Unhappy Domino 500 Owner

[Blackerty]

Ta for that LMT, it sounds like a possibility. I'll take a proper look at the cutter situation when I get back to the tool in a day or two and report. (other stuff on at the moment)

My initial inclination was to try to keep an open mind on the matter - against the admittedly unlikely possibility that because the tool was cutting on size slots that any clearance in the bushing might have been intentionally put there to avoid a seizure risk. Wood dust can be surprisingly problematical in bushes and bearings.

It's looking like it'll at least be well out into next week before there is any response from Festool on the possibility of rectification - Monday is a holiday here...

 

[Blackerty]

An update and some interesting findings - the plan was to defer stripping the tool for a day or two but....

The horizontal fence assembly slides up and down on rails machined into pillars on the main casting. It clamps only on one side as a consequence of pressure applied by a triangular clamping block. The two pads on the block add some friction by bearing on a mating machined flat vertical strip on the user side of the fence assembly. The real work however is probably done by the clamping force pulling together the vertical 45 deg angled lands machined on on the horizontal fence assembly (the part that moves) and on the other side of the pillar - see first pic.

The following emerged:

1. The 45 deg lands contact across most of their width - see the pic below showing how the marking blue wiped off.

2. The 45 deg clamping lands on the fence assembly turned out to be coated with what looks to be over spray of a dark grey dry lubricant coating applied to the non clamping front surface/rails on the horizontal fence assembly - see the pics below. It's partially worn off the 45 deg lands. (guessing but there must have been a problem during development with the fence sticking that led to an ad hoc fix)

3. The cutter spindle bushing is tight - I was mistaken. There is backlash in the oscillating drive which permits likely harmless horizontal movement of the cutter but it doesn't come from the bush.

4. The fence slips every time under firm but not heavy hand pressure applied to the top of the assembly - no matter how tightly (short of stripping threads) the levers are done up.

It's hard to know what to think. I'd expected to possibly find that the 45 deg clamping lands were slightly misaligned relative to each other - so that there was only line contact. (I'd previously needed to shorten the pin on the clamping block a hair as needed to get the pads on it bearing over their full widths)

The lubricant coating can't be helping, but it's hard to know if it's enough to cause the entire problem.

The design appears to live dangerously in that the 45 deg clamping lands are narrow - but who knows. Friction however is proportional to area.

I haven't been able to contact Festool local service (still no answer to the phone) but the sales rep has undertaken to at least look at the problem if I brief him....