The old mill/drill vs small knee mill dilemma!

[Pfowler67]

Hi everyone, I’m brand new to this so bear with me regarding my profile and whether or not I am doing this correctly!

I have finally come to end of my tether, trying to find more information via Google on the two milling machines I am researching. My question to begin with is, which mill should I buy from these two? (See attachments)

It’s basically a toss up between a small knee mill with 8x30 table and an RF45 clone. Both are the same price but the RF45 has more added to it. I will have to add at least the DRO to the knee mill but the power feed doesn’t bother me at this point. Most of my work is small scale and I don’t work on auto stuff. The convenience of switching speeds on the RF45 is the most tempting feature vs the belt changing on the knee. But I rather like the sturdy design of the knee mill and wonder if it might be much quieter. Has anyone compared the two machines for noise levels? Being a home shop guy, noise is a huge deciding factor for me.


Any thoughts would be awesome.

Thanks,
Pete

[Pfowler67]

One more thing... Can I just add I realize the only way to get a feel for these things is to go and see the machines in the stores, but I guess I’ll have to wait until this awful virus leaves!

Pete

[Paul Alciatore]

I have purchased both geared and belt driven machines and can say the geared one is a bit louder. But not enough to negate the advantage of making the speed changes from the front instead of changing belts at the top. My present, geared, FR45 style mill is in my garage/shop which is just off my breakfast room. My den is on the other breakfast room wall and if I close the garage door, my wife has zero complaints about the noise, even when she is trying to sleep in there. My neighbor's bedroom is across from my garage (25 feet?) and I have checked with them. They have never even heard it. I do work late at night.

As far as I am concerned, the vertical, dovetail column is superior to a knee style mill because the table is always at the "right" height. Of course the head does go up and down on the dovetail column design but for a given job, you will use the table controls more than the ones on the head. I do not know if there is any difference in the rigidity of the two designs.

I would be very tempted by that DRO.

I do not see comparative numbers on the quill feed distance. I like as much as I can get because you often run out of operational range going from a short, collet mounted milling cutter and a long drill in a Jacob's chuck. Even though neither of these machines has a round column, moving the table or head up or down is still an extra operation. And if you are not careful you can still be off on your X-Y calibration by a thousandth or three.

[Paul Alciatore]

I just noticed one more thing. It appears that the Busy Bee, knee mill has the On/Off controls on the side of the column. And they face to the SIDE. I guess that is to discourage the operator from leaning over the table to reach them. But either way, that is a strange place for them. A few more feet of wire would have allowed them to be mounted in the front.

I do not like that.

One more thing that I can not tell from the photos: does either of them have a motor on the vertical movement (head or table)? My Grizzly FR45 style does have a motorized head movement and it is GREAT. That saves a lot of cranking.

[Pfowler67]

Paul, thanks so much for all your advice. This forum idea works!! Haha, I’m clearly a newbie!

So, assuming the RF45 is quiet enough, has it had any downfalls in terms of stiffness while taking bigger cuts or matching harder materials? While I currently work on a lot of aluminum and smaller projects, I’d really like to make this new machine as future proof as possible. I guess that’s why I am also considering a knee mill, wondering if it would be more solid. I’d rather add start with a solid base and work my way up from there. Do you think an RF45 mill is already as capable as a knee mill of this size? I see much more info on the RF45 verses the 8x30 knee mill. There’s hardly any info on the latter, which makes me wonder if it just a toy/Bridgeport wannabe.

[nickel-city-fab]

I would be very tempted by the geared head "Oxford" model from Bell machinery.... can't see very many drawbacks to that deal!

[Hopefuldave]

If the RF45 is a round-column mill, I'd hate the head going out of alignment if raising or lowering it, knee mill would be my choice.
If the RF45 comes with more extras at the same price, it's because it's a cheaper machine, built to a lower price. Basically it's a drill press with an XY table on it.

