I have a LR2 2 with a pretty high Z axis for cutting foam (10" Z 5" for foam, another 5" for end mill).This means adding a vacuum to the router plate doesn’t do much since it is so far away.
I’ve seen some guys use angle aluminum or even linear rails but that is out of my budget. Although the angle aluminum or steel could be done over time but not immediately.
Wondering if there is a way to add a brush or something to clear the path.
are there other ideas anyone else uses that have been successful?
One is printed parts that bolt onto the wheels and add a sort of snowplow to clear chips and debris from in front of the wheels. One at each wheel pushes chips and dust off of the edge of the table as the LR advances.
There’s no real reason why a brush or similar appliance couldn’t be used, perhaps even just brushing off the tops of the wheels themselves would be adequate.
If you wanted to be extra sure, you could probably gear up circular brushes off of the wheels. Say a 3:1 ratio would be plenty to get good speed brushing off chips and dust. It would take some power off of the Y axis to do it, but that should be a relatively minor thing.
Regardless, you probably want to prevent stuff from entering between the wheels.
Angle iron would be cheaper than aluminum, and ought to do the job for fencing off the wheels, too. If you can get some lengths about 15-19mm high and attach them to the table just inside the wheel tracks that should do the job. Bonus, it also assists the LR’s Y axis tracking.
There is a bolt going through that wheel, with a big hex head on it.
I used 3/4" for Mike, IIRC. Only the rubber part of the wheel touches it.
The first one I made was from 3/4"x3/4" plywood cut on a table saw and that worked fine for tracking. I assume it would work just as well for keeping the dust out.
I’ve used wooden strips for aligning the wheels and preventing chips from landing on the track, just because I didn’t have angle iron…but I found when I run test cuts with foam the flying pieces still made it onto the track.
The thing that worked the best for me was a hacked together dust shoe made of an acetate sheet (overhead projector plastic for those old enough…) with slits cut in to feather it into a brush-like setup.
It gave me visibility and enough rigidity to catch the foam without interfering with the cut. Maybe someday I’ll have a 3d printer and I can make a proper looking one but this in combination with a vacuum keeps almost all the foam from flying onto the track.
For your situation you might be able to make a version with really long feathers to account for the height of your setup. The vacuum may not add much. It’s really the fact that the plastic slows down the flying pieces of foam.
The oldest cnc router in our plant uses rack and pinion for x,y and z. The x axis has the rack facing up on both sides of the bed. The bed is 10’x18’. There was an issue of aluminum chips landing on top and building up in the rack teeth. Added small air knives to blow off the rack as the axis moves. It works very well.
I’ll see if I can get a picture of the setup in a few days.
Well, got the 3/4 rails installed yesterday. Didn’t have any plywood, but had some poplar.
this also shows my DW660 mount. I haven’t cut wood yet but feel confident.
I hope I didn’t get too tight against the rollers. I tried to keep them touching but not pressed against it. seems to move fine…
There are a number of limitations to the LR2 design that I have noticed - dust build up on the wheels/rails is one such problem. I’ve used mine to flatten a lot of large 6’ slabs of hard maple using a 1" surfacing bit at a 1/2" depth of cut at 25 mm/s. Needless to say that makes a ton of debris.
The best way to solve this is with a different table design. The track the wheels ride in is best several inches above the cutting plane (and it’s best to cut a V-groove in the track for the wheels to ride in). That way the dust simply hits the side of the track rather than shooting all over your wheels & Z screw.
It’s also best if that track is separated horizontally with a gap from the table so that the dust that is flung sideways falls to the ground after hitting the side of the track. If your track is raised 6" higher than the cutting surface, you need the router to go down 6" to compensate. I am not sure how you would solve that for a DWP611 or similar router setup, but with a spindle it’s pretty easy to do since they are held in place by a pinch-grip which allows you to adjust their height quite a bit (and they are quite a bit longer).
Another thing you could try is putting a dust shoe on the 611 plate and use the vacuum port. I found that didn’t work for me just due to the sheer volume of chips I was generating - the vacuum port couldn’t keep up.
It works quite well. The downside is that there is a larger lever when cutting. If you cut close to the x rails, like how the unmodified LR2 is, there isn’t much lever action. If you drop the cutting surface down 6" the cutter will act like a lever on your machine which in theory could limit your cut radius/depth/speed.
Another option is to add a guard to your Y plate assembly. I have seen some but didn’t like many of them. They would have to ride as close to the table as practical, and go up above the X rails equal to your total Z axis height plus an inch or two. There would have to be slots for the X rails move up and down. That way when cutting at your maximum Z the guard would still block chips from getting into the Y rollers / z screw / etc. The downside is that with slots for the x rails to move up and down, some debris would still get in and this also doesn’t stop dust buildup on the x rails themselves.
Simply dropping the surface cutting height keeps both the Y/Z and X assemblies clean, the tradeoff being the lever action that is applied when cutting.
I have a similar problem and going to blast the table with a large fan to blow away the foam.
Compressed air works quite well, so considering something automated to blow away foam from the compressor. Of course this means a pretty messy shop. But with that quantity of foam getting ripped, there’s no chance for a vacuum.
