Dovetail column vs small knee mill

T

Taz

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I've been a good boy and got myself all tooled up first, cabinets are full of setup and precision tools, and now it's time. I still have the uncertainty in long-term location that keeps me looking at smaller mills. My work has moved me all over these past 5 years, I have a feeling I'm heading back to the west coast soon and don't want to lug around a several thousand pound tool. I was feeling pretty confident in purchasing one of the RF-45 clones, but I've been leaning toward one of the smaller knee mills, for instance this one which even comes with the stand for $100 more than the RF-45 model, and about the same weight.

http://www.wttool.com/index/page/pr...ng+Machine+(WT)&update_continue_shopping=true

Anybody own one of these bench-top knee type mills? I like the idea that the motor and head don't move, and its more like the full size and trusted platform, but I'm concerned that there is something that makes a mill of this type far lower quality or less capable at the same price as one of the dovetail column mills.

Any guidance would be appreciated, I actually have the wife's approval on this one so I'd like to buy my first and last mill all in the same shot if that's at all possible. I'm still seeing full sized mills within a couple hours drive on Craigslist for about the same price so all things considered I'd be willing to go that route too if It were the only way to ensure I don't have to buy another later (something still makes me want to fix-up a used machine anyway).
 
Seems OK at first glance but I see it has 12" from nose to table (max). With an endmill holder, a 2" long bit, a vise and possibly a rotary table... things are starting to get very cramped. With a 45, you'll have 4" more headroom and 200lbs more beef. The 45's are tried and true as well. I can't speak about that particular mill but I've seen some that have very coarse "fine quill control" whereby setting quill depth would be challenging. I'd want to get to the bottom of that before ordering one.

Ray
 
Taz said:
I've been a good boy and got myself all tooled up first, cabinets are full of setup and precision tools, and now it's time. I still have the uncertainty in long-term location that keeps me looking at smaller mills. My work has moved me all over these past 5 years, I have a feeling I'm heading back to the west coast soon and don't want to lug around a several thousand pound tool. I was feeling pretty confident in purchasing one of the RF-45 clones, but I've been leaning toward one of the smaller knee mills, for instance this one which even comes with the stand for $100 more than the RF-45 model, and about the same weight.

http://www.wttool.com/index/page/pr...ng+Machine+(WT)&update_continue_shopping=true

Anybody own one of these bench-top knee type mills? I like the idea that the motor and head don't move, and its more like the full size and trusted platform, but I'm concerned that there is something that makes a mill of this type far lower quality or less capable at the same price as one of the dovetail column mills.

Any guidance would be appreciated, I actually have the wife's approval on this one so I'd like to buy my first and last mill all in the same shot if that's at all possible. I'm still seeing full sized mills within a couple hours drive on Craigslist for about the same price so all things considered I'd be willing to go that route too if It were the only way to ensure I don't have to buy another later (something still makes me want to fix-up a used machine anyway).
Click to expand...

My thoughts are, owning a RF-45 (a PM-45PDF) and having used numerous knee mills, that a knee mill is preferable to a dovetailed column mill drill. 250+ pounds of weight hanging off a column isn't a recipe for smooth and accurate movement. My mill's head has sagged forward about 0.002 to 0.003 since I bought it despite gib adjustments and making a whole new Z axis gib and Z-axis movement isn't really good enough for anything but rough positioning prior to using the quill for fine adjustment.

Presumably the mill you're considering uses belts to change speeds? That's a nuisance if you ask me... Maybe it isn't an issue for you. I'm spoiled by the coned belt drives we have on the Bridgeports at work and the gearbox speed change levers on my RF-45.

Also, the maximum spindle to table distance on the RF-45 is about 4" more generous - if that mnetters for what you plan on using it for.

For what it's worth: spindle travel on the knee mill is 3". For the RF-45 it's more like 5". This is only uselful for drilling deep holes. 5" of RF-45 quill stocking out of the head isn't a recipe for rigidity.

As for any other pros and cons of that particular mill, I cannot say. In retrospect, I'd look more closely at a knee mill than the RF45 I have now.

If you have the room, and the wife's blessing, get a used Bridgeport. That WILL be the last mill you every need to buy.

John
 
I hadn't noticed the spindle distance... Good save guys. I lost my entire collection of tools last time I bought bigger than I could afford to move on short notice. Ill spare you the details, but it was a huge loss, otherwise space isn't that much of a worry, long as it'll go through the garage door. I think I may be looking for one of the big boys now. I should know better than to think I can "dip" into a hobby LOL.
 
Yes the spindle to table distance is short on that Knee Mill. My Clausing ( considered a small knee mill) has 15 3/8". I have a low profile rotary table and have run into no problems as yet, but I am looking into putting a 2" riser block to raise the spindle.

In your case if it were me, I'd choose the mill/drill.

"Billy G"
 
I was an actual owner of that WT mill for a couple years. It was before the RF45 got popular (I didnt even know about them)

There are 2 major flaws to this mill - as already mentioned is the lack of distance between table and quill, although this can be greatly helped with a column spacer. The other is the "six" in the 6x26 table dims. A decent sized 5" vise will over hang the back of the table and reduce the 'Y' travel even more, and of course going to a smaller vise is self explanatory... This problem has no fix and I found it to be more and more aggravating as I used the mill over time.

I think without question the major plus for this mill is the knee - a knee is just plain better than any column arrangement.

Grizz (and I think KBC) offer a very similar mill in a 8x32 size with the corresponding better travels - course its also more $$, but probably a near ideal small machine.

All that said, I would go for the RF45 if I was starting out now.

This is a pic of mine as it stood when I sold it, with MANY improvements/enhancements including a 5" column spacer (I just could not improve on that lack of Y travel)

6x26.jpg

6x26.jpg
 
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Thanks Pacer! Just what I was hoping for, good input from an actual owner. Although buying a new vise is simple enough, my current vise is very large, just over 15in, and though cheap I invested a lot of time into it. As you said you wound up upgrading. As it turns out, there is a machine shop close by that is closing (sad story), and he's selling a Bridgeport with spares for $1400. I left him a message, we'll see if it's still available.

Any tips on what to look out for in a Bridgeport, or is any Bridgeport a good Bridgeport?
 
If I looked behind me a few steps I bet I find you on the same road I am on. I wound up going the used boprt route instead of the new baby mill. Most of the components are small enough for one or two guys to lift. You could move it dissasembled and put it back together in its new home. As for what to look for, wear. I'm going to get into some scraping, but a lot of guys don't want to get that deep. I guess I just collect hobbies. The price sounds more than fair for a local running bport with extras. Sounds more than fair for running bport without extras. I would jump on it. Someone will, and probably quick. Good luck.
 
Sorry for resurrecting an old thread, but.... doesn't it depend on the machine as to what is better? I mean I have a dovetail machine and in my opinion, it is likely every bit as good as a knee mill in it's weight class. It is very rigid and I have 15 3/4" of clearance between the table and the spindle (without a tool in the spindle of course).

I understand that my machine may not be the rule but it would be worth it to look at machines with the right clearance and travel in mind and then use these factors to make up your mind rather than just one feature of the machine.

Paul.
 
Paul- i agree that a well executed machine is more important than style.
We all do what we need to get done what we need done.


Bernie
 
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