I am designing my frame, which will be made of metal, be fairly lightweight, will easily and quickly break down and store. I’ll create a separate thread with pictures when it is finished. It will be unique. I plan on 12’ motor separation with 30" distance from top of sheet to motor centerline. I also have a metal maslow sled with ring and I am installing my own 1/2" teflon rods around the perimeter and not using the supplied plastic ring. I have searched the forum but have a couple unanswered questions:
When cutting near the outer edges of a sheet (any of the 4 edges) is there a need for an “extension table” or support for the sled so that it doesn’t try to tilt off the sheet? If so, I was thinking of adjustable waste strips (wide enough so the teflon perimeter rods would maintain good dust removal seal as well).
I spent LOTS of time reading through ideas and experiments on tensioning systems for the lower corners but I didn’t find anything where it had been solved per se. To be honest, I can’t imagine myself walking away from the machine when it is cutting…perhaps it is the nuclear worker in me… so if this hasn’t been fixed yet, has anyone simply assisted the sled while in the corners by adding a little force with their hands, using the slack in the chains as a guide as to how much force it needs? Among many of my projects I have in mind, a teardrop camper is one. I can’t imagine destroying an entire sheet while cutting a camper side if I could just help out a bit with my hands and eyes?
Thanks for your info in advance. I do have a habit of overkilling things so I’m especially interested in the answer to #1.
Jerry
RE tefon pieces vs teflon ring: you are referring to the sliding surface under the sled? This may make dust collection more challenging if there is a lot of space between the teflon pieces
I do that more than I should… help it out a little in the corners because it isn’t wise to leave it unattended and semi automated is better than fully manual.
When cutting near the outer edges of a sheet (any of the 4 edges) is there
a need for an “extension table” or support for the sled so that it doesn’t try
to tilt off the sheet? If so, I was thinking of adjustable waste strips (wide
enough so the teflon perimeter rods would maintain good dust removal seal as
well).
search the forum for discussion of ‘skirts’
you don’t need anything at the top
you need 2-3" of support onthe side
you need 6=8" of support on the bottom
something L shaped that you can adjust to match your workpiece thickness should
work well
I spent LOTS of time reading through ideas and experiments on tensioning
systems for the lower corners but I didn’t find anything where it had been
solved per se. To be honest, I can’t imagine myself walking away from the
machine when it is cutting…perhaps it is the nuclear worker in me… so if
this hasn’t been fixed yet, has anyone simply assisted the sled while in the
corners by adding a little force with their hands, using the slack in the
chains as a guide as to how much force it needs? Among many of my projects I
have in mind, a teardrop camper is one. I can’t imagine destroying an entire
sheet while cutting a camper side if I could just help out a bit with my hands
and eyes?
you are unlikly to accurately compensate manually, I would suggest cutting on
cheaper wood and then adjusting your CAD to compensate for any error (with a 12’
top beam, you will have a lot less issues than with a 10’ top beam)
So the MetalMaslow sled seems to have been changed over time. What I got was a laser cut plate which is I believe 14-1/2" square with rounded corners. It does not have a plastic edge like you often see but I was sent a piece of 1/2" dia plastic rod with holes in it. After scouring many photos online, I determined that the plastic rod is intended to be bent into a circle and installed below the sled. so effectively, the 14-1/2" square sled becomes a 14-1/2" diameter contact area via the plastic ring. This rod had been curved for shipment but not along the plane of the predrilled holes, which put a set in the plastic which caused a couple areas to have a gap between the sled plate and the plastic rod. Now I’m of the belief that little errors and such only multiply so I purchased 1/2" dia teflon rod (the rod in the kit was not teflon…my error earlier) and I will be installing it along all the straight edges underneath and at 45 degrees in the 4 corners. essentially, it will serve the exact same purpose as what came with the MM kit but there will not be a wavyness to it and instead of 14-1/2" dia., it will be more like a square. I doubt the friction coefficient is much better than what was provided in the kit.
Very interesting. Yeah I was reading a thread from 2018 and several people including yourself seemed to be close to a solution with block and tackles, etc., but then towards the bottom I sensed the enthusiasm was waning. I have to say, some of the experiments were quite encouraging. I’ll probably leave any experimentation to post operational time and keep it simple for now but I do like to refine things.
Jerry
I find that this UHMW is great for sliding, but as you mentioned, it has a set to it and doesn’t seal very well for vacuum extraction. Most evident by the chips that gather below the router on the gantry during cutting. The previous sled I had had very very little chip collection other than in the bag of the dust collector. I’ve been thinking about how to fix this, so I’m interested in how yours turns out.
This is what I’ve done for now… laser cut a small piece of acrylic to make the top hole smaller so less crud jumps out… The acrylic was a temporary test, and has been there about a year now. I sealed as many holes as possible… But honestly I rarely look at the bottom of the sled and was suprised the tape was still there.
the only approach that I’ve seen that I believe has a chance of working is a
telescoping pole anchored on a pivot at the top center of the frame that pushes
out, and to make that work you need to have it driven by weights (or constant
force springs), so that it doesn’t end up applying the least force when you need
it the most and the most force when you need it the least.
other than that, a wider top beam (so that the chain angle isn’t as close to
vertical really is the change that makes the most difference. That extra foot on
each side doubles the force available to move the sled towards the outer edge.
Hey I like that plexiglass you added. I was thinking of doing the same. I was also thinking of making a smaller channel for the vacuum like you said but I wouldn’t want it to cause drag, therefore I would probably make it out of the same material as the plastic ring but sand it down a little so it doesn’t quite make contact with the wood being cut. The issue I can see happening though would be wood chips the size of the space would get caught and lift the sled. Also fine dust might get into the non vacuum area and build up, causing issues. In hydraulics, a spool valve that is not cycled for some time can get stuck when particles the size of the clearance of the spool to the bore get stuck. Smaller particles pass through but start to silt up the valve. I can imagine the wood chips and dust doing similar phenomenon. Here is a picture of the teflon I installed. I haven’t attached the corner pieces yet. When I am finished I will lightly sand all the joints to remove the little burrs from the saw.
