Domino DF500 Accuracy/Alignment Issues

[Bugsysiegals]

I bought a DF500 today, figured I’d better test it before 30 days is up, and I really can’t believe my eyes ... I’ve not been able to make one flush joint yet!!

Here’s what I’ve done so far ...

I pushed some strips of 3/4” Maple Plywood up to my bench dogs, clamped the wood, set the DF500 on top of the MFT/3 table, aligned the finger with the edge of the wood, the face of the Domino tight to the face of the wood, and plunged slowly (7-10 seconds). I repeated this on the other end and then on the other piece of plywood.  Afterwards, I could see the surface wasn’t flush and my fingernail catches if I rub it across the pieces. When looking at the end, I can see the offset of the layers in which I’d be likely to sand through the thin veneer which seems terrible. How much variance/offset should be considered normal/acceptable?

I repeated the process above using different clamp pressures to ensure I wasn’t deforming the board, moved the clamp in different positions, and had the same end results.  I then tried several tests with the fence in the down position, with the bottom not touching the MFT/3, and had the same end results.

At this point I felt like Deja Vu as this was the exact same experience I had with my DF700. I decided I better check the wood is flat before my next test since I’d not done that previously and to my surprise, the pair I was going to use next were not completely flat. I’m considering the previous tests inconclusive and confirming the wood is completely flat before all future tests.

I couldn’t find any scrap Maple which would align perfectly but found some 5/8” Baltic Birch which did when checked on my table saw so I figured I’d give it a try; however, when I re-checked it on my MFT/3, I found it was no longer perfectly flush! While not terrible, it’s not completely flat, so I figured I’d need to eliminate the MFT/3 from the variables.

I then moved over to my table saw, locked the fence, clamped a stop block to it, wiped the table and plywood, put the plywood up to the fence under my JessEm Clear-Cut TS Stock Guides, and pushed it up against the stop block. I then wiped the bottom of the DF500, laid it on the table, ensured it was resting flat without any wobble, and plunged. The joined pieces were no longer precisely flush and actually have a slight bowing when joined. I thought perhaps the edges weren’t 90 degrees so I separated them just a bit but the pieces remained bowed. It seems either the Domino isn’t cutting parallel, I’m not holding it flat (definitely am), I’m plunging at the wrong speed and the bit is wandering, or the wood somehow lifted as I plunged.  I’m going to test again but find a different method to clamp the wood so I know it’s not the wood lifting.

All that said, please help me understand the best way to test the tool to determine if it’s the tool or me...

What wood should I use to test with?  Should I buy something like MDF, try to find some plywood that’s flush, or mill some hardwood?

Should I stick with the table saw surface to ensure I’ve the best flat reference for the wood/Domino or should this really not matter?

Should I continue to set the base on the surface, rather than using the fence, to ensure it remains parallel throughout the plunge?

Is there anything else I might be doing wrong or overlooking?

 

[ChuckM]

A few photos could've been much more helpful to understand what you had been trying..but were you resting your doimino joiner's fence on the reference face of both boards or were you placing the machine base on the table saw or mft?

 

[Bugsysiegals]

A few photos could've been much more helpful to understand what you had been trying..but were you resting your fence on the reference face of both boards or were you placing the machine base on the table saw or mft?

I don’t have photos at the moment but will try to upload some tomorrow. 

I tried it with the machine base flat on both the table saw and MFT/3 as well as resting the fence on the reference face of both boards while the boards where clamped to the MFT/3.

I figured the machine base method is more foolproof than the fence which is why I started with it but didn’t rule it out of my testing.

Sent from my iPhone using Tapatalk

 

[ChuckM]

Boards can vary in thickness or flatness, so any test should be done registering the fence against the top & reference face of the boards to be joined, not by resting the machine base and boards together on a surface.

Even if the table or surface upon which the boards are placed is not dead flat, it doesn't affect the result.

Make sure the end of the boards overhang from the table saw or mft edge before you make the plunge. Lock the fence tight too.

