Having had my Sieg X1 (actually, it is Harbor Freight 47158) manual milling machine for over a year now, not being mechanically inclined at all, I find it hard to do anything I thought I could do. I have been using it as an expensive drill press at most. So I have always been itchy about converting it into CNC machine. Now, finally, here it is!
The Sieg X1 manual mill is a very sturdy little machine and is sold by many vendors such as Harbor Freight, Grizzly, etc. Its cast iron construction, dove tail column and table bed are far more superior than any other homebrew CNC mills or routers I found on the internet. Though, I have been using mine as an expensive drill press because I am not trained as machinist, most of the difficulties that I encountered, such as positioning tables, and uneven hand wheel cranking that causes "ripples" in finished surface, can be resolved by CNC conversion.
So, combining its superior mechanical properties and CNC capability, a CNC converted Sieg X1 mill can be a serious tool in making really good parts. Best of all, its small footprint make it perfect candidate of desktop mill for hobbists.
Of course, for me, I am still not a machinist, even with a CNC machine, but having this little thing sitting there collecting dust, knowing its capabilities when armed with right stuff, I just had this urge to convert it into a CNC mill machine. Now, I have done it, and surprisingly, total cost for a three axis CNC conversion is under $300. What does this mean? For a total of $600, you get a sturdy, 3-axis cast iron CNC mill machine. Better yet, the cost include stepper motors, stepper motor controller, stepper motor mounting hardware and power supply, too!!! Compared with other available CNC mill machines, this is unbeatable.
Performance wise, it is OK for me. I can do circular cut at 6 IPM feed rate and 0.025 inch depth on 6061 aluminum sheet. The "air move", ie, when not cutting, are 18IPM, 12IPM, and 9 IPM, for X, Y and Z axis respectively without missing steps, this is not bad, at least for me who only work on pieces less than 6 inches in any dimension. So here is the summary:
— X rapids (air move) is 18 IPM.
— Y rapids is 12 IPM
— Z rapids is 9 IPM, no counter weight mechanism is installed.
— Cutting speed can be set at 6 IPM and 0.025 inch depth for 6061 aluminum.
— X backlash compensation is 0.003 inch
— Y backlash compensation is 0.003 inch
— Z backlash compensation is ZERO.
Backlash is measured using an indicator and some G code to command tables to move certain distance and move back. I am not sure if this is the "professional" way to do it, but it seems that is what backlash is.
As they say, the best method to test rigidity of a CNC machine is to do some circular cuts. I did not notice any oval shaped circles while doing test cuts. This is good because it means all backlashes (which is the root of oval shaped circle) are compensated well. But computer speed, gibs adjustments, motor strength, and cutter sharpness matters a lot.
Some rough edges of my test cuts are results of broken spindle motor gear when I miscalculated the Z height. The end mill just ramped into cast iron clamping kit. I wish I saved that broken plastic gear and take a photo of it, it was basically a "toothless" gear — I did not realize it was broken and continue to use the machine until all teeth on the gear were broken.
The following comments make up all procedures of the whole process. They are:
— Stepper Motor Mounting Hardware (costs around $60 for all three axis)
— Stepper Motors (~$120 for 3 axis high torque ones) and Controllers (~$60 for 3 axis) with PC interface (~$20).
— Power Supply (~$20). If you already have a spare one, you can use it.
— Future Expansion Ideas.
All information presented here are for informational purpose only. Modifying, operating machinery can be dangerous and precaution must be taken all the time. I am not responsible for anything that results. Use information presented here at your own risk
Posted by mjkzz (a.k.a zwdeal) on 2007-04-28 21:15:26
Tagged: , Harbor , Freight , Micro , Mill , CNC , Sieg , X1