A sloppy RF-45 mill/drill

I contacted Thomas Skinner again, and ordered the lead screws and nuts. They do mostly industrial CNC, now., They have to order from Rong FU in Taiwan. Maybe some day I'll see them. I've had some long waits for parts from Grizzly, before. This could be a couple months or more.

Even if I only have a improvement of a couple thou from the new lead screws overall, any will help. This still will leave the dovetails on the Drama Queen to scrape. So back to the question of what will I need at the minimum and where to find the tools.

Oh, BTW, that was very good idea about the ball screw conversion, I never thought of that.

When I was in Grizzly show room Thursday , I did look, drool, at the mills. But a baby Bridgeport, same capacity, is $8000 landed here in Canada.
 
Look at the way scraping section on the forum. Most people would need a small granite plate, a camelback, a scraper...and lots of time...
Oh and a ballscrew wont hold if you are cutting, it will want to rotate, that is why manual mills are typically acme screw. Tim
 
https://www.surpluscenter.com/Power-Transmission/ACME-Thread-Lead-Screw-Nuts/

I'm in Australia, and you blokes over there at the top, have this bunch in your backyard. Yes, bought a bit of stuff from them. Even with freight, is a good proposition.
(Star note, what ever I did, don't do it again, it posted before I was finished) enter. tab ...something????
Buy, 2 nuts, to set up your own "adjustable backlash remover". I did it some years ago, on the Z axis, still adjustable and as good as a Ball Screw. Which, I have since done for X, ball Screws from Aliexpress.
More than 1 way to screw a cat.
Mark Needham
 
You can have one fixed nut and another that is seperated with a spring washer to remove the backlash, but i would make it out of brass, use a split nut, creating 2 nuts in one, then use 2 pins to keep the 2 nuts from rotating and the washer puts pressure on them to remove the slack, crap, I wish I had a pic
 
All Rong FU does for backlash adjustment is cut a slot in the nut block and have a bolt ( allen head cap screw) that you can tighten to take up the wear. Crude . Mine are all the way in ! Nothing left. I have a shop built 6" shaper that will get a version of the two nut backlash adjustment when I change over from 1/2"-13 UNC to 1/2"-10 Acme. Using an off the shelf acme rod, I think I'll need something like that.
 
Downwindtracker2 said:
All Rong FU does for backlash adjustment is cut a slot in the nut block and have a bolt ( allen head cap screw) that you can tighten to take up the wear. Crude . Mine are all the way in ! Nothing left. I have a shop built 6" shaper that will get a version of the two nut backlash adjustment when I change over from 1/2"-13 UNC to 1/2"-10 Acme. Using an off the shelf acme rod, I think I'll need something like that.
Click to expand...
Make the slot larger?
Mark Needham
 
If you happen to find a source of nuts corresponding to your lead screw selection, possibly something like this principle could be adapted. Looks like he employed it on a CNC type machine. Other ABL nut assemblies I've seen are adjusted like a screw within a screw rotational adjustment but I'm not sure about how accessible it would be on the RF-45. It would be nice to be able to adjust them from the end without a major disassembly. Cant help you on ball screws. I asked that question elsewhere & the consensus seemed to be divided. The yes camp said it will work as long as you lock your table before every single cut (which is good practice). The no camp says that's different than electrically holding the leadscrew position like via a stepper motor. Above my pay grade. I guess try & find someone who has a working example.

There is no guarantee a Grizzly part will fit your machine. I guess if its cheap enough, not much harm in trying & maybe it can be adapted.

 
That looks interesting, but knowing my skill level, I think I'll end with something cruder for the shaper.

Tomorrow, I'll Email Jesse at Thomas Skinner a Happy New Year. It's only been a month. But that should remind him of the order. There is a warning there about imported machinery.

To put it in service, I did buy Grizzly parts. There is a considerable difference in finish quality between Chinese Grizzly and Taiwanese Rong Fu .

Lately , I've been working on some lapidary equipment for the wife. Just finishing a Frantom grinder/polisher as a Christmas present. . I'm guessing this one is from the '60s or '70s. Nothing more than an arbor that I'm mounting 50k and 14k 8"diamond wheels on. Tom and Fran , a husband and wife team,made them, that's where the name came from, kinda cute. The next project is used 24" rock slab saw. A millwright made this one. The feed was from a floor polisher, remember those, that packed it in. I got a 60/1 small Radicon for it, break that, to get the 2 or 3 rpm needed. But I'm always surprised more rockhounds aren't electrocuted . They are a bit stone age when it comes to electricity.

To get an idea of rock saws, here's a commercial one. https://www.kingsleynorth.com/skshop/product.php?id=94916&catID=842
 
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The spring loaded lead screw nuts will remove backlash and will compensate for varying wear of the lead screw as long as the applied forces don't exceed the spring force.
I use a similar concept on my Atlas/Craftsman 6 x 18 lathe. It works there because in virtually all of my use, the reactant force is outward. If I were performing operations like counterboring where the work will be pushing inward, any significant reactionary force by the work will defeat the preload.
On the other hand, a mill is run in both directions. Moreover, climb cutting will tend to pull the work into the cutter. A stiffer spring can be used to reduce the effect but with a stiffer spring comes increased wear on the lead screw and the nuts.
 
All the force in one direction is on the three little pins. An antibacklash would have to be able to take full load that the nut takes. This discussion is good, I have shop built shaper project.

I got a reply back, tomorrow I'll get the price. He has to figure it out.
 
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