Fineline Shutdown or Perpetrating a Fraud!!

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Originally Posted by wmgeorge

But if its not binding and cutting square is it still wearing? Everything wears, its part of the cost of using a machine. I doubt a hobby user would wear one out if its not binding, and if its does.... buy a new set of bearings after 20 years or so. Its amazing we have not heard these complaints over on the CNCRP area.

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Bill, I question whether you can correlate cutting square with wear. You can always force the gantry square (to a limited degree with a welded gantry) when homing, but not so much as to cause obvious binding. So the machine may cut square, but still over stress the bearings and cause premature wear. How much wear is an open question.

I believe it is premature to expect to hear much about the topic on the CNCRP forum. It hasn't been that long since CNCRP switched over to linear rails on its pro machines. Time may show that it it works well, or they don't hold up. IMO, it's too soon to tell.

Gary

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Originally Posted by ericks

That was why i spent extra money for good quality German made extrusion. Also the company supplying it in Australia cut it very precise...

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You are lucky. I spent hours milling the ends of my extrusions square and to equal length. As far as flatness, mine seem pretty good. Part of it is the material; part my design.

Gary

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Originally Posted by wmgeorge

But if its not binding and cutting square is it still wearing? Everything wears, its part of the cost of using a machine. I doubt a hobby user would wear one out if its not binding, and if its does.... buy a new set of bearings after 20 years or so. Its amazing we have not heard these complaints over on the CNCRP area.

Gary Campbell does a fine job and I have seen pictures of his work posted, IF I had a commercial shop and needed a machine I would have one of his for sure.

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There have been posts where hobby users have replace the Linear Bearings, they do not have to be binding for them to wear, 20years good luck with that, hobby users have more than just alignment problems, lubrication corrosion and dust adds to the wear problems as well

There have been posts where hobby users have replace the Linear Bearings, they do not have to be binding for them to wear, 20years good luck with that, hobby users have more than just alignment problems, lubrication corrosion and dust adds to the wear problems as well


So what do linear bearing blocks cost? I see USA sourced bearing blocks on a rail for $350 per side on EBay? So if they last 10 years, its a cost of what? I never see posts of anyone replacing any?

So Gary Campbell has posted pictures of his builds, how are you doing yours that are headed for the commercial market and export? Pictures like Gary posted would tell us.

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Having said all this, I do quarrel with the notion that using linear rails on extrusion-based machines is a total waste, which seems to be your position. Clearly less than optimal, but I'm doubt anyone really knows what to expect over time.

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I'd argue that linear rails bolted to extrusion are still better than any other system on an extrusion based machine.

The quality of the bearings probably also comes into play, as many machines are using Chinese "off brand" rails and bearings.
I'd expect genuine, name brand bearings to last longer as their tolerances and quality are probably much better. You get what you pay for.

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Originally Posted by wmgeorge

There have been posts where hobby users have replace the Linear Bearings, they do not have to be binding for them to wear, 20years good luck with that, hobby users have more than just alignment problems, lubrication corrosion and dust adds to the wear problems as well


So what do linear bearing blocks cost? I see USA sourced bearing blocks on a rail for $350 per side on EBay? So if they last 10 years, its a cost of what? I never see posts of anyone replacing any?

So Gary Campbell has posted pictures of his builds, how are you doing yours that are headed for the commercial market and export? Pictures like Gary posted would tell us.

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Bill,

Here's a thread from back in 2011. I believe it should satisfy at least some of your curiosity. I'm satisfied he's the real deal.

https://www.cnczone.com/forums/cnc-w...ld-friend.html

Here's another thread you might find interesting:

https://www.cnczone.com/forums/cnc-w...dle-build.html

Gary

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Originally Posted by ger21

I'd argue that linear rails bolted to extrusion are still better than any other system on an extrusion based machine.

The quality of the bearings probably also comes into play, as many machines are using Chinese "off brand" rails and bearings.
I'd expect genuine, name brand bearings to last longer as their tolerances and quality are probably much better. You get what you pay for.

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+1

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Originally Posted by GME

+1

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And except for one or two persons comments to the contrary, this is something I would not loose sleep over Gary, its going to work and be just fine. If its not binding the chances of you and I wearing our machines out is pretty darn slim!! If it does... will replace as needed.

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Originally Posted by wmgeorge

And except for one or two persons comments to the contrary, this is something I would not loose sleep over Gary, its going to work and be just fine. If its not binding the chances of you and I wearing our machines out is pretty darn slim!! If it does... will replace as needed.

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Thanks, Bill. I'm not worried and haven't been. I've been aware of the limitations all along and went to extraordinary lengths to minimize them. I believe mactec54 and Gary Campbell were correct in sounding an alarm. On the other hand, like Gerry, I believe linear rails arguably the best alternative for extrusion-based machines. As you point out, excessive wear can always be addressed with "replace as needed" - assuming it shows up sometime downstream. Unfortunately, high quality rails and bearing blocks (e.g., Hiwin) are a major expense. Peruse this site to see what I mean: https://motionconstrained.com/ This is where I bought mine. Shipping was included. The prices were the best I found.

I don't know what to say about your Saturn. If you're happy with the way it runs, that's what's important. I am pleased you got one of the good ones - maybe the last good one.

Gary

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Originally Posted by GME

Thanks, Bill. I'm not worried and haven't been. I've been aware of the limitations all along and went to extraordinary lengths to minimize them. I believe mactec54 and Gary Campbell were correct in sounding an alarm. On the other hand, like Gerry, I believe linear rails arguably the best alternative for extrusion-based machines. As you point out, excessive wear can always be addressed with "replace as needed" - assuming it shows up sometime downstream. Unfortunately, high quality rails and bearing blocks (e.g., Hiwin) are a major expense. Peruse this site to see what I mean: https://motionconstrained.com/ This is where I bought mine. Shipping was included. The prices were the best I found.

I don't know what to say about your Saturn. If you're happy with the way it runs, that's what's important. I am pleased you got one of the good ones - maybe the last good one.

Gary

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So are the rails and blocks sold as matched sets or can you buy the bearing blocks sold separate?

You can buy individual bearing blocks, individual rails or rail/bearing block sets. I've assumed that if there is wear sufficient to warrant replacement, you'd replace the set.

Gary

To test out if the extrusions under the rails will help me get things right, I am going to design some parts I can 3d print out of polycarbonate blend I have on hand. If they work well enough I may just leave them in place, also if they work well I will post up a link to the file for others to print or have printed. I'm trying to decide how extensive I want to make them...for example making them so you can adjust "toe in / toe out" as far as flatness goes. On my last and final attempt to parallel the rails, I had one rail tightened down and it rolled very smoothly with the other rail loose...when I tried the same test with the rails reversed (swapped tight and loose rails) the action was back to being with much more drag...seemed odd to me.