# newbie with Rong  Fu 31 Vertical mill / drill set-up



## lo7us (Nov 4, 2014)

I am joining this collective groups in hopes I can partake in the wisdom of the more experienced machinist. LONG ago I use a Bridgeport (mostly to miter tubes)  and was hooked in what can be done with a vertical mill... flash-forward many decades I finally replaced my bench-top drill with a bench-top mill/drill (Dayton - Rong Fu 31 round spindle type)

I picked up a (old) vocational classroom book and have been reading the very basics, as I build up my tooling and better understand many of the best practices that are expected from machinist knowledge and skills. Soooo much to learn, but at least I have some gear to start.  

So far I've set up the 220v, moved 700 lbs of hefty mill/drill to my work area, and picked up an assortment of end mills, drills, a serious vice, parallels and squares and padding / holders and several .001 starrett and federal guages.  

After learning how to tram my spindle, and tram the vice I have milled the precise "block" and done a drill and "pocket" with VERY close edge tolerance to observe cutting (end mil type) over both X and Y axis and passed the .003 variance of specification... so looks like I am ready for my project that will be first to improve the Rong Fu 31 (Dayton label)  lead-screw backlash replace it with with a ball screw set-up.  

I've been doing a lot of reading and see that I have many options, but at this point my goal to it make backlash acceptable for a later-on CNC conversion, (kinda a series of small steps)

My hope is to buy / make a "adapter" that I can screw into the ACME lead screw thread of the OEM ball (nut) and identify the proper length ball screw and support bearings to have handles and a servo motor. The best example of the goal (but at a price I can not afford) is the Flashcut CNC modification... it reused the lead screw nut so it's mostly a matter of adapter to ball screw inserted where the lead screw (acme) went. 

I suspect someone has already developed a bill-of materials (vendor and part numbers) for the ball screws, support bearings and ends for handles and servos, as well as the modified ball-nut to attach to the Rong Fu 32 table... but so far only the Flashcut CNC people have a kit, and they are very proud of the $1k kit so I am hoping to find or if necessary make the parts to accomplish the same goal. 

Any help is always appreciated!  Remember I'm a newbie so my learning curve is steep, but I catch-on quickly. 

Looking forward to meeting some of you.

Oh BTW I am building a Lotus Super 7 (90% complete) and now in the "jewelry phase" so billet Aluminium controls will be artifacts of my new leanings.   

Lo7us (aka John S)


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## darkzero (Nov 12, 2014)

Moved your post to the Rong Fu section for better visibility, hopefully someone can help you out.


Oh and...


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## Holescreek (Nov 12, 2014)

Don't mess with ball screws until you're ready to do the conversion. With zero resistance it's too easy for the "fixed" axis to move. I'm fairly confident there isn't any kind of adapter from ball screw to acme. 

Take it for what it's worth (nothing usually) but I believe that until you know how to run a machine manually you shouldn't consider making it CNC. 

I converted an RF-30 many years ago, my goal was to do the conversion for under $1000. I made all my own parts, machined the hardened ball screws, bought boards and electrical components to build the controller etc. I don't know how much a ready made kit costs but none of the parts was simple, AND you need a machine to use to make the parts for the one you're converting.


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## lo7us (Mar 6, 2015)

Thank you Holescreek as you can tell by my late reply, I've been going through a steep learning curve... And better appreciate the manual steps I've been working with, not to mention work setups. I'd really appreciate specific details on the ball screws you used... Length and diameter, anything because your right, I'm need my mill working to make the parts. The projects in doing will require cnc so I'm eager to start making the same parts I see you crafted.  Please send details on design if you are inclined.


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