X Axis Is Traveling

[Shipfitter]

Has anyone noticed at all if their X axis is traveling at all. I will verify my X,Y home location after cutting a segment of my job, and have noticed that the X axis is traveling. For instance, the job that's in my shark right now has an X axis that is .064 off. Using a lazer pointer, checking the piece of wood, comes out parallel to the machine .The work traveling across the bed is not a problem (bolted down pretty good with 1/4" bolts.), I do not want to relocate it, might mess up the rest of the work I have to do. I have about 15 hours of work in this piece.
My question is , does anyone have any little secrets to try and keep the controller in a good mood. Doesn't matter how many jobs I do with this machine, I get the same result. The more I do with the work piece the farther away the x axis will travel.

Thanks
Mike Morin
Lewiston, Maine

Using a shark HD PRO plus
Aspire 3.5

[tonydude]

Mike,

Have you check the couplings on the motors to make sure they are tight? Sometimes they are not tight and have to retighten them.

Tony

[Eagle55]

Hi Mike,

It might help to post a picture or try describing it a little more. I'm having a hard time understanding what you mean by "X Axis traveling". Are you talking about the x axis not being parrallel to the table? or the x zero changing during the run of a job? I'm just not sure what traveling means.

Roger

[drueth]

Shipfitter

Another 2 question I would ask with out any idea what you are cutting. Is you cut to agressive. This can cause the Shark to lose it place. Have you hit the limit the X can travel .

[Shipfitter]

I will have to check the coupling today. One of the screws are kind of hard to get at. Is there any way to get at it without cutting an Allen wrench to get in there on the X axis coupling?
I don't cut aggressively. .70 cut with a .070 stepover, and thats if it's a sharp endmill bit.
And yes, the x zero changes. The work piece remains solid on the table (parallel to table). I checked it yesterday with a lazer edge finder along the Y axis. Attached is a pic to show the mounting procedure. Flat bottom holes, 1/4" deep, with flat washer, and I even place another nut on top of the one I use to tighten it down with. (Lock Nut). And I do torque it down pretty good. No axis limits were exceeded or touched.


Mike Morin
Lewiston, ME

[drueth]

Shipfitter

If your cut is 0.70 or almost 3/4 of an inch and you are moving it in an X or Y motion YOU are going to have a problem. Unless you are cutting something like foam. Please post a pic of what you are doing. It would also be nice if we knew what size of bit and the feed rate you have set. One thing many of us have learned it to slow the feed rate down and than move it up a little at a time once you have a better understanding about the whole CNC thing.

One quick check to see if there is play in any one of the drive motors. is With the controlller on and power to the stepper motors can you turn the X or Y or Z worm drive BY HAND ( do not use any tool only your fingers) it should not have any play in it.

[Eagle55]

Not sure if that was a typo or not but .7" per pass is extremely aggressive at almost any step over and especially 10%. What happens is your control box tells it to make steps that it physically can't do and it looses track of where it should be versus where it really is. I'm guessing it may be a rather large bit or it would have broken by now. And example of a rather aggressive cut would be 1/4" end mill cuting 1/4" pass cut with 40% step over. I'm not sure I would even attempt that. With the cut perameters you are saying, if the axis is not loosing zero it would certainly would flex the gantry enough to give the illusion of a line "traveling".

Roger

[Shipfitter]

Meant .070 . It's hard to get anything by some of you folks. Which is a good thing.
The .70 cut reminds me when I first purchased the machine, and was not putting the zeros in , and couldn't for the life of me at the time figure out how come it was reacting the way it did by taking a 1/2 inch cut or whatever it was at the time. Yes, I have broken a couple of bits when I first started out. Thanks goodness I double / triple check those dimensions now..
Have any of you folks ever disassemble one of these sharks? The piece that is in question here is the bearing on the X axis. Will that just slide out when I loosen up the servo and go to slide the whole assembly off to one side a tad when I go to check the tightness of the set screws on the coupler?

[drueth]

Shipfitter

Are you finding you have play in the X wormdrive and it is because the coupling bolt/screew is loose that connects the wormdrive to the motor. If so maybe I am lost. I have a Shark Pro HD and I can get to that very easly . Maybe it time to work with NWA. I don't what to tell you something to do because I am NOT following you correctly. If I understand what TonyDude was sujesting you should not have to take anything apart. At least it is that way on my machine. TonyDude do you understand what Shipfitter is asking. And to be sure we are on the correct access X is form side to side

[tonydude]

Shipfitter,

How are you lining up your material on the bed? The bed of the shark may not be square to the gantry so do not line up material with the edge of the slots on the bed. Here is an article that was posted back in sept. about play in the x axis.

http://www.cncsharktalk.com/viewtopic.p ... 486#p10486

Might be of help.

Tony