[arizonavideo]

I cut mine across at the ends leaving just the part that catches the pins. It only took a second.

[saabman]

IH is still sending Aarons instructions so I dont think you are at a loss. You have to order the table extentions (Y visible in Bobs picture above) with the ballscrews (since the ball screws must be longer than normal)

The entire zip file of instructions is too big for one email, but I would be happy to zip up individual parts if you are insterested. Just PM me your email address.

Chris

Chris

[jetflatline]

Thanks -- I think the instructions I have are Aaron's from when they were on the web site.

[jetflatline]

Finished the Y table today, but I'm concerned about the amount of slop/backlash in the ball screw. I can wiggle the pulley a few degrees without any movement on the Y table. Once I get it moving things feel a bit tight, but I'd assumed that the ball screw was zero backlash. Is it the case that the turns-per-inch of travel is so high that a few degrees of play is no big deal?

[arizonavideo]

What ballscrew are you using?

[saabman]

If your pulley has a few degrees of movement before saddle movement, it could be insufficient ballnut preload but more likely the pulley is not seated. When you feel the "slop" look at the spacer that sits between the pulley and the axial bearing. Can you rotate it?? The pulley needs to be very tight against the spacer and all of the ball screw itself must be snugged good and tight (this is particularly important on Z). I had the same issue when i first installed Y.

Rest assured that all that you learn on Y, will translate to smoother sailing on X and Z.

Chris

[jetflatline]

The ballscrew is whatever brand shipped with the IH kit, preload is set to .25 turns. They suggest .2 and have .5 as the max, .25 was easy to measure.

I thought I had the pulley tight enough, but after re-reading some posts on the forum, maybe I don't. Will go buy a strap wrench today and give it another check.

A simple test would be to hold the ball screw in one hand and wiggle the pully, d'uh.

[saabman]

Make sure you have the gib tight. If you do not have enough resistence you cant tell if the pulley is tight enough.

Here is a tip for the X axis. Get yourself a 4 foot pipe clamp. With it you can mock up the placement of the servo bracket and run the ballscrew full travel. I carefully chucked a 1/2 drill on the end of the shaft and drove the table left and right. i listened for changes in motor pitch.

I found the with the IH mount, it was not tall enough to let the ballscrew nut rotate. I put a 1/8 spacer under the mount. This allowed the nut to be turned in place with the mount fastened to the table.

Another heads up, the saddle machined edges are not parallel (or at least they were not on my mill) The gib side had .020 runout. So if yours is like mine, measure front and back on the non gib side. I was able to get within .0008 and the ballscrew feeds smoothly through its entire travel.

[jetflatline]

ball-screw rod is moving in sync with the pulley, so maybe it's just a matter of tightening up the pre-load?

[saabman]

Not a sufficient test. if you have axial play, the ballscrew will turn but it will move outward. This is why I suggest checking the compression on the sleeve behind the pulley. Rock the pulley back and forth, watch the sleeve relative to the bearing housing. Does it seem to move in and out (we are only talking a few thousands)

Chris

[jetflatline]

Thanks, I think I get it.

I used the support form on IH's web site and got mail from "Gene Spada" including the latest assembly instructions in PDF and they are quite different from the ones I was working with before. I'm going to re-visit the entire Y-table assembly and see if I screwed something up.

[jetflatline]

Drilled a bunch of holes and cut some grooves on my friend's Authentic, No ****, it's Really a Rong-Fu, RF-31 bench mill. So glad I went with an RF-45, even if it's a clone.

Now for some more assembly and to start looking for a PC to run the controller software.

[saabman]

So did you resolve the backlash you were seeing in Y?

[jetflatline]

Yeah, it turns out to be pre-load on the ball screw. The IH docs say minimum .2 turns, max .5, and I had to crank it up to almost .5 to get the pre-load to the point there was no slop.

[jetflatline]

...and the modified z-nut arrived back from IH a week after I mailed it to them. Maybe they've hired someone to mange workflow?

[jetflatline]

Note to self: drill ball screw mounts for one-shot BEFORE BOLTING EVERYTHING TOGETHER.

[saabman]

I think they may have hired someone. I have talked to a "Dave" a couple of times in the last few weeks.

Sorry, should have given you that tip (been there) I didnt drill my Y mount prior to mounting and had to do a blind hole from the top of the saddle. On the X mount I put the hole (and fitting just behind the wiper (inside the mount). I wanted to shoot the oil on the top side of the screw so I installed the spigot high. This coupled with the 1/8 spacer I used caused some slight interference with the end of the table during installation. Some quick work with the grinder fixed that.

[jetflatline]

Some (all?) Rockfords are tapped on the ball-screw housing itself and I forgot to check these before I installed them. Injecting oil supposedly keeps the ball bearings cleaner, but I'm not going to drill/tap the bearing housing and risk really screwing things up.

[saabman]

Any updates?

[jetflatline]

Not really -- I've got the grooves cut for the one-shot then discovered I was missing some connectors. Those showed up just as someone asked me to do some welding, so I'm officially behind on everything. :-)