Domino seems to be cutting oversized mortice

[matt.mackinnon]

I recently bought the DF500 Domino, and I just can't seem to get the unit to cut the mortice the right size.  I am using the 5mm cutter and for whatever reason, the mortice is  between 5.5 and 5.7mm thick.  The width also seems to be oversized too.

I have called Festool and they suggested trying a different cutter head as I have a spare 5mm that came with the Domino Tennon Assortment pack.  The new cutter didn't make any difference.  I also tried cutting at different feed rates and just practice cutting to see if it was me moving the cutter.  But no luck.

Is there something that I could be doing wrong without realizing it that would cause this.  It's hard to say if it's a Stupid User Error, or a defect in the unit.  Any help is appreciated.

Matt.

 

[dltflt]

Have you tried a different size cutter?  It should not make a difference but is worth a try.  Try plunging slower.

 

[Administrator_JSVN]

Matt,

What type of material are you mortising?
Are you measuring the mortise or just guesstimating the size as compared to the tenon?
I, too, would recommend another cutter and tenon size which would help eliminate the tenon being undersized or other possibilities.
Are you making multiple plunges into the same mortise to "clear" it out?
Are you using dust extraction?
Are you going into end grain?
Are you making a horizontal mortise or vertical into the face of the material with the Domino standing up?
Is it every mortise or just some?
Do you have one hand FIRMLY on the handle on the fence and use the other hand holding the machine way back near the power cord while plunging?

Sorry for all of the questions but the more we know the better the odds someone will recognize what's causing the problem.

Shane

 

[jvang]

I recently had the same problem. My supplier sent it in for me, the returned it is a very short period of time. Before i sent it in I tried the 8 mm bit and it was slightly better than the 5 mm that would actually fall out of slot if you turned it over. After getting back I purchased a new bag of 5mm and 8mm domino's. I ran a test of approx. 60 of each size on three different woods. The adjustments they made to machine mad the 8mm much tighter and many had to be tapped in with hammer. The 5mm was better and could be very easily put into to slot, no of them needed to be tapped in and none fell out when turned over. I am concerned over the next year it may wear loose and the slot become larger again. The paperwork the sent said unit was ok.

I have asked for the tolerances Festool allows and expects and was told they do not share.

I suggest sending in to have reviewed, the turn around system they have works well.

For those wondering, when i ran my test i did half with a clamp on the wood to machine and clamped to table. the other half were done free hand with no clamping to machine or to table. The results were the same as i mike'd each slot.... after showing to my supplier he said it's not about technic (spelling?)

in some ways i feel like returning for replacement and in another i feel like just living with it.

Sorry Festool.... just being honest!

john 

 

[ccarrolladams]

Matt and Everyone,

Please remember there is no other power tool working the same was as a Domino! Because to work its magic the cutter is both rotating and swinging from side to side, the Domino mortiser vibrates differently than any other tool.

This means there is a significant learning curve for the Domino. Probably the best way to shorten this learning curve is to receive expert coaching.

Most of the Festool End User Training Classes include use of the Domino. Without question the two most experienced and talented Domino Coaches in North America are Steve Bace, the Henderson, NV Festool Trainer, and Brian "The Sedge" Sedgeley, the Lebanon, IN Festool Trainer.

While waiting to participate in Festool Classes, can you find someone local to you who has Domino experience?

For nearly all of us, the secret of good Domino mortises is the very firm pressure on the front handle. The actual plunge needs hardly any force. What works for me and everyone who routinely uses the Domino is the approach taught by Steve B and Brian S, and also mentioned my Shane above.

Use the hand not pressing on the forward grip handle to gently control the Plug-It end of the motor. That hand should not actually be on the motor housing while plunging. Start the motor spinning, then with hardly any pressure plunge the cutter and let it return to start position without trying to keep it bottomed in the mortise. The dust extraction will clear the mortise of dust. The Domino is designed for the 27mm hose, which works just swell. There is no harm in running your dust extractor at full speed. The 27mm anti-static hose supplied with Festool CT extractors is ideal, but the longer 27mm AS hose works as well.

You did not saw if your mortises were so over size the Dominoes were a sloppy fit. The appropriate fit is snug, with just enough room for some glue squeeze out. The Domino mortiser has settings for the width of the mortise: minimum; medium; extra wide.

Different kinds of wood and different orientation of the mortise require appropriate plunge-rates. Only practice will teach you what will work best for each situation.

 

[davee]

Loose dominos definitely shouldn't be an issue.  Mine are so tight I have to use pliers to extact them after dry fitting.  As mentioned earlier, much of the issue is technique.  At the Festool training in Indiana, my partner and I each cut several domino.  I went what I thought of a slow and he much slower.  His mortices were noticably tigher.  Also as mentioned earlier,  firm pressure on the fence knob is essential.  Pushing the domino slowly from the very back where the cord attaches is good practice to prevent inadvertant up and down motion on the handle which results in loosness.  Or, some thing is not right with your tool or cutter.

 

[jacko9]

I agree with all of those that mention slow plunge rate and firm grip on the front end.  Over the past 4 years I have noticed that every now and then I grab a tenon that is looser then the others so, I put it aside in my "dry fit bag".  The loose tenons are very seldom so, I have to sand some of them to have enough "dry fit" tenons.  I have to admit, that with practice over time my technique and results improved noticeably.  I had a slot mortiser attachment on my Inca table saw and used that for 20 years with end mills and I can definitely say that the joints made with my Domino joiner are much more consistent.

 

[Kev]

Best thing here would be for you to try a different Domino unit and for an experienced person to try yours.

 

[matt.mackinnon]

I, too, would recommend another cutter and tenon size which would help eliminate the tenon being undersized or other possibilities.

