[elalto]

Hi All,

I have been following build threads for a number of years and have been blown away by the talent and skill shown by so many of you, WOW! It seems that every build is different with so many inventive solutions it is hard to focus on just one way.

About 5 years ago I bought an ENCO ZX0045, a RF 45 clone, with the intention of doing a CNC conversion on it. That machine has been sitting in my garage since. Over the years, I have been using my Grizzly round column mill/drill and have gotten pretty good at milling with it, however, I WANT my CNC!

I wonder if there are any suppliers that sell X & Y ball screw sets for this clone 45, I really don't want to buy something that ends up not working or worse working poorly. If there are no "kits" available then some good exact measurements and specifications would be very much appreciated.

Can anyone help me out? Thanks

[Sparky_NY]

There are a LOT of different ways to approach the ballscrew part of the retrofit. A lot comes down to price like everything, better costs more. Ground ballscrews are the ultimate but new ones are cost prohibitive for a retrofit of this sort, used ones come along on ebay routinely. It would be normal to shy away from used screws but I have found good used ground screws will run circles around the cheap rolled screws so commonly used. Next is new chicom screws from ebay. Those chicom screws are getting very good reviews by most users and the seller will machine the ends for a small extra charge.
The last resort, in my opinion, is something like rotron screws. They were never intended for such applications as machine tools. I used them on my first retrofit, never again.
There is some room for choices in the size of the screw you use, meaning diameter. Bigger is better here but there are clearance issues to contend with under the table and such. Reading through some of the many build threads will give you some idea of what others have used.

I am doing a RF45 retrofit right now. I was lucky enough to find some 24mm C3 grade ground screws on ebay about 4 ft long and snapped up all 5 that were available. The screws have a extremely low profile ballnut which will make clearances a non issue.

[elalto]

Hey Sparky,

Thanks for the reply, I am thinking about the Chinese units, while I look for some used ground ball screws. I am concerned about ordering the Chinese ball screws since I am not sure what size to order (length) as far as diameter, I'm thinking 16mm or 20mm at most. Is there a standard for the machined end or do I have to provide a detailed drawing?

Thanks again for the info.

Marcos (elalto)

[jid2]

You need to take your machine apart and start measuring. Every RF45 clone is different. I found that out as I started measuring and designing my conversion and found that I could not do things that others had. The ball screw ends are up to you, it will depend on your bearings, bearing block, tightening nut, pulley or direct drive etc.

RF45's require you to do all the designing and work to build the conversion - there are no kits, and each companies variant is very different at the detail level.

[arizonavideo]

You will want 20mm for the X and and 16 or 20 for the Y. I'm running a 16mm ground screw for the Y and it is fine. The Z is about 200 pounds so you want a 25mm unless you have to save money and the 20mm might be OK.

Steppers would be fine for the X-Y but you should really do a servo and belt for the Z.

From what I have seen it looks like their is at least three sizes of the RF-45 clones and the real RF-45. The Y movement tells a bit, some with 7" ,8.5" and some with 9.5" and the IH with 11". If yours is made by ZAY then it will be really close to a IH mill.

It is fairly easy to do but the Z will be a bit different for many.

[Sparky_NY]

The other two replies summed up the concerns very well, so I won't repeat any of that info. You will have to design/make support brackets for the bearings at each end of the screw and the dimensions of those brackets and their bearings will effect the dimensions for the screw ends and its length. Study some of the other retrofits, you can use the same design, only need to verify dimensions against your particular mill. The "drawings" for yours and others would look the same, only the dimensions would be different, probably not by much.

[elalto]

Thanks Guys,

I have seen that the Chinese providers also sell the driven and free ends for their screws, are they any good? Will they or can they be fitted to the 45? I plan to use stepper motors for the X & Y and will probably do those first while using the fine quill wheel on a stepper until I figure out the Z. The head on this mill is very heavy so I will be taking my time with it.

If the Chinese bearing blocks will do the job, I can order the screws longer than I need then trim & turn the "free" end in my lathe. Also, by using their blocks I won't order the wrong dimensions on the machining. What do you all think?

Thanks again, good info.

[Sparky_NY]

Thanks Guys,

I have seen that the Chinese providers also sell the driven and free ends for their screws, are they any good? Will they or can they be fitted to the 45? I plan to use stepper motors for the X & Y and will probably do those first while using the fine quill wheel on a stepper until I figure out the Z. The head on this mill is very heavy so I will be taking my time with it.

If the Chinese bearing blocks will do the job, I can order the screws longer than I need then trim & turn the "free" end in my lathe. Also, by using their blocks I won't order the wrong dimensions on the machining. What do you all think?

Thanks again, good info.

I think you have something confused. The china screw providers sell the SERVICE to machine the free and driven ends of their screws, not some type of "accessory" end. Many have used this service, you supply the dimensions and they do the machining. Reports on this service are good for the most part.

You can order the driven end machined, along with ordering the screw with extra length so you can machine the free end yourself later. There are packages on ebay with 3 screws, various lengths, which would be the most economical approach. There is also a "zero backlash" type they sell that has oversized balls fitted at the factory, something very desireable.

[dracozny]

read the description by the sellers very carefully, some will machine the end to your specifications, and some will use a default spec if you fail to provide the specs, many sellers will also give a diagram of the length and diameter of the screw itself but not the ball nut.

[pippin88]

The chinese bearings blocks tend to be pretty crap. They need adjusting and the bearing races shimmed, but they do the job to get you going.