Ormerod 3D Printer

My son convinced me to buy a kit to print some parts that are just easier to make than machine on my mill.

The Ormerod kit is available from RS Components, and the kit was well packed and complete. Construction was done following the instructions on the website. The build took a lot longer than it should have, but I took my time and made sure everything went together properly.

Engraving

The main modification I made is to install a 12,000rpm spindle at the front of the mill for engraving. This works really well. I also added a rod assembly so it is easy to swing down an indicator for levelling work, making sure the vice is square, as well as checking calibration of the axes.

Here are a few pictures and a video of engraving on my CNC mill.

Maintenance

Some of the items that have needed replacement or repair:

  • Timing belts - these just break! It is worth buying a few extras, particularly for the spindle.
  • Spindle motor - this blew out after a few years and I bought a replacement. If it happens again, I will ditch it and go to a servo motor.
  • Spindle index - this stopped working so I changed it for a 3D printer optical endstop which works quite well.
  • Stepper motor - I had one on the X axis that I think had a bearing problem, but it was easy to replace.

Modifications/Accessories

The main modification I made is to install a 12,000rpm spindle at the front of the mill for engraving. This works really well. The standard spindle is way too slow for a small diameter cutting tool.

I swapped out the original main 5 amp fuse for a 5 amp circuit breaker. I found that I was blowing a lot of fuses and it was a bit of a pain swapping them. Was simple to swap out and fitted the same hole.

Changing toolholders is easy if you add a spindle lock. Just press in and use a ring spanner to loosen the drawbar. There is a guy who makes these for the M3.

Base Unit

My milling machine started life as a standard Sieg X3.

There was a company called Promica that did a conversion kit as well as sold these as a turn-key unit, which is what I got.

There are quite a few videos on YouTube showing their equipment in action.

Unfortunately they subsequently went out of business and I am now on my own! The controller is propriety so when this fails, it will mean a total upgrade, probably to a Gecko G540 like my mini lathe. The machine came with a 4000rpm conversion, but the fastest I can get is about 3400rpm.

Base Lathe

I believe that there are numerous versions of the 180mmx300mm (7"x12") mini-lathe, all with varying degrees of workmanship!

After quite a bit of research I found that a German company sells the Optimum lathe which is built in China to their specifications.

The features that I liked:

Toolpost

Since I completely removed the compound slide, I needed a much higher toolpost than is usually used on a lathe of this size.

So, I purchased a 200 series 75x75mm toolpost on Ebay. This is the same toolpost I use on my 1m bed lathe and allows me to share tools between the two lathes.

The bolt holding the toolpost is M16, so I drilled and tapped the new aluminium slide top I made to suit. IMG 1 shows the toolpost installed on the cross slide.

MOV2 shows the first cut! This was only a light cut on 30mm diameter aluminium to make sure everything works as expected.

Spindle Index

I used a Fairchild H21A1 photo interrupter to clock the spindle for threading (index in Mach3 language). These are very cheap, so I may use these for home/limit switches as well. I found a simple circuit on the web showing how to hookup this sensor. It needs 5v, so I found an old USB cable, cut off the other end and used the red and black wires to supply the power to the H21A1. For the disk, I made an 80mm diameter aluminium disk 2 mm thick, with a 27mm hole for the spindle, and an 8mm gap milled for the infrared light.

Homing/Limits

I am not planning on using a positive Z limit switch since I don't see much benefit from this since it all depends on the length of the workpiece. The negative Z axis limit will be installed near the fixed end of the ballscrew. A plastic cover screws over this.