Help with panel glue-ups using dominos

Md woodworker

Member
Joined
Dec 19, 2014
Messages
23
Recently I glued up some panels using 5mm dominos and my new DF-500. The panels are 24" wide and made up of three 8" pieces. I noticed when clamping them that the joints are off anywhere from 1/64 to 1/32 in some places. Is this normal? All pieces were planed to a uniform thickness prior to assembly and the domino was referenced off of the same side of all the boards. Thanks in advance for any help.
                                        -Jon
 
No, it's not normal, at least in my experience. My Domino joints are finger tip test smooth.

Perhaps, it could be a flaw in your technique.
 
I had an issue when I didn't realize my domino base was touching the bench top instead of the fence bottom. After I discovered that I now make sure my work piece overhangs the work top before plunging.
Other than that they line up real nice.
 
You sure that you didn't flip the reference side to be underneath on some of the boards?
 
Edward A Reno III said:
You sure that you didn't flip the reference side to be underneath on some of the boards?

Edward, I'm sure. I marked the reference side when laying out the dominos. I'm thinking maybe the 90 degree stop on the fence isn't exactly 90 degrees, or the edge of the boards aren't  exactly 90 degrees to the face of the boards. I'm going to use the domiplate on some leftover cutoffs to rule out the domino fence and double check my jointer fence for squareness. Any other suggestions?
 
MD woodworker said:
Is this normal?

Check to see if the the Domino is making the holes parallel. There have been some users who have experienced twisted domino holes causing misalignment when gluing up boards.
Tim
 
Tim Raleigh said:
MD woodworker said:
Is this normal?

Check to see if the the Domino is making the holes parallel. There have been some users who have experienced twisted domino holes causing misalignment when gluing up boards.
Tim
Do you recall what the cause of the twisted holes was?
 
In my experience, the misalignment occurs from plunging too quickly.  I read somewhere on the FOG to plunge 1 second for every mm of thickness.  For your 5mm dominos, it should take about 5 seconds to plunge the hole.  8 seconds for an 8mm thick domino, etc.  That lets the machine plunge smoothly and easily without twisting and distorting the hole.

Steve
 
MD woodworker said:
Do you recall what the cause of the twisted holes was?

One side of the fence is moving slightly as you plunge, so you can check that. The cure seems to be to buy a  Seneca Domiplate. Some users experience this with 500's and some 700's. I don't have a Domino that does this, or rather I don't use mine to make panels so I can't say it's from personal experience.
tim
Tim
 
Not sure, but I think this may have something to do with it. It appears the fence is not square to the cutter face when the fence is in the 90 degree position.

 

Attachments

  • IMG_0559.JPG
    IMG_0559.JPG
    1.5 MB · Views: 656
That fence is way off; are you sure you have it seated and locked down?  The locking levers aren't the most secure in the world.

Ditto the plunge speed.  Initially I ruined a lot of wood until I slowed the plunge way down.

DrD
 
When I first purchased my DF 500 several years ago, I noticed that some holes were inclined and not parallel to the wood surface. There was a .015"-.020" difference in height from one end to the other. I just slowed down and paid more attention to the plunge operation.

I think the initial contact of the cutter with the wood surface is the most critical as that determines the tool path the cutter will then continue on. After that first moment of contact, the cutter just follows the "rut" that was made initially.

Ease into the wood and then plunge at a uniform speed.  [smile]
 
A splinter  can easily offset the boards.  I use a brush and blow the area with my mouth and still run into this.

Doesnt really matter to me tho since after the panel is dried, removing squeeze out removes all the offset.  Handplane also makes short work of evening out the panel.
 
In addition, observe yourself when plunging. Depending on how you hold the barrel of the DF500 when plunging, it's easy to raise it up slightly during the plunge. After cutting quite a few Dominos perfectly I found myself raising the barrel during the plunge one day. It wasn't much and it was hard for me to detect but, once I found the problem and corrected it, they were perfect again.

Of course, given your picture of the fence, it does need to be square, so correcting that first, whatever the problem (adjustment or repair) is important.
 
The picture makes it seem almost as if the fence is bent with a slight curve! 
 
MD woodworker said:
Not sure, but I think this may have something to do with it. It appears the fence is not square to the cutter face when the fence is in the 90 degree position.

I am not sure this would affect the glue up.
If your boards are accurately milled and there is no wave in the reference surface and you are getting a consistent 1/32 or so difference along the length of the joint, then yes it would be an issue. An inconsistent difference points to the fence moving or as others have noted an unsteady feed. Do some experiments with you feed rate and see if that introduces the problem.

Tim
 
Looking at your picture of the Domino fence, it appears bowed. If actually bowed, you could get a rocking chair effect as you cut the mortises. A bowed fence would make cutting accurate mortises very difficult. I'm not sure if a bowed fence would cause the mismatch you are getting, but it's a possibility.

My guess is that the Festool dealer would exchange your Domino for another one if within the return window or Festool service would fix your machine under warranty.
 
I checked the fence on my Domino 500 and it is perfectly flat with none of the bowing shown in your photo. When set at 90 degrees to the cutter face, it is perfectly square.
 
[member=15289]Birdhunter[/member]

Thanks for checking your fence. I was able to getter better results by modifying my grip on the domino, but the joints still aren't perfect. My next step is to contact the service department.
                                                                                                                                -Jon
 
Back
Top