[SJ781]

Just recieved a new dovetail column mill from enco yesterday. Now I've got plenty of work to do. My last conversion was on a round column mill 14"X-6"Y-4.5"Z and had a rapid of 65ipm. I'm shooting for 250ipm on this one preload ball screws, software controlled motor, coolant, enclosed cabinet, and tool changer if I can figure it out. This one will have a larger work envelope also 20"X-7.5"Y-16"Z..

[JOE65]

Sounds like lots of fun.
Keep us "posted"

[cncadmin]

What did that cost you?

[TyRex]

What type of spindle is on it???

[JFettig]

wow thats an awesome mill, do you have any links or other information on it?


Jon

[SJ781]

It was just over 1500.00 shipped to the door. the spindle is R-8 but I may modify it to something similar to a cat30. I want to add a tool changer, and an R-8 spindle would'nt be very practical. I plan on using an air cylinder to hold and eject the tool. Here is a link to the Enco site:
http://www.use-enco.com/CGI/INSRIT?PMAKA=325-5184

[SJ781]

Got a good bit done today. It is now in pieces. I have a little clean up work to do but that will give time for the servos and ball screws to get here. I hooked power to it before I tore it apart to make sure the motor ran right and got a nice surprise. The motor when switched from forward to reverse and vise-versa changes directions almost instantly no matter what the spindle speed. Soo...I should be able to tap with this machine also. My old machine when switched from forward to reverse would keep going in the same direction you had to let it spin down before changing directions (not good for tapping).

[SJ781]

another pic

[lt paul]

Wow the finish on the ways looks absolutely amazing. have you done some work on them or were they like that out of the box. either way they shoul be very nice to use. :wee:

[SJ781]

That's staight from the factory. The way under the table had a little surface rust on them because it was hard for them to put the protective greese on them I guess. Other than that I am impressed with the machine. It runs smoothe and quite also.

[owhite]

First, I just have to say it -- gawd, I wish I had a milling machine.

alright, fine its out of my system -- what size motors are you going to put on that for cnc? steppers or servos?

owen

[SJ781]

I've got 690oz/in 2150rpm servos on the way. If I run them at 20A (max current of the gecko drives) I get over 900oz/in. I'm going to run them 2:1 which will give me 1380oz/in and 1075 rpms at the screws give or take friction loss in the pulleys. I'm going to run 500 line encoders on the lead screws so I don't loose any accuracy through the belts and pulleys. Ideally I want the screw to turn 1000rpms to get 250ipm. I'm going to run 1"dia x .250 lead ball screws. My current computer is a 1600 athalon with 256mb ram, g-force2 video card and 20g harddrive. By the time I'm done with the mill it may be upgraded to a P-4 2.5-3g 512 mb ram. I plan on running 70-76v 15A to the servos. I played with steppers for a very short time and realized that servos are the only way to go...imo...

[owhite]

sounds like you have it handled but I have some experience with power supply design, described here:

http://nilno.com/laser_dir/2003_12_01_archive.html

and

http://nilno.com/laser_dir/2004_02_01_archive.html

these is a "blog" of recorded diary entries so it might be a bit confusing.

this was very useful:

http://nilno.com/laser_dir/power_supply_design.pdf

good luck,

owen

[owhite]

Originally posted by SJ781
I have a little clean up work to do but that will give time for the servos and ball screws to get here.

by the way, can you describe what the ballscrews are for? I would have guessed you could just mount motors where the handles are and away you go.

owen

[ESjaavik]

Ballscrews have almost no friction loss at around 90-95% efficiency. Typically Acme screws is around 40% up to 60% but in that case with quite some backlash. So the cost of ball screws will to some extent be saved on smaller step/servo motors and drive electronics. I knew this before I started, but thought that the friction of the cast iron slides would be dwarfing the screw friction. But really now I can turn the screws with two fingers on a 20mm shaft!

Ground and preloaded ballscrews have no backlash. The backlash can be compensated in software, but only to some degree, not fully. Also without backlash you can climb mill giving a better surface quality less wear and less spindle power needed.

Go to Swede's web site www.5bears.com and take his advice on how to get them for a reasonable price.

[rvan]

How heavy was the heaviest piece? I am considering purchasing one of these, but I a concerned I may have difficulty bringing it down into my basement.

[SJ781]

The head or the table I'm not sure which. Me and my dad picked those pieces up together. maybe 150-200 lbs. You could dissassemble them outside and take them down to the basement on a handtruck. and then reassemble.

[IJ.]

My catalog lists it at 350 Kgs or 771 Lb's not something you want to take a chance with be careful.(stairs+350 Kgs= danger Will Robinson)(waving arms like a nutter) !

My guess would put the head at roughly 1/4>1/3 the total mass (based on my big Mill)

[rvan]

Originally posted by SJ781
The head or the table I'm not sure which. Me and my dad picked those pieces up together. maybe 150-200 lbs. You could dissassemble them outside and take them down to the basement on a handtruck. and then reassemble.

I was definately planning to dissemble it before bringing it down. There is no way I am going to move 750 pounds down a flight of stairs. How difficult was it to re-assemble the Head? I'm thinking this may be a three person job. Two to hold and position the Head, and a third to bolt it.

This may seem a bit silly, but how did you get the box into your garage? I assume I can get them make the delivery with a truck with a liftgate, but I don't have a forklift or a pallette jack to move it arround.

Can the box be moved using a hand truck, or did truck driver bring a pallete jack to move it? Since it going to be delivered to my home, I don't have a forklift or a pallette jack to move it around, and I am a bit concerned on how to move the box off the truck into my garage. I suppose I could rent a pallete jack if I needed too.

I also may have a problem because my driveway is extremely long and up a hill (.15 mi). The last couple of heavy items I purchased, arrived in an 18 wheeler. Moving a couple hundred pounds using a hand truck was difficult. Moving 750 pounds would be reckless. I tried both times to make sure the deliverly doesn't arrive in a 18 wheeler, and even paid an additional delivery service fee for one of the deliveries, but my request was ignored.

[SJ781]

I have not reassembled it yet.. But the head should not be too difficult. I removed the motor and then lowered the head down on to some 2x4s and then unbolted it and slid it forward off of the bolts. Reassembly should be the opposite. If your driveway is cement or asphalt there should be no problem unless it's really steep then just get someone to help push. You do need a pallet jack to move the crate though. The delivery guys came in an 18 wheeler with a lift gate and they had a pallet jack. They unloaded it in the street and then wheeled it down my driveway and into the garage. My driveway is cement and about 120' long. The crate was about 32"x32"x50".