Piranha Issues

[Eagle55]

I'm not sure who recommended dry teflon and I am not doubting that they did and not trying to contradict them, but...... I'm just not sure how much I would be voting for that as a lube for CNC work. I used to use it in locksmith work and still would use it for a lot of things but I'm not sure my Shark is one of those things. As Bob has stated from his experience it is possible to get too much of a good thing and when that happens you could experience some binding and "erratic" results. And if my supposition is correct that is exactly what you are looking for in terms of the problem that you are experiencing. Personally, I use CRC Heavy Duty Silicone in the red can (once sold at Lowes but their wisdom in merchandising has sent me elsewhere to buy it). Silicon is a good lube to stay on/in for longer periods of time (and not collect dust and grime) and if you get too much on it, it runs off. (BTW I wouldn't consider WD40 at all for lube) I also found similar problems in high dollar, high security lock cylinders such as Medeco who once recommended a dry teflon lube and because of build up and jamming of precision mechanisms went to a...... (drum roll.....) silicon based lube. Not wanting to step on anyone else's recommendation but lubrication would be one of my suspects with the problem you are experiencing as well as possibly something that is loose.

Roger

[sdiccenso]

OK, so I'm new to this and most of you were right. I previously checked all the fasteners but missed the collets on the threaded shafts. I found one with some play in it and when I tightened it the problem went away. Now I have another question. How do you tightened the fasteners where the nuts are buried in the frame. I put a screw driver in the opening to try to hold the nut, but it still spun a little. I did not want to put too much pressure to try to hold the nut as I was afraid to damage the black frame. That is the only other item that is not completely tight.

Roger, the Dry Lube was recommended by Next Wave. Specifically they recommended Dupont Teflon Dry Lube.

Thanks again for all the help.

Steve

[Bob]

My memory is a little fuzzy, but I'm pretty sure that NWA recommends the DuPont Teflon/Silicon lubrication. It's a mixture of both. not just Teflon.
Bob

[Mimbler]

My memory is a little fuzzy, but I'm pretty sure that NWA recommends the DuPont Teflon/Silicon lubrication. It's a mixture of both. not just Teflon.
Bob

Yes, it is on their site. Dupont Silicone lubricant with teflon.
Mike

[TOM G]

OK, so I'm new to this and most of you were right. I previously checked all the fasteners but missed the collets on the threaded shafts. I found one with some play in it and when I tightened it the problem went away. Now I have another question. How do you tightened the fasteners where the nuts are buried in the frame. I put a screw driver in the opening to try to hold the nut, but it still spun a little. I did not want to put too much pressure to try to hold the nut as I was afraid to damage the black frame. That is the only other item that is not completely tight.

Roger, the Dry Lube was recommended by Next Wave. Specifically they recommended Dupont Teflon Dry Lube.

Thanks again for all the help.

Steve

Steve,
I had the same problem and NWA instructed me to loosen the allen screw on the shaft the take off the electric motor. Take out the screw add lock tight. Then tighten the screw on the motor first. Then mount the motor and do the same for the screw on the shaft. The lock tight is the key.

Tom G

[Fean]

I'd say you were driving the cuts too hard and making the open loop steppers skip counts but your problem is only at the direction changes and is consistent on all the cuts so losses of steps would accumulate. Therefore something is moving, either the gantry because of bearings or deflection in the supports or something in the router itself. Make sure the router is mounted tight, wiggle everything to see if there is motion anywhere. Also check your bits, you should be using carbide bits that are sharp and clean. When a bit is dull it will not cut evenly. You also need to make sure the bit is as far into the collet as possible, with just a little bit of a gap so you can remove it later, so that there is only a small amount of shaft deflection as the load changes. You should also check that the bit is tight in the collet and that the bearings in the router are good. A bad collet will do what you have as well as if the bit and/or collet is not clean when you insert your bit. The final cause would be if the backlash on the drive screws is not compensated properly. And of course make sure your depth of cut is small enough, your feed rate is slow enough and your bit shank is as thick as possible.