Hello everyone.
I am planning my frame while waiting for the Dewalt to arrive and trying to figure out the best way to build the frame.
Is there a number to how much tension/force does the motors produce at max?
Would 2 opposite motors pull so much that a 5 m 2x4 could flex if it was laying flat?
And what are the numbers for the belt limit? How many kg can the belt pull/lift?
In regards to the frame design that Bar puts forward on the main site: unless you do some sort of additional cross bracing or skin the frame on front and back to create a torsion box, you’re going to see some flex in the frame.
I don’t know the specific numbers, but you should be able to look up the motors and get those values pretty quickly.
I would very much expect a 2x4 of that length to flex, even across the longer edge. That’s about a meter longer than my frame is wide.
If I had to rebuild my frame at the current size, I would likely start with an X, build an hourglass shaped frame with a torsion box for a center, and potentially also use ratchet straps on the back of the frame to keep that X in tension. I’d also consider having that in multiple sections that are bolted together with 1/2" bolts and braced with longer pieces that each bolt across every section so I can take it down and move it more easily when I eventually need to.
This post covers a secondary frame design that has proven quite effective and is the partial inspiration for what I described above:
https://forums.maslowcnc.com/t/m4-hourglass-frame
Yes, I was thinking about the hourglass shape using 2"x4" and 2"x6" C24 material with bolts in the majority of the joints.
Something like this:
I’m not planning to move it much, but I’ll most likely make a stand with wheels as it probably weighs around 100kg with only the parts in the current model.
Definitely with wheels
I don’t think you’ll have an issue with flex, especially once you put the waste board on.
Looking at the design I made earlier made me realize that it could be possible to fold it with som tweaks.
So I made a prototype of it and threw in some hinges so that it can be partly folded for easier transport without taking it all apart.
It seems to be sturdy enough when unfolded. Some latches on the back of the 2x8 that locks it in place with the left and right vertical 2x4s would be needed for stability of the 2x8 itself.
Anchorpoints are 11’ and 8’ apart.
The middle 2x8 might work in a vertical position to shed some weight. I chose 2x6 for the sides to be sure they don’t flex, but 2x4 might be enough. That has to be tested in full size.
There’s probably possibilities that I haven’t thought of to make it fold even more. And maybe use fewer parts to get the weight down.
Feel free to use the design and iterate upon it. I’d love to see what else could be done with it!
Please refrain from charging anyone for plans 
This frame is sick! I’m curious to see what fitness value you get for calibration with all those moving parts. Keep us updated!
Hehe. Thank you Anna 
I just got word that I have to wait 2 more weeks for the Dewalt router, so I might as well spend the time planning the frame 
It’s not like I have other projects waiting to be finished anyway… 
If you can put a cylinder of the right size on the assembly so the spools have something to pivot around, you can calibrate before you get your router.
(1 more thing in the “using the router as a structural part is something that would be beneficial to engineer out of the design” pile)
That is an excellent idea actually…
I was thinking the router was cumbersome to remove and insert again after completing the build, but the only parts that relies on it fully are the spools!
Great!
Now I don’t have to pick up any of the non-existing projects I don’t have laying around yet after all! 
Like I say to everyone else
“Get a spindle” - even the little 500w machine I bought still works better than a router
Yeah. I have looked into spindles, and I’ll probably get one at a later stage. Not sure what type and power I should chose on a spindle.
How does a 500W spindle compare to a 900/1.3W router?
“A LOT LESS NOI” (switches to spindle) “noisy”
A lot better and simpler speed control, that you can access while the M4 is travelling around (depending on how you wire it up of course)
Also, you don’t need that extra power when using it in a Maslow, assuming you aren’t using hulky great bits
The 500 watt spindle has been used for quite awhile on the maslow classic versions with no issues. It was an improvement over the routers.
I ordered this(kit 7) 2 days ago.
Just got a message from Fedex saying that it’s on it’s way and possibly delivered 5th August.
Seems that I need to get building!
@anna, @bar or anyone that might know. I’ve read about the encoder that might need soldering on the encoderboards. Is that something that goes for all the current M4’s? Or is it just some versions?
all of them
Hmmm… I’ll have to look at doing that and changing the belt guards with the newest version after finishing the frame. At least I have had the time to start building the frame. As with most projects based on “what I have at hand” it isn’t looking anything like the initial drawings 
, but it’s a fun project either way!
If I’m lucky I might even get in a few extra TV-channels with this design!
@bar: During the build, there has been a few eye-openers regarding size and flex for sure. And some theories have popped into my sawdust filled brain. They might already have been discussed, and maybe even answered?
1- Am I right in assuming that the old Maslow had less restrictions in regards to movement in the outer corner-edges?
2 - Did that lead to more accuracy at the edges even with a smaller frame?
3 - What would happen if we were to move the center of material further down, as in an asymmetric placement of the material in the Y-axis. Could that be configured in FluidNC?
4 - How would asymmetric placement of the bottom anchors compared to top anchors affect the angles of the arms and belts? Apart from needing longer belts on two arms.
For example:
3 -
take a look at http://lang.hm/maslow/maslow4_frame.html for the red areas, that is based on the allowed angles and distance between adjacent anchors. The green area is based on the allowed angle and distances between opposite anchors (so the green lobe in the top right is based on the angle and the top left and bottom right anchors) All the calculations re in the html (it’s done in svg), I would be willing to work with someone who wanted to adapt it to non-rectangular anchor positions.
the old version of the maslow didn’t have the 4 vertical posts, so it didn’t have the same problem with the angles. However it had much weaker motor drivers and a smaller power supply, so you could run out of power at the top center. And in the bottom corners you are entirely dependent on gravity to move you towards the outside edge.
Also, with only the two chains, there was no way to self-calibrate the way the maslow 4 does, so you had to very carefully measure where the motors are, so in practice, the maslow 4 is more accurate than just about anyone was able to get with the earlier version
As you go to use your machine, put a camera pointing at the anchor corners, I suspect that they will flex sideways to the arm a bit.
Quite the opposite! Having the lower belts lets is maintain tension closer to the corners
Thank you @dlang and @bar. I have used the page a lot to find out how big my frame should be It’s a really nice tool.
I guess I had the right idea when thinking about the angles, but failed to consider the tension of the belts.
With regards to the flex of the arms, it will get more support from horisontal beams. The anchors are 4500 and 3000mm apart. It should fit a full 2440x1224 plywood in the green zone. The “material-area” is fine-tuned to have the center and corners in the exact same height.
The model is a quick prototype based on the available materials. Looking forward to get the Maslow set up and test it properly to see where I need to improve it.
