I have been working on modifying my Maslow 4 to have larger arms that hold 8.8m of belt using a full 10m belt on each arm with stops 1200mm from the ends.
This uses a 107 tooth spool and the arms are 30mm longer. I am using concrete anchor points that are 33’x18’. I am using a rotary cutter drag knife over 7 full sheets of plywood to cut synthetic fabrics. This is still in progress and I have many things to finish.
This is spectacular! I can’t wait to see the finished product. Let me know if you get hung up on anything, I would love to help 
Super cool! I worked at an industrial sewing shop for 4-5 years and set up a CNC fabric plotter/cutter. That machine used a vacuum table to keep the fabric in place, how are you going to keep it from moving? Even with that table some materials like truck vinyl would stretch out from a bunch of cuts, which was a pain. Fixed it by measuring and scaling the design to accommodate for the stretch.
That is pretty cool implementation. I’m not familiar with drag cutter tooling. What sort of offsets or lead ins do you have to consider in CAM tool pathing?
This will require some pending changes or a custom compiled version (the arm lengths are hard-coded currently)
There is a large cleanup patch nearing completion, after that is in the changes to allow different size arms can be submitted again.
the big cleanup change was merged, so I created
to make it so that the length of the belt ends and the arm lengths can be set via the config file (and if I did it right, still default to the same thing if there is no entry in the config file)
Do you think line 229 in maslow.h
int frame_dimention_MAX = 5000;
is going to cause me problem when I set the frame to 10058mmx5486mm
Devin Draper wrote:
Do you think line 229 in maslow.h
int frame_dimention_MAX = 5000;
is going to cause me problem when I set the frame to 10058mmx5486mm
Yes it will, I submitted a PR to increase it to 5000, but I didn’t think big
enough, we’ll have to change that as well.
David Lang
Here it is with the 10m belt on the machine to verify clearance. Unlike the standard arms the bottom arm can’t have any belt wrap on the spool out side the edge or it interferes with the bolt hole connecting the bottom plate.
the patch I have queued allows for additional belt length to be different for each arm.
just changing the beltEndExtension value in the current code won’t quite do the right thing. this is due to the fact that this value is assumed to not flex in the Z direction (the fix that I wrote that went into .85 allows for that)
take a look at the big stack of fixes that I have queued up in PR 175
given that a drag knife needs very little Z movement, you may want to play around with the varient I’m tinkering with in Onshape (look at the ‘custom spool copy 1’ tab for making the parts)
I haven’t tried printing anything yet, but running a drag knife seems like it should be a very low-force thing that would let you get away with using the lead screws as your only vertical supports (especially if you go with short ones instead of the 300mm ones I show here)
it lets you specify any size spool and how much belt you will fit on it, making sure that you have clearance. (note that the configuration option to set the tooth count doesn’t work, so you will need to clone the document, let me know if you want to get together online and go over it or if you want me to generate parts)
I also think that you could get away cutting off the screw mount that you are hitting if you needed it
I looked at you onshape model and played with the size and realized that I don’t need the fasteners in the Center I can gain like 2 wraps and the 10m with fit without sticking out.
That’s exactly why I built that 
also note that my design flips the belt around, teeth in. and touches up the shape of the spool center to be more efficient. This gives most of an additional layer of belt on the spool, and gives you additional grip on the belt so you can unwind a bit more of the belt before you risk pulling the belt off of the spool.
