info sought on esoteric qualities of Festool drills

[alladd]

I've developed a product  (a small power feeder) that uses a cordless brushless motor drill, 18V or bigger, as a power source.  The resulting tool's user friendliness is partly a function of the qualities of the particular brushless motor drill used to power it, qualities that aren't mentioned in owners manuals, or even available from inquiry to manufacturers. I have tested many models of brushless motor drills, and not found one that has the best of  all of the several  qualities that matter for this use.  I haven't tested Festools, deterred by their higher price and difficulty to find used (which speaks well for them).  In use, the drill is held in the "on" position at a specific speed with a simple "switch", with the ability to vary the speed and hold it, for as slow as possible, up to about 150 RPM.
The qualities that matter are  : low minimum rpm,  close speed spacings between speeds as one ramps up the speed, relatively large amounts of trigger travel between speeds, so a "switch" can lock in a given speed reliably, whether or not they easily slow speed under  modest load,  and lack of "auto-shutoff", so drill can operate continuously. I'm looking for a few Festool drill owners who can inform me about these parameters for their drills.

For production woodworkers or safety conscious woodworkers who work with stationary tools, I can offer a modest incentive some might find of value for this information, but I'm also appealing to Festool owner pride and general curiosity. See here for these specs on other drills:https://powerfeeder.alladd.com/about%20_drills.html

 

[DynaGlide]

I can't comment on your questions but your power feeder is really creative. I tracked down the Fine Woodworking article.

 

[AlexThePalex]

As far as for your speed requirements, I would say yes, that's absolutely what Festool drills give you, very precise speed control, especially in the lower RPM's.

But for the rest, continious use, being controlled from a distance ..... I don't think Festool drills lend themselves well for that. Festool drills have more electronic measures in them with their protective circuit and their electronic clutch, and those things might not give you, with your specific needs, the best use out of it. For instance, the drill could shut itself off.

You could try one out though, Festool has a return policy for 30 days in the US if the tool doesn't meet your needs.

 

[FestitaMakool]

Yes, you’ll find one of the best speed controls, wich is load compensated, to maintain a constant speed when load varies and are applied in Festool drills. But I doubt that you’ll find any technical data sheets.
Makita and Panasonic are two other to check out. Makita started as a motor company, thus have been in the front of many competitor in that department.

You are looking for near or indeed fully stepless trigger control, as well as load compensated speed control. These are the components that cost more, thus less likely to find at the top level, except on more expensive drills, then throw in the motor itself to meet the qualities of the controller, and you have: Festool.

I am pretty sure that Festool uses sensored speed control on their brushless motors. Most likely there’s higher ratio gears, because brushless motors runs smoother and has more linear power above certain rpms. (If no cost is an issue, they’ll probably run smooth at very low rpms, when built for that purpose.

Some older Makita’s among a few others had 4 pole brushed motors, with excellent electronics.
Brushed motors where, and in many cases still have, better linear control and low end torque than brushless. In the RC world, big name brands still have brushed motors in their crawler cars for low end high torque control.

You could however look into the RC world of brushless motors and speed controls, but not too much to choose from in 18V (However, there’s a wide range of batteries available)

 

[six-point socket II]

Not sure my english is good enough to convey this properly, but I think that high load at low speed (electronically reduced) is not exactly something that any drill/driver is meant to deliver for prolonged times as it will overheat - since the cooling doesn't work as intended - which explains your results with the Milwaukees.

The best example I can give is a small angle grinder. If you turn down RPM, to use a wire brush for example, then use that for a prolonged time under load, the angle grinder will get incredibly hot.

So while I'd say the trigger sensitivity of Festool drills would be right for what you want to do, I doubt the drills will "like" this kind of use, as the cooling isn't there.

Or you would have to incorporate a process, where the drill is removed from the feeder, and run without load at full speed to cool the motor down - at certain intervals. This would be try and error I guess.

Personally, I wouldn't use my drill/drivers this way.

