Maslow Home Maslow Community Garden Newsletter

Is there A 3d printed solution for the wooden arm triangular kinematics set up?

#1

in order to get them to the right height, instead of cutting the little doughnut shapes with the maslow.

http://maslowcommunitygarden.org/Maslow-triangulation-linkage-kit.html?instructions=true

To mount your linkage to your sled you need to determine how far off the sled it should be. If you were previously running a stock Maslow then you may have already determined a good spacing for your chains (the space between the work surface and the chain). A good rule of thumb is that the linkages should be mounted roughly near the sled’s center of gravity in the z-axis. This measurement is not extremely critical but if it is off by too much it could cause the linkages to bind or rub in a manner that is not conducive to accurate cuts. Ultimately the goal is to have the chains running parallel to the work surface, so the distance of your motors from the work should match your linkages. Once you have determined a good spacing (let’s use 2” as our example) then cut 4 blocks of wood 2” long. The blocks don’t need to be very big but they should have sufficient surface area for glue; I suggest about 1 ½” square. Drill a 3/16” hole all the way through each block in the 2” direction. Counter sink the 3/16” holes in the sled from the back to accommodate the head of the #10 machine screws. Insert the provided 4” #10-24 machine screws from the back of the sled and through the spacer blocks (See troubleshooting note about Z-Axis kit below). Add a washer (provided) to each #10 screw, then carefully attach the linkages with the nylon bushings sliding over the #10 screws. Add another washer to each screw then finish them off with a 10-24 nylock nut (provided). You should be able to tighten these down snugly and the linkages will still move freely. A small amount of friction is completely acceptable in this design. If things are binding then you need to find the friction points and fix it. Once you have tested your spacer blocks and are happy with the balance they should be glued securely to your sled. You can use it without gluing the blocks but things will be more structurally sound if they are glued.

0 Likes

#2

I can only answer to the title as good as i understand it (onthe way to bed):
Is something like this what you are looking for?:
http://maslowcommunitygarden.org/3D-Printed-Linkage.html

For triangular, the setting ‘Rotation radius’ in GC lets you adjust to the standard ring, bigger rings, to top-mount kits, normal or wider and the wooden linkage kit plus any copy at any size of almost any other material.
I did not read that cluster of letters, to sleepy, hope i’m still close to the question.
N8 and kind regards, Gero

0 Likes

#3

Hey Gero, Thanks for your reply. I am looking for 3d printed spacers for the wooden linkage kit. The ones you use to make sure the chain is parallel with the cutting surface. So far i have seen suggestions to make them out of wood, but i would like to print some.

0 Likes

#4

Ok, do you mean like the 32 circles i cnc’d out of acrylic?

Edit: I see a benefit to make them as one block, if you already know the right balance height.
To get that you could just use a hole-cutter on cheap thin material to balance first, determine you optimum height and then print.

Edit2:

The path i follow is:

  • Balance the sled. Holding your sled by the chains and have the sled surface be vertical or slightly tilted from the top towards the sheet.
  • Then you measure the height from the chain to the sheet (height of spacers + thickness of sled)
  • The motor sprockets/motors are brought out/moved in to make sure the chain is parallel to the linkage kit.
0 Likes

#5

First you need to figure out what the right height is for your sled/weights,
then you want the stand-offs to be as rigid as possible (if they can flex
sideways, even a little, it will cause errors)

a cylinder of height X with a hole in it should be trivial to make to whatever
height you need. but we can’t know what height you need for your machine.

David Lang

0 Likes

#6

has it been determined if the linkage is better/more accurate than the ring?

0 Likes

#7

As far as i know there has been no direct comparison under same conditions.
I’ll share what i think:

It depends on what you get and/or how high you router/z-tower is.

  • Ring:
    Both rings i received (the standard and a bigger one) where placed on a paper with a circle drawn with a compasses. Both did not maintain a constant radius and got wider towards the open ends. The L-brackets i got seem to be from the first batch designed for the z-motor. To thin for the task, i think that is solved and they sell them thicker now. It was a no-go after mounting a the ‘thumb-push test’. Ring was never tested on my side.
  • Linkage-kit:
    The parts have been checked for alignment of the holes by stacking them on bolts. It felt and looked just perfect. The screws are very thin for the expected height over the sled. With unglued spacers the flex on the thumb-push was about the same as with the ring. The solution was to cut and drill a template for the 4 screws, so i could align the screw tips while gluing spacer by spacer in 90° to the sled (after determining the best height for the kit). Flex is gone.

For all kits, the lower you can mount them to the sled, the better (only achieved by keeping the router/z-tower as flat as possible and weight as close to the sled is you can. {or perhaps with a metal sled, but that’s open for discussion in an other topic}). You will minimise flex on 2 sides:

  • On the sled. Lower mounting height, lower flex.
  • On the motor mounts. As a result of the chains being closer to the sheet, you can reduce the amount to bring the motors out. Depending on how you mounted the motors there can be a reduction on flex here as well.

Just my 2 fils.

Kind regards, Gero

1 Like

#8

I think this thread is as close as the community has come to answering that question. I believe @MeticulousMaynard had been doing a lot of great work on this thread most recently.

0 Likes