Rong Fu RF-20 manual

[happymacer]

Hi all, I have a manual for a RONG FU RF-20 (includes the RF-15 and RF-30) and I thought I would scan it and post it here. Considering the age, I cant imaging anyone complaining. I have had a look at the FAQ's but could not work out if the forum would be happy to have it here, and where to put the document. Any directions appreciated!

If we dont have a document repository, how about we start one?

[myford]

I am in dire need of a manual for a Rong Fu RF-20.

[TrickyRicky]

Hi myford,

As luck would have it, I bought an RF-20 today and found the manual of the HF-33686 to be near identical.

http://www.harborfreight.com/manuals...3999/33686.PDF

The RF-20 specs differ slightly as follows :

MT3 Taper
92mm column
3/4 HP motor
Spindle speed (pulley) 90 - 2150 RPM
X Travel 320mm
Y Travel 160mm
Table 520mm x 160mm
14mm T slot
Swing 404mm
Spindle Stroke 100mm
185 Kg

[TrickyRicky]

Update :

Finelinehair.com has the RF-20 manual amongst its list of wonderful links :

http://www.finelinehair.com/home/Ron...ill_manual.pdf

... which is, as mentioned before, near identical to the HF 33686 manual, but with better diagrams towards the end

[happymacer]

Hi Myford, in case you still want a copy, here it is. Sorry about the delay - I dont get round to viewing this site often. I bought my Rong-fu in South Africa about 25 years ago and its still going strong. Had to replace the bearings a while ago and I think it runs better now. BTW, I know it says its an R8 machine, but its not. I bought some R8 cutter holders (sorry the proper name escapes me at the moment) and they dont fit. MT3 fits perfectly. Cheers!

[TrickyRicky]

Thanks happymacer - I found your info most useful as well ... particularly given that I was about to order a set of R8 collets

With regard to the bearing replacement you performed - does "running better" mean that you found it to be more accurate (for your needs).

thanks!

[happymacer]

Hi TickyRicky, now that you mention it, I never measured it before or after, so I dont know! On the other hand the old bearings felt "rough" when turned by hand, and the new ones smoother....so I guess they are better? For that matter, we didnt clean the machine when we received it, and its done very little work (it's a hobby) so cleaning off the old oily/waxy goo has improved things too. Im not sure if Im imagining it, but it seems to me that the head is very clightly crooked on the vertical pillar. So it seems to mill more with the left hand side of the cutter than on the right looking at it from the front. Does yours do this too?

[TrickyRicky]

I've seen what I think you may be refering to being spoken about by other RF owners :- if the column base is slightly off the vertical, you may get what you describe. I recall one RF owner using the blades of a feeler gauge to then shim the base appropriately!

The problem I noticed on mine is as per attachment :- more of a wobble of the bit itself, as I've tried to show using red and blue. I'll play around with it some more to see if it's just and adjustment somewhere, but I can't say that I noticed major problems in the delrin that I've been practicing on in terms of runout.

Bearing wise :- The ones I've been thinking of replacing are those referenced as 3-07, 3-15 and 3-18 in the manual you posted as I think they are most likely to address the issue I have at this point.

BTW - I've gave the table screws a cleanup and then coated it with copper-slip : that made a world of difference!

[happymacer]

Bearing wise :- The ones I've been thinking of replacing are those referenced as 3-07, 3-15 and 3-18 in the manual you posted as I think they are most likely to address the issue I have at this point.

BTW - I've gave the table screws a cleanup and then coated it with copper-slip : that made a world of difference!

Those are the same ones I replaced! I used NSK bearings, 2 off NSK6007Z, 1 off NSK30205J (might be "K" or "F" if I could read my writing) and 1 off NSK30206J (may be an "E"). Note that item 14 is a left hand thread! It took me a while to figure that out! And I had trouble deciding how tight to fasten it again afterwards. Eventually I just guessed, but there should be a way to do it properly. BTW be careful of the spring item 3-29 as I have heard that it can break and if its under tension when you release it it could cause an injury. Besides if it does break where do we get a replacement?

Ill give your idea of using copper slip on the table screws a test-getting them to run freely would be excellent.

[TrickyRicky]

hiya happymacer!

Thanks for the tip on the left hand thread and bearings. I don't see mention being made of torque setting in the manual, just "tighten bolt X" ! A cheap and nasty method I've used on bikes is to dab a permanent marker onto the join of the base metal and the nut *before* loosing (and cleaning of oil with acetone, say) ... and then tightening again until they line up. I've tested this method using a torque wrench on bike axle nuts to 100Nm - it works!
... but yes, one can only torque to spec ... if one knows the spec ... and has the right tool :/

Cool! I'm on the right track with those bearings then Don't think they cost too much ... but will wait and see.

Here in SA, "WD-Hearn" have been selling the machine for years ... so I won't imagine that spares would be a problem. In fact, I need to get a quote from them for several items anyway so will ask about the spring as a matter of interest.

I intend applying some copper-slip to the tapered sliding plates in the near future, but machine oil had to do in the interim (slightly messy, but effective).

PS. The main reason I wanted the free turning table-screws was to satisfy my curiosity of maybe using stepper motors. I get slightly "increased" resistance for about the last 20mm of travel as the bed nears the column (Y-Axis). No significant increases in resistance on the X-Axis - hence my intention of getting at the sliding plates with the copper slip as well.

[happymacer]

Thanks for the tips TrickyRicky! I was hoping to find a dealer as I dont know of an Australian supplier although they are a copy of an English machine. The right tools for the job is just the problem, from memory you need a c-spanner, but how to torque using one of those? I like your idea to mark the nut position - if only I had thougt of that before. Oh well cant win them all.

I am also interested to make it a CNC machine - at least on the x and y axis. But llike most things that has been delegated to the "one-day" pile while more pressing things get done... The Z-axis is a bit too difficult for me, but one lives in hope.

BTW, does "WD-Hearn" have a web site? Ill keep it on file if I need any bits...if you dont mind can you please let me know what the spring would cost? Maybe I should get one as backup. How about some photos when you finish your conversion to CNC?

[TrickyRicky]

Always a pleasure happymacer - play it forward, as you've done

Yes, WD Hearn has a site, which has changed a little since I last visited :

http://www.wdhearn.co.za/contactus.asp

I'll definitely enquire about the spring and keep you posted - no problemo.

Err . before I tackle the CNC conversion, let me get the hang of doing things manually! I'll also be satisfied with just X-Y ... one day ... but there's lots to learn (and lots to save the pennies for). Of course, I'll post pics!