Milo V1.5 1210 Ballscrew Conversion

[PFarm]

I like to give credit to Hans on Discord for sharing his experience, BOM and step files for this conversion. Some technical stuff first, Milo V1.5 uses TR8-8 leadscrews. What do those numbers mean? The leadscrew is 8mm in diameter and has an 8mm lead, which will travel 8mm on a 360-degree rotation of the stepper motor. Jake England, the designer of the Milo 1.5 and V2, recommends an optional 0802 ballscrew on the Milo V2 for fitment and price. Since you can only spin the stepper so fast, they tend to stall.

The 1210 ground ballscrews have a 12mm diameter and a 10mm lead, which is a closer fit to the TR8-8 leadscrews. The issue is the fitment of the ballscrew inside the 2080 C-beam.

The ballscrew nut needs to be machined and 1.3mm removed for it to fit. I've machined a ballscrew fixture to hold it in the vice.

Here you can see how much is being removed.

 

With the proper end mill, coolant, and correct feed and speed, hardened steel can be machined on the Milo.

The steel chips have a dark colour, which means the chip is absorbing the heat generated by the cut and moving it away from the part. The shiny chips are from the aluminum fixture holder.

Both ballscrews machined!

You can see the fitment on the new Y ballscrew nut holder

This will be the Y ballscrew assembly

and the X ballscrew assembly

 

 

[PFarm]

Before doing the ballscrew conversion, I wanted to have parts on hand to stiffen the Z column. Found a laser cutting/forming Canadian company cutmyparts.ca, all parts are 6mm steel and shipped for $219.00 CND . 

• Next is priming and painting to prevent corrosion between dissimilar metals
• Drain the water from the cooled system and flush
• Install the new proximity sensors for the endstops
• Install new ballscrews and printed parts
• Fill Z column and Milo base with sand and epoxy 
• Re-tram and tune

[PFarm]

Primed, painted, and some holes tapped.

[PFarm]

Proximity sensors installed and tested.

X/Y Axis

Z Axis

[PFarm]

Well, Milo is out of its home and ready to start the ballscrew conversion, resin/glass-bead pour into the extrusions, and Z-column reinforcement. Resin being delivered today — let the disassembly begin.

[PFarm]

I've decided to use glass bead media instead of kiln-dry sand for the extrusion resin pour because I have some on hand for my sandblaster, and second, it has a higher density than sand by weight.

 

[PFarm]

Weeks/months to build, but 1 1/2hr to disassemble. Resin/glass bead pour and ballscrew update

[PFarm]

Resin/glass bead pour is completed, as everyone mentioned, it's a messy process 

[PFarm]

Anyone interested in doing this resin pour, here are some STLs and step files I used.

80x80 clamp for holding the Z column C-beams together at one end. nutclamp 80x80.stl

Here is the step file for the cap on the other end. top cap v2.step

 

I used duct tape to seal off the seal of the two C-beam put together.

Used these step files to pour resin/glass beads into the C-beam extrusion voids.Milo Z Extrusion Cap.step  C Channel Funnel.step

 

 

 

 

[PFarm]

Installed the steel modified FMJ Plate and the aluminum one together to stiffen the Z column.

Installed and L bracket securing the Z rail extrusion to the Z C-beams

Installed a steel stiffening plate at the rear of the Z column

Ballscrew installation of the X/Y axis is next.

[NewGradRN]

Nicely done. Will the added weight make it difficult to put it back in the casa? 

[PFarm]

@NewGradRN Yes, I could maneuver it alone before, but it will take two of us to put it back into Casa. The added steel should make the Z column stiffer, and the weight should dampen chatter. 

[PFarm]

Some progress on the conversion. Made a drill jig to trim some extrusion on the Z column since the ballscrew is 12mm, 4mm bigger than the 8mm leadscrew.

Worked well using a hole saw.

Trimmed the front extrusion as well.

Installed the ballscrew into the Y C-beam, secured it with an M10 nylok nut and spacer.

 

Installed the Y stepper motor adapter.

T nuts install for the FMJ plates, and used hot glue to keep them in place.

 

[PFarm]

Completed the conversion and the resin pour; it's definitely gained some weight. Look at the legs on the sawhorse.

[PFarm]

Got Milo but into its home, need to drill a new hole for the water cool spindle plumbing since Milo was shifted approximately. 50mm to the right. The ballscrews are 50mm longer than the stock leadscrews.

[PFarm]

Got Milo moving, the X/Y motion is a lot smoother than it was with leadscrews.

 

I need to move the door panel to the outside of the frame so the X stepper can clear the door.

 

[claudermilk]

Dang. That's some weight. I have a set of those same sawhorses I think, and it takes a bit to get them bending like that.

[PFarm]

1 minute ago, claudermilk said:

Dang. That's some weight. I have a set of those same sawhorses I think, and it takes a bit to get them bending like that.

Yeah, it went from being able to move it by myself to a two-person job to move it.

[PFarm]

First cuts since doing the ballscrew conversion and resin fill. Sounds much better 

[PFarm]

Received my X Ballscrew Nut Holder from JLCCNC today  . The geometry was a little too much for my CAM skills to mill myself.

https://jlccnc.com/