[jjh122]

Does anyone have any plans for building a "Z" axis stepper mount? I have a two axis now, and was thinking of adding a third...
Thanks; John

[M96Jay]

I got on here looking for the same thing. I'm tired of manually setting the Z.

[mc-motorsports]

I bought the Elrod conversion. Nice, but expensive. I would also be interested if someone has a proven design they would share.

[chevdrgtrk]

I constructed a box for mine. The base is 1/2 plate aluminum, the sides are 1/8 aluminum welded to the base with 6 pieces of round stock (also welded to the base) drilled and tapped to secure the cover. When I called to get a price on this pre-made, it was $1,300. I think I have about $50 in mine including pulleys and a belt. My setup drives the table.

[jjh122]

MC, What was the price for the Elrod unit? I went to the website and there wasn't a price listed....
Chev, can you post some pics of your conversion?
Thanks; John

[WagonWheel]

I do not mean to speak for mc but if it helps I did the Z elrod conversion last year. It was $6384.00 from EMI. It is possible to just buy the mechanical parts from elrod, but then you need to source the rest of the components. I did the conversion myself and must say it is not for the faint of heart.

[mc-motorsports]

MC, What was the price for the Elrod unit? I went to the website and there wasn't a price listed....
Chev, can you post some pics of your conversion?
Thanks; John

I think $1900? Somewhere right around there. It came with the ballscrew, quill-nut (part that attaches to the quill) aluminum housing is cast, motor mount, nuts bolts, all that good stuff, just add a motor and belt, that was the price for a series 1 bridgeport 2 year ago. I think there is someone who sells them? Found thier website a couple years ago, they sell them for list price so I went directly through elrod thinking if something was wrong I was not dealing with a middle-man if I was paying full price either way.

[mc-motorsports]

I do not mean to speak for mc but if it helps I did the Z elrod conversion last year. It was $6384.00 from EMI. It is possible to just buy the mechanical parts from elrod, but then you need to source the rest of the components. I did the conversion myself and must say it is not for the faint of heart.

What all did that include? I was just taling about the Z axis hard parts, minus motor is what I mean.
MC

[WagonWheel]

Sorry for the confusion and getting the thread off track. The price I mentioned was for duplicating the Bridgeport series 1 Z conversion using the Elrod unit. I talked to Elrod at first and his mechanical conversion only was $1700.00 and something if I remember correctly.

The additional parts include: new servo axis motor with pulley and belt, motor mount bracket, motor and encoder cables, newer style Z drive card, axsbob card, cabinet wiring harness and instructions, scale and scale adapter cable, 3 axis software and manual. It also included a couple of hours of support which was very helpful in tuning.

Just a heads up: Elrod did not provide an installation tool with his kit now for his conversion. It is simple to make if you have a lathe that will hold decent tolerances. He does provide a drawing with dimensions.

[boaterri]

I have been pricing components for a J-1 Bridgeport conversion too. Here is what Elrod quoted:
x-y bracket $1166
Ballscrews $1756
Ballscrew Yoke $ 431
Limit Switch Kit $ 607

Micro-Kinetics has similar products for a bunch less and they have a knee drive bracket. The only problem with the Elrod and M-K brackets is that they are drilled for a NEMA 43 motor. Most people are using NEMA 34s.

Hope this helps,

Rick

[jjh122]

OK, I've been looking at the Elrod and the Micro Kinetics "Z" conversions and I'm thinking that it shouldn't be too hard to come up with something myself(ourselves) and build one instead of spending the big bucks buying one already made..... A couple of questions first..... Does anyone have any comments on driving the knee instead of the quill? I know it's heavy, but with all the weight pushing down, I don't think a ballscrew is needed... as there won't be any backlash as there would be when changing directions.... I personally don't like the idea, but I'm keeping my options open..
Second.... Where does the quill mounted version bolt up to? I can't find anywhere on the front of the head to even make an attempt to bolt anything to, except the four bolts that hold the head onto the column....
Any comments?
John

[mc-motorsports]

WHOA! Those ballscrews are too expensive! http://www.icai-online.com/product.php?productid=17070 is what I have and I just made some mold inserts with .002" tolerances and held them to .001" no problem.

