Portable cordless drill press

Technical Manufacturing
1

In my engineering class, we’ve been assigned a final project, which is to invent something useful for your community. All we have to come up with is a semi-working prototype. Since most of the team members I know cannot drill a straight hole with a cordless drill for the life of them, I decided to make a cordless, portable drill press.

I’m making this from scratch, out of the remains of an old 6V drill of mine and a CIM. I have a couple of questions:

First, do you think that simply putting the chuck off of the drill directly on the output shaft of the CIM would do for a test model? The CIM would spin relatively fast for a drill, but it does have variable speed control, and it would not operate at no-load speed…

Secondly, I have the control components (squeeze trigger and directional control) from the 6V drill, but I was hoping to wire a 12V cordless drill battery through them to power the CIM. For the brief periods I’ll be using this drill press for (very brief, just for 1-hole demos), do you think I need beefed-up components, or should the 6V components do?

Thanks!

2

why dont you just use a portabe, premade battery drill, or at least a drill motor and tranny from previous years?

As for the 6 volt components, I believe they would work…but whys the worst that can happen if they dont?

Good Luck,
Kevin

3

This drill press should also be functional with a nice table. It would be easy to take a production drill press and swap a 12VDC motor in it with a battery. The cheapest new press I found was $70 but you could probably get one off ebay for cheaper.

I’m not sure what the top of a drill press spindle looks like but the top of a mill spindle is a hex shaft that you could spin with a cordless drill and a socket. That’s another possibility.

If you wanted to go all custom you could just mount a 12VDC corless drill to some sort of frame with a spring loaded rack and pinion mechanism to raise and lower the chuck. I found a new 12VDC cordless drill w/ keyless chuck for $15.

4

*Originally posted by sanddrag *
This drill press should also be functional with a nice table. It would be easy to take a production drill press and swap a 12VDC motor in it with a battery. The cheapest new press I found was $70 but you could probably get one off ebay for cheaper.

The key word here is portable… I don’t know many people that want to haul around a 50lb drill press.

When inventing something, people try to modify existing designs. The true essence of inventing is to think of new ways to do things or something completely new.

How about, instead of making a portable drill press, make an attachment that fits over the chuck of any drill (since they are pretty much standard sizes). It would keep the drill perpendicular to the drilling surface, and would be spring loaded. When you wanted to drill straight, you’d put the end of the attachment onto the surface, and then push down. If you’ve seen a nailgun, it would be something like that. The difference is the part that compresses in a nailgun is a safety feature, whereas here it is a feature to drill straight.

You’ll have to figure out a way to conform to the part, in order to keep the drill perpendicular to it. Either that or you can make it go around the part and put it on the thick wooden block that the drill could drill into. Viola, a 2 piece poor man’s portable drill press. The wooden block thing would be easier because it would be difficult to keep the drill parallel to the part if you are drilling a thin part. To make it easy, you could make it fit a specific model of a drill that you may have lying around.

Now that you have the idea, the trick is to make the spring part. You can’t just use a solid shaft because it will hit the drill motor. However, you have to make it rigid enough to keep the drill straight as you press down.

If you market this and make millions, I want 10%.

However, if you a dead solid on making a drill press, the CIM should be fine if all you want to do is demonstrate it. At 5000 RPM the CIM (stock) puts out 1 N-m of torque whereas the bosch drill motor puts out 3 N-m at 1500 RPM (both at 40A, but that’s scalable). Just as long as you’re drilling into something soft like wood or plastic, the CIM should work fine.

5

I think the first question is: Will the drill be brought to the material or will the material be brought to the drill? The answer behind this question will define your design. The latter is a true drill press.

What about something like this only with a drill motor and chuck instead. Heck, you could even hold it in there with hose clamps as long as you could get it perpendicular to the table in both planes.
http://www.dremel.com/html/images/products/attachments/large/212.jpg

6

*Originally posted by Jnadke *
**<snip> When you wanted to drill straight, you’d put the end of the attaching onto the surface, and then push down. **

That would be a nifty way of keeping a drill perpendicular, but one of the great advantages of a drill press is the ability to control your feed rate. Your suggestion wouldn’t prevent the drill from grabbing and “screwing” the drill into a piece, though the spring load might reduce the tendency. If you’ve tried to drill through sheet metal with a hand drill, you know what I mean.

Maybe you could add a small hydraulic cylinder with an adjustable needle valve to control your feed rate - like used on horizontal band saws.

7

*Originally posted by Gui Cavalcanti *
**First, do you think that simply putting the chuck off of the drill directly on the output shaft of the CIM would do for a test model? The CIM would spin relatively fast for a drill, but it does have variable speed control, and it would not operate at no-load speed…

Secondly, I have the control components (squeeze trigger and directional control) from the 6V drill, but I was hoping to wire a 12V cordless drill battery through them to power the CIM. For the brief periods I’ll be using this drill press for (very brief, just for 1-hole demos), do you think I need beefed-up components, or should the 6V components do?

Thanks! **

Gui,
The pictured drill press above with the Dremmel works OK for very small diameter drill. As you increase the size of the bit the speed must go down and the power(torque) must rise. The speed is in the 100’s for RPM not the 1000’s so a reduction of the shaft speed is needed without reducing the electrical input to the CIM. We all know that the CIM is pretty powerful so a gear reduction should work fairly well.
On the controller, I can’t give you a good answer on whether it will work at 12 volts. The components are price sensitive as to voltage breakdown and when you are making a run of 1 million, a few cents makes all the difference. A low voltage part may have been used. It will take some research to find the part number and then the breakdown.

8

I’ve seen small mount-drill-or-dremel-here drill presses before, and they haven’t worked very well in my experience. What I’m after is a tool that has the drill-straight functionality of a drill press while maintaining the hand-operated cordless drill functionality. This would mean being able to use the “cordless drill press” on an oddly-shaped robot, for instance.

