Need help with RF-45

stingxc

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After years of using a Harbor Freight mini-mill to make parts for antique cameras, my hobby, I bought myself a retirement present. A Rong Fu RF-45 with power feed and DRO. That was 8 years ago, and I am just now getting to use the mill. I have a few questions I could really use some help with.

  • The RF-45 has a fitting on the power down feed that’s not mentioned in the poor excuse for a manual that came with the mill. Is it a grease fitting or an oiling port? What lubricant does it need?
  • The mill arrived pre-cleaned and lubed, but I have no idea what products were used. The manual says to use “Lubriplate” but that’s a company not a product. My thought is to clean off the current grease and use one of the ones recommended on this site. Anyone have any idea what the “internal spline drive” might have been lubed with? It’s hard to clean it off and I don’t want to mix grease types.
  • I want to change the gear head oil. The manual says to tilt the head 90 degrees to drain the old oil. Is this really necessary? It’s perfectly vertical to the bed right now and I hate to mess that up.
  • The horizontal power feed has a speed dial, but it’s not calibrated. Is this something I need to do or am I just not understanding how it works?
Any help would be very much appreciated!
 
I don't own a RF-45, but I'm familiar. I do own a few rather expensive manual machines, maybe that qualifies me to answer. Or not. But I'll start and we'll see what the consensus is.

The geared head most likely calls for ISO 68. Many oils will fit that bill. It's a high pressure high compatibility oil that is meant for splash oiled gears. 90% of the machines out there spec this oil.

The fitting on the power feed might be for grease (if it lubes the sprag gears) but is more likely for oil if it lubes anything else like the quill.

The internal splines on the quill would be fine with any type of tacky NGLI grade 2 grease. It's a low heat application.

Lube the ways and acme screws with Vactra #2.
 
I don't own an actual Rong Fu but I do have a RF-45 clone so some things might be different on mine.

My PDF gearbox does not have a zerk fitting or ball oiler. Mine has an oil cup. Lift the lid to add lubricant. I squirt way oil in it, it doesn't need a lot. I don't use grease which wouldn't work for an oil cup anyway.

There's not much to lube often other than the ways & leadscrews. PDF gearbox doesn't require oiling often unless you use it daily. The quill rack & pinion I just use Super Lube grease.

By internal splines I assume you mean at the top/inside the spindle where the drawbar goes in? Grease would be fine for that too, I haven't added grease there yet on mine but I probably should.

Don't know about tilting the head 90° to drain the oil. Does your head have a drain plug on the side? My drain plug is at the bottom of the head, have to look up inside to see it. Remove the plug, oil drains right out, no need to tilt the head. Fill plug is on top.

If your table power feed is the bolt on style commonly used on mill/drills, then the numbers on the speed dial don't mean anything other than for your reference. The numbers don't correlate to a specific speed. Nothing to calibrate but what I did with mine is adjust the dial so that 0 is at the 12 o'clock position for ease of visual reference.
 
I do own an RF-45 N2F (that's the power downfeed version). ISO68 is what you want for the geared head. Yes, to fully empty the head of oil, you have to rotate it 90-degrees - there is a sump inside the casting that will not empty unless you do so.

If the arrow in the photo below is the zerk fitting you're asking about, that is to lubricate the pinion gear assembly that drives the quill down when using the handwheel or under power downfeed. For the past 18 years I have used a way oil with stickifiers added and it's worked fine. I use the same thing on the ways on the table and column, and on my lathe bed. You can make your own from Vactra #2 and add a stickifier like STP about 10:1, or Mobil makes the ideal way lube that will not run off under the brand Vacuoline1409. It's available in 5 gallon pails from any Mobil lube distributor, or is sold in repackaged small quantities by BRW Technologies. I get mine here, but it's carried by McMaster and a ton of other lube suppliers.

The X-axis power feed has no calibration markings. To know your feed rate, you need a DRO that will display that datum.

Hope this helps.

David

screenshot_5696.jpg
 
I don't own a RF-45, but I'm familiar. I do own a few rather expensive manual machines, maybe that qualifies me to answer. Or not. But I'll start and we'll see what the consensus is.

The geared head most likely calls for ISO 68. Many oils will fit that bill. It's a high pressure high compatibility oil that is meant for splash oiled gears. 90% of the machines out there spec this oil.

The fitting on the power feed might be for grease (if it lubes the sprag gears) but is more likely for oil if it lubes anything else like the quill.

The internal splines on the quill would be fine with any type of tacky NGLI grade 2 grease. It's a low heat application.

Lube the ways and acme screws with Vactra #2.
Thanks!
 
Thanks! I've found some good advice on products and a table that helps.
 
I do own an RF-45 N2F (that's the power downfeed version). ISO68 is what you want for the geared head. Yes, to fully empty the head of oil, you have to rotate it 90-degrees - there is a sump inside the casting that will not empty unless you do so.

If the arrow in the photo below is the zerk fitting you're asking about, that is to lubricate the pinion gear assembly that drives the quill down when using the handwheel or under power downfeed. For the past 18 years I have used a way oil with stickifiers added and it's worked fine. I use the same thing on the ways on the table and column, and on my lathe bed. You can make your own from Vactra #2 and add a stickifier like STP about 10:1, or Mobil makes the ideal way lube that will not run off under the brand Vacuoline1409. It's available in 5 gallon pails from any Mobil lube distributor, or is sold in repackaged small quantities by BRW Technologies. I get mine here, but it's carried by McMaster and a ton of other lube suppliers.

The X-axis power feed has no calibration markings. To know your feed rate, you need a DRO that will display that datum.

Hope this helps.

David

View attachment 415196
Thank you! That's exactly what I wanted to know. I'm paranoid about damaging my toys without knowing I'm doing it. One more question. When I rotate the head to drain it, just how heavy is it going to be? Is it something I can hold or do I need to rig my shop crane to keep it from crashing?

I love making things and the little bit I've used the RF-45 makes me really glad I bought it. I made my first parts on it last night. Just a simple mounting plate with a few holes but I had to make 10 of them and, using the DRO, they came out exactly the same. Something that never happened with my mini-mill.

I got interested in making stuff when I got the job of programming an early minicomputer back in the late 60's to run an automated, that's what we called it, mill for making complex parts.

Thanks again!
 
The head on the RF-45 is pretty top heavy because of the motor. You can extend the quill and lock it, then you have something to grab hold of as it rotates. Keep the locking bolts snug to prevent a run-away situation. There are 3 bolts total - one is hidden under the head.
 
Man I'm late to the party, wish I had seen your questions earlier! I could have helped with at least a few of them. I bought an RF-45 at auction a few years ago and when I found it, it was in pretty rough shape. I've tried to fix it up the best I can, but as you said the manual is pitiful and there doesn't seem to be a whole heck of a lot of information on the web for them. Outside of doing a CNC conversion that is...
 
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