It's not acceptable to me if the boards properly mortised are off by the amount you described. No sanding should be needed to bring them flush.

 

[Bugsysiegals]

Thanks [member=57948]ChuckM[/member], I tried using the fence for this reason but when it didn’t work I went back to the base method thinking it would be more foolproof.

It’s clear now that using the fence will align the top and using the base will align the bottom; however, the fence, assuming you hold and plunge the Domino correctly, will be more accurate since the base is affected by uneven warped surface like MFT/3, clamping pressure school may compress layers, etc. 

I’ll follow your suggestions and run several tests tomorrow or Monday with the Maple plywood since it’s what I’ll build cabinets from and attach some pics.

 

[wmarazita]

It seems to me that if you use the base of the Domino referencing on the table of.....anything, you will introduce the possibility of an error (warped table, different clamping pressure, debris under the Domino, the wood not lying flat on the table, etc.) I always use the Domino fence against the reference faces of the pieces I am joining, unless this is not possible for some reason.

One thing that hasn't been mentioned, but you need to check, is to make sure that your Domino fence is locked down well with the locking lever and that you have checked that it is square to the Domino cutting surface. The detent stops should be accurate, but need to be checked to rule that out. In other words, it is crucial that the cutter plunges into the test pieces precisely parallel to their faces.

I would also suggest trying a pencil line across the two boards you are joining and use those as your marks for your mortise locations. This will guarantee that those two faces will be oriented correctly when you check for fit (make sure you see both pencil lines when you are checking for fit or else you have inadvertently turned one of the boards over.)

Once you are referencing both mortises off of a locked-down, square fence, apply downward pressure and pressure into the wood you are mortising and then plunge. A five second plunge rate for each mortise seems to work well for me. Consistent downward pressure so the fence doesn't come off of the face is most important part of the technique. The Dominos should fit into each mortise snugly on their faces. If you do all of this and are still getting finished surfaces that aren't flush, it seems to me there is nothing else to check or try on the Domino machine itself. I'm not really sure what defect there could be in the Domino machine though that could cause the misalignment and would still suspect an operator error of some sort. Although there are a lot of settings, it is really a pretty simple machine.

Two more things to remember (which may or may not be obvious):
1. You can only expect for the reference faces to be flush unless the two pieces of wood are exactly the same thickness (plywood is notorious for thickness irregularities throughout the same sheet and may not be flush on the non-referenced sides.
2. You can only expect for the reference faces to be flush directly over the locations of the Dominos.

 

[ChuckM]

To be clear, even if two boards are not the same in thickness, they can still be flush on the reference side when the mortises are properly cut.

The machine's base is not designed to be used in the manner the OP described for joining. In a joining operation, the fence should be used.

 

[Bugsysiegals]

To be clear, even if two boards are not the same in thickness, they can still be flush on the reference side when the mortises are properly cut.

The machine's base is not designed to be used in the manner the OP described for joining. In a joining operation, the fence should be used.

FWIW - I always lower the fence with it upright and gently set it in place before securing it firmly.  I then lower the fence and ensure it's firmly secured.  I checked the fence height on both sides with the base sitting on my table saw and they seem very close in measurement and I'd say for sure less than 0.10mm and probably less than 0.05mm (hard to hold it absolutely still).

I’ve cut several pieces of Maple plywood to the same length, squared pieces next to each other, and put 2 lines on each piece for visual reference only as I'm using the alignment pins.

View attachment 1View attachment 2View attachment 3

For Test #1, I clamped the wood so the end was hanging off the table, slid the Domino up against the reference pin, squared everything up, clamped the fence to the board, and carefully plunged while keeping an eye that the White dots didn’t raise (rear raising) and that the fence where the dots are located didn’t create any gap (front raising). One end seems close while the other is not.

View attachment 4View attachment 5View attachment 6View attachment 7View attachment 8View attachment 9

For Test #2, I repeated the steps above but didn’t clamp the fence to the wood. I’ve similar results.