Kind regards,
Oliver

 

[alladd]

Thanks for these replies --which run a gamut of mostly skepticism.  Mo one has really answered my plea for actual data which they could obtain from the Festool drill they own. If nothing else, I'd love to know if they have auto shut-off, which would take 5 minutes to establish.

To be clear, I have tested the use of  brushless motor drills for this purpose at significant length. Most stay cool as a cucumber for this use. There's no dispute as to if this can work with most brushless drills. See six minutes into this video:
I understand that typically they rely on higher speed for cooling, but for whatever reason, on some it's an issue, and they get hot, and can even shut off, even with no load, if left on at low speed for a few minutes, but most happily chug away for hours at a time, lukewarm at worst. Kind of a secret  superpower.

The low speed I seek is a concern mostly for resawing with a band saw, where one can easily want feed speeds down to about 2 fpm (10 rpm's). Here's what that looks like :  This is with a Makita xfd-131, which is one of the few that slows under modest load, but then holds that slower speed under even heavy loads.

I realize this isn't a tool that will appeal to everyone, and there's perhaps a fundamental paradox between Festool's top of the line reputation, and a power feeder made with plywood and skateboard wheels. But for many woodworkers, especially in a home woodshop or studio furniture maker, my power feeder is probably the best available tool for their uses period,--just as I imagine is true for a Festool drill.

FestitaMakool--that's really interesting there may be brushed motored drills that would work for this. "Some older Makita’s among a few others had 4 pole brushed motors, with excellent electronics. Brushed motors where, and in many cases still have, better linear control and low end torque than brushless. " Any idea which models? Most plug in drills have low torque at low speed.

 

[FestitaMakool]

Aladd, thanks. I believe the Makita xfd-131 is more or less the same as my European version; DDF-484Z Except the reinforced metal gear box. These are 2-speed.
The load compensated speed control on these are close to Festool’s offerings.
How much better you would need for your application I’m not sure of. Looking at video #2 it seems like the drill are coping well.
One thing is for sure, you need a drill with good electronics, a trigger with a near stepless curve AND load compensated speed control.
Brushless drills seem to have quite higher speed reduction ratio on their gear boxes, compared to brushed. Thus the fan spins faster on BL motors, as well as they give the “humming” sound.
Therefore, I know a few professionals who miss, and keep their older brushed drills (including me, but not a pro..) just for their controlled low speed torque.

A Makita drill you might easy get hold of used are the BHP 451 - I think it had/has the same designation in the US too. I have this particular model myself, I use it for exactly that, high torque or high speed demanding tasks, due to a very strong motor, 3 speed gear box with percussion mode as well. It has the same power as the old ELU/DeWalt 3 speed XRP drills, but it has fantastic electronics to control speed, torque and trigger sensitivity for its time (2008MY)
In first gear it barely moves, and it doesn’t stop if you try. No need to feed more on the trigger, the electronics does that for you, maintaining near constant speed without input or load. (It twists your wrist off.., I’ve hurt my arm more than once)

In Festool world, today this would mean DRC 18/4 or PDC 18/4. These are 4 speed brushless with exemplary electronics.
How would one look for the data you are seeking from the Festool’s?

The BHP 451 has loads of torque at the two lower speeds, 1 gear moves heavy load immensely slow. I don’t own any of the two 4-speed Festool’s, but I think they are very close.
The today’s equivalent of my old Makita would be the DDF 481Z (European designation) but it is 2-speed, and Makita users says it’s not all the same as the old BHP 451.

Edit: Funny enough, many years ago my sons friend came to show me something he had worked on (they were about 10-11 yrs old). He had motorised his skateboard with his fathers DeWalt XRP 18V drill, with direct belt drive from the chuck to the wheels.. he had 3 speed gearbox and string controlled throttle to the trigger [big grin]. It work quite well, I was impressed by his creativity and that the drill held up.. [blink]

 

[harry_]

I personally cannot speak to specifications, however one was used in the makings of this table it may be something for you to consider.