anchorman
Titanium
- Joined
- Dec 19, 2005
- Location
- Opelika, AL
Hi all,
I have a CNC router in my shop that has become somewhat neglected/orphaned since the original manufacturer was bought by a new company, and the new company is less than stellar about customer care, especially on legacy machines.
The drives for all three axis are 440 oz in steppers with a chain reduction to the pinions that drive the machine. The reduction is 3.6:1. Chain is #25 1/4" pitch. I've noticed a fair bit of slop in the tolerances, and found that the chains were pretty slack from lack of maintenance, which allows excessive backlash. given how old the chains are, and in order to preserve the gears, I'm looking at buying new chain, but there are a whole lot of options out there, ranging from browning brand chain for $1/ft to morse brand and others for upwards of $25/foot. I see varying grades of the stuff, and am wondering when one starts to see diminishing returns on quality? Pre-stressed (to reduce stretch) seems like an important feature, are there any other things a person might want to consider when buying this kind of chain? All seem to have roughly the same working strength and tensile strength numbers, though some are rated as stronger than others.
As to maintenance, how tight does one make the chain? I realize that too tight, and you just get excessive wear. the adjustment is to loosen the bolts holding the motor, and lift up on the motor, then re-tension. What kind of lubricant is best? These chains are covered and sort of protected, but they do get dusty both from the machine cutting, and other stuff that happens in the shop.
I'm considering getting timing gears and timing belt to replace the gear and chain setup, and building a simple mechanism to allow spring tensioning of the pinion on the rack, too.
I have a CNC router in my shop that has become somewhat neglected/orphaned since the original manufacturer was bought by a new company, and the new company is less than stellar about customer care, especially on legacy machines.
The drives for all three axis are 440 oz in steppers with a chain reduction to the pinions that drive the machine. The reduction is 3.6:1. Chain is #25 1/4" pitch. I've noticed a fair bit of slop in the tolerances, and found that the chains were pretty slack from lack of maintenance, which allows excessive backlash. given how old the chains are, and in order to preserve the gears, I'm looking at buying new chain, but there are a whole lot of options out there, ranging from browning brand chain for $1/ft to morse brand and others for upwards of $25/foot. I see varying grades of the stuff, and am wondering when one starts to see diminishing returns on quality? Pre-stressed (to reduce stretch) seems like an important feature, are there any other things a person might want to consider when buying this kind of chain? All seem to have roughly the same working strength and tensile strength numbers, though some are rated as stronger than others.
As to maintenance, how tight does one make the chain? I realize that too tight, and you just get excessive wear. the adjustment is to loosen the bolts holding the motor, and lift up on the motor, then re-tension. What kind of lubricant is best? These chains are covered and sort of protected, but they do get dusty both from the machine cutting, and other stuff that happens in the shop.
I'm considering getting timing gears and timing belt to replace the gear and chain setup, and building a simple mechanism to allow spring tensioning of the pinion on the rack, too.