Newbie- Setting up gibs? How to? Noob needs help

[TheWolf]

Does anyone have a technical write up or could explain to me how to setup the gibs on a x2? I've tried searching but I've come up empty handed. I've got my motors hooked up now and they work quite well. There's just alot of play in the gibs and it causes the table to wobble. An 1/8th of a turn and they're to tight to move. I must be missing something?


Also what IPM gain will you get by say converting from the stock screws to say a CNC fusion ball screw kit? Thanks

Kris

[Fixittt]

They should be like anything else. You set them so that the table will not wobble

for my maxnc I normally run them all the way in, then slighly back them off. I do it about 5 times in a row to get a good feel. The idea is to have the same amount of pressure thru all the gib screws.

Also the type of job your doing is going to determine how tight the gibs need to be, I cut wax, so I can have a loose table. Alloys might require a tighter gib adjustment.

[BobWarfield]

lots of approaches. Since you dont have the feel of a manual machine, something more analytical is called for. I've seen a couple to consider.

First, you could use a dti and tighten until backlash is minimized. If you overdo it, backlash goes up because the tight gibs force the machine to flex.

Second, connect an ammeter between the power supply and the axis driver. Lock gibs tight enough the axis won't move and note the current. Now make the gibs very loose and note current. Tighten to 30 pct of the difference.

Best,

BW

[Regnar]

Lock Axis's with axis lock. Tighten Gib screw to finger tight. Tighten gib nuts while holding allen wrench to screw so screw doesnt tighten or loosen. Release axis lock. Learned it from here http://smartflix.com/store/video/912...s-101-volume-5

[The Blight]

As far as I know, stepper motors don't draw more current when not in the right position.

The quality of the ways on the X2 is not exacly the best. The gibs might be perfect in some possitions, while in others it locks up or has too much slop. You might want to consider lapping the ways ("sanding" down the high spots) and the gibs. This helps a lot, and you can tighten the gibs so that there is allmost no slop in any position.

I also read once about someone who made new gibs for their machine (I think it was a lathe) out of brass. Another more extreme way would be to make steel gibs with nylon inserts (you will loose some rigidity, but it will be more forgiving when it comes to uneven ways.. I thought about this, and dropped it because I want my machine to be as rigid as I can get it). I also took a trip down the "nylon screws road" to press on the gibs. It worked like crap.

After the ways are cleaned up, you should do it like Regnar said. If still too tight, just loosen them a little.

[TheWolf]

what do you use for way lube?

Found out tonight why enclosures are a must... I've got fly cut aluminum chips 10' in every direction.... time to do that tommorrow.

[The Blight]

Grease. I have no idea what type it is, but it works for me. I have tried oil, but it was too thin, and then I found a tube of grease at my parents house, and tried it instead.

Have sent chips flying everywhere with flycutters before. Delrin is actually the worst, because it gets static and sticks to everything. Brass is also quite bad.. actually it can be the worst if it gets into your shoe. Had to throw my socks away because of that once. Stings like a moth..f.....

[cadmonkey]

I'd avoid grease - any contamination creates a nice grinding medium as the contaminant can't escape.

I use a medium/light weight oil. Have been using std 30wt but am switching to something more in the 50-70wt range so there's less dropage and waste from my X axis. My local tooling supply house stocks Ashburn Way Oil 68 which is 60-75wt and claims it won't emulsify with waterbased machining coolants. At $17 a gallon it should last a long time (as the $3 30wt quart with waste has lasted a while) so I'll give it a go.

[The Blight]

Hmm good point. Might get some way oil from my work instead. The machine has been sitting still the past few monts, so I will take it apart to clean it once my new controller is done.