Drills For Plastic (making holes!)

[Miatatom]

I thought I'd found the drill I needed to do the job at Harbor Freight. I even posted a topic on it. The trigger had great sensitivity and it was easy to start holes and gradually increase the RPMs. Well, since then, it's lost that sensitivity and starts with a fast spin. YGWYPF. Before that, I started off using an adapter bit in an electric screwdriver but it doesn't have enough speed. I've been looking at the Tamiya 74041 Electric Handy Drill. One feedback I read said it had a speed of 400 RPMs. Does it? Does it start slow? Is it easily controlled, etc.?

Pin vises are difficult for 74 yr. old hands to use. I'm also using Harbor Freight drill bits. The tips don't look much like a drill bit tip. Are the more expensive sets worth the money? Which ones?

[Tom Geiger]

I have had this Exacto brand battery power drill for at least 25 years. I use it for all of my modeling work. It can be used with the very small drill bits, like number 72 bits. I bought it at a hobby shop back then, and I've never seen another one.  The design is perfect since you hold it directly above what you are drilling.  And the switch can be clicked on and off after each hole.  It has one speed, I don't know what it is,  the only markings on it are "Exacto - Made in Hong Kong".  If someone sold a unit like this today, I could sell oodles of them in our hobby.

For the very small bits, like number 80,  I found I could glue them into scale heater hose to work with my drill.

[SfanGoch]

I have a Dremel 8050-N/18 Micro Cordless Rotary Tool. By far, it's the best and most versatile rotary tool I've ever owned. 

I also use a Dremel keyless chuck

on the Micro which I picked up at Widget Supply. It'll securely handle bits as small as .3 mm. This combination is great when I need to drill multiple holes. Pin vises are good; but, too darn slow, especially when drilling more than 100 holes at a time for resin nuts, bolts and rivets. Since the drill is multi-speed (5-28K), I set it at 5K rpm when using the smaller metric and decimal bits to drill styrene.

[StevenGuthmiller]

22 minutes ago, SfanGoch said:

I have a Dremel 8050-N/18 Micro Cordless Rotary Tool. By far, it's the best and most versatile rotary tool I've ever owned. 

I have the same one.

When I got it from my wife for my birthday a couple of years ago, I never thought that I would use it much.

I use it constantly!

Not only for modeling, but a lot of other things.

It recently proved invaluable for cutting small glass tiles for a kitchen back splash!

 

Steve

[BigTallDad]

If your pin vise has a shank, put that rascal in a garden variety Variable Speed Drill and carefully drill away. An important tip: don't have too much of the drill bit exposed...that leads to breakage

[Miatatom]

On 6/10/2018 at 6:01 PM, SfanGoch said:

I also use a Dremel keyless chuck

on the Micro which I picked up at Widget Supply. It'll securely handle bits as small as .3 mm. This combination is great when I need to drill multiple holes. Pin vises are good; but, too darn slow, especially when drilling more than 100 holes at a time for resin nuts, bolts and rivets. Since the drill is multi-speed (5-28K), I set it at 5K rpm when using the smaller metric and decimal bits to drill styrene.

Just ordered the Dremel Keyless Chuck. I've got a corded Dremel. Maybe that'll be the answer. Thanks!

[NOBLNG]

Yes a better set of drill bits is worth the money! You may luck out and get a fairly well sharpened cheapo set, but the tips on the two sets I bought and returned looked nothing like a drill bit should. Here are pics of two good sets. (The Morse set is better than the mascot so I save them for drilling metals.) I also use a straight pin to center punch the hole location on plastic.

http://www.modelcarsmag.com/forums/topic/130290-drill-bits/?tab=comments#comment-1891232

 

Edited June 13, 2018 by NOBLNG

[peteski]

Best drill bits for me are the Tungsten Carbide (TC) bits with 1/8" shafts used in the printed circuit board (PCB) industries.  They have split point cutting edge (even the smallest sizes) and they are super sharp, so they cut through stuff like through butter.  TC is a very hard material, so they stay sharp pretty much forever (for what we used them in modeling). But because the TC is so hard, it is very brittle. You have to either have very light touch when using them in hand-held power tools, or use a drill press.  Also, because the all have 1/8" shank, chucking them is problem-free.

