Resuming this thread as I also got a Rong-Fu clone, mine is a Jet-16 but they are all the same Rong-Fu RF30 clone, there were a couple for sale around me for well under $1000, once I barter a little I got mine for $650 but it costed me an extra $100 to get help for loading-unloading, it included a stand (that I will replace in the future) and the original vice as well. Needs some TLC but it works.
Here in Norcal you find plenty of those from Grizzly, HF, Enco and Jet around the $1000-1200 mark that are not as old as my Jet-16 and maybe with some extra tools in the mix.
IMO mini-mills aren’t worth it. They are around $2000-$3000 new these days which is insane, parts are mostly plastic, they have lots of clearance issues, aren’t particularly rigid or true, and replacement parts are way over-priced. I have the King “milling drilling machine” from about 12 years ago, I think it was about $1200 then and it’s not even worth that much money tbh. I have blown up one motor on it and have had to replace multiple parts. They are the same as grizzly, busy bee, and I think another brand name that is all just the same body re-badged. King wanted $900 for a replacement motor and I found the same one through grizzly for $300. I have an actual mill now, so the king lives out its retirement as a glorified drill press. Honestly, given the footprint, I’ve been considering getting rid of it and picking up a smaller drill press instead.
There are hacks for using them, you can stiffen them up and some youtubers have videos about workarounds, but honestly I think if you are looking for something to do holesaw miters you tend to out-torque the machine and have to be extremely careful to either not damage your tubes or blow the machine up. You’re better off spending money on a robust old drill press which are much easier to find second-hand, heavier duty, physically lighter, and cost much less. You can also get cross-sliding vise which will give you a bit of x-y axis adjustment.
Get a bench mounted tube-notcher to use for holesaw mitering, something in the 3-400$ range, and spend a little bit of time and money making it a bit more rigid, build in a centering block or angle gauge or something like that, and that will be much smaller footprint, weight, cost, power requirement than a mini-mill.
Another thumbs-up for the dreaded round-column mill-drill. I too have a Rong Fu (RF-30) clone from the previous millennium, badged as Enco. People complain about the round column but not me, a couple simple workarounds can make it a non-issue, and the sheer mass of cast iron you get is way more than a little benchtop dovetail mill, for a small fraction of the price. I can run a 4" face mill on steel. The 2 HP motor is not omnipotent, but it is pretty hard to stall, actually I never have. I have used Bridgeports at work, so I do see the limits of a benchtop mill, but honestly this thing comes close, within its smaller work envelope. Mitering with holesaws is childsplay for it, never a hint of chatter
I hear lots of complaints about modern mini-mills burning up their motherboards, which are stupidly expensive to replace. Mine has no electronics, therefore nothing to burn up. Well, I did replace the motor with 3-phase and a VFD for speed control (and all the other advantages of 3-ph) so there’s electronics in the VFD, but I got a good USA-made one. I still have to change the belts now and then for more speed range than the VFD can handle, but much less frequently now. Belt changes are annoying on these, gets old fast.
In my somewhat-limited experience, used 3-phase motors are a good deal. There’s hardly anything that can go wrong with one. Well, bearings I guess, but they’re replaceable. I’ve bought 5 of 'em now, all are still running perfectly. I got all my VFDs used or “open box” too, probably more risky but (knock on wood) all have been reliable. Lots of people will go for a new Chinese-made VFD, and they are indeed cheap, but you’d better buy two to have a spare, if you don’t want so much downtime when they inevitably let a puff of smoke out the back. Even buying two, they’re still cheaper than a good brand like KB, Teco or Hitachi, so I see the appeal. I just hate buying crap.
I too am a big fan of 3 phase motors and a vfd. They are pretty easy to install if you do the research and allow you to run almost any manual machine off residential power.
I have a hardinge horizontal mill I use for tube notching. I found a 3 phase inverter-rated 5hp 240V motor on Craigslist that someone pulled out of their new ironworker and swapped that for the original 480v motor. I bought the cheapest VFD for it off ebay. I expected it to be garbage based on the price, but it’s been going strong for about 2 years now!
