Domino 700 bit break

[mike9]

I have the 700 with the Seneca bit extension. I was using the 5 mm bit and it snapped after 6 cuts. I am guessing it's the power of the 700 with such a small bit.
Wondering if this has happened to anyone else

 

[Birdhunter]

I've snapped 2 #5 bits with the 500. Both were cutting into end grain of very hard wood. One instance was my sloppy technique and one just very hard wood (Ipe). The Domino machine puts a lot of stress on the bits.

 

[Tinker]

I've snapped 2 #5 bits with the 500. Both were cutting into end grain of very hard wood. One instance was my sloppy technique and one just very hard wood (Ipe). The Domino machine puts a lot of stress on the bits.

I have not used the two smallest bits with my Domino 500 yet.  I have, however, wondered about possible breakage of those small bits.  I have used 1/2" uncut spiral bits for doing deep mortices in the past.  It puts a lot of strain on the bit when i go deep.  My longest spiral bit will cut 3" deep.  By the time I get into the wood, I take only 1/4" plunge at a time.  there seems to be a lot of side force resistance even then.

Once i looked over my bits when i first got my domino, i picked up a spare 5mm bit for Justincase.  He is just like Murphy and pops into the shop when least expected. [scared]
Tinker

 

[Kev]

I haven't actually used the smallest cutter .. looking at the physics involved, I think I'd be plunging at an absolute snails pace!

 

[WarnerConstCo.]

My 5mm cutter has made 1000's of holes in ipe. 

 

[Tayler_mann]

My 5mm cutter has made 1000's of holes in ipe.

Im the same too I have gone through 3 big boxes of the 5 mm and a few small boxes and have never had a problem. I've done everything from teak, pine, lacewood, wenge, Baltic birch ply, LVL, and even some Sintra PVC sheeting and it is still running strong. I think if they break there is manufacturing defect or being much to hasty with the tool.

 

[Cheese]

I routinely use the 4mm on oak trim. Never had a problem with it. I think the most important thing to do is to present the bit to the piece gently and then to use a nice smooth consistent feed. Herky-jerky movements can become an issue.

 

[Birdhunter]

My sloppy technique that snapped the #5 was to let the Domino tilt slightly as it was at a full depth plunge. The Ipe instance was done putting the mortise into the end grain. I don't think I plunged too fast as the bit snapped just as it touched the surface. That particular bit had seen years of use, mostly in exotics.

 

[johninthecamper]

Complete speculation,but I think that the most dom bits, that get broken, is#5,look at the neck,compared to the others,it is thin

 

[AIPDX]

You need to make sure that your Domino stays put when you plunge and remove the bit. You use one hand to press it down, and the other (usually, your dominant hand) to plunge it. Since there is such a big leverage due to the length of Domino, it is very easy to move the Domino sideways or upwards with your dominant hand when plunging the tool or letting it go. You need to make sure that you press it firmly into the place with your non-dominant hand and very gently and slowly plunge it, paying extra attention that it should only be motion in one direction. Do not hurry to move to the next hole. If you think about moving the tool to the left or to the right next, you will move it while cutting and your bit will break.  I found that for me personally the odds of making a wrong movement decrease significantly if I hold the "on" slider with my finger and turn the tool on before plunging and turn it off after each hole, rather than keeping it running all the time. This helps me to separate plunging from moving to the next position. I move the tool only when the motor stops. I broke I believe two cutters, always because I moved the tool sideways or upwards while the cutter was still in the hole. The modified work flow helped a lot, bit breakage stopped. Also, do not force the tool, plunge it slowly, do not exert too much force on it. In hardwoods it will be a little slower than in soft woods.

The bits are very hard (which helps them to stay sharp longer) but the downside is that they also brittle. They cannot withstand a significant bending force.

 

[mike9]

For the members who said they haven't had a problem, are you using it in a 700 like I am.

 

[greg mann]

It may seem counterintuitive but the domino cutter is subject to the same deflection forces throughout the cut. The cutting is done within the first millimeter or so. It is the chamfered corners that remove most of the material and the size is established by the outside diameter of the carbide tip only. The steel shank does not touch the walls of mortise, unless the operator lets the machine slip out of position which has already been identified as one cause of breakage. There is always the possibility of a defective brazing job attaching the carbide tip to the shank and if it is defective it could show up very early. If the OP lost his at the blazed joint I would conclude it was a bad braze and want Festool to replace it. On the other hand, if Darcy ever breaks his after all the cuts in Ipe I would just chalk it up to finally getting dull. It does demonstrate how long one should expect the cutters to last if they are made well and used properly.

The 700 is about 14% slower on spindle speed. That doesn't help you with the small cutters. I have no personal experience with the aftermarket cutters and the adapter needed to use them on the 700 but every component added is another opportunity for problems. That said, there are numerous testimonials to their effectiveness. Of course, in this case, Festool won't be replacing anything.

 

[Tayler_mann]

For the members who said they haven't had a problem, are you using it in a 700 like I am.

I hate to say it but there is a reason they have a 500 and 700 domino machine. Even with adapters obviously enough the machine has differences. What is being said throughout the thread IMO is that the 5mm shouldn't break if used properly. With a Seneca adapter, again IMO, is not meant to be used with the 700. If you want to use a 5 or 4 mm bit than buy a 500 or possibly break bits with the 700. As Greg just stated the 700 has a slower spindle speed since it is meant to be used with double the size cutters.

 

[Locks14]

I have the 500 & 700. One thing that occurs to me is that the poorer ergonomics of the 500 mean you are forced to be slower and go more gingerly when plunging the cutters. The 700's handle is a lot more heavy duty/easy to grip, as such it requires a little less "feel" and can apply more force.

Bottom line, the 500 delivers feedback to the operator of how the smaller cutters are cutting, put a smaller delicate cutter on a 700 and you can a) apply too much force and b) not get sufficient feel/feedback to tell if you're forcing the cutter faster than it's cutting.

As stated above, the adapter to use 500 cutters on a 700 is not a perfect solution and the 500 & 700 both have their place if you want to use the full range of domino sizes.

 

[peter halle]

Router bits break, drill bits break, domino bits break.  Just part of woodworking.

Peter

 

[jacko9]

I agree that all tool bits break at times but, so far I haven't broken a Domino cutter (lucky I guess).

Jack