I have not tried a different sized cutter, but I have tried two different 5mm cutters.  The sizes given were based on taking measurements from 20 different cuts.  The first 4 were with the original cutter that shipped with the unit.  The last 16 were with a second 5mm cutter that shipped with the domino tennon assortment pack.  I am thinking that as I have used two different cutters that it isn't the actual cutter itself.

What type of material are you mortising? I am using soft maple
Are you measuring the mortise or just guesstimating the size as compared to the tenon? I have measured it with a set of calipers

Are you making multiple plunges into the same mortise to "clear" it out? Initially I did for the first two cuts.  Those are the ones that are at the larger end of the mortice size (5.7mm).  Then the 3rd and 4th   I did a single plunge, and more slowly.  Then the next 16 I did signle plunges with varying speeds.  I know that a couple of those cuts, the domino did shift slightly and the cut is not perfect.  I ignored them in the measurements.
Are you using dust extraction? Yes. hooked up to my CT36
Are you going into end grain? both end grain and side cuts were made.   This is for a dishwasher front panel.
Are you making a horizontal mortise or vertical into the face of the material with the Domino standing up? Horizontal, aligned by the front fence set to 10mm height
Is it every mortise or just some? All of them that i have cut so far have been oversized.  All using the 5mm cutter head
Do you have one hand FIRMLY on the handle on the fence and use the other hand holding the machine way back near the power cord while plunging? Yes, one hand is on the handle on the fence.  the other is holding onto the body of the unit behind the power switch.

Hope this helps to isolate the issue that I am having.

Matt

 

[semenza]

Matt,

It is critical that you do not put any up /down force on the Domino body while plunging.  However you grip the body be sure that the only force applied is pushing the the plunge forward. This may seem obvious but can take some practice, it takes so little to throw off the thickness of the mortise.  And as has already been said , plunge slowly. Even exagerating the slowness , it helps get the feel as well as keeping the force going only forward.

Seth

 

[Ken Nagrod]

Matt,

One big thing that stands out is you responded to Shane's question regarding how you hold the Domino during use.  Don't grab it around the motor where the power switch is located.  Just gently hold it around the tail area where the plug-it cord connects.  Use that area just for pushing in the machine into the material to make your mortise.  That change can have a huge effect on the quality (straightness and size) of the domino mortise.

Two other things to consider.  First, worn Domino bits (cutters) create more tear out and a larger mortise.  The bits look and feel sharp, but the results are visibly different and you can even hear the change in cutting while you're going into the wood.  It's not smooth and you may hear some cracking of the wood instead of a clean shearing action.  It's odd that the bits would go so quickly in maple unless you're plunging too fast for the bit.  Slow and smooth, allow the bits to do all the work.  Just barely put force on the rear of the machine as you plunge.

The second thing is double cutting (or double plunging) your mortise.  I frequently did that out of habit, probably carried over from doing that while drilling holes.  I'd plunge the Domino in, then give it a "clean up" plunge.  That's enough to widen the mortise giving your domino a loose fit.  No need, don't do it.  Fight the urge.  [big grin]

One last bit of info.  Sometimes the wood, whether it's solid wood or sheet goods, has an odd spot or area that just crumbles inside while Dominoing, routing, drilling, etc.  This is especially true with lower graded goods.

 

[matt.mackinnon]

When I say recently bought the unit.. I mean 'I bought it 3 weeks ago'.  This is the first time using the unit, so it is NEW.  If the cutters are worn out, then either my NEW unit was used before I got it, or the cutters were not ground from the factory.

I will give it a try to re-cut new domino's using a light pinky hold at the very back of the unit.  what has me puzzled however is it's not just the height of the slot that is off, but also the width.  I must be wildly rocking the unit when cutting in multiple directions.  Perhaps I need to stick sandpaper to the fence as it's sliding during use.

I will give it a try this morning to see what I can do and report back here.

Matt

 

[ajones]

Hi I have not read all the thread you are using the narrow setting for width? on the round dial on the top front of the machine.

 

[matt.mackinnon]

I did another 30 cuts with my left hand bridging between the handle on the fence and the adjustment front face of the unit, and put my right hand on the back of the domino where the power plug is connected.  Pushing real slow, I can now get tighter cuts most of the time.

It is funny, but it's far easier to get tight cuts with a 6mm cutter than either of the 5mm cutters.  I guess it will take more time and practice.

Thanks for letting me know this is how you need to use it.  Pitty there is not a photograph showing hand placement in the manual as it seems this is the only way to use it with proper results.

 

[agehall]

The Domino is indeed a difficult beast to handle properly. I'm very happy I was drooling over videos on youtube long before I got mine. That helped a lot when it comes to understanding the technique you need to use.

 

[barnowl]

I did another 30 cuts with my left hand bridging between the handle on the fence and the adjustment front face of the unit, and put my right hand on the back of the domino where the power plug is connected.  Pushing real slow, I can now get tighter cuts most of the time.

It is funny, but it's far easier to get tight cuts with a 6mm cutter than either of the 5mm cutters.  I guess it will take more time and practice.

Thanks for letting me know this is how you need to use it.  Pitty there is not a photograph showing hand placement in the manual as it seems this is the only way to use it with proper results.

1. Turn the Domino on.

2. Position it using one hand of the front knob, and the other hand on the body.

3. While holding the front knob firmly flush with the surface, remove the other hand from the body.

4. Grasp the plug it with your thumb and 2 fingers, and slowly and gently plunge, using only the thumb and two fingers.

 

[sancho57]

You said you have owned this tool for 3 weeks.

Its with in the 30 day warranty period, go back to your dealer, tell him whats up.

Have him confirm the issue,  trade it in and get a new one , check it out at the dealer to ensure no issues with this one ,

then go home and try it. If issue persists its operator error and not tool.