Miter Saw Accuracy

[Scott C. Williams]

I build school house clocks using a cross cut sled with a jig and fixture to cut the eight sided clock face. I am considering the puchase of a miter saw to make this part. The saw I am looking at is the Bosch 5312 slider. For those familiar with this saw will it be accurate enough to cut the joints for the octagon clock face.

[Joe Jensen]

I doubt any slider will be as accurate as your crosscut sled, but others may have a better experience.

[Rick Fisher]

Hmm.. I have a Hitachi which is marginal.. I use it for miters but cut both sides without moving the saw.. otherwise they never end up right..

They are handy saws, but not really dialed in accurate..

[Larry Edgerton]

Rick has the key to what you are doing. Set the saw as accurite as you can and cut both sides, if possible, without moving the saw. When you cut one face up and one face down from the same side of the saw any differences are cancelled out.

For example, and this is an extreme example, you need a 90 degree corner. You set the saw at 45 degrees, but it is actually cutting at 44. You make one cut face up which is 44 degrees, and then one cut face down which ends up being 46 degrees so the end result is a 90 degree corner.

You can't do this with everything because some profiles will not allow it but when you can it works.

Larry

[john lampros]

There is too much play in the sliding arm to get accurate enough in all the sliding chop-saws I tested. So I went with a non sliding 14". Get the thickest and best blade possible. you might want to consider a guillotine cutter Like framers use (which are usually set up for 45's) but can be adjusted or modify a stop for the correct angle. Thats about the only thing thats going to be as accurate and possibly faster than shooting. I believe Lion makes a good one. I see grizzly has knocked one off as well but I know most of the framers in this city use the standard. the cuts are perfect laser strait and no tear out what so ever on any wood. You'll still need to "rough) cut them on a chop as the guillotine is just for the final cut and fitting.

[Larry Edgerton]

I have an original Lion trimmer. The company is no longer in business, another victim of the knockoffs. They do a great job but it is a slow process and be aware that you are limited in the width of stock that you can miter.

For the kind of thing that you are doing I usually use one of my old Delta cast iron straight miter boxes, the one with the jackshaft that holds the blade. I consider them still to be the best reasonably priced chop box ever made. Once tuned they stay that way for a long time. I have four, so I'm set for life.

Larry

[david brum]

I had high hopes for the accuracy of a pretty expensive Hitachi slider when I got it a few years back. I found that I had to do lots of trial cuts to get complex joints to fit just right and it wasn't repeatable. I eventually threw in the towel and made a version of this http://www.in-lineindustries.com/single_dubby.html which allowed me to make 12 1/4 degree cuts that came out perfectly. 22 1/2 degree cuts are a cinch. Rockler also has one http://www.rockler.com/product.cfm?p...63&filter=sled.

[Rick Gooden]

I have recently retired my miter saws for accurate angle cuts. I finally found the machine that allows for the type of accuracy that you are looking for, it's an old Millers Falls miter box with sharp Diston saw. It cuts quick and accurate and is an absolute pleasure to use, and the miters (4 sided, 5 sided, 6 sided, etc.) are all dead on. Cost for one in very good condition will be in the $3-450 range, but worth every penny.

[Richard Wolf]

I agree with the Dubby, http://www.in-lineindustries.com/double_dubby.html. This guy has made a living out of his fixture which is designed to do exactly what you are doing. He is getting older and sometimes his customer service has been lacking, but his product is great,

[paul cottingham]

I have recently retired my miter saws for accurate angle cuts. I finally found the machine that allows for the type of accuracy that you are looking for, it's an old Millers Falls miter box with sharp Diston saw. It cuts quick and accurate and is an absolute pleasure to use, and the miters (4 sided, 5 sided, 6 sided, etc.) are all dead on. Cost for one in very good condition will be in the $3-450 range, but worth every penny.

+1 on the mitre box. I have an old Stanley with a disston saw. My mitre saw is now on a shelf.

[George Makra]

You could use a shooting board. It dosent take long to make a adjustable shoot board.

[richard poitras]

Anyone have there own opions of the saws on the most accurate miter saws reviews list? As I am looking for a new saw and the Kapex is just out of the question do to the price. Its not going to have to be portable, but being accurate is the key to my search
.

[Steve Rozmiarek]

Like everybody said, super precise repeatability of miters is hard. If you cut a master cut making it as wide as possible, then you that to check your settings by just looking at blade alignment against it, you will be good to go.

Some saws are better than others. My old Makita 1013 is great as long as you hit the mitre detents from the same direction every time. I've got another that is not as good.

[glenn bradley]

I doubt any slider will be as accurate as your crosscut sled, but others may have a better experience.

I have read threads by people claiming adequate accuracy from a miter saw but, read far more that deny it. It could be a case of "the eye of the beholder". Skil to Festool, there seem to be more posts of inaccuracy than of accuracy. This could also be the typical negative reviews outweigh positive reviews scenario.

If you are used to a quality tablesaw and sled for joinery, a typical CMS is going to seem crude in my experience. I don't even have a CMS in the shop anymore; it lives out in the shed and comes out for trim work and construction stuff but, that's me.

[John Gornall]

I have a shop where I've made my living for 40 years - part of our work is making wood parts - have cut and joined 500,000 various frames.

Miter saws are made for carpenters - designed to cut the biggest piece of wood the blade can cut - not precise. Put a 2x4 on the saw and drop the blade to contact the wood, not running - you will notice the first contact has the teeth cutting up through the wood not pushing it down against the table.

There are saws made for making frames - have a completely different geometry. The fence is outside at the outer edge of the blade - you pull the wood towards you against the fence - so the blade is always cutting down against the table - no wood movement. 2 blades fixed at the angle required. Look at CTD saws.

You can make a miter saw work. No sliders - hopeless. Get a basic chop saw. Move the work piece up from the table and out, towards you from the fence so the blade is always cutting down against the table. Put a 2x6 flat on the table and a 2x2 on that against the fence. All wood milled flat and square. Make cuts, test, adjust. Get 2 saws, these are cheap, leave them fixed left and right.

10 inch blade, not 12 inch unless you need 12 - less deflection

Thick kerf, negative rake, blade of 80 teeth not 100 or 120. Bigger carbides, more sharpenings, longer life. And the bigger carbides run cooler.

Try different blades - I like triple chip for hardwoods.