Replies

1. 
   saschafer | May 06, 2009 03:31am | #1

   Hardboard is somewhat abrasive. That, combined with a dull blade, could be the culprit. A sharp blade shouldn't heat up, but it will dull fairly quickly.

   -Steve

    

2. 
   hammer1 | May 06, 2009 05:57am | #2

   Sounds like you tension on the blade may not be enough, or your pin for the circle is in the wrong place. It should be in line with the front edge of the teeth. If it's not the work will bind. If binding causes the blade to slip, there isn't enough tension. You should not have any trouble with hardboard, Masonite, MDF or most any such material, for that matter. It always helps if you give every little detail about your set up, which saw, which blade, how you position the blade, set the guides, attach and adjust the jig. Something is really wrong if you are burning tires.

   Beat it to fit / Paint it to match

1. 
   cbrazik | May 06, 2009 02:11pm | #3

   I put your suggestion and it cut ok. The first group of circles cut fine but then I got some binding and changed blades to a blade with more teeth per inch (?) and 1/4" width to make it turn easier. That blade did fine.I did re-register the line and the pin when I changed blades. I also made a tension device like on the video on line FW and that probably helped as well. I have always been able to cut hardboard, mdf, etc but for the tire to melt had me a little baffled.Thanks,Chuck

1. 
   hammer1 | May 06, 2009 06:17pm | #4

   Hi Chuck. I used to cut 1/4" plywood into circles for wedding cake bakers, hundreds. Sizes ranged from 8" to 24" in diameter. In my house trim work, I often cut circular trim for arch top windows that can range from 18" radius to 8'. My favorite blade is 1/4" 6TPI, regular. I've been using Olsen All Pro. I'm running an older Delta 14". Finer toothed blades may load up with sawdust and wear quickly.I can't comment on the FWW video, I'm not a paying subscriber. I still have the original crowned rubber tires. I set the blade so the center is on the crown. This keeps the teeth up and off the tires. I usually set the tension with the deflection method but I'm not afraid to add a bit more, especially with the typical tension spring on a 14" saw and a 1/4" blade. Of course, I have a touch, so to speak, with my own saw. I back the guides completely off until I have the blade running true on the tires, with tension. I bring the guides in so they just kiss the blade. The rear bearings and the side blocks don't touch the blade when it's running without engaging any work. The rear bearings will spin once the work is engaged but not much. If I touch the side blocks, I'm doing something wrong and forcing the blade sideways. If the rear bearings are spinning fast, I'm feeding to quickly. Full contact with the blocks or bearings generates heat and that quickly shortens the life of the blade. If you have had your issues with the blade that is currently on the saw, it's probably toast. I found that the position of the pin is critical. A 1/16" either way won't give accurate results. The point should be right on with the tips of the teeth. I've had the same blade on my saw for close to two years. In that time, a good deal of my work was cutting arcs in softwood, hardwood and MDF. An accurately set up circle jig actually extends the life of the blade since the feed is spot on. If you have things set up well, you shouldn't have any running, burning or resistance. Your finish will land right on the start point.
   Beat it to fit / Paint it to match

1. 
   cbrazik | May 07, 2009 02:30am | #5

   Thanks. Those are all great suggestions. I am doing them all but think the one I will check again is the position of the point. I have used several sizes of blades recently and have three lines.