# Mini Mill vs Round Column Mills



## ChandlerJPerry (Aug 31, 2020)

Exactly as the title states, I would love to hear from anyone who has used both to hear what they prefer. I see the round columns for sale occasionally in my area, but having come from mostly using a Bridgeport at work, something about the round column just feels wrong! Unfortunately no room in my garage for a full sized BP so I'm limited to small-scale machines like the infamous Chinese mini mill or combo mill/drill round columns.


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## MrCrankyface (Aug 31, 2020)

Have you considered something inbetween like a ZX45/BF45 or similar, they seem quite capable for their size?
One big problem with anything that has a round column is loss of position if you need to raise/lower the table.


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## C-Bag (Aug 31, 2020)

I don’t see how you would be happy with either the mini or drill/mill coming from a Bridgeport. The Rf45 square column mill requires less strategic planning because you don’t lose register if you have to change Z like the round column. There is a nice work work around/add on that one of the members here came up with that I plan on adding to my RF30/round column to rid me of the problem when I get a chance. But I’ve gotten so used to thinking strategically I’m not sure I’ll benefit. There are quite a few of us here who admit to having a drill/mill and do good work with it. I like mine. I bought it super cheap and it fits my budget, space and pocket book. And at 3x’s the mass of the mini mill can actually get something done.


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## Mitch Alsup (Aug 31, 2020)

When I had to make a similar decision, I decided to settle for nothing less than a knee mill.

Quills are for drilling, knees are for milling.


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## markba633csi (Aug 31, 2020)

There is another option- a small horizontal mill with a vertical head added.  Small footprint and very versatile. I have one.


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## Larry$ (Aug 31, 2020)

Take a look @ ThatLazyMachinist YouTube site. He has an excellent one on the use of round column mills and how to cope with maintaining alignment when needing to raise the head. All his videos are good!


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## Superburban (Aug 31, 2020)

I have had a round column for over ten years. If you plan your tool changes around the quill travel, you can do a lot. If you need to move the head, I have a 1/2" hole drilled in the corner of the vise jaw. You record your X & Y distance to the hole, then after you move the head, find the center of the hole, and you have the X&Y distance to get you back to your point. You could do the same with any hole on your project if you have one. For smaller cutting, it is still my main go to mill. My big mill, is a Van Norman, which has no quill, so you need to use the knee for the Z axis. Not hard, but just not as comfortable with it as I am with the Rungfu. I have seen and considered a lot of the different methods people have come up with to keep the head in position when you move it, but just never felt any were either trustworthy or cost effective enough. I guess it is the difference between an optimist and a pessimist.


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## DavidR8 (Aug 31, 2020)

I have no issues with my round column mill. Does everything I need. As others have mentioned dealing with the loss of X & Y is easily managed.


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## pontiac428 (Aug 31, 2020)

I don't mind working with my round column mill at all.  It's really not bad once you start thinking like @Superburban above.  It has a lot of power, and is rigid enough to leave a nice finish with the fly cutter or face mill.  The width of the ways is quite a bit larger than other mills its size.  It takes up a lot less room compared to full-sized mills.


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## mikey (Aug 31, 2020)

Wow, Pontiac, that room is so clean its abnormal!


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## Larry$ (Aug 31, 2020)

Pontiac,  I see a Shars?? tool grinder. How do you like it? What do you mostly use it for?
I've got one and found it easy to grind lathe tooling or sharpen the end of a drill bit. But end sharpening a 4 flute end mill and getting it to center cut has been a challenge. The Tool & Die Guy has some helpful videos, so does Stefan G.


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## pontiac428 (Aug 31, 2020)

mikey said:


> Wow, Pontiac, that room is so clean its abnormal!


It sure is!  I've just moved my machine tools into my semi-finished shop, still have two storage units full of general mechanic's and fabricator's tools, welding suff, etc.  So the only chips in there are the ones that hitchhiked their way in.