These bits are available from several sources, including Micro-Mark and eBay.  Shop around for best prices.

 

[NOBLNG]

The circuit board drills look like a real good option!

https://www.ebay.ca/sch/i.html?_from=R40&_trksid=p2380057.m570.l1311.R2.TR2.TRC0.A0.H1.Xcircuit+board+drill+bits.TRS0&_nkw=pcb+print+circuit+board+carbide+micro+drill+bits&_sacat=0

[Chariots of Fire]

Go to drill bits unlimited.com.  They have all sorts of very sharp and very small drill bits that have 1/8" diameter shanks.  They are very brittle, however, and it is not easy to use them in a power driven drill.  You can start a pilot hole with one and a pin vise and then switch to a power drill to do the final drilling.  You can get complete sets or you can get multiple drills of the same size if you have one or two favorites.  They are very reasonably priced.  I use them all the time.

[peteski]

6 hours ago, Chariots of Fire said:

Go to drill bits unlimited.com.  They have all sorts of very sharp and very small drill bits that have 1/8" diameter shanks.  They are very brittle, however, and it is not easy to use them in a power driven drill.  You can start a pilot hole with one and a pin vise and then switch to a power drill to do the final drilling.  You can get complete sets or you can get multiple drills of the same size if you have one or two favorites.  They are very reasonably priced.  I use them all the time.

Those are the Tungsten Carbide PC Board drills I mentioned.  I love them and because they are so brittle, I have lots of spares!

[Art Anderson]

23 hours ago, Chariots of Fire said:

Go to drill bits unlimited.com.  They have all sorts of very sharp and very small drill bits that have 1/8" diameter shanks.  They are very brittle, however, and it is not easy to use them in a power driven drill.  You can start a pilot hole with one and a pin vise and then switch to a power drill to do the final drilling.  You can get complete sets or you can get multiple drills of the same size if you have one or two favorites.  They are very reasonably priced.  I use them all the time.

Another, and more durable type of small (tiny) drill bits, that are quite sharp, but have a very strong shank, is what's called a "center" or "centerline" drill.  This type of drill bit comes with a 1/8" shank, with the outer end sharply tapered, down to the desired drill bit diameter.  The drill bit portion is generally about 3/64" inch long.  Most of the ones I've got are made in high speed steel, and are actually quite durable--plus the 8th inch shank fits perfectly in the larger 1/8" Dremel collet (also works well in the Jacobs chuck I often fit into my Sherline vertical mill.

Art

[Art Anderson]

On 6/13/2018 at 8:52 AM, NOBLNG said:

The circuit board drills look like a real good option!

https://www.ebay.ca/sch/i.html?_from=R40&_trksid=p2380057.m570.l1311.R2.TR2.TRC0.A0.H1.Xcircuit+board+drill+bits.TRS0&_nkw=pcb+print+circuit+board+carbide+micro+drill+bits&_sacat=0

They are very nice, and very sharp, but be advised that they DO NOT work at all well in a hand-rotated pin vise, as tungsten carbide is extremely brittle; the slightest flexing will break them.  Now, if one has a truly precise miniature drill press, they do work well (a HS classmate of mine develops custom printed circuit boards on the side, uses them a lot).

Art

[NOBLNG]

On ‎6‎/‎12‎/‎2018 at 7:54 PM, NOBLNG said:

Yes a better set of drill bits is worth the money! ... Here are pics of two good sets. (The Morse set is better than the mascot so I save them for drilling metals.)

I'm not sure the Morse set is better anymore. One of them shattered the second I put pressure on it.

[John Pol]

On 13/06/2018 at 8:52 AM, NOBLNG said:

The circuit board drills look like a real good option!

https://www.ebay.ca/sch/i.html?_from=R40&_trksid=p2380057.m570.l1311.R2.TR2.TRC0.A0.H1.Xcircuit+board+drill+bits.TRS0&_nkw=pcb+print+circuit+board+carbide+micro+drill+bits&_sacat=0

This drill bites break real easy

[Pete J.]

