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How difficult is your z-axis lead screw to turn?

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How difficult is your z-axis lead screw to turn?

Postby Awesomeness » Thu Apr 01, 2010 10:04 pm

I'm assembling my new BlackFoot 4.0 z-axis, and the lead screw seems very tough to turn in the anti-backlash nut. Even turning just the screw in the nut, by hand, was tough. Now that it's installed, it seems harder. Turning the coupler-half by hand is uncomfortable, though not painful.

Does that seem correct?

If you don’t have time to do it right, when will you have time to do it over?
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How difficult is your z-axis lead screw to turn?

Postby turn » Thu Apr 01, 2010 10:13 pm

I just noticed this as well. I thought I was cross threading it. So I took the backlash nut off and threaded by hand first to make sure, but I agree it seems really tight. The motor seems to handle it though for now.

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How difficult is your z-axis lead screw to turn?

Postby Awesomeness » Thu Apr 01, 2010 10:25 pm

Yeah, my motor seems to turn it ok, it just seemed severly more difficult to turn than the gangsta' threaded rod lead screw on my "book" machine. haha

If you don’t have time to do it right, when will you have time to do it over?
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How difficult is your z-axis lead screw to turn?

Postby graph4sure » Fri Apr 02, 2010 4:57 pm

Yes, it is all quite common at first. When I finished the Z-Axis on my blackToe v2.1
4x8, it actually grinded with my first jogging trials.

But there is a post on here a while back about adding a LITTLE
WD 40 spray lubricant to the threaded rod.

It actually has to break in over some time- like a new pair of shoes.
The more you use it, the better. Mine works fine now.

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How difficult is your z-axis lead screw to turn?

Postby homebear » Mon Apr 12, 2010 5:42 am

I'll second that. I had to use a machine vise to thread mine initially. It was grinding like crazy at during the first jogs, but after a few weeks it was smooth and perfect.

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How difficult is your z-axis lead screw to turn?

Postby Awesomeness » Mon Apr 12, 2010 6:00 am

Even better than WD40, I found some DuPont™ Teflon™ Multi-Use Lubricant at Lowes for a few bucks. It sprays a dry wax product, that is embedded with Teflon. It's great stuff, and doesn't leave any greasy stuff to attract saw dust or get on your clothes.

If you don’t have time to do it right, when will you have time to do it over?
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Re: How difficult is your z-axis lead screw to turn?

Postby alkex » Tue Nov 30, 2010 11:33 pm

Same here on my bluechick. Was really hard to thread by hand but a piece of cake for the motor...
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Re: How difficult is your z-axis lead screw to turn?

Postby Rye » Fri Aug 19, 2011 10:43 pm

I may have stumbled on one of the reasons the Z axis lead screw is hard to turn.

I am building a BlackToe 4.1 and after installing the leadscrew into the Z axis assembly -- with bearings, collar and coupler installed --, I noticed that the screw would turn easily for about 180 degrees and then hang up and become quite difficult to turn. After some looking around I found that both the top coupler and the lower collar were rubbing on the outer race of the bearing. I cut out a pair of thrust washers to fit between the coupler/bearing and the collar bearing. They were .5" ID and just unde.75" OD so that they did not rub on the outer race. Now the screw turn easily.

I cut the prototype washers out of poly and then out of melamine (formica) by clamping the material in the drill press, drilling a .5' hole for the ID followed by a .75" hole saw to cut the OD. The melamine washers will probably work for a while until I can find something better. I have attached a photo of the washer assembly which shows the initial white poly washers. Poly is way to soft..

I have contacted Diego on this but so far they havent come up with a resolution. I am hoping that they will find a good washer from Boker's and mail a pair to each of us who have the problem.
ThrustWasher.jpg
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Re: How difficult is your z-axis lead screw to turn?

Postby Awesomeness » Sat Aug 20, 2011 3:15 am

That's a good find to note, but it's a different problem. My screw was hard to turn in the nut when it wasn't even installed in the machine. Other builders should definitely look out for your issue, though.
If you don’t have time to do it right, when will you have time to do it over?
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Re: How difficult is your z-axis lead screw to turn?

Postby chris... » Tue Oct 04, 2011 6:30 pm

Sometimes I use an abrasive like ajax mixed with oil for the initial wear in
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