Domino fence slip fix - my solution

[Samurai Dave]

Here's what I did:  (double-click images to enlarge for a more clear view)

1 ) Disengage the fence from the motor (as if you are going to change a cutter bit)

2 ) Locate the black plastic Limit Stops
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3 ) Notice the retention "lip" on the Stop
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4 ) With a pair of padded pliers (or wrap tape around the teeth) slightly lift up the front of the Stop to clear the retention lip. Pull back.
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5 ) Here's what the Stop looks like after it has been slid backwards.  Remove them.
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6 ) The fence can now be slid up and away.  Put the other Domino parts far away, so metal filings don't get onto them.
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7 ) File the face of the arresting surface FLAT with a fine metal file.  Be gentle.  The aluminum is soft and will gouge easily.  It doesn't need to be completely shiny, just the majority of it.  (Now is NOT the time to be getting out the belt sander and using it instead of a hand file.  Too much metal will be removed, and you'll have a frowny face.   )  Filing at this angle helps mate with the teeth on the fingers that apply pressue to arrest the movement of the fence.  You may be tempted to run your finger along the surface to test for smoothness, but resist this temptation.  You finger will deposit skin oils on the surface of the metal, defeating the purpose of this whole process.
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8 ) While we have it disassembled, the sides of the base have some flash on them that prevent the Cross Stop accessory from snugging-up against the base properly.
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9 ) Gently file each side of the base plate.  Keep the file square to the surface.  Again, it doesn't have to be completely shiny, just the majority of it.
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Blow/wipe ALL filings away.   (The last thing you want are problems caused by metal chips!)  Reassemble, and you are good to go. 

If the Festool folks are looking for suggestions, adding these few steps to your process at the factory would make an already impressive machine close to perfect.

UPS had just delivered my Domino today.  8)  I had been forewarned by several posts on the FOG about the fence slipping, so that was my first order of business.  Upon examination the explanation is pretty clear.  I have a fair amount of metal working background, and I can see the issue.  The surface of the fence being clamped is a raw aluminum casting, which has oxidation (which rubs off easily, acts like a lubricant).  Also the part has been machined which means it has taken a bath in coolant (cutting fluid) which contains mostly water (to cool the cutting bit and remove swarf) and some oil to keep down rust on the machine (the CNC mill, not the Domino).  To expect the movement of the fence to be arrested with those strikes against it is a very tall order.  I clamped the fence, right out of the box, to maximum pressure.  I then applied some downward force and the fence slowly slid downward, as suspected. 

Being one of those kids that always disassembled things (but then had problems putting them back together  ) I couldn't resist attempting a fix to this otherwise wonderful machine.  (I have improved my rate of successful reassembly over the years...)

After the simple filing, I clamped the fence and applied downward pressure.  No movement!     Then I really LEANED on the fence, still no movement.   ;D  You may have to adjust the clamping pressure by backing-out the screw and moving the lever a few notches.  I adjusted mine 2 notches and have plenty of clamping pressure now.  Can't wait to actually make some cuts and install some dominos!

 

[Brice Burrell]

Dave, nice work! While I wouldn't recommend anyone do this kind of modification for fear that it might void the warranty. I believe Festool generally doesn't want customers attempting to fix new tools or ones still under warranty. Not because they don't want the tools to work but because more often than not the customer does more harm than good. I'd like to hear what Festool has to say about this fix.

Again, great work on the documentation.

 

[Samurai Dave]

Good point, Brice.  Not sure about how this modification will affect the warranty.  I suppose to be "safe"  I need to assume my warranty is now void.   :'(

Out of the box, the slippage was to the point that I would have had to send it back.  I was pretty sure any replacement would have the same issue.  UPS is the only winner in that game.  Frankly, I didn't want to go there.  The advantages of the Domino are not available in any other power tool (that I know of), so I took the risk to make the modification myself.  The simple fix did work, so I'm a happy camper.   ;D  Being a weekend warrior I'll use it infrequently, so hopefully I won't stress it enough in the next few years to require warranty work.  The Domino is so well built I'm sure it will outlast me.

