Z-axis is very tight, have to almost max out the z-axis pot on gshield

Same as title.When I put it together(before adding steppers), I noticed that the acme screw was very difficult to turn. Couldn’t do it by hand. And now that I have it all together and working, the pot it almost maxed out and I’m worried about heat. Is this normal, or could I have done something wrong? There isn’t much to the z-axis and I took it apart and reassembled just in case, but same thing.

Mine was very tight too, I used some molybdenum grease and it is ok now but maybe your bearing is damaged?

Also run the delrin nut up and down the screw just by itself 10 or 20 times to free everything up. It’s not unusual for the nut to bind a little at the very top or bottom of travel. Mine did when I first made mine, I shimmed the v-wheels slightly so that the acme rod was vertical.

I’ll check this when I get home. I got way out of order when building mine while waiting for parts to show up, so I bet I missed the hand tightening part.

If you follow instruction, it tells as requirement that, you must use your hand drill, hold delrin nut and run back and forward until it becomes loose before install.

:flushed: what did you do to loosen that much. Don’t tell me you’re using WD40.

:tired_face:

I did this a few times last night and put just a dab of lubricant on it and it is working great now. Was able to turn the pot down a full have rotation. Thanks much!

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You can take your delrin nut and rod off, put in boiled water for 30 seconds, nut must be on the rod and clamp nut to acme rod from four sides, wait for cool down. :wink:

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Boiling make delrin soft, clamping to acme rod and cooling makes it tighter. Tested several times by different guys with fairly good result. Especially those far Countries and nice Islands like yours with ordering replacement difficulties.

There are, but they are expensive:

http://www.mscdirect.com/browse/tn/Threading/Taps/Acme-Thread-Taps?navid=12106032