So I'm working on a project that has many firsts for me. First time creating mortise and tenon joints, first time using my mortise attachment for my drill press, first time using my table saw tenon jig. Creating the mortises went fairly well once I got the attachment set up properly. The tenon jig, not so much. I think I need to do finite adjustments with my gauge to make sure it's perfectly square to the miter slot. I used the table saw to cut part of the tenons and the band saw for the rest. My tenons ended up as trapezoid shapes instead of rectangles! See pictures below. This particular project doesn't require perfection, hence why I'm starting with it, but I'd like to learn how to do better for the next time around. Can anyone offer suggestions on what I did wrong and how to correct it for next time? Thanks!

 

 

 

Looks like the saw blade was was slightly off of vertical. I use one of the "Wixey Angle Boxes" to be sure the blade is 90 degrees to the table.

 

https://www.amazon.com/Wixey-WR300-Type-Digital-Backlight/dp/B00T6YZ0K6

I agree with Lew, looks like your saw blade needs tweaked. But check your tenon gauge as well...the face of the plate holding the work piece should be at 90° to the table as well.But I'd bet it's the saw blade.

Edited August 22, 20241 yr by Fred W. Hargis Jr

Could also be that the tenoning jig isn’t vertical. Check your jig fir square against the saw table

What table saw tenon jig do you have?

I have a Delta tenon jig. However, it was only used for part of one cut. The wood I'm using is extremely hard and seems to burn/smoke with the slightest cut. The tenons were mainly cut with a band saw. I stood the board vertically, used the fence on the band saw, and pushed the board through from the end to the shoulder. This caused the cut to be narrower at the shoulder and wider at the end. I didn't think to check the band saw fence and blade for alignment. I'll check the alignment and see what I'm dealing with. I've been painstakingly meticulous with the table saw set-up. I guess I should do the same with all of my other tools. So much for getting actual woodworking done this weekend. Sigh...  Thanks for the input everyone! Once I check things out, I'll report back. This has definitely been a learning experience... for the things not to do!

My Taiwanese bandsaw has a lot of drift and trying to cut a straight line, using a fence, is an experiment in futility. I really need to replace the "cool blocks" with bearing guides but they cost almost as much as I paid for the bandsaw!!

 

I have that Delta tenoning jig. It's a beast! I just always check to be sure the table saw blade is parallel to the table saw miter slot- my saw is a contractor type with the motor that hangs on the tilt trunnion. When I tilt the blade and then return to 90° vertical, the blade may no longer be parallel to the miter slot. That can cause burning. 

 

Also, when using the tenon jig, I check to be sure the vertical jig fence is perpendicular to the table saw table and that the saw blade is perpendicular to the table saw table

I had enough time today to pull out my alignment gauge and check the tenon jig. It was waaaaaaay out! That would explain why it didn't want to cut. After much time and effort, I finally got it aligned properly. I hope to check the band saw tomorrow.

 

Small side note... I have to say that the deluxe gauge from In-Line-Industries has been one of the best investments I ever made for woodworking. It's a shame the company has gone out of business. Jerry is (was?) a genius. I'd give the man a hug if I ever met him. The PALS and alignment gauge are two of the best products ever made for woodworking, in my opinion. Fortunately, Peachtree Woodworking is still producing and selling the In-Line products.

Looks like I'm going to have a second chance to make the tenons. I had everything assembled, glued, and clamped. When I went to put the posts into the base I discovered that I goofed in my measurements. I was off by a solid inch! However, this turned out to be a good thing because clearly my tenons weren't tight enough! I used a pipe clamp and popped everything apart. Now I will definitely double check and tune-up the alignment on the band saw before starting again. I guess this is what we call a learning experience?

Thanks for the suggestions and reminders everyone! I checked the alignment of the band saw last night. The table was not at 90 to the blade and the fence was not parallel to the miter slot. After much time and use of my gauges, I finally have the band saw dialed in.

 

I made the mistake of making assumptions about the machine. I bought it used from a retired woodworker. I assumed everything was aligned properly. I will never make that assumption again, even for a brand new machine.

...and check the alignment often.

Noted @lew and advice that I will remember!

 

So I remade the braces with the tenons today. It's amazing how well machines work when properly aligned!   I hope to complete the project tomorrow. If I do, I'll make another post so you can laugh at my blunders and offer suggestions for improvement for the next time around.

8 hours ago, Drumone said:

If I do, I'll make another post so you can laugh at my blunders and offer suggestions for improvement for the next time around.

  Experience is a wonderful thing; it helps you recognize a mistake when you make it again. 

On 8/31/2024 at 9:48 AM, Drumone said:

I assumed everything was aligned properly. I will never make that assumption again, even for a brand new machine.

Wise words.  My table saw, radial arm saw, and band saw all needed careful adjustment/setup before using.  All bought new. 

If your table saw blade is parallel with your miter slot then your fence is easy to keep parallel with your blade.  I have a 1947 Unisaw and the miter slot is 3/4”.  Since I used the miter slot to dial in the blade I can slap a 3/4” board into the miter slot and bump the fence against it to check it for parallel.  Fast and easy.

Hands down, one of the best investments I have ever made for woodworking machinery is the A-Line-It Deluxe alignment system. I swear by it! It has made the difference between a saw being literally unusable and making clean cuts easily. I'll spare you the details, but I probably should do a review of it here. That set does so many things, at an incredibly accurate level, that I can't recommend it enough!

Check your drill press 90° to the chuck and don't let any of that sawdust get under your tenoning jig on the table saw after you check it for 90°.