I am thinking of making 4 2 ft square torsion boxes with triangular emt conduit 2 ft long for attachment of belts. With 2 sides of thee boxes having torsion sections extending out of the boxes so space between bixes can be changed as needed. Also they provide support for work pieces. The boxes I want to also be vacuum capable for hold down. So all 4 corners are held in place. Vacuum will hols through particle board as destructive board if needed. I am still working on details. Not sure if entire 2 ft space needs to be vacuum or just a small area within that space.
If belts being level means 2 ft can be cut down to 1 ft the height could be adjusted in a threaded rod and conduit can have a slight angle
No you are 100% correct. The belts anchor to the router which moves up and down with the depth of cut. The change in length is small (A 10mm change in the depth of the cut results in about a 1mm change in the length of the belts) but it is compensated for in the firmware.
This is right, the belts angle down to the wood from the router. This has the advantage of pulling the sled against the surface as it cuts.
Thank you bar. The amount of angle on the belt is mostly derurmined by how close to the corner the router is. Looks like I am going to need to use horizontally. Which means entire weight of sled is above cut. It should not need any additional force from the belts. If diameter of sled is 14" then 7 inch extension for belt ends should be able to get bit to edge of board. Not 2 feet or 18 inches. I believe that added distance is due to the belt being at an angle. That is why I was trying to find out the different belt heights. But realize now that those heights will change even with a bit change.
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Starting to wish i could experiment now. Since belt height veries with z axix. How about being able to adjust belt height with z axis on each corner. That way the belts would not twist or stretch as much. I am sure i already have the items it would take. Question is how much improvement it would give.
No you are 100% correct. The belts anchor to the router which moves up and down with the depth of cut. The change in length is small (A 10mm change in the depth of the cut results in about a 1mm change in the length of the belts) but it is compensated for in the firmware.
huh, the belt pivots are on the moving piece? not anchord soldly to the sled?
I expected a fairly solid tube anchord to the sled that the router slides in,
not that all the electroncs/motors are anchored to the router with the sled
being just loosely attached.
in the latter case, your explination of errors in this week’s video doesn’t make
sense to me, it wouldn’t matter much what flex is happening on the Z axis if
it’s the router itself that’s being pulled around, while it would cause problems
if you are pulling the sled and there is flex between the belt mechanisms and
the router.
you are correct that the Z travel amount is unliely to be a significant source
of error.
This is right, the belts angle down to the wood from the router. This has the advantage of pulling the sled against the surface as it cuts.
and the disadvantage of causing additional friction when horizontal
David Lang
another limitation is that as the angle betwen two belts gets closer to 180
degrees, you get closer to no force to move the sled closer to them (as someone
else mentioned, consider a string on a bow. LOTS of force on the string, but you
can move it in the middle with very little force)
David Lang
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you don’t want to adjust the belt anchors while they are moving, but it may make
sense to have the belt anchors at different heights in each corners to better
match the height where they attach to the sled. They don’t have to be perfect,
so the inch or two of Z travel won’t matter that much, but the closer they are
to parallel to the plane of the workpiece when you are doing most of your
movements, the less wear there will be on them.
David Lang
The way I now see the project. Works OK at 75 degrees but is crap trying to use 0 degrees. No consideration for chip removal. Too excessive amount of friction especially if needing to use a vacuum. I agree that if belts had been anchored to sled greater accuracy would accuracy in any position but that is not what I am seeing being constructed.
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What I am looking at is the angle the belts get at as they near each corner. I have a total gym and low angles very little weight but as angles increase the weight increase to move in the horizontal plane. That is why servo motors are needed for xy plane when at 85 deg. The two upper motors need to share the total weight of the sled plus any pull from the lower motors. But there is very little force towards the direction of the vertical plane. Which is why belt force is needed to keep bits in the wood. But when board is vertical gravity removes cut wood chips to the ground. When using horizontal all the chips stay on the board which the sled will just run over raising the bit out of the wood. Entirely different problems. Need some means of keeping board free of chips. Too much suction and sled will become like a vacuum vice . Suction is very good at holding wood in place. No screws or clamps needed. It was advertised as working horizontally but have seen no effort made in the needs of using such.
If you connect a vacuum or dust collector it will do a very very good job of sucking up all the chips. Almost no chips are left behind.
Other than some quick tests I haven’t worked much on horizontal because 1) It’s in my living room and there isn’t enough space 
and 2) The upright case is much more challenging (particularly on the hardware) because in the upright case the motors need to (like you said) fight gravity and the force from the lower belts so my main goal was to make sure that the hardware and electronics were strong enough to handle that. In the horizontal case we don’t have to fight gravity so if the motors have the power to handle the vertical case, they can handle the horizontal case.