5 hours ago, Art Anderson said:

They are very nice, and very sharp, but be advised that they DO NOT work at all well in a hand-rotated pin vise, as tungsten carbide is extremely brittle; the slightest flexing will break them.  Now, if one has a truly precise miniature drill press, they do work well (a HS classmate of mine develops custom printed circuit boards on the side, uses them a lot).

Art

 

3 hours ago, John Pol said:

This drill bites break real easy

I have to agree.  Carbide bits will not tolerate any flex at all.  I have a lot of them and use them all the time for both plastic and metals and they work very well.  But then I only use them in my Sherline mill with the sensitive drilling attachment. This setup is very precise and easy to control.  I this setup to drill holes as small as .013" in brass strip that is .020" wide.  However, any off center at little as a few thousands of an inch will snap the bit.  A good quality HSS bit if far better for  most people who use either a Dremel  style drill of pin vise.  I keep both just because there are times that it doesn't make sense to set up the mill for hole drilling.  Carbide bits are not cheap but cheap bits of any kind will frustrate the heck out of you.  Get the best you can regardless of the kind you buy.  

[peteski]

Yes, as I mentioned when I first recommend the Tungsten Carbide bits that they are very fragile.  I also use them in a precision drill press, but I often use them in a pin vise and drill by hand (when I drill plastic). Yes, I sometimes break them (especially the 77 and smaller sizes), but that is why I buy lots of spares.  I can find them affordable enough that I can deal with some breakage.

[Pete J.]

1 hour ago, peteski said:

Yes, as I mentioned when I first recommend the Tungsten Carbide bits that they are very fragile.  I also use them in a precision drill press, but I often use them in a pin vise and drill by hand (when I drill plastic). Yes, I sometimes break them (especially the 77 and smaller sizes), but that is why I buy lots of spares.  I can find them affordable enough that I can deal with some breakage.

I mention it because I use them on aluminum parts and have ruined a piece I have spent hours on when the bit breaks deep(well deep is relative) inside the hole and there is no real way to get it out.  Trying to drill it out only results in another broken bit as there isn't much that will cut carbide of any sort.  Chip clearance and lubrication are great factors in drilling with little bits.  77 and 78 are really common for what I do. 

[peteski]

30 minutes ago, Pete J. said:

I mention it because I use them on aluminum parts and have ruined a piece I have spent hours on when the bit breaks deep(well deep is relative) inside the hole and there is no real way to get it out.  Trying to drill it out only results in another broken bit as there isn't much that will cut carbide of any sort.  Chip clearance and lubrication are great factors in drilling with little bits.  77 and 78 are really common for what I do. 

 

Yes, in that scenario the broken bit will be stuck (unless you can drill from the other side, and push the broken bit out from that side).

[BigTallDad]

Another option is to get one of these; that way you don't have to pay more for the tiny bits with large shanks.

https://www.micromark.com/High-Precision-Micro-Pin-Vise

Put the bit in the pin vise, then chuck the pin vise into a hand-held drill or a drill press. Remember to have a minimum amount of bit exposed...the more the bit protrudes, the more it is likely to break.

[Pete J.]

8 hours ago, peteski said:

Yes, in that scenario the broken bit will be stuck (unless you can drill from the other side, and push the broken bit out from that side).

Peter, the thought of trying that in some cases, just makes my head hurt.  Last time I had this happen I was boring a #76 hole through a piece of 1/2 inch 7075 aluminum.  I can't imagine the precision measurement that would be required get the holes to line up. I can also hear in my mind's eye the sound of the second bit snapping the instant it hit the tip of the first bit. Then I have two bits broken in the same hole.  On a thin piece of plastic I can see that working, but on some of the pieces I am working on, I just can't make it work but thanks for the advise.  It is an option to place in the arsonal. 

[Chariots of Fire]

I use mine in a pin vise and in very thin metals like brass and aluminum.  They work in plastic too but if you are doing deep drilling, chances are they will snap.  The slightest off center pressure will do it.  Nothing worse that having one snap in a hole you are drilling and the broken piece is just inside the hole where you can't get at it!  Can't push it through and can't pull it out!