Hare and Forbes 46B (Rong Fu clone)

Ha, fair enough, I won’t. The conversion is about to begin but I’m still planning a few things, although all equipment has arrived apart from the one thing you can’t buy via mail…time. I’m in New Zealand so I’m converting a Hare and Forbes 46B, identical to your machine pretty much, I.E. A Rong Fu clone of same size but what’s available down at this end of the planet. I’m making my own plates, ballnut mounts etc because 1/ I’m cheap and 2/a sucker for punishment.

I’m using Lichuan 1kw servos with their A4 drivers on all axis, similar to the metalmusings youtube channel although he is using 90frame as compared to my 80frame, physically different size, but same servo. Like him I have glass slides on my machine so am closing the loop with a 7i85s back to my 7i76.

I’ve recently finished constructing it’s base with an epoxy granite levelling layer, on top of that is an upcycled stainless shower tray for coolant catchment with a large cutaway under the machine that returns via a tray filter to the pump below…eventually, once I build the enclosure …etc etc etc.

Here are a couple of pics, the planning in fusion and the the “donor” machine going in and now awaiting the treatment.

The point of the epoxy grout levelling layer is so that I can use my machinists level for quick setup and fixturing. I.E if I know the machines perfectly level, then using the precision level I can then quickly level any part to the machine, I.E. less faffing about with dial gauges. That’s the hypothesis, it remains to be seen if it makes it to theory. :wink:

I am stoked to follow this build. The epoxy leveling layer is a fantastic idea. I am going to be building an enclosure soon, so I may incorporate this into the new stand.

reposting here.
Thanks David, yes I’m eager to get it cutting as well, although I’m fairly slow I hate to say, I’m involved in some prototype engineering as a consultant enginerd as well as teaching one day a week so the dance card is quite full, it leaves little time to play with my new robotic baby. I tend to get blocks done in bursts with long periods of zilch in the middle. But yes I’m happy to share the journey as I go. Ill post some pics of the servo situation and cabinet build soonish.

Here is a little graphic showing my planning out the order of operations for manually milling the mount for the z axis ballnuts as well as calculating just how large a piece of steel I need. The three jaw chuck is attached to a rotary table. This mount has two ballnuts either side of it that are in tension with each via sandwiched Bellville washers in the middle (to eliminate backlash). This arrangement allows some preload adjustability and wear compensation. I hope these kinds of noodlelings are interesting or of use to someone.

Wow I’m jealous of your modeling before milling. Have to ask now: what do you teach?

Its a digital fabrication sort of deal. Fusion 360 through to additive, subtractive and workshop skills for manufacturing and production. Just a part time number, one day a week, to pass the batten as much anything, and it’s fun. I was an instructor for Alias designer and Maya way back before Autodesk bought Alias and found out I loved teaching, much to my surprise.

To give credit where it’s due for this model though it began life as one made by KCJ aka Kurt Jacobsen , the author of probe-basic. KurtJacobson (Kurt Jacobson) · GitHub

I took his data set for an Enco RF45 conversion and have done admittedly extensive modifications/additions/mutilations to it to adapt it to the dimensions and castings of my machine. Although these machines are all sort of the same, the Precision Matthews included, they are also different enough to be annoying. I designed my last CNC from scratch, a mill/router and it was actually a lot faster to model because I was making it up as I went, unlike a conversion, existing art. So having his work to draw on was a great starting point. I think my machines going to have to have a little plaque on it in his honour “The Kurt”. It has a ring to it :wink:

A couple of his links that inspired me.


Some pictures of the equipment awaiting installation.

Din rails, way oiler and lines etc

Y and Z servos, endstop transducers

DIY fogbuster bits along with tool height setter, disc couplers, pulleys belts, braking resistors.

bearing blocks fitted with matched angular contact pairs, Belville washers

two of the servo drivers

Ballscrews X: 2005x800, Y:2005x 400, Z:2505x700

Man I am pumped for your conversion. Have you picked out an electrical cabinet yet?

I am going to build an enclosure soon and may just re-do my current electrical box because every time I think I buy one of sufficient size it quickly becomes too small.

I’ve been looking at them for a while yes and was about to go for a 500x400x300 number but have had a flash of inspiration re a steel trolley, several sheets of black ACM and some locking castors that I have on hand. I suspect it will end up looking a bit like a very early prototype cubist black Dalek but should be functional, particularly as I can mount my touch screen atop it with a monitor arm and perhaps have enough space to include an essential tooling drawer above the electronics. I like things that can be easily moved about. Its going to be the weekend project. Watch this space :wink:

1 Like

Ok, work has finally begun. I’ve been going over every dimension and triple checking stuff along with 3d printing mockup parts to verify fitment and clearance etc… many revisions later…I have it nailed down and have sized all the stock ready for milling into bearing plates, ballnut holders etc. The hand assembled nature of these machines is a curse to reverse engineer and has required fastidious and mind numbing measurement gymnastics. (every hole a unique and “special” (other words have been used) individual in terms of spatial placement)

I have finished with the mill base modifications now (extended y travel, x bearing clearance, y axis hole) and about to mill oil channels into the saddle and bed ways with my other machine. Awaiting oil elbows to arrive that are small enough to fit into the very tight space available under the bed.

A few photos from the adventure.

About to be torn down.

lots of this, although this machine is similar to all others, practically every dimension is subtlety different. I suspect this is a common theme among these clones and no doubt the reason why conversion kit makers supply kits for very specific manufacturers models only, there is just too much variation. As a side effect It makes sharing files etc somewhat pointless.

slabs’o’steel, this one the x bearing holder and mount for slideing servo bracket (belt drive on x to reduce footprint)

blued slabs’o’steel

adjusted bed for FK15 bearing clearance

a die grinder and paint make me the machinist I ain’t (doesn’t need to be pretty, just sufficiently out of the way)

like so

3d printing, the huge template upgrade over bits of manky cardboard.

Boring picture (yes for some reason the front surface of my machine is 27mm thick)

another boring picture

yet another boring picture

Mill base hacking complete

Cabinet layout planning.
Using a 600x400x200 Tibox mounted in the bottom of my tooling trolley, likely I will have another of these backing onto the first that will be dedicated to pneumatics and oil etc.

Here is a link to the DIN rail clip I whipped up for this task, someone may find it useful.

MesaDIN by m3chanist - Thingiverse

milling of oil galleries in the saddle ways

cast iron is interesting stuff to mill, its very soft but you can’t go fast

So sorry for my late reply! Do you have an update on this project?

BTW that DIN Mesa mount is clutch. I added that to main CNC mill project page.