Very Loose tenons with Domino XL

[Berber5985]

I’m working on my second project where I’m using my domino and I’m using the Seneca small mortise adapter for the first time and doing 6mm tenons in some rails. I did about 12 total for the project and every single one of my joints is very loose on top and bottom. Like a decent amount of play. The first project I did with the 8mm cutter and tenons was a table with rails and those tenons were tight as hell. I’m not sure it’s user error, the cutter, the adapter, etc. It’s got a fair amount of play in the joint where you can even twist them slightly. I glued them together like that so we shall see if they hold after they dry, but I was kinda deflated. Has anyone experienced this? Could it be user error on every single mortise even though my first project worked out perfectly or potentially another issue? Oversized cutter from the factory, wobble with the Seneca extension, etc?

 

[ChuckM]

Can you check the cutter's size as well as the width (height) of the mortises with a caliper? If they aren't the same, it could be due to the adapter and/or user error.

 

[ear3]

[member=74527]Berber5985[/member] Welcome to the FOG! Sorry you're having this problem.  There's a bit of a learning curve with the machine, but given your narrative I would try to rule out the adapter first. So run some tests without the adapter on all the cutters and see if you get tight mortises like you did the first time.  Then repeat with the adapter and the smaller cutters.

The only time I have gotten loose, oversized mortises with the XL was when using the CMT branded 10mm cutter.  Have never had a problem with the OEM Festool cutters.

 

[Berber5985]

I’m gonna give that a shot tonight and see if it’s just the 6mm cutter, the adapter, or myself. Just seems odd that it worked great for the first project and then really Loose for the 2nd project and all I changed the was the size of the mortise and the adapter. I glued up the project to see if it held together. Fingers crossed because I really don’t want to remake the whole thing.

 

[ChuckM]

It's hard to tell if the joints will fail as you didn't provide any info. on what they are. If it's edge jointing (panel glue-up), there should be no failure risk. On the other hand, if the joints will be subject to stress/racking, it's a different story. Many joints fail (chairs are good examples) only after a period of prolonged use.

 

[mrtmr]

I agree with the comment above about the learning curve. I found the surfaces weren't as nicely aligned with some of my first projects. But got better with practice.
I also found a correlation between the wider settings for the mortises and slightly offset joints. My preferred method that has consistently worked well is to mortise one side of the workpiece on the tight tenon setting and using a wider setting on the opposite side. I use this method for the aligning planks for tops, or detailed furniture/door joints. Only problem with this method is the cross stops work best for same width mortises.

 

[tsmi243]

Maybe you got my old one....

I exchanged it under the return policy, and the new one works just fine.