[bentwings]

Anyone use this mill?
http://www.harborfreight.com/cpi/cta...emnumber=40939

I just ran across it at HF. It looks like it might make a nice cnc machine with a conversion.

[hoss2006]

for about as much money, i'd go with this square column mill from grizzly.
It would be easier to deal with the Z axis on this one and it has 21 5/8in. X travel and 7 1/2in. Y travel. compared to 15 1/2 x 6 for the HF.
This might be my next mill instead of the X3.

[Smitty911]

for about as much money, i'd go with this square column mill from grizzly.
It would be easier to deal with the Z axis on this one and it has 21 5/8in. X travel and 7 1/2in. Y travel. compared to 15 1/2 x 6 for the HF.
This might be my next mill instead of the X3.

Grizzle might be a better option but does it come with the "Goose Neck Lamp"? LOL

Industrial Hobbies at that point.

Smitty

[voltsandbolts]

We actually have one of those at work, I think we got it about 2004 and it has had the snot beat out of it by the untrained and unqualified and it’s still running today. I have used it my self and it seams like a robust little machine. When the company is ready to part with it I’ll make an offer. I think it would make a great CNC conversion and a step up from my X2.

Rob.

[Regnar]

For the price you could Craigslist a nice Bridgeport or clone. http://tampa.craigslist.org/pnl/tls/1229087824.html

[philbur]

A knee milll is not the best choice to CNC. If you all ready have one is one thing, buying one specifically to CNC is another.

Check out for conversion kits for knee mills vs square column mills, buy the mill that has CNC options.

A good design for raising the knee for Z can be a challenge. Z on the quill is crap and is to be avoided.

A knee mill for manual use is another thing. Then the knee becomes very attractive.

Phil

[SCzEngrgGroup]

A knee milll is not the best choice to CNC. If you all ready have one is one thing, buying one specifically to CNC is another.

Check out for conversion kits for knee mills vs square column mills, buy the mill that has CNC options.

A good design for raising the knee for Z can be a challenge. Z on the quill is crap and is to be avoided.

A knee mill for manual use is another thing. Then the knee becomes very attractive.

Phil

Phil,

I'm really curious what you're basing your comments on... I have a full-size knee mill, and currently use the knee as my Z axis - all 600+ pounds of it - and it works just fine. One of these days, I'll get off my lazy butt and CNC the quill, at which point that will become the Z axis, and the knee will be used for tool length compensation. The conversion was a no-brainer - in some ways even easier than the one I did on my old X2. LOTS of people have converted knee mills, and used them for years, with excellent results. I can hold better than +/-0.001" tolerance in all 3 axes all day long without even thinking about it, and the performance is great (>>300IPM in X/Y, >75IPM in Z, 3HP/8200 RPM spindle, almost >8 cu. in./min. removal rate in aluminum).

Were I shopping for a machine in this price-range, I'd go with the Grizzly RF-45 clone. Much greater travels in all directions, easy to CNC, and lots and lots of other owners to help out. Both machines have very active followings on their dedicated Yahoo groups.

Regards,
Ray L.

[philbur]

Ray you kinda answer it yourself when you said:

"Were I shopping for a machine in this price-range, I'd go with the Grizzly RF-45 clone. Much greater travels in all directions, easy to CNC, and lots and lots of other owners to help out."

I didn't say a knee mill can't be done. I bet that moving that 600lb knee for some delicate 3D work requires some real extra ummmf though. Z moves with the quill means its not very rigid when extended and probably sloppy if the quill to housing fit is not spot on, which apparently it almost never is, and there's no adjustment.

There is lots of discussion out there on 6x26 knee vs a 45 square column and you made one of the most important comparisons yourself.

I'm sure the OP doesn't take my word for it. But hopefully I have given him something to think about. I also didn’t expect everybody to agree, but differing opinions is for the OP to work through and form his own.

Phil

[hoss2006]

The OP hasn't made a post since 2007, doubt he much cares anymore.

[philbur]

Some of us have long term projects that run for decades.

Phil

The OP hasn't made a post since 2007, doubt he much cares anymore.

[HackMax]

Phil,

I'm really curious what you're basing your comments on... I have a full-size knee mill, and currently use the knee as my Z axis - all 600+ pounds of it - and it works just fine. One of these days, I'll get off my lazy butt and CNC the quill, at which point that will become the Z axis, and the knee will be used for tool length compensation. The conversion was a no-brainer - in some ways even easier than the one I did on my old X2. LOTS of people have converted knee mills, and used them for years, with excellent results. I can hold better than +/-0.001" tolerance in all 3 axes all day long without even thinking about it, and the performance is great (>>300IPM in X/Y, >75IPM in Z, 3HP/8200 RPM spindle, almost >8 cu. in./min. removal rate in aluminum).

Were I shopping for a machine in this price-range, I'd go with the Grizzly RF-45 clone. Much greater travels in all directions, easy to CNC, and lots and lots of other owners to help out. Both machines have very active followings on their dedicated Yahoo groups.

Regards,
Ray L.

Hi Ray,

Have you done a project thread on your mill? I have a cousin interested in converting his knee mill and I told him I would see what I could find out about it. I have found bits and pieces on it but not really a decent article.

Thanks,
Rick

[SCzEngrgGroup]

Hi Ray,

Have you done a project thread on your mill? I have a cousin interested in converting his knee mill and I told him I would see what I could find out about it. I have found bits and pieces on it but not really a decent article.

Thanks,
Rick

Rick,

Not really - too lazy, and I did it in a hurry, so didn't take a lot of pictures. Actaully did two machines at once. I have posted pictures of parts of it on here, but don't recall where. The conversion on X/Y is really very simple, and there are plenty of threads on here about how to do that. The quill is more complex, and I haven't done mine yet (but very soon....). For now, I'm just using the knee.

Regards,
Ray L.