Again, only a few swipes with a fine metal flat file will do the trick.  Be gentle, since the aluminum is SOFT.  If your file loads-up with lumps of aluminum shavings, clean it with a fine wire brush before continuing.

At the risk of sounding like "fine print":

This modification to your Domino will most likely void your warranty.  Do not attempt this modification if you wish to keep your Festool warranty in effect.   

 

[Mike Goetzke]

I have a new Domino too. When I tried it out the first time I found the fence was slipping several thousands of an inch per cut. I call CS and they said to tighten it harder. I think the amount I have to tighten it will do more damage than your fix. Unofficially I have heard Festool has gone to a rougher surface spec of this face.

 

[Enrico74]

Dave,

I refrained from disassembling my domino several times for the same problem.
Mine is second hand so warranty is not an issue, but those black plastic stops that hold the fence were telling me "I will break if you dare to put pliers on me".
After reading, re-reading, re-re-reading... your post, I decided to go for this domino surgery.

All I can say is that my domino fence used to have a slipping problem

Thanks for the nice photos, that helped a lot.

Thomas

 

[Samurai Dave]

Thomas,

Good to know the fix worked for you.    Glad the pictures helped. 

I understand the hesitation when removing the dovetail stops from the top of the fence.  I kinda' figured that they were held-in with those tabs, but there could have been some hidden screw coming from the bottom (or some glue) holding them in place.  [Unlikely since I had studied the Domino parts diagram on the Festool website, but you never know...]  I was very relieved to see them slide back once the front of the stop was tilted up to clear the tab.  I figured worst case scenario I was going to have to order some new stops, but this is yet again another example of how prayer does work. 

Merry Christmas to you, and everyone at the FOG!

Dave

Dave,

I refrained from disassembling my domino several times for the same problem.
Mine is second hand so warranty is not an issue, but those black plastic stops that hold the fence were telling me "I will break if you dare to put pliers on me".
After reading, re-reading, re-re-reading... your post, I decided to go for this domino surgery.

All I can say is that my domino fence used to have a slipping problem

Thanks for the nice photos, that helped a lot.

Thomas

 

[Samurai Dave]

Mike,

Thanks for (unofficially  ) confirming the issue. 

I predict that if Festool incorporates those few steps into their machining process, they will find the number of calls to Customer Service for those new units related to this issue will be minimal.

As for the units already in the field... 

Merry Christmas!

Dave

I have a new Domino too. When I tried it out the first time I found the fence was slipping several thousands of an inch per cut. I call CS and they said to tighten it harder. I think the amount I have to tighten it will do more damage than your fix. Unofficially I have heard Festool has gone to a rougher surface spec of this face.

 

[Dave Ronyak]

Dave,

Thanks for documenting your "fixit" procedure so well.  I experienced minor fence slippage the first time I used my Domino machine, my machine was among the first lot sold to the public in USA.  To stop the fench slippage on my machine, I only had to adjust the clamp lever a couple of notches so I could tighten the clamp a little more than the way it came from Festool.  Despite a similar visible parting line/mold flash on my machine, I have not had any problems installing the Cross Stop (which I do not use) or the Trim Stop (which I do use).

Some points to ponder:

If the fence slippage problem is primarily due to residual cutting lubricants between the parts of the clamping mechanism that depend on friction to hold a setting, why not simply remove those lubricants by using a spray of degreasing solvent such as that sold by automobile parts stores as "brake cleaner"?

I am not a metal working expert, but I have worked a bit a little with products made of aluminum.

You're correct that aluminum naturally forms an oxide layer on its surface; that's why it doesn't quickly corrode completely away.  If a manufacturer really wants to protect the aluminum against further oxidation, the aluminum parts are anodized after machining, and possibly thereafter additional protective coatings are applied.  As you may know, there are many different aluminum alloys and many different anodizing procedures which produce different final results.  Absent a quality (hard) anodized surface treatment, I think it likely that unlubricated aluminum parts rubbing on one another or most other common metals such as steel are going to create fresh aluminum surfaces that are going to be prone to further rapid oxidation.

I cannot dispute that your teaching of judicious filing works, your testimony and that of others who applied your technique are proof enough.

