I want to expand the tools I have at my disposal so I can actually excecute more of the little ideas I have. Building mechanical parts from metals & plastics, milling PCB’s. A small milling machine may fit the bill. Looking for a suitable hobby milling machine I searched the internet for information. After checking my budget, I found my options were fairly limited.
I first compared the Proxxon MF70 and the Sieg X1 Micro Mill.
| Proxxon MF70 | Sieg X1 Micro Mill | ||
|---|---|---|---|
 MF70 in the X1 |
 Proxxon MF70 |
 Sieg X1 |
|
| These numbers come from their respective datasheets. For numbers in the US Imperical system see harbour freight & proxxon mf70 links below. | |||
| Speed | 5,000 – 20,000 rpm | 100 – 1000, 100 – 2000 rpm | |
| Taper / Collet sizes | 1.0 – 1.5 – 2.0 – 2.35 – 3.0 – 3.2 mm collets | MT2 | |
| Table Size | 200 x 70 mm | 240 x 145 mm | |
| X-Y Travel | 134 x 46 mm | 180 x 90 mm | |
| Vertical Travel | 70mm | 30mm (fine) / 230 mm (coarse) | |
| Overall size | 130 x 225 x 340 mm | 430 x 355 x 690 mm | |
| Max. Power | 100 W | 150 W | |
| Volts | 220 – 240 V, 50/60 Hz. | 220 – 240 V, 50/60 Hz. | |
| Weight | 7 kg | 32 kg | |
There’s a lot of information available for DIY-converting these manual machines to CNC (Computer Numerical Control), plenty of people have done so succesfully and documented their efforts in great detail. If you’re still operating it by hand, which is a good way to get familiar with it, make sure to read this guide on adjusting the X1 properly.
How did I choose my machine?
- Specifications
- Availability of the mill
- Availability of CNC conversion-kits
- Manuals
Specifications
The MF70 is the lighter & smaller machine of the two, with much less weight (7 kg) and little less motor power (100 W). It does have a much higher spindle speed. This allows it to use much smaller diameter milling bits (1.0 to 3.2 mm shank with the collects I found available) and makes it suitable for fine work, like juwelry and model building.
The X1 has a slightly more powerfull motor (150 W), and with it’s MT2 taper it takes Morse Taper 2 collets for any diameter mill bits up to about 12-13mm. The X1 allows for larger parts to be made because of it larger table travel, nearly twice in the Y-axis. The weight difference suggests it to be of a more sturdy construction as well, so for tougher jobs the X1 would be better suited. The Z-axis of the mills are different in design.
The MF70 uses a single handle to adjust the height of the toolhead. The X1 has a seperate handle for the coarse and fine mechanism. The coarse mechanism is located near the top and back of the machine. It adjusts the overall position of the spindle motor used a handle like the ones for X and Y. The fine mechanism can be operated in 2 ways. The larger handle at the right operates like your average drill-press.
You pull the handle down, the drilling head moves down and a hole is drilled. A mechanical switch opposite the handle engages the smaller handle at front. This allows you to much more finely adjust the Z position of the tool. Both of these 2 ways have a limit of ~30mm. The coarse Z-adjustment at the top/back allows for ~230mm of travel.
Availability of the mill
Proxxon is a fairly well known brand in The Netherlands.
A few retailers in Amsterdam sell their products:
Online you can buy the MF70 at conrad.nl. Buitelaar sells it too.
The Sieg brand, on the other hand, remains completely unknown and unmarketed. In only a few stores in the The Netherlands where I could find a (rebranded) Sieg machine. One is Buitelaar, the other is VDH. Buitelaar sells it as the HBM X-1 Super Freesmachine. VDH offers the JMD-1 Frees-/ Boorcentrum. Since they had a fairly good price, I bought it at Buitelaar, and picked it up.
Abroad it’s sold by various hardware stores:
- United States : Harbor Freight, Grizzly, Micro-Mark, Homier, Smithy
- United Kingdom : Arc Euro Trade, Axminster, MachineMart.
- Germany : Rotwerk, Jeddeloh, Ar-Tec
- Australia: Jet
Some of the stores no longer sell the X1 series, but start at the largers models like the X2, or the slightly different SX1 (tiltable column). If you know about retail- or webstores that sell the X1, SX1 or X2, let me know!
Availability of CNC conversion-kits
If you have chosen a run-off-the-mill-mill there might be kits available for your machine. This goes for motors, drivers and controllerboards too. Especially on the mechanical construction buying a kit will save you an infinite amount of time, but takes away the fun of building it yourself.
The availability of CNC conversion kits for the MF70 like the one sold by USOVO USOVO and KDN Tool make it a temping offer. Zaerotech seems to produce a kit as well, not much information on their website though. These kits make it really easy to transform a manual millling machine to a CNC operated one.If you plan to do the conversion yourself, be prepared to spend a great deal of time on it.
For the X1 a few kits are available too. Again KDN Tool offers one, and CNCFusion another one. Little machine shop sell a belt drive kit as well as several accessoires, add-ons and table extensions.
Now, how to go about converting it into this little mini-factory you’ve always wanted? The basic plan seems simple, and it is.
- Buy a small milling machine
- Add a motors where the handles are now
- Have a computer control these motors.
- Instruct the computer to make parts.
- Done! (Have your coffee now!)
In practice there is a bit more to it.
- A milling machine. Find one of your choice. Small, big, somewhere in between. Buy as big as you need and can afford.
- Motors. (steppermotors or servomotors are most commonly used.) Servo motors are considered high-end, steppermotors more low-end. This has to do with the feedback these motors are capable of giving to their control circuitry, their precision, power, etc. Price is a factor too, a steppermotor-setup is usually a less expensive than a servo-motor setup.
- Drivers. These bits provide the control and the power to the motors. Sometimes they come as a single part to drive several motors, with other types you need one for each motor.
- Controller board. The parallel-port of a computer can be used oftentimes. It can convey enough I/O signals to control 3 motors (X/Y/Z), 3 limit-switches (X/Y/Z) and an emergency stop. Nowadays slowly more USB CNC controllers are appearing. Usually they have more I/O so you can control a coolant setup-controller, spindle-speed controller if available too or a hand-held pendant controller. I’ve compiled a list of various controllers here. (red: not quite yet).
- Various mechanical parts. You will need to connect the motors to the machine.
Manuals
Here’s a list of various manuals of the micro mill I have been able to find online.