DOMINO XL CROOKED CUTS

[LOCOMOTIVE]

Looking for help! I have had my Domino XL for a couple months now, and everday find something new to use it for - the problem is from day 1 it has seem to cut crooked... The left side of the cut is always a hair lower than the right end, and the hole even dips down at left edge, and up on the right edge. So when you insert the domino, and put the two pieces together you have to twist the two pieces to be joined for them to be flush.
So browsing the internet for a solution, I have thought it to be operator error, and have tried numerous times to correct it, built jigs to help with holding product, slowed down, sped up, distributed weight,etc.... I am starting to doubt it being operating erorr at this point... My only way around this is to sand my tenon material down, which is a stupid work-around....
First, should the domino cut be straight and parallel to the top surface?
Second, should the cut be perfectly linear, or should the bit dip on one end and rise on the other (I can't seem to find any closeups of a cut from another machine to verify)?
Third, is Festool proactive is fixing this issue, or has anyone else had problems??

Big $$$ for no owner adjustability. I am trying to put this into a daily production machine, not just a once and a while tool, but it is driving me nuts!

 

[peter halle]

First,  [welcome] to the FOG.  To answer your major question, what you are experiencing is not to be considered normal.  You seem to have made all the normal adjustments to operator style to adjust.  I might suggest that you try to flip the fence up and while the machine sits on a flat surface make a cut into something that is also on the same surface.  Look at that cut and check for parallel.  Then have this info in hand when you call Festool.  Festool is very proactive in trying to help their customers.

Peter

 

[Birdhunter]

That's a neat trick!

 

[Administrator_JSVN]

Welcome to the forum. Sorry that you're having trouble with the XL.

It sounds like you've ruled out some of the more obvious and user-induced reasons for mortise issues. The most common is probably plunging too fast which can cause a climb cut since the bit is rotation while oscillating.

It's possible that there is a problem based on what you've written. The short answer to your questions: it doesn't sound like your tool is working properly and it's definitely supposed to cut parallel to the surface of the material.

There's no widespread issue with the machine, so there's nothing to be proactive about on a broad scale, but speaking of being proactive...

Can I assist you in getting the tool in for us to have a look at it or have someone give you a call to troubleshoot via phone? If so, please send me an email with your full name, address, and phone number and we'll issue a return shipping label to get it picked up.

If possible, feel free to share some photos here on the forum of your results if you feel it would be helpful.

Shane Holland
Festool USA
sho@festoolusa.com

 

[LOCOMOTIVE]

I just ordered a new 8mm cutter, and I am going to give this a try first. When I use the 12mm cutter I have, the problem seems to go mostly away (or at least isn't as pronounced - and it cuts linear and doesn't pull up and down at the end of the cut). The 8mm bit seems to pull more when it cuts, not sure if it is dull or slightly out of true.... Seems a possible cause? If not it might be time for a trip back to the factory....

 

[Administrator_JSVN]

I think you would notice a wobble while cutting if the cutter was out of true. Also, a visual inspection would probably be able to detect it by looking at the cutter while it's running through the "window" in the fence. But, it's plausible. Keep us posted.

Shane

 

[Stone Message]

Hi Locomotive and Welcome to the FOG

When using a Domino one needs to do the plunge reasonably slowly, partly to let the cutter do its job but also to allow the dust to get taken away. With the larger DF700 a slightly slower rate of cut makes for a more stable (and hence more accurate) plunge. The fact that you have had good results with the 12mm cutter (stiffer lump of metal) and not so good with the 8 mm one seems to suggest that a slightly slower plunge would help.

If you try this and I am wrong at least you will have ruled this out as a possibility.

I am right handed and use my left hand on the front grip. If you do a cut when the front fence is upright (as you would if doing a plunge into the surface of a sheet of ply) then the Domino will be less stable and you need to compensate for this by clamping a support piece in place or taking things extra carefully.

Peter

 

[bkharman]

I have had my 700 for a few months and have never seen/felt anything like you describe.  I also run the Seneca bit adapter and have cut numerous small mortices (5 and 6mm) and never had an issue.

The only tidbit of info I may have is that I wanted to make a little octagon on a friends decking and had to take my sweet time as it was into Ipê.  i was running an 8mm bit there, and didn't notice anything abnormal but i did have to plunge several times to ensure that it was going slow and clearing the cut properly.

One other thing that I often do with my 700 (not sure if others do as well) but i don't always hold and plunge with the handle.  Similar to what a lot of 500 users do, I hold the back of the 700, cradling my four fingers under the back venting area with my thumb up near the handle.  I don't always cut that way, but sometimes when i have to be particularly slow, it helps.

cheers

Bryan

 

[John.Y]

I've only had my 700 for a week and I am definitely noticing the same issue.  I thought it was my bad technique as well and even tried to switch hands (I'm right handed) but it is still crooked when two pieces are put together.  I then tried what Peter suggested by putting the fence up and laying the machine down on a flat surface and plunging in but the alignment is still crooked when two pieces are joined.  With the mortise closer to the surface of the board, I can see one side is closer to the edge than the other.  I'll try to get some pictures tomorrow night.

-John

 

[jacko9]

I just ordered a new 8mm cutter, and I am going to give this a try first. When I use the 12mm cutter I have, the problem seems to go mostly away (or at least isn't as pronounced - and it cuts linear and doesn't pull up and down at the end of the cut). The 8mm bit seems to pull more when it cuts, not sure if it is dull or slightly out of true.... Seems a possible cause? If not it might be time for a trip back to the factory....

Let us know what happens when you get your new 8mm cutter.