@Larry$, yes, it is a Shars.  I like it very much!  With a small selection of wheels, I can do lathe bits, drill bits, spot drills, countersinks of multiple types, and a few other odds and ends.  I do sharpen 2-4 flute end mills (faces and flutes) but this type of grinding setup sacrifices the center cutting ability of some mills.  This is often the case, where the center cutting edges are obliterated with a gash cut or a centered face cut on the end mill.  Center cutting is overrated anyway.  The dressed quality of the wheel will determine how small of an EM you can cut and how close you can get to the center.  Cheap wheels don't retain enough fine edge material to get close.  A 1/2" end mill with only the outer half of the face cutting edges intact will still perform very well, you just can't shouldn't plunge with it.

Edit:  D-bits are easy to make with this grinder.  You can custom grind any slot cutting profile you can imagine with a D-bit.  I've been cutting little pieces of 1/2" O1 rod and making cool D-bits and countersinks as needed.  Anything that saves ordering tools on a day off that I won't be able to use for a week.


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## Larry$ (Aug 31, 2020)

pontiac428 said:


> It sure is!  I've just moved my machine tools into my semi-finished shop, still have two storage units full of general mechanic's and fabricator's tools, welding suff, etc.  So the only chips in there are the ones that hitchhiked their way in.
> 
> @Larry$, yes, it is a Shars.  I like it very much!  With a small selection of wheels, I can do lathe bits, drill bits, spot drills, countersinks of multiple types, and a few other odds and ends.  I do sharpen 2-4 flute end mills (faces and flutes) but this type of grinding setup sacrifices the center cutting ability of some mills.  This is often the case, where the center cutting edges are obliterated with a gash cut or a centered face cut on the end mill.  Center cutting is overrated anyway.  The dressed quality of the wheel will determine how small of an EM you can cut and how close you can get to the center.  Cheap wheels don't retain enough fine edge material to get close.  A 1/2" end mill with only the outer half of the face cutting edges intact will still perform very well, you just can't shouldn't plunge with it.
> 
> Edit:  D-bits are easy to make with this grinder.  You can custom grind any slot cutting profile you can imagine with a D-bit.  I've been cutting little pieces of 1/2" O1 rod and making cool D-bits and countersinks as needed.  Anything that saves ordering tools on a day off that I won't be able to use for a week.


The ToolAndDie guy has a good video on making D-bits. I've tried it and actually got it to work. Robin has a great video on improving the Shars grinder. As per typical of him way beyond what I could do. I need to disassemble the lower shaft and see what i can do to make the fit better to the casting that holds the work. It takes excessive force to get it to hold. I might try boring it out and putting a sleeve in it.


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## mike44 (Aug 31, 2020)

ChandlerJPerry said:


> Exactly as the title states, I would love to hear from anyone who has used both to hear what they prefer. I see the round columns for sale occasionally in my area, but having come from mostly using a Bridgeport at work, something about the round column just feels wrong! Unfortunately no room in my garage for a full sized BP so I'm limited to small-scale machines like the infamous Chinese mini mill or combo mill/drill round columns.


I had the Grizzly  G8659 mill when I started machining. I got another large mill-drill  G0705 I use almost exclusively for milling.  After a year or so with the larger mill i sold the small mill.  Small mill was fine to learn on and for smaller work. The mill-drill is a round column heavy duty machine. Very satisfied with the mill-drill, round column has not bothered me at all. If I have to move the head up or down i can find an edge, center or whatever easily. I made layout points for several size R-8 holders. 3/8/1/2/5/8 and 3/4". After moving the head I install a point  in the holder and move the X Y axis to suit under the point. Takes a couple of minutes at most. Just having a power feed on the X axis makes machining a pleasure.
The only problem with the smaller mill was head drop. I could not get around this problem except to come up to height ,not down. Similar to a table saw blade drop when using dado blades. Raising the blade to height will solve this on table saws and  helped some on the small mill.
mike


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## C-Bag (Aug 31, 2020)

Mitch Alsup said:


> Quills are for drilling, knees are for milling.



as a noob I’m curious. So you don’t use the quill on Bridgeport if you‘re milling?