But could it be that your "fix"may be the result of tetter engagement of the parts when clamped as well as removal of the residual cutting lubricant?

Dave R.

 

[Samurai Dave]

Howdy Dave!

Sure.  Any method used to increase the coefficient of friction between the clamped parts will arrest the fence movement.   There are probably other ways to accomplish this, other than taking a file to a brand new tool, as I did.     If "wearing away" the oxide layer by allowing the fence to slip to scrape the metal will do it, then terrific!   

I didn't attempt the degreaser option, but if it were swabed (not sprayed) on only the clamping surfaces, then that might remove any residual lubricants.  (Not sure how it would tackle the oxidation, which is the main culprit.)  "Degreasers" can etch or discolor the surface (metal or plastic), so spraying it on is not a recommended practice.  Perhaps someone else with a new Domino can try this option and report back to the FOG.

Being a metal worker, the solution was pretty straightforward.  I am used to repairing or modifying tools.  Since it only required a pair of pliers and a flat file, I figured I would share it with the FOG; and hopefully the Festool folks will enhance their production process as well.   

Merry Christmas!

Dave

But could it be that your "fix"may be the result of better engagement of the parts when clamped as well as removal of the residual cutting lubricant?

Dave R.

 

[Warrior]

I got my domino when they first came out and the fence slipped a bit. To fix the slippage I only adjusted the clamping lever. I use the domino frequently and recently completed a project that had 448 mortices on 56 different parts. The fence held just fine with the first piece morticed joining up perfectly with the last piece morticed.

 

[Novice Dave]

Dave - Thanks for the tip.  I found this Owner's Group while looking for some data on the Kapex.  Out of curiosity I joined and then read your post on the Domino slippage.  I could never figure out why it was doing it.  Now I know.  I love the tool and have done alot of joinery with it but alwasy had the slippaged problem.  Have not yet tried to fix mine but will look into it.  Thanks

 

[Samurai Dave]

Howdy Dave!

Welcome to the Festool Owner's Group (FOG).  Glad you liked the tip on the slippage fix.  The FOG is a unique forum for a unique brand of tool.  The members of the FOG are very helpful and want to share ideas. 

I normally do not buy a new tool design (like the Domino) the first year it is out, because anything that is in its first released is gonna be a beta-test.  However the Domino is a radical departure from any other joinery tool, so it was too good to resist.  The Domino had some teething problems.  However, the FOG kept me aware of the latest issues and I knew what to look for when mine arrived. 

After resolving the fence slippage I:

1.  Calibrated the locating pins (used Page 21 of Rick's TERRIFIC manual)
             http://www.festoolusa.com/media/pdf/domino_df_500.pdf
2.  Insured the slots were cutting true (not skewed as some posts have warned)
             http://festoolownersgroup.com/index.php?topic=5099.0
3.  Confirm the thickness of the domino inserts (some are too thick, fit way too tight)
              See Dave Ronyak's post (2/3 the way down the page)
             http://festoolownersgroup.com/index.php?topic=5455.0

At the risk of sounding anal, I took all (several hundred) domino inserts and measured each one for thickness with a digital caliper.  The vast majority were .000 mm to .009 mm + or - the stated thickness.  After a few test fits, I decided my threshold is .100 mm over is too thick to use, and will require a trip to the belt sander to "kiss" the sides into tolerance.  The dominos that are .008 to .009 over-sized I set aside in a separate bag to use for a tight fit when locating critical joints. 

I'm sure the dominos left the factory at their stated thickness, but wood is a natural material and will swell or shrink (slightly) with the humidity.  Open the bag and let them acclimate to your environment for a few days BEFORE making measurements.  The 5 mm dominos had the widest range of thicknesses, while the 6mm and 8mm had less variability, with the 10mm being the most consistent.  Now that I am confident the domino thickness is a known quantity, I can proceed with projects knowing my glue-up will not be interupted (as often) with a too-tight domino.

After cutting some slots in scrap pieces, I feel confident I can use it to complete a current project.

Good luck with your Domino.  It is a very innovative approach to a age-old woodworking technique for joinery.

Happy New Year to you, and everyone at the FOG! 

Dave