Harbor Freight / Rong Fu Improvements (HF #33686 Round Column)

[scottyp]

I recently received an HMEM membership sticker in the mail and stuck it to the side of the pulley cover on my mill and was amazed at what an improvement it made. The thing does not clatter like it used to and it is so quiet and smooth, almost a mirror finish cut instead of looking sometimes like a wild animal gnawed away at it, just a crazy difference. The thing now cuts like it is enjoying what it is doing rather that pounding it's way through a cut.

The more I think about it, I also did just receive some German made bearings for the spindle/quill and threw them in tonight after work and over a beverage, OK maybe 2. I knew the originals were not that great, I could tug on a drill chuck and feel and hear the play, I didn't bother to measure the runout. I thought about trying to improve the situation by repacking the bearings and messing with preload and such, but I found references to the ***/Schaeffler angular contact bearings and went that route. I highly recommend this if you have one of these machines, well worth it and a pretty straightforward process. The new bearings are a bit thinner than the originals so I added a shim washer under the castle nut to make up the difference. Bearing part numbers below:

Upper: *** 7206-B-XL-2RS-TVP
Lower: *** 7207-B-XL-2RS-TVP

 

[Tug40]

My bearings are still fine after 19 yrs.
but…i’ll write those numbers in my manual for future reference
Thanks..

 

[Lloyd-ss]

Alas, this machine is no longer carried by HF. Sounds like those new bearings, and the HMEM decal of course, gave better results than "the laying on of the hands." Was it an early bench top mill? Curious. Thx

 

[scottyp]

I'm not sure when HF first sold these, but I think mine was from the early 2000's. I'll double check on that.

 

[arnie]

I have an early one, I think Harbor Freight was called something else at the time and didn't have many if any retail stores.

 

[harborfreight8x12]

I have the round column 33686 which I purchased in 2016 with a coupon. The discount coupon paid for the shipping and much of the initial tooling. I have been very happy with this mill/drill.

 

[Lloyd-ss]

It is mixed bag at HF, always buyer beware. But the quality is definitely improving. 2 products I have purchased in the last few years I would rate as excellent quality and value. One is the Milwaukee portable metal bandsaw knock off. 1/4 the cost and I have cut sooooo much metal wit it. 2nd is the smaller Honda engine knock off for a little over $100. A drop-in replacement on a 1950's roto tiller. Starts 2nd pull every time. Not try to hijack the thread, just saying.

 

[harborfreight8x12]

It is mixed bag at HF, always buyer beware. But the quality is definitely improving. 2 products I have purchased in the last few years I would rate as excellent quality and value. One is the Milwaukee portable metal bandsaw knock off. 1/4 the cost and I have cut sooooo much metal wit it. 2nd is the smaller Honda engine knock off for a little over $100. A drop-in replacement on a 1950's roto tiller. Starts 2nd pull every time. Not try to hijack the thread, just saying.

I absolutely agree with you. When buying from Harbor Freight, one must do their due diligence. Some items are 5 stars and some are junk, it is up to you to read all the reviews and research YouTube.

 

[Lloyd-ss]

I absolutely agree with you. When buying from Harbor Freight, one must do their due diligence. Some items are 5 stars and some are junk, it is up to you to read all the reviews and research YouTube.

And I absolutely agree with you. You get what you pay for, and if it beats your realistic expectations, then you won one.
I once read a review by someone who had bought some $3 bales of pine straw at Home Depot. They were complaining about finding a few sticks in the bales. I wanted to remind them that should have bought the "clean" $9 bales at the fancy garden center instead, LOL. I can pick a couple of sticks out for $6 a bale.

 

[master53yoda]

if any one would like a fine feed for the quill on these early HF mill drills, I made one for mine and I have the prints if any one would like them.


Art B

 

[animal12]

I'm interested to see what ya did Art
thanks
animal12

 

[master53yoda]

This is a modified Drill press that I se for a mill, with all mods it will handles a 2.5" face mill in mild steel, most of my milling is in aluminum.
The finale Fine feed mod was the spring loaded cam for easy milling to drill press change over.

if interested if have autocad drawings for the fine fee.

Art B

 

[animal12]

Art if it's not too much of a hassle i'd like to see the drawings you have . I have one of the Big Red mill drills from HF & it has no fine feed
thanks
animal

 

[awake]

Here are 3 key mods that I made to my Big Red mill, including a fine downfeed.

#1: a bolt on each side to keep the head from rotating on the column. For those of you used to the Rong Fu type of mill-drill, this would not work, as the head travels up and down the column, but in the Big Red mill, the head is clamped to the column and the column moves up and down in the base of the mill. If one needs to swing the head to the left or right, of course the bolts must be removed ... I only had to do that once in 15 years of owning this mill/drill.

#2: A quill "DRO" - just a cheap digital caliper which I affixed to the head and to the quill. Nothing unusual or special about it, but it surely did increase the usefulness of the mill/drill by at least an order of magnitude.

#3: Fine downfeed. The Big Red had a ring around the quill downfeed that could be tightened to set a downfeed stop, or loosened so that the quill could travel the full range. I made a collar to go around that ring, with a worm gear "hobbed" onto it (using a tap in the lathe, spinning against a blank that could rotate freely - a crude method that works reasonably well, though not with super high precision). The collar was affixed to the ring, and the shaft with the matching thread was affixed to the head to engage it. When fine feed was needed, just tighten the clamp on the ring (the one originally used to set a stop), and now it is in fine feed mode. Loosen the clamp, and the quill can be moved freely. This worked extremely well, especially in conjunction with the "DRO" in the previous picture.

Finally, a shot of the whole mill with these modifications. Later I swapped out the original motor with a treadmill motor, giving me variable speed (still able to use the pulleys to select the speed range and multiply torque) and the ability to reverse instantly; this allowed power tapping. If you are wondering what the silver-colored bar with a hinge is just to the left of the column ... that's actually my garage door behind the mill!

I must say that Big Red served me well for many, many years; in spite of its many limitations and annoyances (6 tpi feed screws - really?!?), I was able to make a good many parts with surprisingly high precision. About 5-6 years ago, however, I stumbled across a very good deal on a Bridgeport, and brought it home. I thought I would continue to use Big Red as a "second op" mill ... but in fact it just gathered dust; the BP was so much more capable and so much easier to use especially with its X-Y DRO and X-axis power feed. So I finally sold Big Red in the last year, so that it could benefit someone else.