Homemade vertical mill drill

ericc, just curious what head you used? I own a Pratt & Whitney 3C bench horizontal mill and I want a vertical head. I am actually gathering parts for a home-made version based on some I have seen on Youtube.

Thx
 
I used the whole horizontal mill and put a vertical head on the overarm. Somebody hit the horizontal drive countershaft with a tractor.
Ok, I thought you still had the drill press setup....
 
The main problem was the quality of the import XY table.

Hi Ericc,

I'm wondering how much worse these are than the tables on a cheap mill/drill from China? Did you try and tighten things up on the one you had, or just use it as shipped?

BTW, I'm originally from Cupertino....

Thanks,

John
 
Guys, I should also weigh in on drill press conversions. I bought a vintage Craftsman from a dude that had replaced the bearings and kept it in great shape. It came with a Craftsman collet chuck typically used for cutting wood or plastics. I bought a Shars x-y table and tried milling some aluminum. It cut but I was not impressed at all. The Shars table has heft to it but is not very precise. It definitely needs taking apart, cleaning up and deburring, and lots of adjustment. That's why I recommended finding a table like I have from Burke. It's OK for drilling holes but not for milling.
 
I am pretty sure you don't want to hear this but I would search long and hard for a used off brand mill, even a mill/drill, before I would ever try to make one. You will be $$$$$ ahead in the long run and have a better, more accurate mill. I have seen used off brand mills sell for little more than scrap value because 1) people are fixated on bridgeports and CNC mills and 2) mills are heavy and expensive to move if you have to pay someone to move it. IMHO unless you are a very skilled machinist/fabricator I think that it would be very hard to even duplicate the accuracy of a round column mill/drill in a home made mill.

I paid around $500 for my round column Excel 31 mill/drill. The table is smooth and accurate in both the x&y directions and I don't seem to have flex or movement in the head when milling. The quil is accurate in the z direction. With careful planning I have not had to raise the head to change tools. There is no way that I could have cobbled together a home made mill that would have been anywhere near as precise as my mill/drill.

Maybe I am missing something here.
 
I am pretty sure you don't want to hear this but I would search long and hard for a used off brand mill, even a mill/drill, before I would ever try to make one. You will be $$$$$ ahead in the long run and have a better, more accurate mill. I have seen used off brand mills sell for little more than scrap value because 1) people are fixated on bridgeports and CNC mills and 2) mills are heavy and expensive to move if you have to pay someone to move it. IMHO unless you are a very skilled machinist/fabricator I think that it would be very hard to even duplicate the accuracy of a round column mill/drill in a home made mill.

I paid around $500 for my round column Excel 31 mill/drill. The table is smooth and accurate in both the x&y directions and I don't seem to have flex or movement in the head when milling. The quil is accurate in the z direction. With careful planning I have not had to raise the head to change tools. There is no way that I could have cobbled together a home made mill that would have been anywhere near as precise as my mill/drill.

Maybe I am missing something here.

No, I don't think you're missing anything.

My old mill was a Gorton 1-22 that I got for just being able to haul it away so I know what a real unit looks like. I'm well aware that what I'm attempting is a challenge but I don't have to make high precision parts right away and my current space limits me to something no bigger than the Rong Fu units that sometimes pop up for what I expect to spend on my project.

I could also buy something new if I really wanted to but honestly, if I just needed to get parts made I have a great local machine shop that can do anything I want for less than it costs me to do it in-house.

I've spent far more on less satisfying things in life so why not give it a try, I know when to stop if it's going sideways and I can probably sell the parts I have to someone else for what I've got into it. But thanks for being a voice of reason, we need more of those;)

Cheers,

John
 
Actually sounds like a fun project - determine how much of a mill's capability you actually need, and build that. If you stumble across a great price on the perfect mill, you can disassemble the home-made one and fashion a tool cutter grinder out of it or something.

So, those X-Y tables. I have one bolted the drill press table (one of them Porter Cable floor jobs), with a drill press vise bolted to it. The vise and the drill press table introduce so much imprecision themselves that it's difficult to determine how sloppy the X-Y table is. It was pretty bad until I took it apart, cleaned/stoned the ways and tightened the gibs. If I have the drill table locked and trammed, then the X-Y table will hold to a straight (scribed) line for drilling multiple holes, and is repeatable. I think this is the one I got: https://www.shars.com/products/workholding/machining-tables/compact-machine-slide-table . I can chuck up some drill rod and measure the runout of the T-slots if you're curious, but it you'll probably be going with the larger model (https://www.shars.com/products/workholding/machining-tables/heavy-duty-mill-drill-table) so the information won'tbe very helpful.

The main thing you're going to have trouble with is rigidity. I'm sure you've seen the gingery stuff, made out of cast concrete. I'm a little hesitant to trust something as brittle as concrete for the entire casting, but filling large-diameter square tubing with concrete should do the trick. Use lots of down pins to join the frame together so that the load isn't entirely on the weld.
 
ericc, just curious what head you used? I own a Pratt & Whitney 3C bench horizontal mill and I want a vertical head. I am actually gathering parts for a home-made version based on some I have seen on Youtube.

Thx

Hi Dan. The head I used first was a Harbor Freight rotary tool with a speed control and 1/8" end mills. I lost the 1/4" collet, and I think that this was good, since this setup is marginal for the larger end mills. I am trying to graft a more substantial head that should be able to run larger end mills. It will be made from the headstock of a wood lathe. Once I got past that stupid xy vise, which is barely adequate for a drill press vise, the setup could make good parts.
 
Hi Ericc,

I'm wondering how much worse these are than the tables on a cheap mill/drill from China? Did you try and tighten things up on the one you had, or just use it as shipped?

BTW, I'm originally from Cupertino....

Thanks,

John

I think that they must be much worse, since I see good work coming out of the Chinese import mill drills. Although I don't personally know anyone who owns one, from indications on the Internet, their main problem is the column rigidity. The problem about the XY vise is that the dovetails are not precise. They are NOT machine slides. If you tighten them enough to bind, they will still rack and ruin the part. They need to be tuned up, and they are so imprecise that even a cold chisel would be better than nothing. They are not even good for lining up a drill location, since the gibs must be so loose that the whole thing wobbles when the drill point hits the punch mark. If you tighten them, they shift and the drill point gets bent. The main reason I have one on my drill press is that they keep the metal from spinning dangerously if the drill point catches. They are not even flat on the bottom, so if you put a piece of material on parallels, it will drill off square. Correct me if I am wrong, but it is possible to drill square on a Chinese mill drill, right?
 
I would skip the XY table completely and go with linear rails. Make your own table!
 
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