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View Full Version : Anyone hear of These CNC mills?



madman
12-14-2014, 07:03 PM
The cnc masters Mill with cnc 10 grand brand new/ Anyone have one of these cnc s in there home shop or garage, Any good reviews ? Thanx Mike


http://www.cncmasters.com/index.php/cnc-supra-vertical-knee-mill?gclid=CP7X69DexsICFQeQaQodl1gAnw

gundog
12-14-2014, 10:20 PM
Here is a thread about them from a while ago.

http://bbs.homeshopmachinist.net/threads/60455-CNC-SUPRA-from-CNC-Masters

tyrone shewlaces
12-14-2014, 11:25 PM
Well I hope the darned thing didn't fall over on the guy as he was unloading it. September of last year and no post-delivery posts. I'd be snapping pictures and showing them off here if it was me.

philbur
12-15-2014, 02:45 PM
Looks like only 4.5" travel on the Z axis under CNC control, this I think is not good.

Phil:)

macona
12-15-2014, 02:58 PM
This is pretty typical of converted knee mills that do not use the Knee as Z.

Toolguy
12-15-2014, 04:31 PM
It is typical and it is not good. A Z travel of 4.5 is very limiting in terms of what parts and tooling will work.

justanengineer
12-15-2014, 05:46 PM
Looks very 1980'ish with regard to the technology, not 2014.

garyhlucas
12-15-2014, 06:40 PM
Having run a CNC knee mill for four years after running a Fadal 4020 I swore I'd never have another CNC with just a quill. My homebuilt toy CNC has an 18" Z travel! You spend so much time trying to find short tools, or cranking the table up and down, or repositioning the table so you can load a tool, its enough to drive you mad.

John Stevenson
12-15-2014, 07:36 PM
Why do you need a nod and tilt head on a CNC ? Unless it's to take advantage of the Bridgeport ™ high tensile licorice design ?

gundog
12-15-2014, 08:42 PM
Well I hope the darned thing didn't fall over on the guy as he was unloading it. September of last year and no post-delivery posts. I'd be snapping pictures and showing them off here if it was me.

If I remember right he did post pictures and talked about it after he used it do a search using his name.

Toolguy
12-15-2014, 09:20 PM
Why do you need a nod and tilt head on a CNC ? Unless it's to take advantage of the Bridgeport ™ high tensile licorice design ?

I don't like the CNC'd Bridgeports. To me that is a poor way of doing things. That said, I have 2 CNC bed mills with Bridgeport style heads on them for prototyping. They don't nod but do tilt. I would just as soon have them fixed vertical, but couldn't buy them that way. I got the Bridgy heads so i wouldn't have to write a program just to drill a hole or 2, just use the quill for that. It has worked out very well. The small one has 20" of Z and the larger one has 24" of Z. I have used most of the Z axis on both of them on several occasions.

skunkworks
12-15-2014, 10:38 PM
http://www.cnczone.com/forums/knee-vertical-mills/52529-cnc-software.html

macona
12-16-2014, 02:53 AM
Why do you need a nod and tilt head on a CNC ? Unless it's to take advantage of the Bridgeport ™ high tensile licorice design ?

If you have only one mill it comes in handy on mine from time to time. Like when I needed to Trim out the V's on my lathe's saddle for moglice. I can set the head over and cut the angle.

Though my mill is not like in the link, it is more like a copy of a Series II and the knee is the Z axis, not the quill.

philbur
12-16-2014, 08:15 AM
I think that extending a quill for the purpose of drilling is one thing, extending it as a part of a milling operation (without locking) is whole different ball game. Even if the tolerances on the quill and barrel diameter are good it will still be a bit floppy, and if the tolerances are not so good, which is a distinct possibility on a low end mill, the quill will be all over the place with anything but the lightest cuts.

If you must have a knee mill then it is the knee that should be cnc’ed not the quill. But even then I think it will only be good for indexing type movements as 3D milling may be too slow due to the relatively high mass of the knee and the consequentially slow acceleration and maximum velocity (especially up).

If you already own a mill with a cnc’ed quill you may have to live with its limitation, but to go out and by a new one in the second decade of this 21st century is highly questionable, I think it is a dinosaur and belongs in a museum.

Phil:)

macona
12-16-2014, 05:11 PM
Boring mills have extending quills, it is not that big of a deal.

My mill has an air balanced knee do it is actually very responsive for Z movement. I also have a pretty large servo driving it. Doing a motorized Z right will cost a lot of money, probably 50% more than what they are charging for the whole mill to add it. Custom air cylinder with ball nut and screw is going to be a couple K right there.

bborr01
12-16-2014, 05:38 PM
Why would you need a ball screw on the z axis. I don't recall ever having backlash on a z axis. If the air balance on the knee is taking all of the pressure off of the knee it likely has too much air pressure on it.

Brian


Boring mills have extending quills, it is not that big of a deal.

My mill has an air balanced knee do it is actually very responsive for Z movement. I also have a pretty large servo driving it. Doing a motorized Z right will cost a lot of money, probably 50% more than what they are charging for the whole mill to add it. Custom air cylinder with ball nut and screw is going to be a couple K right there.

macona
12-16-2014, 05:47 PM
Why would you need a ball screw on the z axis. I don't recall ever having backlash on a z axis. If the air balance on the knee is taking all of the pressure off of the knee it likely has too much air pressure on it.

Brian

Mechanical efficiency. The load on a lead screw to do the same work is much, much larger than with a ball screw. You would need a much larger motor to drive it.

Plus they wear way faster than a ball screw, you have metal rubbing on metal, it just will not last. A properly lubricated ball screw will last the life of the machine. Lead screws are just not used on cnc machines.

hwingo
12-16-2014, 08:27 PM
The cnc masters Mill with cnc 10 grand brand new/ Anyone have one of these cnc s in there home shop or garage, Any good reviews ? Thanx Mike


http://www.cncmasters.com/index.php/cnc-supra-vertical-knee-mill?gclid=CP7X69DexsICFQeQaQodl1gAnw

Yes. I bought one (10 X 54 SUPRA) with the 4th Axis. Somewhere on this Forum I posted pictures. I've been able to do most everything I want to do.

Harold

philbur
12-17-2014, 11:22 AM
Boring mills have extending quills, it is not that big of a deal.

Possibly not on decent quality boring mill, where the manufacturer would have paid special attention the quill. In an-all in $10,000 after-market cnc'ed knee mill I think you may be lucky with the quill, or you may not.

Phil:)

John Stevenson
12-17-2014, 11:57 AM
I read skunkworks link in post # 12 about what is inside one because end of the day that's where the quality should be.
The writer on CNC Zone reckons the best bit is the Gecko 201 drivers. If that is the best bit then God help the rest !! :(
Power supply at $40 ? That's got to be one of the cheap linear ones which whilst OK for many applications is no good in a stepper environment where it has to handle back EMF because they can't. For CNC a massive toroid is king.