View attachment 10View attachment 11View attachment 12View attachment 13View attachment 14View attachment 15

Before I perform anymore tests, should the lines I drew before joining be this far off when using the reference pins?  I suspect most people use these if you only need to place a Domino at each end of a shorter board but every piece I've done with the pins would require clamping and forcing to make flush which seems to defeat the purpose of the pins...

Any other feedback and what I should do differently in the next plunges is much appreciated.

 

[ear3]

When you say you clamped the domino fence to the board, what do you mean?

 

[Bugsysiegals]

I used an Irwin Quick Clamp to secure the fence to the work piece in order to rule out operator error of tilting the Domino. I did not use the clamp on Test # 2.

To further rule out operator error I could flip the Domino upside down, clamp the work piece to the fence, and plunge it in this way if it’s helpful?  I’m not happy with the quality of the images here so I may re-rip the wood with reference side up to get better clean lines?

 

[ChuckM]

A few things:

P. 21 of the manual shows how to calibrate the Edge Stop Dogs/paddles/stop latches, if your machine's paddles caused a misalignment of the pencil lines.

I set the fence height with the fence in its folded position, lock it before setting the fence to 90* and lock the fence (I read somewhere that setting the fence height while the fence is at 90* could move the fence as the fence is tightened or something like that.)

Based on your tests, the problems described didn't seem to be caused by user errors.

 

[ear3]

Hmmm -- I would probably not clamp the fence down to anything for danger of material and machine flexing.  Have you watched videos of normal plunging operations just to get a sense of what the standard operating procedures are?

I would say that to do eliminate variables for a proper test, I would use plywood that is wider than what you've been using with the test pieces.  Something wide enough (4+ inches) so that no portion of the fence is hanging off the piece.  And I would always use the fence when horizontally plunging on a board edge, making sure that the base is not touching any surface that could mess with the flat referencing of the fence on the wood.  Although there are a few rare occasions where referencing off the base on a horizontal plunge may be useful, normally you should do this only on vertical plunges.

It also sounds like you may be experiencing some issues with the pins and/or cursor.  There are a couple of calibration exercises you could go through that may help, including the cursor adjustment mentioned just above (I see [member=3513]PaulMarcel[/member] on the Forum so could also give it to you straight from the horse's mouth):
=UgzPoYULNJeMhD0Qb754AaABAg

In terms of mortise width for edge joining, normally you only want one pair of narrow mortises at the edge you want flush.  All the others can be on the medium setting to aid in fitting.

 

 

[ear3]

You could also check to see if the mortises are skewing relative to the plane of the workpiece (which would be caused by a skewed fence).  Check with digital calipers the distance from the top of the board of either side of a mortise plunged at the widest setting.

 

[ChuckM]

Snip.

I would say that to do eliminate variables for a proper test, I would use plywood that is wider than what you've been using with the test pieces.  Something wide enough (4+ inches) so that no portion of the fence is hanging off the piece.

[/quote]

Good point.

 

[Bugsysiegals]

It seems to me that if you use the base of the Domino referencing on the table of.....anything, you will introduce the possibility of an error (warped table, different clamping pressure, debris under the Domino, the wood not lying flat on the table, etc.) I always use the Domino fence against the reference faces of the pieces I am joining, unless this is not possible for some reason. 

Excellent point!

One thing that hasn't been mentioned, but you need to check, is to make sure that your Domino fence is locked down well with the locking lever and that you have checked that it is square to the Domino cutting surface. The detent stops should be accurate, but need to be checked to rule that out. In other words, it is crucial that the cutter plunges into the test pieces precisely parallel to their faces.

I put the fence in the 0 degree position, raise and gently lower the height of the fence, move the locking mechanism as far as it can move, lower the fence 90 degrees, and move the locking mechanism as far as it can go.  I've cleaned off my table saw, the Domino base/fence, and measured with calipers ... I've 0.13mm difference between the front sides of the fence to the table.  I've tried re-adjusting the fence several times and have the same result.

