Domino 500 - mortise not parallel to fence

[JohnV]

I just got a new Domino DF 500 Q. Unfortunately I'm having the issue where the mortise slots don't come out parallel to the fence. It does it consistently so I don't think it's user error. I made up a demonstration of the problem with a pair of 6 inch long 3/4 thick pieces (see the pics). With a slot in the edge of each piece, I assemble them with a domino (5mm). You can see how the pieces are quite rotated with respect to each other. Googling this, I found several people reporting the same issue over the years, and in some cases the owner sent it to Festool for repair, only to have it returned unrepaired, with some version of "we tested it and it's within spec."

Is it safe to assume this is not something the owner can fix or calibrate? It's going to have to be sent back? I've only had it 10 days.

FYI I'm making the cut with the piece hanging off the edge of the workbench, and the tool base is not touching anything.

 

[Michael Kellough]

This is probably fairly common. At least mine is a little off too.

I minimize the angle by twisting the machine in the opposite direction of the off-angle. At least I think I’m making a difference.
There is so little play in the sliding part of the machine that it might not make a difference.

But this really doesn’t matter if you use two or more Dominoes.

 

[ChuckS]

This is probably fairly common. At least mine is a little off too.

I minimize the angle by twisting the machine in the opposite direction of the off-angle. At least I think I’m making a difference.
There is so little play in the sliding part of the machine that it might not make a difference.

But this really doesn’t matter if you use two or more Dominoes.

I don't think the twist is common among the domino machines; if it were, we would have had repetitive threads like the smoky Kapex EB's. If I recall it correctly, only 4 or 5 members have reported the twist issues (a lot more domino machines have been sold than the Kapex).

The local Festool dealership (one of the largest Festool ones in my country, which I once part-timed for almost a decade), never had any smoky or twisty issues during my time there within their warranty (after the warranty, owners deal directly with Festool).

 

[peter halle]

Not attempting to be insulting, but the vast majority of reported Domino issues have been user issues. It looks so darn easy, but it does take practice - and practice is more than 20 mortises.

One thing to easily check is if the fence is parallel to the base when it is sitting on a table. Won't that tell you if it is a machine issue?

Peter

 

[Michael Kellough]

My sample of one machine is pretty small, so maybe your machine could use an adjustment.

Peter, even if the fence is parallel to the base the mortising mechanism can be out of parallel.
I mostly use the machine with the Domiplate and the twist is still there.

John, ifyou need to butt a narrow stick to another piece and there is only room for one Domino the twist will make that near impossible so in that case a pair of dowels should be used instead. If you send your machine in for adjustment and it is successful, or if you replace the machine and the new one doesn’t have the twist, let us know. I might send mine in.

 

[Jim_in_PA]

I personally don't recall any other report of this issue and believe that Chuck is correct that if it "was a thing", there would be extensive threads about it. I suggest you carefully go over the machine and if you can find any actual variances from square relative to the fence, work a warranty replacement with Festool.

 

[Stevenski]

dang! that really is a twisted end product!

I'm afraid I have no useful advice to offer other than ask a probably stupid question: are the individual mortices parallel to the face they referenced from? ie is the distance from the top of the mortice to the edge of the wood the same at both extremes of the mortice?
Wouldn't this at least tell you if the cutter is milling a perfectly flat mortise?

 

[ChuckS]

I can't tell from OP's first image whether it is the surface or the stock that doesn't seem to be dead flat as I noticed gaps on one side. Maybe both are flat but the photo distorts them.

I'd suggest making a few test cuts with other flat stock (good 3/4" ply scrap) to rule out the stock being the cause for the twist rather than the machine.

 

[JohnV]

I can't tell from OP's first image whether it is the surface or the stock that doesn't seem to be dead flat as I noticed gaps on one side. Maybe both are flat but the photo distorts them.

I'd suggest making a few test cuts with other flat stock (good 3/4" ply scrap) to rule out the stock being the cause for the twist rather than the machine.

