[bp092]

wow I'm at a lost for words.. got it all back together after a tv break.. david thanks so much, how tight did u make the acme nuts? I jogged it up and down and the one on the bottom came loose after awhile

[David Da Costa]

They should not come loose if you have locked them.

Here is what to do lower the leadscrew down so you can get at both the bottom acme nuts, take 2 adjustable wrenches and when the top of the two is in the right position hold it still with one wrench, then with the other tighten the bottom nut against the upper as hard as you can, this will stop either moving.

Move the leadscrew back up into position, fingere tighten the lower of the top two nuts against the bearing then as per the bottom, hold that nut still and tighten the top nut against it to lock it.

[bp092]

nice david, will try that tomorrow morning, now going to finish up the y and go to bed, I really appreciate all the help, you have no idea lol how much frustration I was going through with something so simple

[David Da Costa]

You are welcome - thats what this forum is for.

[bp092]

well my night just got worse, I went to put in the lead rod for the gantry and it goes to the other end and ends up almost a full 8th inch away from being center with the other hole, I had to bend it slightly to force it in then popped the bearing out to see how bad it was.. and yeah 1/8" exactly.. I'm thinking it has to do with the gantry not being square to the table, but the adjustment screws didn't do a whole lot to jack that up or move it into center

[bp092]

yep just checked the gantry, up 1/8th higher on the right side than the left..

[David Da Costa]

Very interesting. Is the leadscrew 1/8 two high?

I had exactly the same problem so what I did last week it to make another HDPE bearing holder with the hole higher.

I tried to square that gantry but it was already pretty square.

[bp092]

but that won't solve the problem, when you cut it's going to climb as it cuts.. for instance if you don't move the z and you cut to the right the cut will be 1/8" less in depth than the left because the rod is up 1/8".. adjusting the bolts (tightening them) only makes it worse , loosening makes the bearings not touch..

[David Da Costa]

Actually just checked mine and it's the same - strange

[mike hide]

You are welcome - thats what this forum is for.

So basically the two upper and lower nuts trap the leadscrew against the inner bearing races. perhaps a tad more than finger tight before locking the final two nuts together. and ensuring the leadscrew turns freely .

Before locking the nuts together presumabley making sure the lovejoys are seated properly with the motor securely to its mount.

That should leave only the antibacklash nuts to adjust . I am presuming there are an allen screw adjustment [or the like] in one of the antibacklash housings.

All in all there are 6 nuts required per axis for a total of 18,I think the hardware listing called for 20 . were the additional 2 added in case of a screw up here or there or were they actually required ?

[bp092]

and yeah the acme rod is too high 1/8" not the gantry itself.. it's weird, it's about 9/16" off the table on one side and 9/16" give or take a 64th on the other. But the holes don't line up. I hope the gantry isn't twisted..

[bp092]

Actually just checked mine and it's the same - strange

gotta get joe's opinion on this, I'm going to measure the parts now and see if the holes are off on my parts.. because if it's the same for you I know it isn't because I milled my angle poorly or something, it might be some of the parts or something I did or haven't tried yet, either way he's the chief..

[David Da Costa]

but that won't solve the problem, when you cut it's going to climb as it cuts.. for instance if you don't move the z and you cut to the right the cut will be 1/8" less in depth than the left because the rod is up 1/8".. adjusting the bolts (tightening them) only makes it worse , loosening makes the bearings not touch..

It does for me it makes my leadscrew be in alignment with the two bearings and the acme not on the carriage.

[David Da Costa]

Yes that could be a problem.

I would not get to hung up on it yet until you try the motor out on it. I was running mine out of adjustment and it was working pretty well. Of course it worked even better after the modification.

Don't get to frustrated by the way, you are already getting way better performance out of your Xylotex than I ever did and it took me a month after completing the build to get things working

[bp092]

lol I get frustrated because I know I'm so close.. but go measure the distance from the table(if spoil sheet make sure its firm down to the skin) to the first pipe, one side then the other, is it off at all?

[joecnc2006]

Sorry i was away, have been moving. Then Lastnight I could not get into the CNCZone don't know why, their page would not load.

But, i have been reading on Brian's problem. I remeasured the holes for the leadscrews/bearing block placement and both sides and they check with each other.

What you should do is measure from bottom of gantry up to the bleadscrew hole should be 24.24". so if you measure 24 1/4" that is it. the problem some people are having is the Z-Axis Carriage is not sitting right. this will make the leadscrew to sit higher on one end than the other. this comes from the placement of the top Y-Axis Bearing Block.

So to Adjust it you need to adjust the Y-Axis adjustment Blocks on top of the Carriage in pears, the front two and the rear two together. by tighting one set from the other it will tilt the Z-Axis Carriage and aligh the Anti-Backlash Bearing up with the Bearing Blocks.

I hope that makes sense and I will Keep checking in while moving.

Thanks, Joe

[bp092]

thanks for the info joe, I will double check today and play with that.. but that still leaves me a bit concerned that that the gantry is 1/8" off exactly one side of the table to the other.. skin to first pipe but I will recheck again now, hope the move is going well and appreciate the help

[joecnc2006]

thanks for the info joe, I will double check today and play with that.. but that still leaves me a bit concerned that that the gantry is 1/8" off exactly one side of the table to the other.. skin to first pipe but I will recheck again now, hope the move is going well and appreciate the help

To adjust the gantry height, you do the same this time adjusting in pairs, the Top Two and them the Bottom Two, and to make slight adjustment in Square it will be the front two and the rear two, turning them the same amount of turn 1/4 turn 1/2 turn etc.

[bp092]

okay now it is even with the table and near center, now just the rod is 1/8" to the right of the hole from being center and my bearings don't touch on the bottom of the carriage

[joecnc2006]

okay now it is even with the table and near center, now just the rod is 1/8" to the right of the hole from being center and my bearings don't touch on the bottom of the carriage

you adjust them simotaniously, meaning for example on the Y-Axis loosen the front two 1/2 turn, and tighten the rear two 1/2 turn, thisway the distance between the bearing blocks remains.