I would also suggest trying a pencil line across the two boards you are joining and use those as your marks for your mortise locations. This will guarantee that those two faces will be oriented correctly when you check for fit (make sure you see both pencil lines when you are checking for fit or else you have inadvertently turned one of the boards over.)

While I didn't mention it, I always draw 2 pencil lines to see if they align back together afterwards and also to ensure the work piece is in the correct orientation.  I'm using the reference pin rather than the clear scale as I know it's not aligned but neither are the reference pins.

Once you are referencing both mortises off of a locked-down, square fence, apply downward pressure and pressure into the wood you are mortising and then plunge. A five second plunge rate for each mortise seems to work well for me. Consistent downward pressure so the fence doesn't come off of the face is most important part of the technique. The Dominos should fit into each mortise snugly on their faces. If you do all of this and are still getting finished surfaces that aren't flush, it seems to me there is nothing else to check or try on the Domino machine itself. I'm not really sure what defect there could be in the Domino machine though that could cause the misalignment and would still suspect an operator error of some sort. Although there are a lot of settings, it is really a pretty simple machine.

I've adjusted my plunge rate, thanks for the suggestion.

 

[Bugsysiegals]

A few things:

P. 21 of the manual shows how to calibrate the Edge Stop Dogs/paddles/stop latches, if your machine's paddles caused a misalignment of the pencil lines.

I set the fence height with the fence in its folded position, lock it before setting the fence to 90* and lock the fence (I read somewhere that setting the fence height while the fence is at 90* could move the fence as the fence is tightened or something like that.)

Based on your tests, the problems described didn't seem to be caused by user errors.

Thanks [member=57948]ChuckM[/member] ... I've not read the manual yet and am relieved to know the paddles are adjustable.  I think I'm setting the fence the same as you, locked in 0 degrees, set height, then fold down to 90 degrees, all knobs locked as far as they can go?

 

[Bugsysiegals]

Hmmm -- I would probably not clamp the fence down to anything for danger of material and machine flexing.  Have you watched videos of normal plunging operations just to get a sense of what the standard operating procedures are?

Yes, I've watched many of [member=3513]PaulMarcel[/member] videos including this one.

I would say that to do eliminate variables for a proper test, I would use plywood that is wider than what you've been using with the test pieces.  Something wide enough (4+ inches) so that no portion of the fence is hanging off the piece.  And I would always use the fence when horizontally plunging on a board edge, making sure that the base is not touching any surface that could mess with the flat referencing of the fence on the wood.  Although there are a few rare occasions where referencing off the base on a horizontal plunge may be useful, normally you should do this only on vertical plunges.

I was worried about using thinner material which is also why I clamped the fence to the work piece but appreciate the suggestion ... I'll rip down some wider pieces for the next set of tests.

It also sounds like you may be experiencing some issues with the pins and/or cursor.  There are a couple of calibration exercises you could go through that may help, including the cursor adjustment mentioned just above (I see [member=3513]PaulMarcel[/member] on the Forum so could also give it to you straight from the horse's mouth):
=UgzPoYULNJeMhD0Qb754AaABAg

I figured it would be easier to use the pins and that I should ensure it's working well before spending time to adjust the cursor but I can align it and do a test with the cursor rather than the pins; however, I wonder if I'll be able to get good alignment regardless with the 0.13mm fence height difference per side...

 

[Bugsysiegals]

You could also check to see if the mortises are skewing relative to the plane of the workpiece (which would be caused by a skewed fence).  Check with digital calipers the distance from the top of the board of either side of a mortise plunged at the widest setting.

It's a bit difficult to get an accurate measure with the wood being soft, etc. but it's a good idea to get a ballpark although I know the fence is not parallel so I'm fairly certain they mortise will not be either.

 

[Mike Goetzke]

Maybe it's just me but your ply seems to have variable thickness in the photos.

 

[Bugsysiegals]

Maybe it's just me but your ply seems to have variable thickness in the photos.

You're correct; however, as stated previously, the distance from the reference surface to the mortise remains consistent, and therefore the joined reference surfaces should be flush with all inconsistencies on the bottom which nobody sees.