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## pontiac428 (Aug 31, 2020)

@Larry$, I replaced all of my hand levers with Kipp stainless levers.  Really feels positive on lockup now.  I know Robin shared your opinion that the shaft is loose.  His fix looked great, but I just don't think I'll need to go to that extreme (you saw the look on his face when the Moglice popped free of the shaft and he had to check if it was the casting that popped or the Moglice did).  I get a 1/4 turn lockup on the main shaft on mine, so there's no cause for further modification.



C-Bag said:


> as a noob I’m curious. So you don’t use the quill on Bridgeport if you‘re milling?



Think about what is more rigid and what locks up tighter, the big dovetails on the knee, or a cam lock on a 3" diameter quill?


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## C-Bag (Aug 31, 2020)

Luckily my Deckel clone didn’t have that problem with the shaft. Everything locks up fine. Where I ran into slop was in cast iron housing for grinding mill flutes. I ended up putting a brass sleeve in it. But unfortunately not needed to do any flutes yet.


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## pontiac428 (Aug 31, 2020)

C-Bag said:


> Luckily my Deckel clone didn’t have that problem with the shaft. Everything locks up fine. Where I ran into slop was in cast iron housing for grinding mill flutes. I ended up putting a brass sleeve in it. But unfortunately not needed to do any flutes yet.


Oh, I see, it was the free rotary/linear slide attachment that was out of spec.  That would be a much easier fix, definitely on the lathe, but the tolerance must have been close!  Flutes are easy, but I don't try to hit any specific diameter when doing flutes. The end mill diameter measures whatever it measures afterwards, as long as it's sharp!  Pro tip:  When sharpening end mill flutes, keep your band-aids close at hand.


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## C-Bag (Aug 31, 2020)

These things are little snow flakes, they all have some different place where they missed the quality mark. The hardest thing was finding something square to reference from. And then when I tried to shape it square it just munched a HSS bit. Never had that before. Had to buy a carbide face mill and once I got all the sides square I used a brazed carbide boring bar on the RF to bore it to interference fit. For whatever reason that went fine.


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## hman (Aug 31, 2020)

I have both a mini-mill (Harbor Freight 44991, bought new) and a round column (Grizzly G1007, RF-30 clone, bought used).  Used both extensively for a number of years.  Being a lightweight, the mini is indeed limited in capacity.  I usually use it for aluminum, but have done some light cutting on steel.  It does nice work.  The Grizzly is for heavier duty work on steel or on for larger workpieces.  The biggest headache on the round column is that you lose XY when you have to change the head height.  This is especially troublesome if you have to go from an end mill (collet) to the drill chuck.  The chuck eats up a lot of the ~5" available spindle travel.  There's lots of schemes out there on the interweb for holding the head true when moving it, but I don't think any of them are really worth the effort.  I just get out the edge finder.

That said, my Grizzly is starting to show its age.  So I've just ordered a Precision Matthews PM-835S "mini Bridgeport" knee mill.  Too bad you're so far away.  I'll be selling the Grizzly fter I have the PM up and running.  You might want to give PM a look. https://www.precisionmatthews.com/shop/pm-835smill/

Back to your original topic - if you have any specific questions about either of my mills, either post them or send me a PM (personal message, not Precision Matthews


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## Mitch Alsup (Aug 31, 2020)

C-Bag said:


> as a noob I’m curious. So you don’t use the quill on Bridgeport if you‘re milling?



Mostly no. Setting depth by raising the knee is (generally) more accurate, and results in a better surface finish.

For work in aluminum that does not need extreme accuracy:: sure I use the quill for milling.