Jack

 

[John.Y]

Below are some pictures using the 8mm bit brand new from the 8mm/10mm XL kit.  I tried both methods using the fence and using the base and both turns out to be crooked about the same.  Maybe the plane where the bit is oscillating is not aligned properly?

To be perfectly honest, I'm pretty disappointed.  This is my first Festool purchase, 700 with CT 26 Vac, and I'm not sure to do at the moment.  Either return it to the store before the 30 days or send it out.  Will they let me return it and order another one?  Maybe this one was just a lemon.

 

[amt]

I had encountered some slight angle in my mortices, so I resorted to literally clamping the wood to the fence to see if it was my technique.  It turns out it was.  When I clamped the board to the fence (very securely and the wood perfectly against the XL) the cuts were perfect.  I have been able to improve my technique, but even now I sometimes move or apply too much pressure to one side while morticing.  I have actually thought quite a bit about different clamping jigs I might want to experiment with.  Bottom line (for me) is that if I need to be 100% sure I get it right, I find some way to reduce the risk of movement as much as possible when using the XL.

Now that's not to say you have the same problem.  But if you can securely clamp the wood to the fence, so there is zero possibility of any movement, it might be worth a shot to see if the mortice is perfectly parallel to the wood.

 

[amt]

In your second picture, are those the two boards which are joined together?  I am not quite certain if that is your test.  If it is, it's no surprise they are not even, since on the bottom board, the fence mortice is way off compared to the top board.  Then again, I may not be understanding how this test is being conducted.

 

[John.Y]

0488.jpg shows the reference surface of the two boards joined when using fence for both mortises.

0491.jpg and 0492.jpg shows both sides of the boards when joined using the base of the DF700 as the reference surface as Peter suggested. The boards were clamped down for the plunges.

0490.jpg is showing the mortises.  One board is slight thicker than the other but when you join them, the reference surface side should be even and the opposite side should have an offset.

I took a dial caliper I had on hand and measured the far side to near side of the mortise (see attached photos).  Looks like there may be three thousands of inch off.  I admit, this is a crude measurement but it's something to work with.  Three thousands of an inch is about 0.076mm error over 13.5mm.  If my math is correct, the oscillating action of the drill bit is roughly 0.3 degrees off from being in parallel plane to the base plate.

I hope it's just my technique and not the tool but it shouldn't be that difficult.  Especially when I clamped the board and held the domino down flat and plunge very slowly.

 

[Administrator_JSVN]

John,

The arrow in this photo denotes the reference face, right? I added another "Base" to make sure I'm understanding the photo correctly. If so, I'm not sure how the result was achieved. If references both of those pieces off the base, the offset of the mortise from the face of the wood should be the same, or at least very close, and it is not. The space colored in yellow is what I'm referring to as the offset. That distance looks too far off to be referenced from the base unless I'm not understanding correctly.

Is it possible the fence is moving when you're using it as a reference? Check the measurement on the scale before and after to see if it's moving. Crank down on the lever to make sure it's securely locked.

Do you get the same results in a soft wood?

[attachimg=#]

 

[John.Y]

Sorry for the confusion.  The fence is being used at all on the "Base" plunges.  The arrow pointing to the surface is what I call the reference surface.  The bottom of the DF700 is the tool's reference surface and the arrow pointing to the surface is the board's reference surface.  The attached picture, 0495, shows the setup of the plunge without the clamps.

What you highlighted in yellow is difference thickness is because the boards are difference thicknesses.  This shouldn't matter because the bottom of the DF700 to the middle of the bit is 15mm.    However, I should have been measuring the mortise to the reference surface incase the board was wedged shape and not parallel.  See attached.  My measurements aren't perfect but I can see a difference.

 

[Administrator_JSVN]

Sorry, I missed the bit about the thicknesses being different.

It looks like there's a gap between those two pieces of lumber. If there's a bow, that could explain the difference in your measurements. I think there are a lot of variables at play. Maybe using some dimensional lumber that's known to be flat, equal thickness, etc. would eliminate some of those variables.

If the mortises are skewed, it's most like that the plunge speed is too fast. That causes the bit to climb since it's rotating.

Shane

 

[John.Y]

I'll keep trying. 

Is there suppose to be a rattle when you shake the DF700?  Maybe from a spring or something?  Mine seems to have something that sounds like a loose screw in it.  It doesn't sound like the drill mechanism when you wiggle it side to side. 

 

[Hookie]

Welcome to the FOG...

Sorry you are having problems with your new piece of kit.
My little tale might help:

I had one of my earlier Domino joints finish out of line. (The mortices were truly horizontal, but the rail was slightly off centre to the style.) I couldn't work out why, but I had noticed a slight wobble as I plunged.
It turned out to be my 'novice' technique, and my old battered workbench surface.  

To be safe, I made an MDF base board, and an accurate, right angled fence. The fence is about 2 feet (600mm) wide and 5 inches (125mm) high. I clamp the fence to the board and use the domino with the work held against this fence., with the board (which I KNOW is flat), under the work. With the work stable on a truly flat surface, I have had no problems since. (As long as I ensure the material is truly square to begin with.... Of course!)  [big grin]

I almost forgot... My home-made fence is all but redundant now, as I have finally taken the plunge ( ;D) and got myself an MFT 3. Oh bliss!
HTH  

John [smile]

 

[Stone Message]

I think John's comment and advice makes a lot of sense. Ages ago I had a slow motion shot of one of my Domino cuts and I too did a 'wobble'. I too have corrected my action and I do take care when making cuts.

The bench surface is important and it is a mistake to do any domino work on anything other than a flat solid support.

Peter