Friday, July 31, 2015

Stepper Motor Failure

Chilod mortality on the Z axis stepper motor.  Groan!  There might be a case for spending three times the money for an industrial CNC mill.


w said...

I'm curious, have you ever looked into finding someone in the Treasure Valley or somewhere else to sub-contract the making of this part for you? Don't recall reading that in this topic thread, but maybe I'm forgetting.

Assuming the cost isn't ridiculously high you could hopefully factor that into the pricing. Though I imagine they would probably require making a large number of them which might be more than you would ever sell and the high up-front cost associated with that all in one large cost investment--still might be cheaper than buying a real mill like a Bridgeport though (yes, I have one of those on my list of things I will buy should I ever win the lottery along with some mint condition 19th century Colt SAA's, Pythons, S&W Registered Magnums, $50K Italian shotguns, helicopters, jet airplanes, 1930's Cadillacs, Auburns, Cords, vintage pickups, get the idea...dream on).

There might even be a Chinese operation that would do that for you--yes I find that idea depressing, etc but that might be another option to make it practical.

How about the CWI Machinist vocational program? Maybe talk to the faculty of that never know...that might lead to someone that could make this part for you. How many of those to you realistically need? Maybe it could be a student build a box of them for you...just brainstorming ideas.

Unfortunately those Hobbyist "toy" mills are just not made for real production work. Fun to play with, make a one off project or perhaps do prototyping with, but in no way practical to go into real manufacturing with. Sort of like most of the woodworking machinery sold in the hardware stores. Fine for the weekend cabinet maker, but would never hold up to full time production.

Clayton Cramer said...

w: Everytime I try to get an estimate, it is so high that this makes sense.

Will said...

There are still Bridgeports and copies available around here. CNC stuff is common, though expensive. Might want to look at the Sacramento area, as that is 3 hours closer to you. For the 3-phase stuff, get a VFD to convert it. Gives you speed control, even with belt drive versions, so a variable speed head type is no longer a best buy.

I'm not familiar with this:

Be careful of school equipment, it is often beat to death, although this is said to be otherwise:

Will said...

You can hire an equipment mover, but for the typical Bridgeport type mill, you can do it yourself much cheaper, I think. I moved mine without difficulty.

You need a vehicle that can haul a trailer capable of holding about 2400 lbs (std Bridgeport). (needs a strong flat floor) Hire a small/med towtruck, one with an extending/lifting boom. A single cable winch on them is rated for 3500 lbs.

Center the sliding mount that the head is mounted on (equal amount of dovetail front and back). Wrap a tow strap around in a figure 8, where the crossing straps are above the tower. That will be your lifting point. If you have a forklift at the pickup point, put the forks under those overhanging dovetails, with a piece of wood for a cushion.

Use multiple tie-down straps to hold the mill in place (not to the table) I've read of people who bolt the base to the trailer, but I would still use some straps for backup/support.

If the towtruck you use for unloading has a wheel-lift (it should), you can use that to push the mill across your floor. Some use lenghts of pipe for rollers to move them any distance in a garage/shop. You can push by hand this way.

If you use a covered trailer or truck, remember that you need to replicate the same setup (forklift?) to remove it at home. Overhead clearance for a lifting boom may be too tight.

The head can be rotated down to the table, if you need to for clearance. It may drip oil, and I've heard that sometimes internal swarf can be disturbed by upending it, so maybe don't, unless needed.