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## ChandlerJPerry (Aug 31, 2020)

C-Bag said:


> I don’t see how you would be happy with either the mini or drill/mill coming from a Bridgeport. The Rf45 square column mill requires less strategic planning because you don’t lose register if you have to change Z like the round column. There is a nice work work around/add on that one of the members here came up with that I plan on adding to my RF30/round column to rid me of the problem when I get a chance. But I’ve gotten so used to thinking strategically I’m not sure I’ll benefit. There are quite a few of us here who admit to having a drill/mill and do good work with it. I like mine. I bought it super cheap and it fits my budget, space and pocket book. And at 3x’s the mass of the mini mill can actually get something done.


Of course nothing will compare to a real knee mill, but compromises have to be made in my single phase, 110 only garage. I've heard pros and cons for the round column units and have been trying to weigh whether they are worthy of the increased cost compared to a square column mini mill, the general consensus seems to be yes. I'll have to keep an eye on local classifieds, mills are few and far between near me.


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## DavidR8 (Aug 31, 2020)

Per chance a round column mill just went up for sale near me today. 
Fully loaded; vise, collets, end mills, power feed and coolant spray for 1200. 
Too far from you but it’s a good deal for here. 


Sent from my iPhone using Tapatalk


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## ChandlerJPerry (Aug 31, 2020)

markba633csi said:


> There is another option- a small horizontal mill with a vertical head added.  Small footprint and very versatile. I have one.
> 
> View attachment 335393


I've been curious about these kinds of setups. Are there more or less universal milling heads available? I sometimes see horizontal mills for sale for quite cheap but I've never seen a milling head on its own locally. I would imagine it would be cost prohibitive to ship such a thing.


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## ChandlerJPerry (Aug 31, 2020)

DavidR8 said:


> Per chance a round column mill just went up for sale near me today.
> Fully loaded; vise, collets, end mills, power feed and coolant spray for 1200.
> Too far from you but it’s a good deal for here.
> 
> ...


That would be a good deal around here as well! Milling machines of any type aren't particularly common, the few round column ones that I've seen for sale hover around $1,000 without tooling in my area. There's actually a Rutland mill/drill in my area for that price right now. Not to say that price is unreasonable, especially considering the price of new. They just always seem to have a way of coming up for sale when I'm not in a position to buy . There's also a Microlux true inch version of the mini mill listed near me for $500, but I do have some hangups about such a small machine that I will likely quickly outpace/grow tired of, especially considering the spoiling I've experienced from the gear head Bridgeport I had access to at my former employer.


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## ChandlerJPerry (Aug 31, 2020)

hman said:


> I have both a mini-mill (Harbor Freight 44991, bought new) and a round column (Grizzly G1007, RF-30 clone, bought used).  Used both extensively for a number of years.  Being a lightweight, the mini is indeed limited in capacity.  I usually use it for aluminum, but have done some light cutting on steel.  It does nice work.  The Grizzly is for heavier duty work on steel or on for larger workpieces.  The biggest headache on the round column is that you lose XY when you have to change the head height.  This is especially troublesome if you have to go from an end mill (collet) to the drill chuck.  The chuck eats up a lot of the ~5" available spindle travel.  There's lots of schemes out there on the interweb for holding the head true when moving it, but I don't think any of them are really worth the effort.  I just get out the edge finder.
> 
> That said, my Grizzly is starting to show its age.  So I've just ordered a Precision Matthews PM-835S "mini Bridgeport" knee mill.  Too bad you're so far away.  I'll be selling the Grizzly fter I have the PM up and running.  You might want to give PM a look. https://www.precisionmatthews.com/shop/pm-835smill/
> 
> ...


What sort of depth of cut can the mini mill manage on steel, let's say with a 1/2" endmill? Also, realistically how large of a work piece do you feel you can fit on it with a milling vise mounted? I'm trying to get a better idea of the limitations as I have never had the opportunity to be hands on with one.


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## Aaron_W (Sep 1, 2020)

Not sure what you consider a mini-mill but an RF-31 or clone which is the usual round column mill is not remotely in the same class as something like a Sherline, Taig or Seig X2 which is what I picture when someone says mini mill.