I’m 50/50 on getting a decent milling machine even if it’s used versus a mini mill. I’m doing this hobby out of a backyard tool shed. I want to get a larger mill, but I literally don’t have the space for one and barely have the space for a mini-mill. My current plan is to get either a lathe or a mini-mill, use that for a few years and sell it used if I ever move out of my current house into a place where I can use the garage or have a bigger work shed.
One of the big considerations for me is using a 4” mill vise so I can attempt to miter the left and right seatstays / chainstays / unicrown fork blades at the same time. I think a 4” mill vise appropriately jigged up is big enough. However, I’m not sure if I can get by with a mini-mill to do that. Perhaps, the Little Machine Shop 6500 series will do that? Or whatever equivalent Grizzly, Sieg, etc. Chinese mini-mill. Basically, I’m just asking if anyone has any experience with these $2k mini-mills to know how big I need to go in order to do mitering of the seatstays at the same time. I know. I know. For that money I can buy a bigger better used mill. I just don’t have the space.
Not sure your area, but you might get lucky finding something like an Arboga. I’ve become a bit of an evangelist - footprint on par with a mini mill, capability much greater, and while a round column mill, it has a key, so you don’t lose position adjusting the head up and down. Also, I’m selling mine
That said, if you really only have space for a lathe or a mill, get the biggest lathe you can fit/move. A 9x20 will do quite a lot, and a 10/11x36 even more. Miter tubes, miter stays (together, with the right fixture contraptions cobbled together), make all sorts of relevant bits and bobs for your fixtures, etc…
TL;DR: mini mills work well enough for just about everything, if they fit your priorities don’t let people dissuade you from purchasing one
@AJAX I’ve been using the mini mill for ~6 months now and I really like it. It works great for tube mitering and has enabled tooling projects and workflows that I wouldn’t have been able to implement otherwise. It’s been super fun to use and a great learning experience, if you’re on the fence and don’t have space for a larger machine I have zero reservations about recommending one.
The drawbacks like lack of stiffness, lack of power, lack of clearance, etc. that people describe are all real, but in my experience these issues are exaggerated and the tradeoffs are well worth it considering the alternatives (no mill at all, the expense/hassle of a larger machine). Just about the only framebuilding tasks you won’t be able to do on a mini mill are simultaneous mitering of the dropout side of seat stays and chain stays and the steerer tube miter on fork blades. For at least the SS/CS miters you should be able to get around this by mitering one tube at a time and determining the angles using careful layout on a sheet of paper. If you want to see one potential workflow check out the Pithy Bikes YouTube channel. He has a few videos showing his process and it seems to work well enough. He uses the ~$1000 Sieg mill so you really don’t need a big or expensive machine to be effective.
I think the steerer tube miter on fork blades is the only miter that there isn’t a workaround for using a mini mill, even considering some of the “larger” versions. I plan on experimenting with 3D printed templates and an oscillating spindle sander for these miters. Hand files would work too.
Some more general details in case anyone else is interested:
If you’re in the U.S. I highly recommend buying from LittleMachineShop.com. They’re great people to deal with and all of their machines are equipped with belt drives and torquier motors than are common on other mini mills. The belt drives in particular eliminate one of the common failure modes (seems to be lots of stories about broken gears online) and are quieter which is a nice quality of life improvement. I think they also ship to Canada but don’t know what extra costs crossing the border incurs.
When you’re budgeting also consider the cost of shipping and the tooling you’ll need to make the mill useful. Those items can easily add $500 - $1000+ to your purchase.
I highly recommend getting a DRO to go with your mill. They make machining projects much easier and drastically reduce the mental load required to make accurate parts. I’d probably use my mill much less if it didn’t have a DRO. Some of the LMS machines come with DROs pre-installed which makes it super easy, but the tablet they come with doesn’t have great battery life, is pre-loaded with a proprietary version of the TouchDRO app, and doesn’t have connectivity to the app store to download the latest version of the official TouchDRO app. It’s still perfectly functional, but a bit annoying.
