Maslow Mark II - 3D

Good idea but there is only 24hr a day - priorities, prioritiesā€¦
Do you know where I can find dxf file with that pattern?
Tomasz

If you asking for workspace width - it is 3000mm see drawings in the Garden project.

I donā€™t, but maybe @c0depr1sm can share :smiley:

Great job on the gantry! I was thinking of doing the same idea. I have a good true sturdy frame to start with

. Your tubing is 40mm which converts to 1.575" but here in Canada I could only get 1.5 in. My question is would the printed corners and roller brackets adapt to that size? Itā€™s about 2mm smaller so Iā€™m sure the bracket could be shimmied but is there adjustment in the guide rollers?

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Great stuff Robert!
Guide rollers (as you call it - I call it carriage rollers) are independent of tubing dimension - carriage will ride just 2mm lower. You can compensate it with workspace hight.
The corners for gantry will accept 1.5" tubing - I made oval holes on the outer side to allow adjustments in X and Y. The bottom holes (also shifted to outer side to clear ballbearing axis) are used only after final adjustments when you committed to distances. Keep in mind that gantry literally hangs on top bearings and lower guide rail is just a support.
Very important is sequence in which you constructing gantry and carriage - I started with assembling carriageā€™s three corner rollers; set gantry width to carriage width; add fourth roller corner to resulted width; committed to dimensions by tightening side screws, screwing bottom screws and reinforcing corners with metal angles. My carriage is 340x340 and I suggest at least 15mm thick plywood for stiffness. The beauty of design is that XY tolerances in gantry/carriage do NOT translate to error in cut - cutting error depends only on Maslow arrangement. Router bit position is driven by chains length. Error in Z depends DIRECTLY on accuracy of gantry/carriage assemble.
I am now working on circular saw adapter for ripping and cutting so keep this option open when building your frame.
Good luck and let me know about your progress. Glad to be of help to my fellow Canadian :wink:
Tomasz

Hi @TomD and @WoodCutter4,
Actually, I shared one of the SVG file in the Zipper tree Challenge post.

You can right click and download the file!

The whole thing is however quite big and requires more plywood than necessary.
So I definitely suggest those who would like to take the challenge to adapt it :slight_smile:

Ah, I didnā€™t notice it could be downloaded. I thought maybe you forgot to attach it in the OP. Considering the source, I should have know better :slight_smile: My mistake.

Also, I see it is only one ā€œbranchā€ of the zipper tree with other branches being slightly different shapes? How did you create the *.nc file? Any change you would be willing to share that too? :smiley:


Hello Tom,

Wowā€¦that looks like it was a lot of work. I am just wondering one thing about this build. You practically already have a full gantry style CNC machine here and you say it only cost you about $200 more than the maslow and router itself. So why are we not building true style horizontal gantry system for that money and be done with chain slag and inaccurate cutting in the cornersā€¦Just my two cents

a coreXY approach would be FAR better than a maslow hanging approach, grbl
with steppers would work very well, servos could be made to work with
modifications to the new code thatā€™s being discussed (the version 2 grbl thread)

David Lang

So are you saying I am correct with my assumption?

Space constraints come to mind. I suppose you could up the torque on the steppers, though. That said, itā€™s a good question

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It is not that simpleā€¦
Force distribution for horizontal arrangement is completely different: accuracy and precision depend on alignment of railing, gantry etc. table and railing are bendy - how you will make cheap tubing to be straight and not bend on the length of 3m? The brilliance of Maslow design is in fact that only one factor contribute to error - length of chain! Z is local and we compromise on speed. This is not the case with XYZ horizontal cnc - no wonder that it cost 4 digit dollars for 4x8ā€™. Another issue is precision - we achieved 0.5mm but going to 0.1mm is completely new ball game.
I think that Maslow is fantastic compromise between price - accuracy - space savings - DIY capabilities. Personnaly I have a lot of respect to Maslow inventors for elegant design. Make it more complicated and costly is easy - KISS theory!
My gantry design is just a variation on the topic - principles stays the same.
Cheers
Tomasz

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Hello Tom,

I am fine with the 0.5 mm accuracyā€¦if it is achieved on the full 4x8ā€™ sheet. And I have respect for anyone that pours his heart into a technically challenging project like the Maslowā€¦and then has the guts to put it out there for people to criticize.

Sincerely,

Aymeric

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Something that hasnā€™t been considered with the gantry that you built is that you can eliminate the ring kit from your design with some minor coding tweaks. The ring kit (and all other triangulation kits) were developed because the math to figure out how much the sled rotated when the chain end points were fixed was complex and, iirc, not very accurate. But in your setup, the sled canā€™t rotate. As such, the math is becomes greatly simplified. All you need to be able to do is accurately determine where the end points are in reference to the router bit (i.e., 5 inches up and 5 inches left/right).

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Wow! Thats something! This would be great simplification - no ring, no rollers, no concentring ring - I love it! I can connect chains directly to router holder where handles were attached (as long as hight is correct). I can lower the weight of ā€œbricksā€ - less stress on motorsā€¦ hmā€¦maybe it is time to go back to Maslow accuracy - simplification proposal
Is Ground Control ready for that now?
ā€¦ on the other topicā€¦ I made my workspace flat and true - it take ages but it is worth it. Picture taken after 2hrs - started from bottom left.


T

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Seems reasonableā€¦ are they threaded? I donā€™t recallā€¦ but if so, maybe a 3D printed screw of something strong can be used with a chain attachment built-in. That way you know precisely where the end point is of the chain. If it is something you are willing to try, Iā€™m sure I can make a revision to the firmware that you can try out (might have a few hard-coded values for simplicity sakeā€¦ based upon how you ultimately attach the chains).

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Youā€™ve made my day!!!
It is 21:00 in Poland so this will be my task for next couple of days :wink:
T

the stock rigid router had bolts holding the handles on. Maybe something like this would work. (I donā€™t recall the bolt size, so just guessed M8)

With the added bonus of defining the workspace, and perhaps adding a lip to hold material at the bottom? Love it!

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Cost and ease of accurate construction.

Look at the prices of gantries and the effort needed to make the rails straight,
square, and non-flexing (and parallel to the bed). That is FAR harder and more
expensive to do than hanging the sled off of one beam on chains.

David Lang

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Wow! Thats something! This would be great simplification - no ring, no rollers, no concentring ring - I love it! I can connect chains directly to router holder where handles were attached (as long as hight is correct). I can lower the weight of ā€œbricksā€ - less stress on motorsā€¦ hmā€¦maybe it is time to go back to Maslow accuracy - simplification proposal

itā€™s not that simple, you still have the chains pivoting on something, so you
need either have a clean pivot point or you still have movement to account for.

Is Ground Control ready for that now?

Ground Control doesnā€™t care about things like this, it just sends the g-code to
the arduino.

David Lang