Have you ever seen a round column mill in person? They are actually fairly large mills with an 8x28" table with pretty good X-Y travel (roughly 20" and 8") and they weigh around 650lbs, so they are bigger / heavier than many of the popular small bench mills like the PM-25 / Grizzly G0704. They are a little bigger than my Clausing knee mill.

Personally dealing with the head on these sounds like a pain but if you find one really cheap or that comes with a decent amount of tooling they can provide a lot of machine for a relatively small amount of money. As always actual use matters, for small precision work a mini-mill will probably make you happier, but the round column mills are a pretty good value if you can deal with their issues.


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## ChandlerJPerry (Sep 1, 2020)

Aaron_W said:


> Not sure what you consider a mini-mill but an RF-31 or clone which is the usual round column mill is not remotely in the same class as something like a Sherline, Taig or Seig X2 which is what I picture when someone says mini mill.
> 
> Have you ever seen a round column mill in person? They are actually fairly large mills with an 8x28" table with pretty good X-Y travel (roughly 20" and 8") and they weigh around 650lbs, so they are bigger / heavier than many of the popular small bench mills like the PM-25 / Grizzly G0704. They are a little bigger than my Clausing knee mill.
> 
> Personally dealing with the head on these sounds like a pain but if you find one really cheap or that comes with a decent amount of tooling they can provide a lot of machine for a relatively small amount of money. As always actual use matters, for small precision work a mini-mill will probably make you happier, but the round column mills are a pretty good value if you can deal with their issues.


When I say mini mill I mean the Sherline/Harbor Freight/Seig class of machine. I've never gotten to use a round column either but am aware of the substantial size difference between the two machines. I would definitely prefer a knee mill, but I've yet to see a small knee mill come up for sale locally. Same goes for square column machines, mini mills crop up from time to time but their bigger siblings are quite rare. I think a bird in the hand might be worth two in the bush here... a round column definitely has some inherent compromises but it's likely my best option for now.


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## Aaron_W (Sep 1, 2020)

ChandlerJPerry said:


> When I say mini mill I mean the Sherline/Harbor Freight/Seig class of machine. I've never gotten to use a round column either but am aware of the substantial size difference between the two machines. I would definitely prefer a knee mill, but I've yet to see a small knee mill come up for sale locally. Same goes for square column machines, mini mills crop up from time to time but their bigger siblings are quite rare. I think a bird in the hand might be worth two in the bush here... a round column definitely has some inherent compromises but it's likely my best option for now.



You might look at something like the Grizzly G0704 or PM-25. They are quite a bit bigger than the common mini-mills but new they are not a whole lot more expensive than the typical asking price of a round column mill. That is probably what I would have bought if I hadn't found my Clausing mill.


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## markba633csi (Sep 1, 2020)

The small horizontal mills are much more rare unfortunately.  With an added vertical head even more so.  I got lucky and found mine locally for 1K$
Plus, I happened to live in the state where they were made (Diamond tool, Los Angeles.  Rotex, San Leandro) 
But most were made back East
-Mark


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## C-Bag (Sep 1, 2020)

For the last couple of months there has been a guy trying to sell a Hardinge horizontal with a Bridgeport head mounted to it for $1800. Seems like a good deal if the two units are in good shape and how the head was mounted is good. It’s funny that there have been drill/mills come and go(presumably sold) for around that. For me it’s just a curiosity because even though it’s pretty close to the size of my rig I can’t justify the expense. Bridgeport heads come up every once in a while in the LA CL.


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## DavidR8 (Sep 1, 2020)

Something to consider when looking at any mill is the amount of Z axis travel. 
When I was looking for my mill I discovered that the amount of Z  travel was about 13".  That seems like plenty but when you add a vise, and some kind of tool holding, the 14" is quickly used up.
As an example, distance from the table to the top of my 4" Glacern vise is 3.625".
I use a ER32 collet chuck which takes about 1.75". My drill chucks are are even longer at about 3". Add in stick out for the tool and it's easy to lose another 3" to 6".

My mill/drill has 19" from the spindle nose to the table.