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Other than some quick tests I haven’t worked much on horizontal because 1)
It’s in my living room and there isn’t enough space
well, you do have the anchors in your driveway…
and 2) The upright case is much more challenging (particularly on the
hardware) because in the upright case the motors need to (like you said) fight
gravity and the force from the lower belts so my main goal was to make sure
that the hardware and electronics were strong enough to handle that. In the
horizontal case we don’t have to fight gravity so if the motors have the power
to handle the vertical case, they can handle the horizontal case.
In general you are correct, but there is a lot more friction between the sled
and the workpiece when horizontal. Remember when you first tried to build my top
beam frame and tilted it back too far so the sled wouldn’t move? We have motors
not just gravity to move the sled, but it will need some testing before release.
Martha, you need to realize that development is ongoing for this. Bar got a
prototype working well enough that he is confident that he will be able to
finish it before he put up the kickstarter, but there is still work to be done,
and I’m sure that we will find some gotchas when other people start stressing it
in ways that Bar didn’t think (or didn’t have time) to do.
I do want to see Bar doing more testing with the horizontal version, I think it
will flesh out some other things in the calibration that we are currently
missing. but almost everything I’m worried about is software related, and that
can be improved over time if needed.
David Lang
I believe you on motor power. My idea found easily compact down to 2 Sq foot board size requiring just over 4x4 ft space but could be expanded as much as belts allow. Might be the type you could make use of.
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Just ordered my vacuum clamp pods to use. Also tachometer to check router speed better than just dial guess. Trying to figure all I will need. Getting a good assortment of bits already. I would really like to see how vacuum attachment works. Is there by any chance an expanded view of parts. I an wondering if a brush attachment would help or not needed.
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Just ordered my vacuum clamp pods to use. Also tachometer to check router speed better than just dial guess. Trying to figure all I will need. Getting a good assortment of bits already. I would really like to see how vacuum attachment works. Is there by any chance an expanded view of parts. I an wondering if a brush attachment would help or not needed.
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I believe you on motor power. My idea found easily compact down to 2 Sq foot board size requiring just over 4x4 ft space but could be expanded as much as belts allow. Might be the type you could make use of.
| bar
September 4 |
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Martha:
Need some means of keeping board free of chips
If you connect a vacuum or dust collector it will do a very very good job of sucking up all the chips. Almost no chips are left behind.
It was advertised as working horizontally but have seen no effort made in the needs of using such.
Other than some quick tests I haven’t worked much on horizontal because 1) It’s in my living room and there isn’t enough space and 2) The upright case is much more challenging (particularly on the hardware) because in the upright case the motors need to (like you said) fight gravity and the force from the lower belts so my main goal was to make sure that the hardware and electronics were strong enough to handle that. In the horizontal case we don’t have to fight gravity so if the motors have the power to handle the vertical case, they can handle the horizontal case.
Here are some closeup pics. We will have adapters for multiple different vacuum hose sizes available so whatever size your vacuum hose is we’ll have a part that it can plug into.
Everything else on the machine is going to be injection molded, but the vacuum hose adapter will be 3d printed. It’s going to be 3D printed because the shape of it would make the mold cost very very expensive and by 3D printing them we can offer the right size for every vacuum. It’s pretty important that it be the right size because having a bulky adapter from one hose size to another hanging off the bottom is really in the way and awkward.
We will also offer free STL files for anyone who wants to print their own.
for router speeds, you can really just adjust it to get chips not dust and be
close enough for woodworking.
the obsession over feeds and speeds is based on a production environment where
you are not only trying to get a good result, but minimize production time, and
so want to optimize overall production balancing tool wear and prodution time.
I expect that with 1/4" bits we will be wanting to run the routers as slow as
they can go (and probably wish they were able to go slower). The maslow 4 can
move substantially faster than the old version, but the router spins faster as
well.
the only time I expect that higher speeds will be useful is if you are using
smaller bits (1/8 or 1/16)
David Lang
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I am trying to figure what height the belts should be attached at. Guessing 3 or 4 inches above top of board being cut. I can think of two ways. In side boards oftorsion boxes cut a swing upwards for attachment point. Or I can see screwing angle into corner of boxes. I realize the belts move up and down with depth of cut. Not ideal but no choice.
I believe my shop vacuum uses about 2 inch hose. But thinking of using 5 gal bucket in between to catch scraps by letting heavier pieces fall to bottom prior to vacuum. Also will want to put vacuum on different electrical circuit. Would you recommend using same size hose or smaller for more flex ability,.
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I will need to purchase. I have thought of being able to 3d make but do not have a machine.