4th Axis Rotary Table PM, etc

When I got my Brother Tapping center it came with a 4th axis. It is a Yuasa SUDX 170. I jogged it around to see that it worked but took it off because I did not need it at the time. This was a few years ago. I would like to reinstall it so I figured I ought to open it up to see what it looked like inside. Not good- nasty smelling something came out that looked more like rotten water than oil. I got it all apart and cleaned up and amazingly nothing really looks damaged. The bearings look good, worm looks good, etc. The only thing that does not look too good is the brake cylinder, which is sort of a big disk in there. I think it will be ok though.

Is this common? My guess is that it must be. At this point I am going clean it up and put it back together, try to seal it as best i can, and check/change the oil frequently. It has a stupid little 6mm bolt for an oil drain. I may drill and tap it 1/8 or 1/4 npt and to put a decent drain on it so it is possible to drain the oil without it all winding up in the coolant pan.

Also, the way the thing was wired in it had about 30' of sealtight like conduit with the cables in it that was coiled up on the side of the machine and wired into the control cabinet. I bought an Amphenol connector with about 30 pins and I think 6 larger pins. I am planning on cutting the cables, shortening, and put this in to clean the installation up some. There are power signals for the servo motor, which I figured I would put on the larger pins, a few switch/solenoid connections, and the encoder signals.

I have a SUDX 280. Mine came with amphenol connectors like you mention, big terminals for power and smaller ones for everything else, that will be fine. I think your on the right track. Change oil fairly often a couple times and see how much coolant gets back in. Previous owner may have never changed it ever. Might be just fine with regular maintenance.

Do you notice any run out with yours? Mine is in great shape, no play or anything and it runs smooth. But im getting over a thou run out that cycles every 720 degrees, or one rotation of the actual rollers in the bearings. Kinda makes me think they used really shitty bearings in these. Really surprised by this considering its Japanese made. Or maybe mine was rebuilt with shitty bearings before I got it? Who knows. Just curious if you noticed this with yours.

Cycles 720 degrees? That is odd. I have not gotten that far. Mine is still in about 50 pieces in the shop. The bearings are cone bearings like car wheel bearings. Maybe a better grade than wheel bearings (hopefully)? The worm gear is mounted in a sleeve with an eccentric bore so the backlash is adjusted out by adjusting two set screws which rotate this sleeve and thereby adjust the worm engagement.

I was thinking that maybe I would use marine gear oil like they use in boat motor lower units. Then as you said change it often. Also, I think the damage to the brake cylinder was due to moisture in the compressed air. I think it would be good to pop the back plate off the unit and check this out on occasion too.

Yes it cycles every 720 deg approximately. The rollers turn at half the speed of the shaft and make a full revolution roughly every 720 degrees. So seems like the rollers in mine are not all exactly the same size. Are there any markings on your bearings indicating extra precision like P5 or just the bearing size marked on there?

I tried regular gear oil 80w90 and it didnt work too well. Mine has a spur gear reduction before the worm gears (I think yours is worm only) and the gears very noisy with 80w90. Seem to foam up and run away from gears. They reccomend Shell Tellus 68 in the manual, which is actually a hydraulic oil. I finally convinced myself to buy a 5 gallon pail even though i probably need less then a quart, and it does in fact run WAY smoother. Maybe regular gear oil would be fine on yours being worm only.

I have some PDF's on these if you want them.

I can't tell much about the bearings. They are still on the spindle and I don't think I want to take them off. I think the numbers are on the back side. Same with the races.

Mine is direct drive on the worm. Thanks for the info on the oil. May experiment some. The only docs I have are an exploded drawing/parts list/specs. Not very detailed but good enough for what I need now.

This is a little bit of a longer term project for me. I don't really need it right now but I see potential for some efficiency/accuracy gains.