One of my many hobbies is metal working using a Sieg X2 Minimill. The Minimill is a great little milling machine but it has one major drawback, plastic drive gears that break at the most inopportune moment. When the plastic gears strip the Minimill is only useful for an anchor till it’s fixed. It usually take a week to get a replacement gear because no one carries it stock locally. Well Sterling Steele has come up with an answer, the Belt drive drive conversion kit. I got my kit from The Little machine shop for about $145. You can also get a kit direct from the manufacturer at Sterling Steele.
There are several other advantages to having a belt drive motor for the Minimill instead of a gear set up. One benefit is that the mill runs much quieter with the belt drive. You don’t hear the gears meshing and grinding against each other. Another advantage is that it is easier to replace a broken belt then it is to replace a broken gear. To replace a broken gear you are required to remove the top plate and motor from the milling machine before you have access to the gear itself. Changing a belt takes about 3 minutes compared to about 20 minutes to change the gear.If you are also unlucky enough to also break the plastic head stock gears you are in for a long hard grueling day.
Yet another advantage to the Belt Drive upgrade is the speed advantage. As it comes from the factory, the Minimill is not really well suited for engraving work. Engraving requires small bit that spin at a high rate of speed. The geared Minimill simply can’t go fast enough to do this well. However, with the addition of the belt drive upgrade kit, the speed range is expanded from 0 to1100 RPM in the low range to 0-1700 RPM. Also in the high speed range the belt drive upgrade expands your range from 0 to 2500 to 0 to 4300 RPM. With these modifications most milling and drilling and boring can be performed in the low range while small diameter end mills, burrs and engraving tool now become an option.
I decided to review this kit simply because I wanted one. I ordered my kit with my own money and here are my thoughts about it.
The upgrade kit is well packaged in a small bow which contains paper packing material. Each of the gears were individually wrapped in paper to protect the finish. There were also foam peanuts to keep things from shifting around during shipping. When you open the box you are greeted with an assembly that is ready to bolt on to your mill. In fact it took me longer to remove the old parts than it did to install the new ones.
The metal work is exceptional. the surface finish is excellent and all the parts fit with no modifications at all. The lexan plastic belt cover is a little bit light weight but does the job. Chances are most people who change gears a lot will remove it anyway just like most safety devices. I urge you to keep the cover in place, it could prevent clothing or hair from getting wrapped up in the machine.
The instruction manual is clearly written and includes a variety of pictures and instructions to complete the steps. The manual was written without using big words or obscure terminology.
It took me about 40 minutes to tear down and re-assemble the Minimill which included lots of stops while video recording. The average person could do the conversion in 20-25 minutes.
The only area of the kit I didn’t like was the fact that the base plate was thinner than the original casting. This made the spindle lock rod a tight fit in the hole.
Based on my experience so far with this modification I would rate it a 9 out of 10 because of the tight fit on the spindle lock. For me this was money well spent.
I created a two part video of the conversion from gear to belt drive. I hope you enjoy it enough to leave a comment either on my blog or on the youtube video. If you like the video please consider signing up for my free newsletter so you will know when I post more interesting projects.