I had my first shop booking on Sunday, I had never used a miter saw before and got some help making beveled cuts to make a pentagon shape out of a board. After cutting the pieces I could not get them to fit together. After careful examination of my cuts the material was not cut consistently in a straight cut as the blade moves downward. The cut surface was not square, it was a rhombus. I have a day of work and lost a whole board of material I can’t use. Maybe I’m crazy but I don’t think so. Have you guys had issues?
Hi Richard,
I have a three quick questions that will help assess what happened:
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Did you check with a tried & true square to ensure the saw blade was at 90 degrees to the base? If yes, then go to question #2. If you didn’t, that may explain why your cut was not square.
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Did you clamp your piece to the work surface to ensure it stayed flat while you made your cuts?
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Did you test the bevel angle with a tried & true compass to ensure the angle was accurate?
Let us know if these three primary tasks were completed. This will help us further narrow down what may have occurred.
Michael
Thank you for the reply. Yes we tested it and it said 89.9 then changed itself to 90. Yes my wood was clamped to the fence.
I don’t have a way to test the cut angle. I don’t think the bevel was off I think the downward motion is off
There are a lot of things that could be wrong, and it’s difficult to tell without photos of what you were doing, your setup, etc… Perhaps the saw is off. However, if I’m doing any joinery with beveled / mitered cuts, I always make test cuts on scraps, and check the angle of the fit. More difficult with a pentagonal final shape, but still possible. 5 short pieces of equal length,and you’ll get a good idea of the setup.
I cant recall his name, he was my instructor for my wood-shop safety class helped me with he cuts.
Regarding the accuracy of a 90 degree cross cut (chop cut), I made several yesterday and every one was dead square both vertically to the saw blade, and horizontally to the fence.
My next suggestion is to check the accuracy of each of your cuts. Using a square, you can test the horizontal accuracy of your bevel cuts. There are compasses on the tool shelf (usually on a shelf under the construction squares) that available to check the angle of your bevel cuts.
It would also be helpful if you can post a picture of the pieces put together so we can see how & where they are off.
This is the first cut of my board. You can see one is thinner than the other. I have been grinding my beveled cuts so they don’t look the same anymore.
I had lined them all up and the lines bowed all over. They should have been straight.
Here are two more photos of the same piece. The cut should be the same length at both ends of the cut.
Hmmm….
Did you stand the board up on it edge so the tall face was vertical and clamp it? Or was it laying flat with the thin edge against the the fence?
If it’s the first, then you made miter cuts—you rotated the saw left to right while the saw blade remained at 90 degrees to the table.
If the latter, you made bevel cuts whether the saw blade remained 90 degrees to the horizontal plane of the table.
Terminology does matter in this case- I’m being pernickety…
So, which cut did you make based on this?
The blade was 90 degree and the board was standing tall clamped to the fence
You should be able to re cut your pieces and end up with a slightly smaller dimension. Things not covered, are your boards flat? It may be the reflection or the angle but in a few photos there seems to be a gap on the bottom center. Are all the pieces the same length? In other words, did you use a stop block to cut them the same? As you indicated, the thickness seems to be thicker on one side. Culprits of that: 1. Blade not square to the table, 2. The board moved while performing the cut, 3. Cut too fast, and 4. The board was cupped (not flat). It looks like you’re using Mahogany, which tends to warp or cup if it is not climetized to the environment. It really is not Mahogany now days if you paid less than $10 BF is Sapele which is more prone to the above. When making these kind of precission cuts, as mentioned use test pieces. The scrap bin usually has plywood or MDF. Cut strips and then your miters and use a band clamp to check the joints.
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It’s Patagonia rosewood and everything was perfectly square. I checked before. I don’t think a test piece would have told me anything. The pieces come together but not like a joint coming together.
I did use a stop block also. Some how all the parts were not uniform length. I think there is a problem with the tool. I kinda hope someone has the same problem.
Sorry you had such a bad experience. I do appreciate you taking the time to post a possible problem with the miter saw. The miter saw is rather new and is a good quality as a matter of fact i have not even used it yet. All we can do is give you suggestions. A pentagon requires very precise cuts. that’s why the suggestion of test pieces was made. Is not a very common shape so you don’t have the alternative of a router bit. Example a hexagon they have a 30 degree router bit. If i remember correctly you would need a 36° chamfer to achieve a regular pentagon (even sided). Maybe a sharp blade and the table saw could be a solution but you did not mention the dimensions of the pieces, they may be too small. Im planing in being at the shop tomorrow morning if you want to meet and look for a solution.
@Richard.diaz Richard, thank you for the detailed responses and pictures. One thing additional thing to consider beyond @JOSEGAYTAN remarks is when making the cut as you described it, is how much wood you were actually trimming off the ends. If you were trying to cut as close to the edge as possible, the saw blade may very well wander as there not enough of a saw kerf to hold the saw blade in place as it cuts.
I’m an early bird at the wood-shop usually arriving at 5:00 am. If your up early, I’d be happy to work through this with you.
Thank you for the advice. I was doing 36 degrees. I did a protoype box with poplar on my bandsaw at home. I think when I recut them I will do it at home.