Electric tools for drilling tiny holes in polystyrene

[cats think well of me]

Hi all,

I have a lot of freight cars on the bench that will need tiny holes drilled into for grab irons and other details. While I've used pin vises successfully for years, between developing carpal tunnel and wanting to maximize hobby time, I get bored with drilling lots of holes manually, I'd like to invest in good power tools for drilling tiny holes. I'll still use pin vises for a handful of holes on a model but feel that power tools would be preferable for efficiency and precision when we're talking numerous grab irons and not just a few holes for trucks and coupler boxes. I just tried a small Skil electric screw driver with a Micro-Mark 1/4 chuck that fits #61-80 bits and the bit does not turn precisely at all. I'll play with it a bit, but I'm open to alternatives. I have used a Craftsman variable speed rotary tool (same as a Dremel) for drilling into resin and metal and it works great but spins way to fast for styrene and I end up with some melted plastic on the drill bits and larger, kind of mangled holes on the models I wish not to have.

Thanks in Advance,

Alvie

[Overmod]

I have used a Foredom-style tool with a control that let the motor turn at appropriately slow speed (under 200rpm) for this fine drilling control.  I believe at least some of the Dremels with electronic variable speed can be made to turn slowly enough for plastic drilling, although I think you'd be better using a flex-shaft accessory and making up a handpiece at small size and correct 'ergonomics' rather than trying to manipulate the whole bulky Dremel to the correct right angle to the work, even if you have a drill guide tube in your other hand.

There are some here who have succeeded in clamping the tool and holding the work, although I've 'never made it without biting'.  A drill press to hold the tool is likely an idea -- I had one made to fit an electric hand drill years ago, I think made by the "U.S.General" or whatever they were called that was an early version of Harbor Freight (they were also the first I remember to make a functional Dremel-size hand-cranked drill with Jacobs chuck, an amazingly convenient item around the house before cheap cordless drills).  Dremel has a drill press but, strangely, I can't remember actually setting one up and using it.

There were also 'router tables' made over the years for drills as well as routers that would hold the bit vertically and control effective plunge depth; those are likely less convenient than a drill press for obvious reasons but might beat alfresco ways of holding big drills for freehanding.

[SeeYou190]

Dremel makes an ultra-cheap rechargeable rotary tool called the "Mini-Mite" that I have found very useful for drilling in plastic and soft metals.

There are two speed, 2.4 volts and 4.8 volts.

The slow speed is very slow and very weak, which is perfect for what we do. It does not melt the plastic unless you apply pressure or try to use a dull bit.

I have experienced excessive drill bit breakage with holes smaller than #65, but if it is your only option, it could work well for you.

I bought mine at Wal-Mart for less than $20.00, but according the WalMart website they are $24.00 now. Still worth it if just for a try. I have worn out one. The current one I own is a couple of years old, and I use it a lot.

I cannot get to mine to take a picture. This is a stock image.

-Kevin

[gmpullman]

About a year ago I recall reading an article in another hobby magazine that had addressed this very subject. The driver suggested was this GENERAL powered screwdriver.    It turns at a quite desirable 100 RPM, even slower if you use 1.2v NiMh batteries in it.

Drill_chucks by Edmund, on Flickr

The downside to this motor tool is that there's no simple way to adapt the chuck to it. I bought several chucks before settling on a decent one and I had a machinist friend make an adapter that is secured to the shaft with set screws.

motor-pin-vice by Edmund, on Flickr

I found this tool to be an excellent choice for drilling both soft metals and any plastics. It is a pity that a manufacturer hasnt made the complete unit available without having to make adapters for the chuck.

Here's a #78 drill in the jaws:

Chuck_no78 by Edmund, on Flickr

The General tool is also a handy choice for its intended purpose as a motorized screw driver. The bits are small enough for most model work and it saves a lot of twisting of the wrist. I bought several, just in case they disappear from the market.

Many of the precision chucks use a Jacobs #0 taper. If only the General tool had this on the output shaft we would be in business.

From what I understand, this MicroMark chuck will fit the 7mm OD shaft of the General tool:

https://www.micromark.com/Drill-Chuck-For-Ultra-Tech-Precision-Power-Screwdriver

This was unavailable for quite some time but I see it is now available again 

I recently used my slow-speed mini drill to bore a headlight wire hole in this smoke box front. This brass was thick (both the back of the headlight and the smokebox front) and I had no trouble whatsoever drilling the hole. Glad I didn't have to rely on a pin vice 

PRR_N2_headlight by Edmund, on Flickr

Good Luck, Ed

 

[cats think well of me]

Thank you for the suggestions guys. I'll keep an eye out for that Dremel Minimite. I looked online and didn't see anything close but I'll try out Wal-Mart soon. Ed, I looked at that General piece and liked it a lot but the lack of an available chuck had put me off. I like how your machinist friend adapted the chuck to the tool as they did. 

Alvie

[gmpullman]

cats think well of me

Ed, I looked at that General piece and liked it a lot but the lack of an available chuck had put me off.

See my update 

https://www.micromark.com/Drill-Chuck-For-Ultra-Tech-Precision-Power-Screwdriver

Cheers, Ed

[hon30critter]

gmpullman

See my update

The specs on the MicroMark chuck state 1/64" to 1/8" (0.0156" to 0.125") so it might not hold a #80 bit (0.0135"). Probably will be okay with a #78 (0.016").

I have the General tool and my attempt to add a chuck to it a while ago met with mixed results. The chuck I bought doesn't rotate perfectly on center so trying to start a hole is very difficult. I can't remember the chuck I used but that doesn't matter because it didn't work. I just ordered one of the MicroMark chucks.