I didn’t have any open bench space when I bought my mill (LMS 6450), so I ordered a stand cabinet to mount it. When I first set it up, it vibrated like crazy during side milling operations. Like, rattle the machine apart, unusably bad vibration. After filling the cabinet with 100 lbs of sand bags this issue was pretty much eliminated. So, I think there was some sort of resonance issue with the original setup. I’d recommend doing the same if you go the stand cabinet route, or to mount it to a heavy workbench tied to your shed wall or something like that. It’ll still vibrate if I take particularly heavy cuts, but its not bad enough to bother me or affect how I use it. I also put some rubber pads between the machine and cabinet, but I’d say 90+% of the benefit came from adding the sand bags. This is the only time the machine’s relative lack of stiffness has been apparent, i.e. from day two it has been a complete non-issue for how I use it (tube mitering & milling aluminum). If you get one of these machines also make sure the gibs are well adjusted, if they are loose they’ll also contribute to unwanted movement.
The LMS 6450 uses a small knob on the front of the machine for the z-axis fine feed, so mitering the full thickness of a tube takes a lot of twists in the stock configuration. This makes it hard to control the feed rate (an important variable to prevent grabbing the tube) and results in a rough, almost serrated cut. I drilled some holes in the knob and attached a ~6" long piece of bar stock to create a handle, and this works great. I get super smooth miters and continuous, easily controllable down feed. The larger the radius of the handle, the better the control/slower the feed, but I haven’t had a need to go larger than the ~6" handle I initially installed. Something like the sketch below.
I did make some taller, slightly longer vise jaws to help grip certain things, but the small 3” vise hasn’t been an issue at all.
Re: the mill vs lathe discussion - for my projects/workflow I’ve gotten more use out of the mill and it’s not even close. Accurate hole patterns, slots, v-grooves, square stock etc. are the foundation of most tooling projects and there’s no way to create these easily on a lathe. If you only want to do tube mitering maybe that’s a moot point, but tube mitering on a lathe just seems like a total PITA to me. Maybe that’s lack of imagination on my part. Three points define a circle, so if you need to locate circular stuff (head tubes and BBs) it’s easy to do using pins and a hole pattern which you can make on a mill.
Hopefully that’s helpful. Mini mills are not perfect, but they’re much more useful than they’re generally made out to be. For me the benefits far outweigh the drawbacks, and I think the same would be true for most people.
This is very helpful, but I also find it humorous, because it really exemplifies the “mill vs lathe” categorization that people tend to fall into once they start buying machine tools. I’m very much a lathe person, and I can see my bias was showing!
Totally! Different strokes for different folks, workflows are such a personal thing. I’ll be setting up a small lathe over the winter and am very much looking forward to using it
Thanks for the good info. Yeah, obviously I’d love to get a larger round column mill, but I just don’t have the space. I figure a mini mill, albeit expensive, would be good to learn on and do some basic less intensive machining operations. Then, I’ll Craigslist it after a few yrs when I get a bigger garage. I do wonder about the work space envelope though. Having already acquired a 4” mill vise and a few other basic random tooling bits, do you have any idea if the Little Machine Shop 6500 series or equivalent Grizzly, Sieg, etc mini-mill has enough space to accommodate a 4” mill vise?
One of the other big considerations is… I’ve always found it super challenging to hand miter seatstays, especially fast-back style seatstays to the seat tube. Also, super challenging to get a nice even miter on unicrown fork blades to a fork steerer. I was really, really hoping to be able to do those left and right miters (ex: fork blades) on a mini-mill without having to do the left blade and right blade independently. Meaning, I hope to be able to miter the fork blades in tandem (left and right) on the same hole saw cut. If I can’t do that, maybe I might start to look at lathes again. I wonder how big a lathe I need to be able to do that? Maybe a 9” x something? Or 10” x something?
