Re: [CAD_CAM_EDM_DRO] Re: Busy Bee retrofit ?

Hi Guys,

I just hate to take the wind out of your sails but I have one of those
units from Busy Bee. They are also well know in the US as the Rong Fu
RF-30 and as far as I know, they all come from the same place in China.
Anyway, about 4 years ago, I did convert one with 530 oz-in steppers
and found that at least with mine, I had to loosen the gibs to allow the
stepper to be able to move the table in X & Y without stalling. I never
did get to fitting ballscrews as I decided to upgrade to a bridgeport
clone knee mill. When you get to machining with the Busy Bee (or Rong
Fu) unit, you'll likely find the slop in the ways to be excessive. It
will be hard to maintain tolerance - in my opinion. To give you an
example of what I mean, wind the table all the way to one end of its
travel in X - the long axis. Pull on the extended end of the table in
the +/- Y direction and watch how much slop you see in the Y saddle.
Try the same thing on a BP type knee mill and I doubt you'll see any
movement. I seem to recall Jon Elson recently measured the column flex
while cutting and it was a lot more than one would ever expect or want
in a precision machine. You also only get about 6" of Z travel and that
poses real problems when you get to do tool changes under CNC control.
You need 4.5" to get an R-8 tool out of the spindle. That's why I cnc'd
the knee on my machine.

This machine was my first conversion and I learned a LOT but I got
frustrated when I tried to make any precision parts or smooth finishes.
Once again, I didn't fit ballscrews with double nuts to eliminate
(virtually) backlash and I'm sure this would have made a big
difference. I still use mine for odd jobs where I have another setup on
the big one that I can't remove - but I don't ever expect to get good
cuts.

I know they are on sale at a great price - but know what you are getting
- before you buy. That's why so many people recommend tracking down a
good used bridgeport - there is no comparison in the quality of work you
will produce - but I know not eveyone has space for a 2200 lb hobby item...

Cheers, Peter



peterboutakis wrote:

>Awesome! I'm going to go out and buy that mill, and get this thing
>off the ground. I'm will go the same route as you, and use the
>acme's for now, and then upgrade to ballscrews later. I will keep
>everyone posted here about my progress and probably set up a site
>with lots of pics.
>
>Great advice, thanks alot for your help!
>
>Peter
>
>PS, I used to be a mac guy, back as far as the Mac Plus, I still own
>a Mac Portable (gasp!). Those were the good 'ol days, when there
>were no viruses, and photoshop came on floppies!
>
>
>--- In CAD_CAM_EDM_DRO@yahoogroups.com, shyningnight@y... wrote:
>
>
>>Hi!
>>I'm a "newbie" at this too.. just designing my own retrofit for a
>>
>>
>very simillar sized machine.
>
>
>>I can let you know a few things I've found out...(and if anyone
>>
>>
>with more experience
>
>
>>contraedicts me, believe them.. like I said.. I'm new...).
>>
>>The NEMA refers to the frame size of the motor, and determines the
>>
>>
>dimensions of the
>
>
>>mounting holes.
>>As for motor power in Oz-In; I'm a little confused about that
>>
>>
>myself... But I've gathered
>
>
>>that you CAN use as little as a 400 Oz-In motors for XY, but more
>>
>>
>is better.
>
>
>>I just bought three 680 Oz-In Stepper motors from Dan Mauch at
>>
>>
>Camtronics (http://
>
>
>>www.seanet.com/~dmauch/). He currently has a GREAT deal on a load
>>
>>
>of motors he
>
>
>>picked up from a distributor. I haven't been "stepper shopping"
>>
>>
>very long, but his prices
>
>
>>seemed REALLY REALLY good for the sizes he has.
>>
>>As for controllers;
>>A LOT of posts here and on other boards recommend the Gecko drives
>>
>>
>(http://
>
>
>>www.geckodrive.com/). Camtronics also sells them.
>>I've had my eye on a cheaper setup from Stepperworld.com, but I
>>
>>
>think I'm going to
>
>
>>chicken out and probably go with the Gecko's since they seem to be
>>
>>
>thought pretty highly
>
>
>>of. I KNOW there are other drivers too...
>>
>>If you want a "bolt on" retrofit "kit"...
>>MicroKinetics advertises one, driver, motors, mounting hardware,
>>
>>
>ball screws.. the whole
>
>
>>deal. But it ain't no how cheap!!! I'm gonna stick to some make it
>>
>>
>myself components.
>
>
>>In the SHORT term, I'm going to use the Acme lead screws in my
>>
>>
>mill, get it up and
>
>
>>running, and turn out a few projects to 1) learn and 2) make
>>
>>
>enough "hobby money" for
>
>
>>the ball screws later.
>>
>>As for software, I've heard good things about Mach2 , but also
>>
>>
>about TurboCNC.
>
>
>>I'm kinda in the dark about that though... I'm a die-hard Mac user
>>
>>
>(run a network of 150 of
>
>
>>them), and learned how to write G-code all by myself way back
>>
>>
>when...
>
>
>>So I'm going to be starting pretty much from scratch with a PeeCee
>>
>>
>and CAM software...
>
>
>>Yes, all this stuff is possible. When I read about it all 10 years
>>
>>
>ago, it was possible if you
>
>
>>had a lot more money, and more electronic knowledge. NOW it's a lot
>>
>>
>cheaper, and
>
>
>>enough of the fine folks around forums like this have done it that
>>
>>
>they can offer advice to
>
>
>>us "dummies"...
>>
>>Hope this helps!
>>Paul F.
>>
>>--- In CAD_CAM_EDM_DRO@yahoogroups.com, "peterboutakis"
>>
>>
><peter@b...> wrote:
>
>
>>>Hi, I am looking to retrofit a busy-bee milling machine:
>>>http://busybeetools.ca/cgi-bin/picture?
>>>&NETID=0345350502040532429&NTITEM=B1976
>>>
>>>First off, would you guys recommend this machine to be a good
>>>candidate for retrofit?
>>>
>>>If so, I was wondering where I could obtain parts for a quality
>>>retrofit? I am assuming I would need quite powerful motors, a
>>>capable controller, and some ballscrews etc.
>>>
>>>What size motors? I have been reading about oz/in and NEMA. It
>>>
>>>
>is
>
>
>>>all quite confusing, but I am under the impression that with the
>>>right hardware this can all be accomplished.
>>>
>>>Is there a controller that is everyones favourite? A company
>>>
>>>
>that
>
>
>>>has knowledgable staff?
>>>
>>>I am assuming that the software to use is called Mach2 by
>>>
>>>
>artofcnc.ca
>
>
>>>is that correct?
>>>
>>>Thanks alot,
>>>From Peter
>>>
>>>
>
>
>
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