have mentioned that I used Rod True's router jig (Bosch Colt in my case) to do the rosette channel routing. That thing is awesome! I even used those end mills from an Ebay source. Not a single issue with them and I got 10 for like $25 (1/32" and 3/32").

Mike

You don't want a lot of tension on the 1/16" blade for sure. If it binds it will break. I have cool blocks for the side guides and they wear after a while with the 1/16" blade since it doesn't have very much bearing. But if it gets too much side movement it will tend to move to the outside of the curve when starting the cut in shell and the beginning will be wider then the finish. By tweaking I mean keep an eye on the side blade movement and keep adjusting the side guide when needed. I also removed my table insert so that dust doesn't build up beneath my jig's base and the saw table. If it does it can also bind the blade after a while and it will break. Without the insert the vacuum does a pretty good job of keeping it clear. A longer blade would also be better at keeping the blade cooler. It should cut wood pretty easy and I'm suprised you broke two blades. I broke a blade on that last rosette I did but I cut a lot of shell that was glued onto some .090" mahogany strips and didn't have the insert removed until I changed the blade when I noticed the build up of dust could be a problem. You will get better mileage from a blade with abalam.

With forums, you usually find out the rules after the violation. After a nice writeup, I attempted to attach more that 8 pics. But that's against the law. So it wiped out my writeup. Here are some of the pics.

Mike

OK, this is my version of Chris Paulick's shell cutter. Of course, you can use it for more than shell, and that's what I did here. Its all made out of poplar (IMHO, the best dimensional, stable wood you can buy at the borg). Oak is OK, just too much trouble.

The aluminium stops are threaded in one hole and not the other. The wood slider block is just loose enough to not bind when sliding. I used 1/8" blades without any problem on wood.

The slider is CL marked for positioning wood in the carriage. There is a slider for cutting the edges as in Chris's design.

Yes, its overbuilt. Even so, I will not be making a "better" one, this one worked great!

Oh, also pictured is Rod True's version of the circle cutter/channeler. You can even see where he signed it! Those end mills were from ebay and cost something like $25 for each case. 1/32" and 3/32".

Mike

Chris, it never ocurred to me to consider dust extraction. That must be what is going on. Quite a bit builds up in short order. I will look at my design and see if I can incorporate an effective dust port.

Mike

I like what you've done. I have that 3rd. center rail that locks the pivot from moving. I like that so as I don't have to worry about moving the pivot point. If I make another from Aluminum I'll use you modification but add the 3rd. locking rail.

You are right Chris, and if I was working with expensive shell, I would add it (probably will). The adjustable carriage gives me more options on width. I never full apreciated your rail design, could not figure it out. Your slider is inside of a close fit channel, mine is not. All of the "accuracy" is maintained by the two rods. Drill press holes through both end blocks (and middle block) and registering on same side gives me good alignment. It is not important that the aluminum be accurate (tight tols). The bigger hole serves to keep the block from spinning (and there are other ways to do it) and they also serve as a bigger "stop".

My only serious goof was how to keep the rods secured near the blade end. I have not resolved that yet (inset nuts on the inside). If they are not inset, they take too much of the small radii cut out of the "performance envelope". As it stands, the blade cut goes right through where the rod is. I have too loosen the rod before removing the jig (since once snugged, it blocks blade exit from the rear)


Making sense?

Mike