12v Drill hacked to powerfeed for Mini Mill

[DaveH]

TroyO,

A very smart piece of work. Congratulations :bow: :bow: :bow:

Dave

 

[TroyO]

One of my goals was to have it flush or below the table top, and roughly even with the table back. The first case, so I could mount long stuff without interference, and the latter so as not to interfere with the installation of a soon to be installed DRO.

I almost made the first goal... LOL. The heads of the screws do interfere slightly with something being flat on the table. One the plus side, they can be pushed out of the way with minimal pressure. I hadn't counted on the slight play in the bronze bushing letting the unit cant at a little bit of an angle. Were I to do it again, I would knock 1/8" or so off the top of the motor mount just so it was well free and clear.

Other than that, this thing is working great, I got to try some sample milling with it last night and the finish was superb! (And my arms don't hurt from cranking either. ;-)

 

[Troutsqueezer]

One of the better looking ones I've seen. Nice work.

 

[bearcar1]

Pretty slick set up Troy, how does it seem to perform while under true milling conditions say aluminum plate using a fly cutter and say .010" DOC? I like your slide to engage feature as well. Could you perhaps use counter sunk screws on the to overcome your clearance issues?

BC1
Jim

 

[TroyO]

Actually, I could probably just take those screws out... LOL. There's still plenty of support.

But, alas.... when something is on the table the flex and give in the bushing also allows it to move enough so that while the screws touch they don't actually keep it from being bolted down flat. Which means... I'll never get a round tuit I'm willing to spend on it, LOL. But, yes... countersinking the screws would do the trick.

I can maybe shoot a vid... no fly cutter (yet) though. How about a 3/4" rougher end mill plowing some serious meat off a chunk of AL? Hehehe... I just got to use one and am just flabbergasted to watch it chew at stuff. It's like magic! ;-P

 

[TroyO]

Here is a little video of it in action, although I think I had my feed rate a little too high on that first pass. (Or spindle speed too low.... )

Also note, the surface finish is only nice on end milling.... side milling leaves a series of grooves.

Bonus vid... I wanted to show a pass using the power feed anyway, figured I'd use the rougher and kill two birds with one stone.

So there you go, bearcar.... real world example. Now to start on my DRO, LOL.


[ame]http://www.youtube.com/watch?v=RHHaK9MHpLA[/ame]

 

[ZipSnipe]

Excellent Troy, probably one of the best hacks ever !!!! Would be nice to see a wiring diagram of the whole set up. I think when I build mine I will add two more rods for the unit to slide on to help keep it aligned as you mentioned yours canting a lil.

Great job !!!!!!!!!!!

 

[Hopper]

That's brilliant. THanks for posting the details.
I am going to do this on my old Drummond lathe that has no fine feed facility other than cranking the leadscrew by hand. Much better than trains of clanky old gears!
And I see those old battery drills at garage sales for next to nowt all the time, never bothered to pick one up because the cost of a new battery is about the same as buying the whole thing!

 

[cidrontmg]

Well, she is done!

I could go back and finish the plans, if someone is interested. It started with a plan, and I ended up kind of winging it, LOL.

Pics of the last steps, and here is a video.

[

I'm interested, yes sir! Anything electrical and especially mechanical, I'd like to copy exactly as 1:1, if possible. Even the C-o-C would be great, but plans would be fantastic.
The "Mini-Mill" is my pimped-up Quantum BF16Var., AFAIK, and I'm thoroughly fed up with winding forever the cranks.
I've been fantasized about feed motors, steppers, servos, direct or 90º angle, gearing, belting, even chain drive, etc. Always exceedingly complicated. But my solution is by FAR the best, I think, it's pure genius.

 

[Hopper]

So, the 12v power supply is one from inside a fullsize desktop PC?
How many amps does it supply?

 

[ZipSnipe]

So apparently this is the originator of this idea and TroyO just made it better

http://www.progressivelogic.com/mf/powerfeed1.html

 

[rodw]

So apparently this is the originator of this idea and TroyO just made it better

http://www.progressivelogic.com/mf/powerfeed1.html

Thanks for digging this up. It is very interesting! I just remembered I have a brand new el cheapo cordless drill in a box here which my 86 year old mother in law who lives in a nursing home won.

 

[TroyO]

I definitely wasn't the originator of the idea. It's been around for a while.

I'll look around and see what I can dig up for plans, that was actually a few PCs ago, LOL. But, the power feed is still going strong although the motor is feeling it's age. (I overheated it a few times pushing it too hard for too long.) Luckily I've already got another crap drill to replace it with, LOL.

I did knock up a quick schematic in CoC though. The colors are arbitrary and if wires connect they have an O but if wires just cross and don't connect there's no marking.

Hope that helps! The direction switch can be confusing you may want to google "motor reverse switch" because I'm sure someone out there has explained it better than I did.

The GoBabyGo switch disconnects the GND wire of the POT so the wiper lead gets pulled HIGH and makes the motor spin full blast. Sorry about the wrong schematic before, I was going from memory and my memory isn't that good.

 

[ZipSnipe]

Troy you are the man !!!! Thanx for posting !!!!

 

[rodw]

Thanks for this thread. I ordered my Chinese motor controller today. I pulled a drill apart a week or so ago and made the first part to engage with the the mill table but have not had the time to get back to it. I am going to follow fourjc's approach and use a electromagnetic clutch so the motor sits behind the table as I don't have room in my tiny shed for it to stick out at the end of the table.

 

[Davo J]

Great work.
I am not up on electrics, I just looked at the ebay ones and they come with a pot, did you use another pot because yous didn't come with one, or did you need a finer pot?

I am using this for another project but read this post and thought thats perfect for what I want.

Thanks for posting it all.

Dave

 

[rodw]

Great work.
I am not up on electrics, I just looked at the ebay ones and they come with a pot, did you use another pot because yous didn't come with one, or did you need a finer pot?

I am using this for another project but read this post and thought thats perfect for what I want.

Thanks for posting it all.

Dave

eBay links come and go. This is the one I ordered yesterday as it has a good match with the 7 amp rating of the drill switch on my donor drill and because I want to use either 14.4 or 18.5 volts to agree with motor rating or proposed laptop power supply so needed better than 12volts. If you don't like the knob, it would not be hard to change it.

http://www.ebay.com.au/itm/200918663145?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

 

[TroyO]

I'm pretty sure I just used the pot that came with it. I may have thrown a preetier knob on it but the pot is the same. Ohhh, and I noticed that the "Go Baby Go!" switch isn't listed as a switch... it is. It's a simple momentary push button switch that overides the speed control pot by shorting it to "Fast".

Ohh and I missed the quastion on the power supply... it's just a 10A max on the 12V rail on that one. Nothing fancy... the whole supply is rated at only like 280 watts.

 

[Davo J]

Thanks guys.
Yes the earlier link never worked as it must be to old, but I found it on ebay easily enough.

Another question If I buy say a 30 amp one which are only around $20 Australian can I use a smaller amp power supply, or would I be better off with a 15 amp or less.

Sorry for the questions, I can confidently wire cars, houses etc, but when it come to fine electronics I get lost.

Dave

 

[aarggh]

Dave, the stated 30A is just the maximum rating, but they are limited by whatever supply you use, so if you use the 30A board with a 1A (or whatever) power supply for a 0.5A motor, you'll only draw 0.5A (usually thereabouts allowing for efficiency, overhead, etc).

cheers, Ian