[MechanoMan]

I'm already noticing my CNCRouterParts Standard rack & pinion drive pinion is shedding metal dust. The rack is located on top of the gantry in my design, and there's a visible buildup after about 10 hrs of runtime- most of which was running raster up and down the gantry, so it has been doing a lot of travel.

It's set at 60 in/min/min acceleration. I have the tension set maybe a bit conservative. I did find that it doesn't seem to take much at all to keep the pinion from slipping, but I did of course tighten it down a lot from that point.

The pinion's end is level with the bottom of the rack right now. That wasn't quite the original intent, there is room for the pinion to extend past the rack without rubbing on the gantry, but the mounting went a bit differently in the end and a significant part would have to be remade.

I did add some molybdenum dry lube to the R&P. I don't want to use grease in this environment, sawdust getting into grease can create a worse problem than it solves.

Any ideas?

[ahren]

MechanoMan,

It's important that your pinion gear is well aligned to the rack and isn't being presented to the rack at an angle. Feel free to give us a shout tomorrow and we can take a closer look at your design.

Best regards,

Ahren
CNCRouterParts

[ger21]

Isn't grease mandatory for a rack and pinion system?

[streetrodlover]

Not mandatory but will definitely help with metal on metal wear. You should at least oil it to lubricate and prevent rust, and sawdust can still stick to that. A little bit of lithium grease would go along way.

Sent from my SAMSUNG-SGH-I337 using Tapatalk

[LeeWay]

I use grease on my plasma cutter. The racks are away from the cuts. Bottom of the outside table and top rear of the gantry. I think it would take a rather long time like years to see any significant plasma dust build up in that configuration.
You may also be able to add a brush cover over your racks. That would help reduce saw dust accumulation. Then for routine maint every two or three months, use a tooth brush and solvent to clean out the grooves in the rack and pinion, then regrease.