[chevdrgtrk]

hey everyone, sorry it took me so long to reply, but CNCzone hasn't been working at night when I get off of work, but here are the pics of my Z axis. I'm running a MCG 1200 inlb servo reduced 4:1, that give a whopping 400 ftlbs of torque on the axis, it runs the table up and down at about 40 in a min without struggling, I also picked up a couple of 4 in pneumatic cylinders yesterday for $20 each to "help" with the lifting so the servo isn't doing all the work, I'm going to put a regulator on them that self bleeds the pressure when the table is going down. If my calculations are correct, at full pressure of 150 psi, these 2 cylinders should be able to lift around 4000 lbs, so a regulator is a must! total (not including the servo) I will have about $90 in the Z setup.

[mc-motorsports]

be careful and make sure you keep the column to knee dovetail clean and oiled. I just broke a gib on a machine and ended up scrapping out the column and knee. The unfortunate part is the old column and knee was in beautiful condition, other than a broken gib that locked them together, and cost me $800 for another column and knee that wasn't in nearly as good of shape, but I was desperate, had to have that machine running...

[mc-motorsports]

Hey, your using the "lowcost cnc" unit, what servo's? They only sell small ones...

[chevdrgtrk]

no, they have several different size servo packages, I have MCG 1200inlb, and from what I understand, they have a bigger setup now.

[mc-motorsports]

Servo? I know they have some bigger steppers, didn't know they sold servo's over 900 in/lbs?

[Sparky_NY]

OK, I've been looking at the Elrod and the Micro Kinetics "Z" conversions and I'm thinking that it shouldn't be too hard to come up with something myself(ourselves) and build one instead of spending the big bucks buying one already made..... A couple of questions first..... Does anyone have any comments on driving the knee instead of the quill? I know it's heavy, but with all the weight pushing down, I don't think a ballscrew is needed... as there won't be any backlash as there would be when changing directions.... I personally don't like the idea, but I'm keeping my options open..
Second.... Where does the quill mounted version bolt up to? I can't find anywhere on the front of the head to even make an attempt to bolt anything to, except the four bolts that hold the head onto the column....
Any comments?
John

I converted my own series 1 manual machine recently, all 3 axis (4 actually, did the rotary table too). I made all my own brackets etc. and used nema 34 steppers. The X and Y are super simple, just a flat 1/2" aluminum plate with some slotted bolt holes for the motor and table attachments. I used 2:1 timing belt drive. I made the timing pulleys on the 4th axis.

For the Z I used a pretty simple aluminum bracket assembly. The main plate mounts up against the factory bosses at each end of the downfeed adjustment screw. Those flat bosses are the first surface machined on the head and used as a reference by the factory as the quill bore and other features are machined so they are a proper locating surface for a Z drive. I drilled/tapped those flats for the 2 mounting bolts that mounts the entire Z assembly. The ballscew is vertical with a standard ball bearing on the top and a thrust bearing on the bottom. The ballnut mounts to a steel "arm" that is drilled through and attaches to the quill using the 3/8-24 existing hole in the quill that mounts the round depth stop ring. The quill drive "arm" has a radius cut at the quill attachment end that matches the quill radius.

On my first try, I used the round hole in the stock quill depth stop ring to drive the quill. Bad idea, the dowel pin flexed and gave lots of backlash. The arm with radius matching the quill solved all the problems.

Oh yea, I used a 425oz Nema23 stepper for the quill because I had it onhand. It drives the ballscrew with a 3:1 ratio timing belt drive. I have the quill set a 80 IPM and honestly do no know how much faster it will go because 80 is plenty fast for me right now.

My whole cnc conversion cost $1500 or less and that is including $700 for a Rockford ballscrew kit for the table. I am flat out amazed how much they get in the market for motor mounting brackets and such considering how simple they are.

[mc-motorsports]

^^^ correct. I would post pics of the Elrod to show you how it mounts, but he has patents and could decide to get pissy. His Z axis conversions are expensive, but quality, do you have more time or money? That's what it will come down to. You could build something equilly as strong, it will just take a while vs. buying one from Elrod and bolting in on. If you want, research his patent, it shows how it mounts.

[Sparky_NY]

^^^ correct. I would post pics of the Elrod to show you how it mounts, but he has patents and could decide to get pissy. His Z axis conversions are expensive, but quality, do you have more time or money? That's what it will come down to. You could build something equilly as strong, it will just take a while vs. buying one from Elrod and bolting in on. If you want, research his patent, it shows how it mounts.

Somewhere here on the forum is a thread complete with pictures of someone that made their own Z quill drive. In the thread there was some complaints of the homebrew being "close" to a patented unit. A little searching here would turn up the thread and its pictures.