Posted: Sat Nov 12, 2011 4:38 pm
Hm... I could use my wood lathe to make a plastic lathe... use my plastic lathe to make an aluminum lathe... use my aluminum lathe to make a steel lathe
Booooooo...http://www.cnczone.com/forums/benchtop_machines/6175-sherline_mill_cnc_conversion.html wrote:CNC will put a lot more wear and tear on the mill.
It really isn't appropriate to use for production. I suggest you keep your current Sherline for prototype work, then buy something a bit beefier for production.
I tried using a Sherline CNC mill for production, and here were my problems:
- backlash increased to unacceptable levels very quickly
- repeatability is not good enough, especially when you are using the extents of the travel to make a lot of parts. For instance, I used a spot drilling cycle, then two drilling cycles, and then two milling cycles for a single lot of twelve parts. The lead screws' relatively low quality/accuracy/repeatability was not good enough to use the entire table, and the finished parts were unacceptable. I can only effectively use 1/4 to 1/3 of the table for production type work.
- You will find yourself increasing spindle speed so you can increase feeds. The leadscrew pitch is very low, and steppers will run out of speed very quickly. My metric Sherline mill is maxed out at ~18 inches/minute, and I dare not go faster in fear of lost steps. I am using 3/16" 4 flute endmills in tempered aluminum, and it needs to feed faster (with 5500 rpm pulleys).
I am going to spend this summer on a new CNC build, the fun part of which is the old machine will fabricate many of the parts for the new. So far I have spent $850 on the motors and controllers and $400 on two lead screws. I expect it will run out to about $3000 when i am finished but that will give me a CNC mill that has a work area of 1200mm x 600mm and enough grunt to machine anything up to mild steel.
Wow... this is actually very reasonably priced: http://www.ebay.com/itm/CNC-Kit-3-Axis- ... 45fa68c680POLAND_SPUD wrote:check ebay.com
Always better to get it from the horses mouth rather than the other end.
Yep, been looking through it.
Cheers for that!
Thinking about it they shouldn't be such a chore.I saw someone on youtube, who made cheapish mounts by hand with an easy to machine plastic. Then used the cnc to make nice time consuming aluminum ones
Not sure I'm happy losing the manual option either... or will I?al-xg wrote:Yeah, not sure you can call your use "production".
Going CNC on a Sherline should be more about getting geometry you could not achieve beforehand, in my opinion.
The Sherline conversions do include the handwheels that would normally come with any given machine. When using a dual-shaft stepper motor, this means you can still turn the handwheels for manual control if you so desire. (NOTE: the stepper motor should be disconnected before you do so to keep it from acting as a generator and possibly damaging your computer.)
POLAND_SPUD suggesting it could be used as a driver for a sentry gun in 3...2...Haha, you can connect a PlayStation style controller to that one on the Ebay link!
I'll bet that it works just as well as more expensive options.It does really seem a bit too cheap, but comparatively, it seems worth a try, you could swap all the parts over for better ones and it would still be cheaper than the first two links posted
Indeed and finding out isn't that expensiveI'll bet that it works just as well as more expensive options.
Just need to make sure, either you can affix a hand wheel to the back of the stepper or have a method of quick removal of the motor.or will I?
*hammers rivets into leg irons*jackssmirkingrevenge wrote:I will dare make a prediction, by this time next year I will have CNC up and running.
That DID cross my mindPOLAND_SPUD suggesting it could be used as a driver for a sentry gun in 3...2...
Actually, it seems that size constraints do not allow this on the Sherline, at least not without extensive modification.velocity3x wrote:Because Sherline is so popular, I'm sure these people would have them on the shelf
I also replaced the brass leadscrew nuts with cast in place Moglice. Moglice is an epoxy product made for macine repair. The nuts are working perfectly- I have ZERO backlash and lower drag than the brass nuts. I think this is a nice solution for a Sherline where fitting ball screws would be very hard.