Dave H. (the other one)

[Doozer]

When I was 25 years old, I bought this Clausing 8520.
I paid $2800 for it from Lost Creek Machine, somewhere in Iowa.
Has it truck freight shipped to me in Buffalo NY.
Very shortly after I got it, I changed out the head for a Bridgeport head
and added a VFD drive. Also I added a DRO and the 5" Kurt vise.
I never looked back at the price. It was worth it many times over.
I still have the mill, even though, if you have seen my Doozer's
Shop youtube channel, I have many larger machines.
I like it because the table is so easy to crank, because it is so light.
I will tell you, just this weekend I rotated the turret around to have
access to mill a part that I had clamped to the table. That is a nice
feature to be able to use. Something you can't do with a bed mill.
As you see, many Asian manufactures have copied this milling machine.
Clausing actually copied it from Johansson and started building it under
their name. Not helping you to make your choice perhaps, just saying
this architecture is a very tried and true design.

-Doozer

[RB211]

A lot of money for not so much mass.

[Doozer]

I think them be Canadian pesos.

-D

[Dan_the_Chemist]

If the RF45 is a round-column mill, I'd hate the head going out of alignment if raising or lowering it, knee mill would be my choice.
If the RF45 comes with more extras at the same price, it's because it's a cheaper machine, built to a lower price. Basically it's a drill press with an XY table on it.

Dave H. (the other one)

This simple sequence of operations was impossible on my RF-45

1) spot drill for a hole
2) drill the hole
3) ream to final dimension

That's because of the difference between the spot drill length (1.5") and the reamer length (7"). I had to move the head in the Z direction, and that meant losing alignment. Oh, I could sort of get it aligned again, but it was always sort of by feel.

When I got my rebuilt Bridgeport I remembered why machining could be fun. Not only did it keep alignment, it's much more solid. I used to feel that the RF was standing between me and doing precise work. Now the only thing standing between me and precise work is my own bad habits.

[Pfowler67]

Doozer, I appreciate your point of view, as I also prefer the design of this type of machine. Seems to be much more solid, especially since the head is not on yet another sliding mechanism like on the mill/drill. The mill/drill is a square column Hopefuldave. Wouldn’t consider a round one.
I suppose I’m just not much of a fan of the square Chinese mill/drill and much prefer the classic style of the knee, however the extras that come with the RF45 are very tempting. The knee has just gone on sale for 500$ less and is only $5k from bbee! There’s also a guy on Kijiji selling his whole shop for 15k with this same knee mill included. But I haven’t got 15k! Waiting to see if he changes his mind...

[deltap]

The ability to quickly and accurately adjust the height of the tool to the work piece is a distinct advantage of the knee mill.

[mattthemuppet]

I think both of them would be fine, they both have a reasonable amount of mass for doing small work, decent work envelopes. Gear head noise vs. convenience of changing gears is a wash.

I have a Grizzly 6x26 knee mill (smaller version of the BusyBee) and like it a great deal, no real desire for a bigger mill, although I will be making a riser block to get some more Z (can never have enough). I also think I would be perfectly happy with a RF45 type mill.

Personally though, that's a $hit ton of money (even in C$) compared with what you could get used, especially if you're willing to wait and/ or travel. That's around US$3500-4000 right? That could get you a reasonable condition BP size mill with some tooling down here, and machinery prices in TX can't be much less than they are in Canadia (I once saw a used HF 6x26 offered for retail + 10%!). There's actually a Mil-rite, similar to Doozer's Clausing, with 3ph motor and VFD on CL down here for $2200, which isn't a bad price. Don't forget, add at least 50% if not more to your budget for tooling and workholding.

[Pfowler67]

Guys, this is all such awesome advice, thanks so much. Always so much better to talk to people isn’t it.

I can see the knee being a very handy feature for keeping things aligned accurately. Tooling isn’t too much of a concern mattthemuppet, as I have a smaller mill/drill with r8 spindle so have collets, vice, rotary table and loads more already.

I guess my main concern with the knee mill now is the belt changing. I think I’ll be able to live with this , but it’s hard to tell until I’m using it of course.

I like the look of the one-shot oiling system on the knee mill. The z height is larger than the 6x26 so I’m hoping that will be ok mattthemuppet. I know 5k is lots of $$$. I’ve seen a couple of these used, will see if this guy gets back to me. See pics!