Benchtop vs Full Size?

[ATV]

Hi Everyone,

A benchtop mill makes great sense if you don't have a lot of room. I am wondering if anyone who has room for a full size mill has ever opted for a benchtop mill instead? If so, why?

It appears possible to buy a bridgeport for about the cost of the benchtop mills.

I'm curious what leads up to a person's choice of one versus the other? In my mind, it seems like the more powerful full size would almost always be the way to go if space isn't a problem.

[philbur]

Maybe, Have you figure transport and handling. Also what condition.

CNCing a bridgeport can also get expensive very quickly.

Other than that take the BP.

Just some thoughts

Phil

Originally Posted by ATV It appears possible to buy a bridgeport for about the cost of the benchtop mills.

[daedalus]

you can buy the iron of a bridgeport for less then some benchtop mills, but when you add transporting the thing home the bridgeport gets a lot more pricey. You may need to do building work to get it into your garage, also your going to need to get a 3 phase supply set up. You wouldnt want to do that if your going to need to move house in the next few years.

Also converting a bridgeport costs a hell of a lot more then a benchtop, just try pricing a servo for one, its more then my X3 conversion cost. Now if you can find a CNC bridgeport with a dead controller thats probably a much better option, even if its a couple thou dollars more.

[tauntdesigns]

If you have the room, get a BP. You can do SOOooo much more with a BP then you can with a bench top of any kind.

One other problem people run into is the electrical service to their house/shop. I live in the city and only have single phase service and most BP's need 3-phase service. Options are to buy a phase converter, or change the motor and get VFD controller.

Cheers,
Jack

[elnerdo]

I toiled over this same question for some time and eventually bought an old Tree Journeyman 310 with a nonfunctional control. From a cost/effort standpoint, I'd recommend a retired CNC machine before a ground-up retrofit since a lot of what you'll need to retrofit and add will already be in place. On the west coast, $2500 will buys an older BP with a Boss control, my Tree (not running) was $2800.

There is a certain cost/intimidation factor of having a 3k lb piece of iron unloaded in front of your garage that you'll need to come to terms with, but it was goes away rather quickly once the machine is installed.

What swayed me in the end, was I liked the quick release collet system, and I realized that I just wanted a full sized mill. The latter took a while to figure out. I must admit that I don't have it running yet and the total price right now including installation is about $4k. Ask me again in a month!

[tai42]

I wound up getting an IH mill for manual work, and a X2 for CNC work. For me, I considered the working envelope of the mills, and the largest job I could imagine doing on each, and both mills fit just fine for anything I could think of. I also considered that a new Bridgeport is WAY more expensive than the bench top mills, and the clones are still about twice as expensive. A used mill can be had for about the same price, but then I would have to put all the work into fixing it up given the condition I've seen on most used mills. Finally, since I probably will move a couple more times before I retire, the weight of the mills was also an issue. So, while I would love to have a Bridgeport I couldn't convince myself that I needed it.

[ATV]

Thanks for the excellent responses. I'm trying to learn as much as I can and to make a good buying decision. I thought perhaps I might be "missing something" with respect to the smaller mills. We have a Harbor Freight about 20 miles from my house. Its very tempting to run down there and buy a mini-mill! Converting it to CNC would be a lot of fun.

But, fixing up an old Bridgeport and getting CNC running on it would be fun, too! I'm into astronomy and a few months ago had need to cut some slots in 3/4" steel plate for a telescope pier. It was frustrating not having the tools to do it myself. Can something like 3/4" steel be milled on a mini-mill or is that pushing it? I'm guessing it can be down by going slow and taking less metal -- but would it take a ridiculous amount of time to mill something that thick?

[sansbury]

Originally Posted by ATV Can something like 3/4" steel be milled on a mini-mill or is that pushing it? I'm guessing it can be down by going slow and taking less metal -- but would it take a ridiculous amount of time to mill something that thick?

Subjective question. Plenty of people mill steel (esp. free machining steel like 12L14) on benchtop machines, even tiny ones like Taigs. If most of your work consists of cutting 1/2" wide slots in 3/4" plate, I'd certainly consider a larger machine. I could do this on my X1 but I'd plan on it taking a few hours, maybe. The only times you can have too much mill are when you're buying it or moving it.

I would not buy an old Bridgeport-type mill unless I knew what I was doing with it or had a good buddy who did. They're a lot like used Ferraris--cheap to buy, but potentially ruinously expensive to own.

[philbur]

If you are into astonomy and want it to stay that way then running down to HF, picking up a mill and then converting it to cnc is going to make a big dent in your available free time, as is a beat-up Bridgeport.

You don't need cnc to cut the odd slot, pocket or profile. Buy an X3 or a RF45clone, put it on a bench and it's there when you need it. You may also want to think about a small lathe.

Phil

PS: A defunct CNC Brigeport is more than likely one worn out son of a b.... If you don't know how to tell the difference then leave it alone.

Originally Posted by ATV .... Its very tempting to run down there and buy a mini-mill! Converting it to CNC would be a lot of fun. But, fixing up an old Bridgeport and getting CNC running on it would be fun, too! I'm into astronomy and a few months ago had need to cut some slots in 3/4" steel plate for a telescope pier.....

[ATV]

Philbur,

The last time I had need of a mill was when I built my pier, that's why I mentioned astronomy. I'll be building an ultralight aircraft and I'll use a mill quite a bit for that project.

I have a mig, a tig and a JD4 hydraulic tubing bender already.

I'll probably build a CNC plasma table too. I'll also be getting a box brake and a lathe at some point in time. I have to hold off on some stuff until after I build my new shop and have more room. But I do have room for a bridgeport now.

Mainly, I was curious about why people were choosing a mini-mill over a full size and vice versa. If a mini-mill is better at some jobs than a full size, than it might make sense to have both. In which case, I'd buy the mini-mill now and have something to play with!

[tauntdesigns]

I went with X3 small mill because I'm running my machines from a wheelchair. If I could stand and had the room I would have gotten a manual BP.

There are things a manual BP can do that a bench top machine can't do. You may not do those type of things all the time but, when you do, you can with a manual BP.

The head ram base will move in and out, left and right, and head will rotate 45 deg up and down, and 90 deg left and right.

Example: I had a rectangular piece of material 1" by 4" by 30" long and I needed to drill some holes in the end of the part parallel to the length of the part. You can't fit the 30" under spindle on any of the machines, but you can mount a angle plate flush with the back of the BP table off to one side of the Y saddle and clamp part to angle plate hanging down. Loosen the head ram and ram swivel and move it to the side right over the top of the part, tighten the ram and head down and machine or drill the part.

If you got the room get the manual BP...... I agree with the thoughts on a cnc BP... if it was worth fixing they would fix it and not sale it.

2 cents,
Jack