never post in here but figure this is a good question for the vets =] was thinking of building a mill on the cheap side.. buying a good drill press with (hopefully) decent bearings to withstand milling steel without breaking in a week I was thinking of buying a cross slide vise and a couple of digital calipers, then modding and adapting the digital readouts for the x,y axis travel of the vise anyone have any luck with a mod like this? lathes are cheap enough but I'm looking at a mill with tooling for under 400 us dollars if possible
A good cross slide vise by itself is going to cost you a pretty penny. I had a similar idea to use a drill press to mill plastic, and tried to cheap out with a generic import vise from an industrial supplier. The POS vise is so rough and jittery that it's useless. You're also going to be very hard pressed milling steel on a drill press, let alone a <$400 one. I would recommend you seriously consider other setups.
It might work but like you say side to side movement on a press isn't something it was made for. Plus think about speed control, different material require different speeds. I'm not a milling expert by any means but I'd save your money and buy a decent one. Would you rather have a cheap POS that you hate to use or a semi-decent one that you enjoy making things on. A mill is a great thing to have and it's always useful. Maybe try finding a used mill
The weakest part in a drill press is usually the column. If you can strengthen it by welding or bolting some steel beams it could work. A drill press can usually handle front-to-back loads pretty well. You'd want to increase the sideways rocking stiffness and column twisting stiffness. As for the bearings you will probably have no luck with altering the bearing seats. Your best bet is a drill press that has relatively large gap between the bottom and top bearings. Changing bearing type might be possible but that is up to the press you choose. Bearing top speed won't be an issue an issue when milling steel. The slower you go the better. Get a drill press with the highest possible torque. Typical bearings will have some clearance that will produce a lot of chatter if the minimum load is too small. Another weak point is the quill. Try to see if the quill can easily be rocked back and forth. If you are willing to give it a go welding the quill to the pulley shaft will take away z-axis movement from the spindle but give higher rigidity. You can handle the z-axis with table adjustment.
ah that makes sense jav.. thanks.. I looked at those grizzley mills but it looks like a lot of people have trouble with the motors over time (made in china).. looking at harbor freight right now that's some good ideas like welding the quill for extra support and strengthening the column.. I could do that I might just give it a shot, go look at different presses this weekend thanks guys
Harbor Freight's is currently on sale for $399 with coupon, but it will require additional work to improve upon its shortcomings. Most of these mini mills are variants of Sieg's X2.
I have spent about four months looking at mills on the internet and reading on the machinist forums. Here is a link to a good discussion on the question of American Made bench top mills: http://www.practicalmachinist.com/vb/general/has-there-ever-been-us-made-benchtop-vert-mill-195514/ To summarize the discussion: Every descent sized bench top mill currently in production is made in China. One of the chief complaints about mills made in China is their lack of precision, but this is not a problem because, for what we are doing, you don’t need to be within +/- .001 of an inch. You will easily be off that much just by using the manual controls. One of my favorite quotes a machine fab guy told me was “no amount of tolerance will fix a bad design.” Here is a link to the only US made bench top mill I could find (it is quit capable, but small): http://www.sherline.com/ Personally I would never buy a mill from Harbor Freight. That is where you will find the lowest quality of products from China. The reason I recommended Grizzly is because of their customer service after you purchase their product. After researching, this is what I plan on buying in about a year: http://www.tormach.com/Product_PCNC_770_main.html Good luck man
Worst part in poorly made products (From China or from USA or from wherever) is that the machined flats in castings are really far from true flat. This leads to bad contact which cannot be eliminated by tightening screws etc. The only real option is to machine or scrape them again or cast or weld them shut.
