[SPENG]

Tom, with all due respect, and I am saying with all due respect here....You arent the only one on the block with the resources to make a nice THC unit

Please take note to the compliment hidden in the above sentence

[Torchhead]

Not sure how the subject morphed to a THC from talking about a Z and the choice of drivers and motors. But I have been doing this (electronics design 38 years and working with CNC plasma 14 years) long enough to understand I am not the only person that can design a THC. The theory in fact is pretty simple. At least once or twice a year on this list there pops up a post about a "new" THC design and how easy it is and they are going to start making and selling them.. Not one of those has shown up as a product. Go on EBAY and the market abounds with THC solutions from Turkey , Poland, China, Vietnam and other sources. Doing the design and making it work in a lab are only part of the equation. Probably the biggest challenge is to support the product to the end user. Documentation is part of that and taking phone calls from non-technical users and being able to explain complex concepts in a way that they can grasp it is a big part of it. One of the reasons my lead support person is a welder/fabricator turned CNC installer/user is he converses in the same language.better than I do. If someone can come out with a cost effective stand -alone THC at least the Torchmate user community would welcome that. We think the market is in integrated and automated Torch Height...then again who knows what will happen in the next six months. :idea:

[SPENG]

Attachment 256566

20mm linear rails
Ceramic ball bearings (wont rust with the water as seen with every other z axis ive ever used)
Cute little anti-backlash ballbearings, Ill do some testing once an assembly is complete. Should be fine accuracy wise but Ill know more once I build one in the coming week.

[fortyonethirty]

^^^

[fortyonethirty]

Why would you bother with ceramic bearings when the rest of the screw is steel?

[SPENG]

having owned the k2cnc type version of this and going through several of them...the bearings on the bottom are the first to go, rust up, and bind causing all kind of issues. ceramic bearings are inexpensive and wont rust.

[fortyonethirty]

I understand that rusty bearings are a problem, my point was more about the screw, if a sealed ball bearing is failing, how could a ball nut fare any better?

[brouser1]

I had to replace a set of those bearings for my K2 setup, they charged a couple bucks each + shipping. That's seems cheap to me.

[SPENG]

I had to replace a set of those bearings for my K2 setup, they charged a couple bucks each + shipping. That's seems cheap to me.

They are cheap, but the cost of the bearings isnt the issue, it is the downtime and hassle that is. Ceramic bearings cost me a whopping $8 each shipped from aliexpress.

I understand that rusty bearings are a problem, my point was more about the screw, if a sealed ball bearing is failing, how could a ball nut fare any better?

The ball nut does fair much better, I cant tell you what grade of steel the screw/balls are made of but they dont really seem to rust and lubing them daily also helps. In a cnc plasma enviornment with a water table, the water splashes straight up and gets into those bearings which locks them up within a few months at best.

[fortyonethirty]

I thought the k2 used a leadscrew? Putting a ballscrew on a plasma torch seems like a waste, its not like there is a lot of force acting on the torch?

[brouser1]

They are cheap, but the cost of the bearings isnt the issue, it is the downtime and hassle that is. Ceramic bearings cost me a whopping $8 each shipped from aliexpress.

Post a link I think I will check them out.

[SPENG]

The ball screws and lead screws were the same exact price from China. a whopping $14 each...