Mitre Saw

jkoyas

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Joined
Oct 25, 2000
Posts
35
Location
East Hanover, NJ
I own a small frame shop & art Gallery and I have a question regarding mitre saws. We have a Dewalt 12" mitre saw using a 100 tooth carbide tipped blade. The problem we have is with chipping. Even with a brand new blade we still have trouble with chipping when we cut moulding. Is there any solutions with this problem without having to purchase a double mitre saw(very expensive).
Any advise is greately appreciated.
 
Miter saws such as this are designed for carpenters and they are designed to cut the biggest possible piece of wood with the blade size installed. When you put a piece of picture frame moulding on the saw table and against the fence you will notice the blade begins cutting at the bottom middle of the blade. The tip of the blade tooth actually cuts into the finish of the moulding and then comes back out through the finish. This causes much of the chipping. When you look at a good quality double miter saw designed for precision cutting of picture frame moulding, you will notice that the blade meets the moulding not at the bottom-middle of the blade but further out so that the teeth of the blade cut down through the moulding and exit the moulding at the bottom of the moulding. To solve this saw geometry problem, put an appropriate sized board on the table and then another board against the fence. Size these so that the saw will contact the moulding further out and up the blade. On 10 inch miter saws I have found raising by 1.5 to 2 inches and out from the fence by 1 to 2 inches is about right but will depend on the saw design. This will reduce the size of moulding you can cut but a 12 inch saw will probably cut an 8 inch board so an inch or two reduction shouldn't matter.

You may also have the wrong blade design. Ask framers in your area what blades they use and where they get them sharpened.
 
I personally used that saw and never liked it.

I fell in love with a Hitachi 10" C10FCD, it belt driven so it runs smoother then a direct drive.

you might find a 12"

The motor is located on the back left side so you can see what you are cutting better.

Cost is around $ 250.00
 
I use a Delta 10 inch with a 80 tooth it cuts better then any large double bladed saw I have ever used. The secret is in the blade and the rpm's, the delta runs about 5200 rpms which is faster then most chop saws. The blade I use has a back pitch to the tooth which helps in the exiting of the blade from the mouldings. The place were I was able to get good information on the chopper and the blades was from the company that sharpens my blades they are full of great tips.
 
Look at the Frame Square Table 10" saw (approx $2200). It cuts 45 degree mitres.... 22.5 with an optional attachment. Very accurate saw. Tooth angles are proprietary and can cut both wood and metal mouldings. I have tried other brand blades on the saw with little or poor success.

Rick-CPFcm
 
I use a Makita 10" Chop saw with a Phaedra Fence System and haven't had to much of a problem until my Blade starts to get dull. I sure like the system Scarfinger suggested, It makes sense to me.

------------------
Overcut the Barbarian
Frame it or throw it away
 
If you go to a show early and watch the salespeople set up the saws and blades they are going to demo you will see them with a dial indicator and special tools adjusting the blades until the teeth are running true within about one thousandths of an inch. If you are having trouble with your cuts get a dial indicator and check the blade on your saw. Your blade may not run true for a number of reasons. The shaft and nut may not be clean. When changing blades make sure everything is clean. There may be a tooth or two out of alignment. Take this one back to the sharp shop. The blade itself may not be flat. Blades often have a bit of bow to them. This can be adjusted with an adjustment plate with setscrews that goes between the blade and nut such as the one sold by Lee Valley Tools. With a dial indicator and this plate you can get the blade right on. Then listen to your blade hum when you start cutting.
 
New saw? New blade?! Your saw and blade combination should give you very good, consistent results. Are you having trouble with gesso-covered/gilded woods, stained woods, metals, or just everything? Is this a new saw? If so, have you had similar trouble with other saws?

Could the problem be the operator and not the tool?

Here are a few suggestions that seem obvious and elementary, but may be useful anyway:

1. Cut slowly. Let the saw reach maximum RPM before it touches the moulding. Then advance through the wood (or metal) s-l-o-w-l-y. Jamming the moving blade into wood or metal could easily cause chipping, especially if it isn't up to speed.

2. Make sure your moulding is securely held in place on the saw table. If it moves *at all* during cutting, something will be wrong with the miter. The slightest side movement could bind just enough to chip gesso.
 
My only somewhat words of widsom is backing up your cuts. What I mean is to make your first cut and then re-cut again only shaving about a 1/16 off. I think carpenters call this a stress free cut. This will take out the rolling of the moulding as well as clean up your cut. Then measure your cut an 1/8" longer on the otherside and do the same thing again. This is kind of labor intensive but will solve your problems until finances improve. Good luck, Rick S.A.TX
 
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