Friday, August 12, 2011

DIY: How to build a 'Poor man's milling machine' using a drilling machine!

This is an interesting 'do it yourself' for all hobbyists and 'DIY' people out there.
Milling Machine: A machine tool in which a rotating cutter is moved against the workpiece (or vice versa) in order to cut the latter to a desired shape
Drilling machines are low cost and easy to procure.  But we still yearn to have at least a milling machine and maybe as a luxury a lathe in our workshops/garages...

The lowest costing table top Milling machines we have seen in the market is at least 60,000 Indian Rupees and perhaps a little more at today's inflation rate. Isn't the cost a big deterrent to have your own milling machine in your garage/workshop unless you are doing milling as a profession or doing tasks for production?



Youtube video showing the working machine

This is our attempt to convert a tower drilling machine we had into a functional milling machine! And it works! So far we have tested it on plastic, nylon and wood as raw materials and it did a fantastic job. We will be testing it on aluminum soon and post our findings here as well.

A plastic piece - slot made with poor man's milling machine.
How do I make one?
Here's a simple recipe of how to convert a tower drilling machine into a pretty good milling machine for your prototyping, hobby and fun work!

Ingredients:


1. A tower type drilling machine - one with a vertical spindle lock capability, and a heavier one preferably. Usually such tower drilling machines come with a belt drive with inverted pulleys of different sizes for speed control.

Important: The spindle of your drill should be absolutely vibration proof. It should also have a spindle lock capability. Preferably, buy a local made one, which are heavier compared to the sleek and less heavy imported ones.

Note: Most of these drilling machines come with 3-Phase AC motors. Exchange it with a single-phase motor with your vendor. (A 1/4 or 1/2 HP motor should do well for most hobby tasks!)

2. A 2-axis table - available off the shelf in the market.

You can get them in various table top sizes such as 6", 8", 10", 12" and so on. for reasonable costs. Make sure the 2-axis bed you buy doesn't have slack when you rotate its wheels.

3. A Low-profile drill vice. preferably buy a 5" or 6" open jaw vice so that you can hold large jobs.
There are a variety of drill vices available in the market. Just make sure it has adequate mounting facility and has a really low profile.



4. A suitable mounting plate. This is the only custom made part you will require to get it fabricated outside or make it yourself :-(.

We made our mounting plate from a piece of scrap metal from the Gujari (ಕನ್ನಡದಲ್ಲಿ ಗುಜರಿ = Junk yard).

Usually the bottom side plates of the tower drilling machines are not designed to mount off the shelf 2-axis tables. It does come with some slots for mounting large vices or job holding jigs, but may not match.

So you have to make a mounting plate that helps mount the 2 axis table firmly on the drilling machine.

5. Nuts and bolts - Off the shelf. For typical drilling machines for use in your hobby and R&D works, M8 bolts and nuts should do fine.
The recipe:
  1. Fasten the mounting plate to the drilling machine base. 
  2. Turn away the drilling table that comes along with the drilling machine to the back of the drilling machine. (This you can later use as the stand to keep a torch-light for illuminating your milling jobs!)
  3. Once the mounting plate is fastened, mount the 2-axis table on the plate. 
  4. Now fasten the drill vice to the 2-axis table using T-bolts. (We managed to do with ordinary bolts too!)
  5. Insert a milling cutter (end mill) in the chuck of your drilling machine...
  6. ....And it is ready!
  7. You will need to get used to setting the right RPM using the belt drive. (Your drilling machine comes with a reference chart). This is fairly easy and you will get it with some trial and error.
 The completed and working Milling Machine!

Feel free to write to us if you are interested in this concept or if you are planning to build one yourself!

And yes... cost of this setup is a lot less than those table top imported hobby.desktop milling machines!

Improvements to do: A 3-axis table if available in the market, one that can do up-down (Z) movements as well along with X and Y ! We couldn't locate it in a hurry.

8 comments:

  1. Aproximately, how much is this supposed to cost?
    I'm new to all this stuff, but I really want to try it!
    Seems like an excelent idea!

    ReplyDelete
    Replies
    1. Hello Anonymous,

      A grand total of maybe about 25,000 Rupees you should be able to build at today's rates.

      1) About Rs. 15000-17000 for a good drilling machine
      2) About Rs. 7000-8000 for the 2 axis bed.
      3) Then an adapter plate you have to get fabricated
      4) Some Fasteners you may have to procure.

      Ideas Unlimited.

      Delete
  2. best milling attachment for small workshops.

    ReplyDelete
  3. Hello,

    Congratulations, it looks very interesting. I found all the parts in a cheap price except the table. It is being a little hard for me to find a cheap one. Any brand that you know of?
    My important question would be: How did you machine work with aluminum?
    Thanks

    ReplyDelete
    Replies
    1. Hi Ferran,

      We are based in Southern India and can find all parts easily. There are many brands of such 2-axis job holding tables available. Costed about 6500 then, maybe slightly more expensive now.

      We used 2mm/3mm End mill to work with aluminum.

      Nagendra R Setty

      Delete
  4. I'm seen the video of making the milling machine through the drilling machine is a great job.

    ReplyDelete
  5. Excellent. I have done the same with a 1942 Craftsman drill press. I do use a collet chuck for milling but still can use it as a drill press when needed. I made my own x-y table so total cost was about $100.00 US.

    ReplyDelete