Loose X axis

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TomTurner
Posts: 33
Joined: Sun Dec 30, 2012 8:25 pm

Loose X axis

Post by TomTurner »

Just finished some carving and when I went to remove the bit from the router I noticed that I could move the x-axis back and forth a small amount. It appears that it will move about 10-20 mils. When I push on it I can see that it moves and I can hear it hit what sounds like a hard stop in both directions. The screw does not move and the screw to motor is tight and solid.

I have not had to do any repair work on the unit as of yet (it is a MAKO by the way). I plan to call Nextwave on Monday but thought I'd ask for ideas from here. Any ideas on what it might be and then how to get at it will be appreciated. Looks like the problem is buried behind the Z-axis drive unit.

Tom

sk8nmike
Posts: 389
Joined: Thu Dec 01, 2011 7:35 am
Location: Carrollton, Tx

Re: Loose X axis

Post by sk8nmike »

Check the coupling on the X axis lead screw, probably just need to to tighten the set screws

bandmill

Re: Loose X axis

Post by bandmill »

There are two scerws that need to be tightened.

TomTurner
Posts: 33
Joined: Sun Dec 30, 2012 8:25 pm

Re: Loose X axis

Post by TomTurner »

Checked the set screws on the lead screw coupling and they are tight. The motion seems to be between the Z axis carriage and the x-axis lead screw.

Any other ideas?

Tom
Last edited by TomTurner on Sun Jan 05, 2014 3:25 pm, edited 1 time in total.

tonydude
Posts: 1547
Joined: Tue Aug 17, 2010 9:23 am
Location: Buffalo,NY

Re: Loose X axis

Post by tonydude »

Have you tightened the screws behind the router? There are 4 set screws behind it, I have a mako also. Take the router out and check all screws.

Tony
Buffalo,NY

"What will matter is not what you bought but what you built; not what you got, but what you gave”

Aspire 10.017, photo vcarve, cnc mako shark extended bed with the new upgraded HD 5 gantry with Led pendent.

TomTurner
Posts: 33
Joined: Sun Dec 30, 2012 8:25 pm

Re: Loose X axis

Post by TomTurner »

Tony,

Screws behind the router are tight. I put a dial gauge on the unit and both the X and Y axis have over .010" of free movement. I can see the deflection from the applied force but after release it comes back to a position that varies by .010"-.012" whether I push back to front or side to side. The Z-axis on the other hand comes back to the same position whether I push up or down and does not have the sound associated with the other two axis.

Do the T-Nuts become loose over time? That is the only thing that I can think of.

Tom

jeb2cav
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Location: Kentucky
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Re: Loose X axis

Post by jeb2cav »

The X and Y axis lead screw just set in the bearing (at the end of the lead screw opposite the motor coupler). I've found that I can remove most of the slack you describe by loosening one of the coupler set screws, and applying gentle pressure along the axis (away from the motor), and while maintaining that pressure, tighten the set screw.

There have been instances of loose or damaged t-nuts - and yes, that is another thing to check on. I suspect that if you try the above though, and it isn't a t-nut issue, that you'll remove most of that slop.

As you have a Mako, you may also want to check the adjustment of the bearing blocks. With use they may get a little loose and that will result in a few mils worth of movement as well.

bandmill

Re: Loose X axis

Post by bandmill »

I had the (z) t nut and the( y) t nut break at the shoulder, my diamond has not worked right since I got it in November of 2013, I think it might have happened during shipping.
The t nuts are made of a hard plastic, they have a theard inside with a flange that either is
screwed or bolted to the frame and the lead screw goes through it to make the cariage and the router move. On the diamond the x axes lead screw is a different size than the y axes and the router lead screws. The bearing on the y axes was missing, if there is supposed to be a bearing on the router lower lead screw end, there is not one there. I have not checked the x axes, will do that tomarrow while i am waiting for the new t nuts to arrive. They sent me the wrong size t nuts the first time..Hope things go better from now on sure would like to use my cnc the way it was made for.

TomTurner
Posts: 33
Joined: Sun Dec 30, 2012 8:25 pm

Re: Loose X axis

Post by TomTurner »

Just wanted to post an update to this problem. I did order anew set of T- nuts from Nextwave. Had to exchange them since I was sent the wrong T-nuts but Nextwave did this after they recovered from a winter storm. I installed the new T-nuts and both the X and Y axis are tight with no free play or slack.

When I went to remove the nuts they spun very freely on the lead screws. I could, give the a spin and they would rotate for 2-5 turns after the spin. When I put on the new T-nuts they turned well but we're not loose and did not spin freely.

I had run into the X and Y end of travel a few times but not excessively. I would not have noticed on 3-D carvings but was doing some precision parts and noticed the 15 mil tolerances errors. I assume the plastic T-nuts must have deformed or been worn by sawdust on the lead screw. This happened after about 14 months of fairly regular but no where near continuous use. All looks good now.

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