It looks like the tooling packages for the LMS 6500 all come with 4” vises so you should be alright there. You can also miter the seat tube side of seat stays on a mini mill without issues - it’s just the dropout side where you’re likely to run into trouble. Here’s a screenshot of that miter from one of the Pithy Bikes videos:
Yesterday I forgot that I’d seen Jackalope Bikes use a mini mill with a rotating head to miter fork blades. Something like this would be required to use a mill for that miter, I think the legs get in the way otherwise. I’m also not sure I’ve seen a machine like this for sale in the U.S. but I haven’t looked too closely.
I don’t have much experience with lathes so I can’t speak to the potential of that workflow. Seems like they’d solve most of the clearance issues as long as you have a good way to attach the mitering fixture.
From another member when I was asking around about mills and stay fixtures:
The Farr fits on my little Precision Matthews benchtop mill with an oversized 6" mill vise. My mill has a max table to spindle distance of 13". Unless you get a real dinky vertical mill, the Farr will fit.
I thought good and hard for a bench top mill. But being from Bridgeport and living a town over now I had to get one and I did. It is way overkill for me but I love it.
Looks like I was wrong about benchtop mills with tilting heads, both Grizzly and Precision Matthews have a couple models that let you tilt the headstock up to 90 degrees. Here’s a picture from the G0704 manual showing a similar machine set up as a horizontal mill - unfortunately it looks like they don’t sell that horizontal table accessory anymore, but a tilting table would probably let you do the same.
A 1" hole saw mounted in an R8 collet protrudes ~3" from the spindle on my mill, spindle to table distances vary quite a bit from machine to machine but I bet some of them have enough vertical clearance to do dropout miters like others have suggested.
I think those mills use a few bolts to tram the head. I had a mill like that and tramming it accurately took a while and was a pain with lots of light taps from a deadblow hammer then tightening the locking bolts without knocking it back out of tram.
It’s a solution if you only have room for one tool, but sort of painful.
Earlier in the thread someone asked about cutting bridges on a mini-mill. Rodrigeuz frame shop in Seattle has one dedicated to that purpose that they’ve been using for at least a decade, probably longer.
I can confirm what @Alex mentioned about how much of a pain it is to tram the head of my Precision Matthews. There’s three bolts that have to be snugged up. As you tighten them they tend to skew the tram. I check the tram of my machine a few times a year and pray it hasn’t moved
But if you get a big enough benchtop mill then you can do all the things except unicrown blades without moving the head. My PM25-MV can hold the beefy Cobra Stay Slayer and do chainstays and seat stays. It’s pretty tight but perfectly workable.
Wow! Look at that work space when turning the milling head sideways! That’s perfect. Well, maybe not. I see that others are saying that it’s really really hard to tram the head back into original vertical position accurately. Ugh! This feature of the mill you have featured sounded so ideal. It still does. Why else would it be marketed as a feature if it were so bad to do? If it’s just a time sink to get tram it back to vertical, I could live with that. It’s only once in a while that I would need to make these cuts requiring more work envelope table space.
What if I just set the mill up in horizontal mode and use it as a horizontal mill and never go back to vertical mode?
I believe there is a distinction to be made between:
I make bikes as a hobby - to keep me entertained
I make bikes as a side business - gains and losses even out
I make bikes as my main business
I am in #1 and re-tramming the column would not be a big deal at all, it will still keep me entertained and away from a computer, if you are in cat #2 it’s a toss-up and it would probably be annoying AF if you have to do it while being in category #3.
I am using my mill-drill as a sturdy and more precise drill press, something I can clamp a jig onto and notch tubing more precisely, maybe work on some soft aluminum piece from time to time and as such, those machines are great, coming from a mitering setup made with a JD2 tool, this is so much easier to handle, the JD2 “The beast” is a great tool and something I will keep for a long time but with a few extra bucks one can find a used drill-mill in good condition, any will do.
@AJAX Do you plan on doing any milling with the machine or are you just hoping to use it like a drill press? Few people are using a dial indicator to tram their drill press so if close enough is good enough it may not be a real issue for you.
