# pin-type push drill, spiral drill



## Les (Feb 11, 2008)

I just saw a tool that looks handy for building models: a brass push-type drill. (It doesn't have to be brass). In case I'm not clear, it's the kind that holds 1-2mm bits, has one or two collets depending upon manufacturer. You push a collar down a spiral shaft and it turns the bit. A spring returns it to top. I own and am familiar with pin drills of the spinning top type. I thought the little 'archimedes' kind would be a nice thing to have. Does anyone use these, or are they just 'toys'? All I've found (on Ebay) I suspect are made in the East. While those can be of acceptable quality, they can also be junk. 

I'd appreciate your comments. 

Les W.


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## peter bunce (Dec 29, 2007)

Hi Les, 

I have one and use it regularly, for certain drills it is very useful; mine is that old that is pre-dates the return spring being fitted! 

As you say they are called Archimidies drills from the screw thread that operates them, their commercial use is for watchmakers I believe.


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## Les (Feb 11, 2008)

Posted By peter bunce on 08/20/2008 4:49 AM
Hi Les, 
I have one and use it regularly, for certain drills it is very useful; mine is that old that is pre-dates the return spring being fitted! 
As you say they are called Archimidies drills from the screw thread that operates them, their commercial use is for watchmakers I believe. 




Peter, 

Thanks for the reply. I think I'll get one of the 'Offshore' ones and try it out. 

I have a most embarrassing question (for me to ask, given I'm a retired machinist) but, WHERE does one find sets of small metric twist drills? I've never had to deal with turning metric threads, and most of the sizes can be closely approximated using SAE (call 'Imperial' now--fractional-inch). The only drills I've found are of the 'one each' variety. I'd like to get a set that includes 1 & 2mm sizes, and whatever other sizes cluster around those two diameters. Perhaps there aren't any. As I said, it's a wholly unfamiliar area to me. The hobby stores are maddenly vague when describing tools. Perhaps you can point me at a website? 

Thanks, Les


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## SteveC (Jan 2, 2008)

Les

Here's one link

Micro-Mark / Metric 0.5 ~ 5 mm (by 0.5 mm)


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## Les (Feb 11, 2008)

Steve, thanks. It happens I'm eyeballing their mini-mill./DesktopModules/NTForums/themes/mls/emoticons/tongue2.gif Time to get a catalog. 

Also, freak of luck: today whilst garage saling I found one of those wooden-ball handled spin drills new in pkg for little of nothing. I got it with some other stuff I wanted. Seems a little clumsy, but I'll find out, I suppose. 

Thanks again, 

Les


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## SteveC (Jan 2, 2008)

Hey Les,

Here's another one, maybe not the best of drills, but for the money you could buy about a dozen sets for the price of one good set.

Grizzly Industrial - Metric Drill Set
1~6 mm (by 0.1 mm) 50 piece set
As for Micro-Marks Mini-Mill it's basically the same China made one sold by many duscount tool suppliers,,, e.g.

Grizzly Industrial / Mini-Mill Item# G8689
Harbor Freight - Mini-Mill Item# 44991-4VGA
Here's a couple of good reference sites...
The Little Machine Shop - Mini-Mill
Mini-mill.com


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## Les (Feb 11, 2008)

Steve, 

I'm a tad pressed for time but thanks for the info. I was a tool & die maker, and inexpensive tooling isn't a good thing for doing first-class or even picky work: one needs the quality. 

On the mills, yes, you're right on. The feature that attracts me is the low initial price, and then the ability to add on/upgrade over time. Helps with us SS types. Harbor Freight has a really nasty habit of advertising 'sales' on merchandise not in stock. It's frustrating to go down there with money in hand and N/S. I'm seriously considering the Micro Mark one, since they appear to offer free shipping. If one runs the numbers, the shipping makes up most of the difference between the two sellers' prices. Also, Micro's machine comes with SAE lead screws, another factor to offset the difference in prices. 

The Mini-mill.com is a new one on me, I'll go look at it right after church. 

Thanks again, 
Les


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## placitassteam (Jan 2, 2008)

One thing to consider with the mills is that some like Harbor Freight advance the table .0625 (1/16 inch) per turn of the lead screw whereas the MicroMark is .050. I find the .050 much easier to deal with.


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## Les (Feb 11, 2008)

You're correct. Micro Mark and other online sources sell SAE threads and nuts to upgrade the HF mills to advance the same as the Micro Mark one, I think the kit costs about $50, another thing that sways me towards Micro Mark's. Point of fact, I've decided MM is the one I'm going to buy. Now, all I have to do is find money.









Les


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