I've done this test with multiple pieces and it's always the same. The pieces in the pictures are factory milled 1x2 popular bought at Lowes. I also tried it with pieces I prepared myself. I have not yet tried it with plywood scraps, but I'll do that today.

 

[Michael Kellough]

I personally don't recall any other report of this issue and believe that Chuck is correct that if it "was a thing", there would be extensive threads about it. I suggest you carefully go over the machine and if you can find any actual variances from square relative to the fence, work a warranty replacement with Festool.

I know I’m not the only one besides John with this issue but it certainly wasn’t (isn’t) a big deal compared to Kapex motors going up in smoke.

When I have a bunch of single mortise joinery to do it’s worthwhile to set up a jig with appropriate shim, but it would be nice if I didn’t need to do that.

 

[JohnV]

I've done this test with multiple pieces and it's always the same. The pieces in the pictures are factory milled 1x2 popular bought at Lowes. I also tried it with pieces I prepared myself. I have not yet tried it with plywood scraps, but I'll do that today.

I tried a test joint this morning with two plywood scraps, and got the same "twist". But I also noticed that the layer lines on the plywood edge make the problem very obvious. Notice how the bottom of the mortise veers off the layer line.

 

[peter halle]

Going back to your original post, you can obviously return it under the 30 day policy. If you bought from a brick and mortar you can probably get them to just exchange for another one. If you bought online you should contact the dealer you purchased from for instructions. And of course you can initiate a warranty claim. I hope you bought from a brick and mortar so that a new tool that works better is in your hands sooner.

Peter

 

[Stevenski]

But I also noticed that the layer lines on the plywood edge make the problem very obvious. Notice how the bottom of the mortise veers off the layer line.

It certainly does look like something is off in the geometry of the milling. I agree with Peter's advice. Sad but a no-brainer - exchange it while you still can do so easily and without discussion. my 2 euro cents

 

[onocoffee]

Beyond the pics, perhaps a video of you making those mortises will be helpful. That way, it can be seen if it is user error. Like Peter said, it takes a bit more use than 20 mortises to get the hang of it. A lot of it boils down to technique.

 

[JohnV]

Going back to your original post, you can obviously return it under the 30 day policy. If you bought from a brick and mortar you can probably get them to just exchange for another one. If you bought online you should contact the dealer you purchased from for instructions. And of course you can initiate a warranty claim. I hope you bought from a brick and mortar so that a new tool that works better is in your hands sooner.

Peter

Yes I bought it from a brick & mortar store, so I'll see if they'll let me exchange it this week. I'll report back here how the new one works; hopefully it will be perfect.

 

[Jim_in_PA]

Yes I bought it from a brick & mortar store, so I'll see if they'll let me exchange it this week. I'll report back here how the new one works; hopefully it will be perfect.

Take some of your cutting examples with you to prove the point that the one you have is not working properly...but you already knew that...

 

[ChuckS]

I tried a test joint this morning with two plywood scraps, and got the same "twist". But I also noticed that the layer lines on the plywood edge make the problem very obvious. Notice how the bottom of the mortise veers off the layer line.
View attachment 379188

This test (sample board) should prove to the store that the machine needs to be replaced. Unless someone at the store can mill a perfect mortise on this board with your machine (which they might), user error can be ruled out.

 

[ReneS]

I just tested mine by making a single mortise in a piece of milled cherry. I measured the distance from the edge of the mortise to the edge of the board with a ruler, and it came out the same on both ends (sides?) of the mortise.

Occasionally, when connecting a rail to a stile with a domino, the rail will have a slight twist to it. I always assumed it was something in the wood since it didn't happen very often, but this thread made me wonder.

Given the test I just did, I am going to assume that when it happens, it is the wood or operator error. But given JohnV's experience, it also looks to me that it is a problem with the tool.

 

[Mini Me]

Clamp the machine to the board to eliminate user error.

 

[Cheese]

Clamp the machine to the board to eliminate user error.

This would be a great final test before you bring the DF 500 in for an exchange. As others have already mentioned, be sure to bring the previous test samples with you for show & tell.