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## hman (Sep 1, 2020)

Chandler -
You were asking about work envelopes and vises.  Here's what my mills have:

Harbor Freight 44991 mini-mill: X9.0", Y4.10", Z10.30" (X&Y slightly less than factory, because of a DRO and X axis power feed I've added).  Vise is a Little Machine Shop (3767 or 3257) "screwless" style.  Bottom of workpiece is 1.07" above the table when held in the in the vise.  

Grizzly G1007/RF-30 round column: X17.77", Y7.25", Z5.54"(quill) + 10.75"(head).  X is slightly less than factory. Vise is a 5" Enco, minus the rotary base (which would cause a loss of about 1.4" of Z).  Bottom of workpiece is 2.53" above the table when held in the in the vise.  I once bought a 6" Kurt through Craigslist, but it was significantly too large for the mill, so I re-sold it.  

Photos:  (1) LMS vise, (2) Enco vise (held in LMS vise on mini-mill) while I was adjusting the ears.  Probably shoulda done this on the Grizzly, but I couldn't figger a way to hold the vise in itself


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## ChandlerJPerry (Sep 1, 2020)

You've all swayed me... This place is a bad influence on my wallet! This came up for sale in my area for $800, I'm going to pick it up Friday. The vise is total cheese grade but the machine looks nice.


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## mikey (Sep 1, 2020)

It's a good mill and can be accurized to perform quite well. I suspect you will be surprised at how capable it really is.


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## DavidR8 (Sep 1, 2020)

Well done. 
Gents, time to get serious and spend some of his money! 


Sent from my iPhone using Tapatalk


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## francist (Sep 1, 2020)

hman said:


> Enco vise (held in LMS vise on mini-mill)


Great photo — makes me think of the old circus strongman posters as he balances an elephant on his shoulders or something... 
Question on your LMS vise: I notice a series of hash marks along the top ledges that I’m guessing were scribed in by the clever John Herrmann to remedy some annoying shortcoming. I’ve never seen them on any other vises. Care to expand on their purpose?

-frank


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## hman (Sep 2, 2020)

Happy to do so.  This was part of an extensive mod to the vise I did in 2009.  Unfortunately, the Yahoo mini-mill group whare I posted the description is now history.  I did describe most of the changes in this HM post in 2017:
https://www.hobby-machinist.com/threads/screwless-precision-vises.55048/#post-455018 - post #10.
The lines were scribed to give me some indication of which hole to put the cross pin thru for a given range of movable jaw positions.  Turns out I don't use them that often.  I just take out the cross pin, slide the movable jaw against the workpiece, take out the workpiece, and look for which hole is closest.


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## ChandlerJPerry (Sep 2, 2020)

I was wondering if based on the images anyone could tell me if I'm dealing with an RF-30 or RF-25? Mostly just so I know how much weight/physical size I should expect to be dealing with. I was also wondering what the base of these machine measure so that I can start searching for an appropriate piece of furniture to mount it to, I was thinking some kind of rolling tool box would be nice if I could find one of the appropriate dimensions


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## AGCB97 (Sep 2, 2020)

Says 30 on the head


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## ChandlerJPerry (Sep 2, 2020)

AGCB97 said:


> Says 30 on the head


It's my assumption that it's an RF-30 because of the 30 on the head, but I figured it would never hurt to ask! The branding and model numbers on these import machines can be a little mysterious at best.


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## mikey (Sep 2, 2020)

My RF-31 has a 8-1/4" X 28-3/4" table. The RF-30 will be the same. The base of your column is also consistent with an RF-30/31.


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## hman (Sep 2, 2020)

I've seen RF-30 clones from various suppliers with various table widths.  What might be more indicative is the column diameter.  IIRC, the RF-30 has a column just over 4" diameter, thr RF-25 about 3 ½".


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## yendor (Sep 3, 2020)

Nice machine I have a very similar one from JET.
1st thing ditch the cheap x/y vise and get a real mill vise.
An x/y vise has no place on a mill that already has x/y actions.


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