My idea was to provide a reasonably flat surface that is perpendicular to the feed axis at the base of the “press”. I’d then have a track welded to this, parallel to the feed axis. Then, have the drill press assembly slide along the track, maybe spring loaded. Nothing too fancy. The reason I wanted just the CIM as a demo is because I wanted the whole press to be in-line to simplify construction (the project prototype is due next week). I also like the CIM because it’s easy to mount, unlike the really oddly shaped drills and transmissions.

Thanks for the input, all, but I’m not quite building a drill press as is conventionally known. There is no table, just a flat surface that you push flush against the surface your drilling into.

9

Im visualizing something that looks the base of a router with a cordless drill sticking out the top. It would slide up and down on rail. What about making the bottow intercnahgeable. Router plate, clamp, etc. Is this what you had in mind.

10

If you have access to using the dril motor / transmission from this year, you can just screw any standard drill chuck onto the threads on the end of the transmission.

If you are going to use the CIM motor, you will need to gear it down at least 10:1, which would give you a 600rpm no load speed. It does not have enough torque to drill with direct drive.

11

Most drill press operate at rpm in the hundreds. Anything above 1500 is nuts(generally).

12

I’m hoping that all I will have to drill for a demo is soft wood, because I can’t afford the gears to gear it down successfully. I may increase it’s functionality later, but for right now the output shaft will pretty much have to output shaft of the CIM.

As for the base plate, it’s not a drill press in that sense. What I’m trying to do is simply get a flat plate with a hole in it for the bit to pass through, and simply press the plate flush against the surface I’m drilling into. That way, if you keep the surfaces flush, you can lower the spinning bit into the material and always drill a straight hole.

Attempt at drawing:

|| OOO
|| OOO
|| OOO
|| |
|| d
||
||

MMMMMM

That would be a cut-away side view. The Os represent the CIM, || represents the guide rail, and the d is the drill bit. The M is the surface to drill into.

13

Like I (as well as many others) always say, “If you’re gonna build somethin’, you might as well build it right.”

Our rigid floor drill press has a max speed of somewhere around 3000 RPM which is still very fast for the smallest bits and the softest material. I think if you are using a Chia it calls for a reduction of some sort.

14

earlier you asked if the 6 volt sp controller would work. I am assuming that you wil be controlling the spd of the motor probably down to 1000 rpm’s.

So the speed of the chippy in not an issue here. As for the desgn, i like it. maybe you could make the feed powered by a cable that wraps around a pulley as it is turned, and pulls a spring loaded cim down.

15

You guys will appreciate this… :slight_smile:

So I’m in our robotics lab getting the pieces together to be sent off to a machine shop for some lathe work when I spot something interesting. Low and behold, a CIM from 2002, with hardened gear pinion and matching reduction! We had a very compact gearbox that year, and simply pressed a shaft onto the gear cluster FIRST gave us. Luckily this gearbox was our broken spare, because the friction fit to the output shaft was slipping too much

So, my drill press now has a reduction on the CIM, taking it down to about 1100 RPM (Someone check that… I forget the exact reduction with that year’s pinion, but I remember it being something like 1:5).

16

So I’m in our robotics lab getting the pieces together to be sent off to a machine shop for some lathe work when I spot something interesting. Low and behold, a CIM from 2002, with hardened gear pinion and matching reduction! We had a very compact gearbox that year, and simply pressed a shaft onto the gear cluster FIRST gave us. Luckily this gearbox was our broken spare, because the friction fit to the output shaft was slipping too much

Ooo well I was about to suggest ripping the motors and planetary gearboxes out of eight dollar drills that seems to work well with battlebots.

17

http://doityourself.com/store/6783377.htm

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*Originally posted by Gui Cavalcanti *
**
Thanks for the input, all, but I’m not quite building a drill press as is conventionally known. There is no table, just a flat surface that you push flush against the surface your drilling into. **

My Dad had a device simialr to what you are talking about that was a Craftsman. It works simlar to how you describe. There is a flat round “base” with a clearance hole through it for the drill chuck. Attached perpendicular to the base is 2 parallell shafts. A “slider” moves freely up and down the shafts. Attached to the slider, is a std issue electric or cordless drill motor.

That “press” tool works extremely well on irregular surfaces or something very large that you cannot fit into a regular drill press. I’m sure by the time you read this post, it will be after you have to turn in your project, but I wanted to let you know I understand where you were going and what you were after. If I can find the unit at my Daqd’s place, I’ll shoot a digital photo and post it so everybody can see what you are talking about.:cool:

19

We have a neat little Craftsman drill that has a water bubble on the back of it (similar to a level). It tells you when you are perpendicular to the earth. Just as long as your drilling surface isn’t slanted, you can make fairly straight holes.

20

*Originally posted by PMGRACER *
**My Dad had a device simialr to what you are talking about that was a Craftsman. It works simlar to how you describe. There is a flat round “base” with a clearance hole through it for the drill chuck. Attached perpendicular to the base is 2 parallell shafts. A “slider” moves freely up and down the shafts. Attached to the slider, is a std issue electric or cordless drill motor. **

I have one of these. The “sliders” are actually like a dual bar vise and the chuck needs to be removed from the drill and attached to the chuck device that comes as part of the kit. You then attach the drill shaft to the other side of the “follower”. The drill, follower and chuck then can move up and down the parallel bars. There is also a depth stop collar so you can repeat the depth of drilling from one hole to another. Additionally, the base has some “v” jaws so that you can drill round stock as well. It does not work with most adjustable torque or hammer drills, though, as these interact with the drill chuck. My Skill hammer drill does not work at all with this setup.

The device is called a “Portalign”.
ed. Al