Dave

[BATMAN]

I have one of these really old Dremel drill presses from the 70s. I got it when I was building R/C planes. It is not watch maker precise but is way better than freehand.  

I see them for sale cheap often on FB or eBay and at train shows. Also, the older Dremels that fit it can be found in the same places.

 

[RR_Mel]

I also use the Micro-Mark chuck with the ¼” hex drive cordless screwdriver and drill.


The Black & Decker L13000 ↑ and Craftsman cordless ↓ drills work great.



The Micro-Mark chuck goes down to almost 0”, smaller than a #80 bit.


 

Mel



 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

[Overmod]

A problem with most of these extend-a-driver chuck modifications is that they greatly extend the rotating length of the tool and increase the unwieldiness of its balance, to the point where it's like trying to point with your elbow to get the little bit out at the business end both aligned and oriented with the hole you want to drill.

For that sort of thing I still think the Foredom #30 style, which recesses a 4mm (or 6mm) accurized chuck into the forepart of the handpiece, is hard to beat.  Even if you chuck a precise collet adapter into this, the 'combination' length is still easy to work with, and if you stone the face surfaces of the three jaws you can get good (if line-contact) centering of even #80 bits without wander or wobble out at the point.

I have not yet found a small-motored counterpart of this handpiece nose style, although it would be almost incomprehensible not to offer one.  In the era before mainstream high-coercivity magnets, it might have been necessary to use a gearhead motor to get the necessary perceived torque at low speed for metal drilling ... but this isn't production metal drilling.

[RR_Mel]

 

Overmod

I agree with you about the “wander/wobble”.  The Black & Decker hex drive is a loose fit and the bits do wander.  The Craftsman has a spring loaded locking hex chuck and there is very little wobble if any.  I made an adapter for my Dremel drill press to hold my Craftsman drill and that works very good except for having to press the trigger to make it go, takes three hands to drill a hole.

 

Mel



 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

 

[gmpullman]

Overmod

I have not yet found a small-motored counterpart of this handpiece nose style, although it would be almost incomprehensible not to offer one.

https://www.foredom.net/product-category/handpieces/micro-motor-handpieces/

20,000 RPM is just a bit speedy for me, though.

https://www.foredom.net/product/h-mh-120-brush-type-high-torque-chuck-style/

Cheers, Ed

[PC101]

Deleated my useless infomation.

Maybe most drills have a trigger lock button to keep them running till you squeeze the trigger again and it unlocks and shuts off the drill.

 

[doctorwayne]

cats think well of me

I have a lot of freight cars on the bench that will need tiny holes drilled into for grab irons and other details....

I've been detailing freight and passenger cars, along with all sorts of locomotives, for years, and the majority of them, at least on plastic models, have been done using a #79 bit in a pin vise.  Some of those cars needed over 70 holes apiece.

For drilling holes in metal (usually brass locomotives) I often use my Job Mate rotary tool (somewhat more robust than my Dremel) and usually equipped with a flexible drive shaft.
For smaller holes, I have a number of collets to facilitate the smaller drill bits.

I've also found that my Dewalt battery-powered impact driver is useful for drilling small holes, but because it's relatively heavy compared to the pin vises, Dremel, and Job Mate, I support the impact driver in the centre drawer of my workdesk, then use my free hand to manipulate the work-piece appropriately to get the holes drilled without breaking the drill bit.

Here's a #79 drill bit in a MicroMark Precision Drill Chuck, which is intended for use with a cordless screwdriver...

...and the impact driver...

While it's easily capable of driving a 4" long #10 screw, it's variable low speed gives me good control by supporting the driver in the drawer, then carefully bringing the workpiece to the bit.

I always use the metal tip of of either a draughting compass or that of a pair of dividers to make a starter dimple in the work, to ensure that the bit doesn't wander when the work is applied to it.

In most cases I prefer the pin vise, especially for small holes in plastic, and no recurring problems yet with carpal-tunnel (despite surgery for it some years ago, due to work-related issues).  I probably benefit from being fairly ambidextrous, like most left-handers.

Wayne

[RR_Mel]

 

PC101

 

I would have to open up the Craftsman and do a mod to the wiring, my wife is very good as a third and forth hand.  She actually likes to get involved and help me with my train stuff, we’ve been helping each other for over 52 years with our hobbies.

 

My grandson gave me the Craftsman drill for Christmas around 2008 or 9 and we both use it a lot, super nice tool!!!!  Eats a 2”x4” easily with a ¼” bit.

 

 

 

Mel

 

Modeling the early to mid 1950s SP in HO scale since 1951

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

[mbinsewi]

I stay with the pin vise for tiny grab iron holes.  I have all of the chucks, electric screw drivers and drills, and dremels that everybody mentions, but I break more bits trying to use them.

Mike.

[gmpullman]

Overmod

For that sort of thing I still think the Foredom #30 style, which recesses a 4mm (or 6mm) accurized chuck into the forepart of the handpiece, is hard to beat.

Thank you Mr. Overmod 

After mulling your recommendation over it suddenly occurred to me that I have a Dremel flex shaft tool hanging in my "other" workshop.

I looked up the Foredom handpieces and opted for a $20 knock-off just to see if I like it before investing $80 in theirs.

Dremel_flex by Edmund, on Flickr

It chucks a #80 very nicely.

Dremel_flex-chuck by Edmund, on Flickr

Now to find my motor speed control to get the 15,000 RPM down to a reasonable speed.

I still won't give up my little cordless General tool anytime soon. At 100 RPM it is perfect for styrene and brass.

Cheers, Ed