Maslow Chain Guide

Maslow Chain Guide

My Maslow CNC was suffering from a jumping chain, which is quite alarming when you are standing near the machine. It mucks up the calibration as well, so it is not a desirable thing to have happen. When this happened before, I used some plywood to lift the chain so that it fed onto the sprocket at the correct angle. This never worked too well as the plywood was not quite the correct thickness to guide the chain properly. After another jump of the chain I decided to 3D print some chain guides.

The guides were created in OpenSCAD, which I use exclusively for all my 3D printed objects. It is parametric, so I can type in the height I want the chain slot to be from the base of the guide and the object generated will be of that size. I need two different distances on each side of the machine, so I'll print two slightly different guides.

I had to file out the guide slot a bit in order to get the chain through the hole, but I'll print the second guide a bit bigger. It's working fine so far, we'll have to see if it has solved the jumping problem...

Maslow Update

Maslow Update

The Maslow is now together:

This morning I moved the motors forwards so that the chains are more parallel to the work surface. Hopefully this will stop the chains jumping on the sprockets when I start cutting thicker material.

The router I am using is quite top heavy and this causes the sled to tend to tip backwards, especially if the router bit it out from the work surface. at the moment I'm putting a rod of steel on the top of the sled as a sort of counter weight. It works, so I'm happy at the moment.

I have made the first 'thing' using the machine:

Well, OK, it's the parts for a thing, not a thing, but this is the sort of thing the Maslow was for. Big plywood things. At first anyway, maybe big scaffolding board things later. These parts are going to be a filament reel for the 3D printers. I've made them manually before and this was way quicker. And I can do something else while the parts are cut out.

The calibration was a bit out before I moved the motors. I'll have to re-calibrate now the motors have moved, but hopefully I can get the calibration back to something as good as I had before. Those discs I made are slightly oval, but I'm hopng I'll be able to manually adjust that out on the next calibration.

The Z axis mount works remarkably well, considering the wood isn't actually attached to anything, it's just wedged in there.

I may have a go at 3D printing a replacement for the wooden version, but this works, so I'm in no hurry.

Maslow L298 Failure

Maslow L298 Failure

My Maslow motors stopped working, so I removed the IC from the PCB, decapped it and had a look. One of the transistors has overheated, maybe shorting some rails out:

For reference, the full chip looks like this:

Maslow Update

A short update of the Maslow. I've added the Z axis drive using a piece of wood, I'm planning to 3D print a thingie to replace the wooden prototype.

Unfortunately, while testing the Z axis I drove the motor into a jammed z axis screw and overheated one of the motor controllers, so I now have a Maslow that only has one motor drive.

I'm going to have to remove the drive chip and put a new one on...

Maslow Arrival

 

My Maslow CNC router kit has arrived, so I have been making a frame for it. The frame is a one-off that fits on a wheeled trolley I made a while ago for sheet material storage. The dimensions seem to be absolutely correct for a Maslow frame, strangely, as I didn't build it with the CNC machine in mind.

The kit looks like this after it has exited the box.

The frame so far is a double A frame with some chipboard flooring for a sacrificial routing surface. (It's really cheap, which means it is comfortably sacrificial).

The A frame is constructed similarly to the standard Maslow frame, and I'm keeping the dimensions very similar even though I will be using smaller plywood sheets than the 8 x 4 foot sheets Maslow was designed for.

 

I'm planning on putting triangular motor mounts on the cross beam, hopefully they will be rigid enough for the motor/chain stresses. If not, then I'll look at a single beam across the top and supports. I'm using up a lot of material I have hanging around, hence a different design and varied materials.