New Machine Build- RF30 with ball rail Z or RF45???

[D.L]

Hello friends,
I am planning a second build, given the transient nature of my life I need a machine that is A; portable, B; rigid, C; single phase.
My 1st build was a xylotex, but is really only good for machining wax.
Metal chips are the 'real deal', I'm focusing on drill mills as they can be broken apart into large but movable chunks. The RF45 clones are a good option, but being a fitter turner I naturally would like more bang for my buck
(bigger).
The RF30 clone has a longer and chunkier table, thicker base, but clearly the round column is it's downfall.
I just happen to use CNC often at work, and one thing you learn quickly is the Z axis works extra hard. The X + Y merely interpolate and feed most of the time.
I like the idea of ball rails on the Z over the iron dovetail, this would involve fabricating a column to bolt on the RF30.

Has anybody else ventured down this path?
What are your thoughts and experiences?

[arizonavideo]

The FR-45 clones come in two main sizes the small table and large table. You are looking at the small one.

It looks like it is a bit hard to find the 8 1/2" Y travel but I found one here.

http://www.use-enco.com/CGI/INSRIT?P...PARTPG=INLMK32

I would get the square column and if it wears out you can machine it flat and add LR to it.

[pete from TN]

I used to have an RF31 and now have a Lathemaster rf45 style machine and the Base on the two of them are near identical and the table on the rf45 is slightly larger?!! The IH style machines are even larger than that? THe only RF30 machine I have ever seen was quite a bit smaller than both of these and had a much smaller table travel... The RF31 is a good machine and the round column can be worked around but I think you are much better off just getting the square column machine and working from there. Mine has been very nice and I have it converted to cnc recently and now it is really nice!!

If you have the money I think that the IH machine is a better choice simply because of the available travels, The LM machine is nice and rigid and is in reality more than enough machine for me but I am always looking to make it do what it cannot so I am probably not someone who is happy with anything... I am sure if I had the IH machine I would be trying to push the envelope with it as well.....

The other nice thing about the Square column machines is the fact that if you ever want to build a toolchanger you can attach about anything you want to that cast iron column. The millhead is VERY heavy tho and requires a stout servo or stepper setup to lift and lower it with authority. SOme have done it with cable systems and pulleys and lower power motors but that is more complicated I think. I also have a nice knee mill here and I chose to cnc the LM machine over it because of the fact that I can enclose the entire machine in an enclosure so it is nice and neat kinda like a very small vmc. Still working on it but it is getting there....

The only real obvious drawback of the square column machine is the gear head. Slow and noisy but stout.... I have found a way around that as well..... good luck with what you buy and be sure to post some pics of your machine and any build thread if you can here....peace

[D.L]

USA gets the best of both worlds!! You get the table length and square column.
I neglected to mention I was shopping in Australia, stocks are thin on the ground and importing attracts a hefty tax for purchases over 1000 bucks.

There are so many builders of cnc's now, it would be nice if the gallery could be sorted into the categories such as the forums so trawling for ideas could narrow down a lot quicker.

Cheers arizonavideo and pete TN.

[scotta]

D.L.

Go with with RF45. I nearly purchased one a few months ago when the 50% tax break came in but have since started on a 8' x 4' router. I have a round column RF25 from Hare and Forbes. Great for doing light work but a pain when having to reposition the head. Hence my suggestion for the RF45.

When I was planning mine I did a lot of research into the various mods that people have done - gas strut counter weight and belt drive conversion of the head were the top on the list after ballscrews.

Scott

[D.L]

The idea for the Rf30 was to weld some 175 or 200 square hollow section tube to some 20mm plate steel and machine, but i'm a bit suspicious the high density of the iron tube would be like a 'big bell', castings are softer and add more mass to dampen the killer vibrations we all dread.
So yes, I must concede. The RF45 clone with a long table is hard to beat!

When you look at most machining centres with X+Y on the floor and Z on the back wall if you stripped away all the sheet metal and tool changer you would be left with a structure not to different to an RF45, only scaled up heaps.

[scotta]

With that setup you would still have to do most of your machining with the quill (limited stroke) as the head is not easily raised / lowered on the round column. Lots of resistance. Yes the linear quide would maintain the head orientation but it would not be a good Z axis (large motor / slow motion)

With the RF45, the quill would be locked and all Z axis motion via the column with suitable ballscrew.

Scott

[D.L]

Yeah scotta, 100% column over quill!
Man, I tune out for 2 weeks and there are 20 new threads in the benchtop section. I think I've found the most busy area in the 'zone'.
Bought a pantograph for 300 bucks to butcher into a benchtop, 900mm X, 400mm Y and 250mm Z. Gunna lay it on its side and hopefully integrate a trunnion table, probably remove half its mass with an angle grinder, add a BT30 spindle bore with a DC servo for synchronised tapping.

Talk is cheap, so watch this space, in 4 weeks i'll check back in with progress.