maker of small drill bits (#78, #80) for hand drilling resin kits


Chuck Cover
 

Group,

I know various drilling methods have been discussed before, however, I have not found recommendations for the actual drill bits themselves.  I like to hand drill for grab irons, etc. and will continue to do so.  I have tried several brands of drill bits such as Jobber, Mascot, and Gyros.  I have found the Gyros to be more fragile than the other two.  Are there any suggestions for favorite drill bits from other modelers?  Thanks

Chuck Cover
Santa Fe, NM
PRR's Shamokin Branch


Hudson Leighton
 

1.  Go to a Machine Shop Supply and buy a good brand, do not buy the Hobby Shop drills.

2. Buy Screw Machine length drills, they are shorter, so they don't bend as easily.

3. Chuck the drill as short as you can, this also helps with the bending.

My current favorite MSC.

-Hudson


Jim Betz
 

  ... I like the style of bit that has a 1/8th inch shaft and necks down to the bit
size.  These often have a collar on them that provides the size info.

  I long ago gave up on trying to hand drill with a #80 and a typical hobby bit.
My solution then - sort of "forced" because I'd just broken the #80 and then
the #79 was to go to a #78 size for holes for #80 size wire ... after the bit is
in you don't notice that the hole is "over sized" and no one has ever said
anything about my holes being too big ... when at least the holes in my
models as opposed to the ones in my head.  *G*
                                                                                         - Jim in the PNW


radiodial868
 

You name the brand or supplier of tiny twist drill bits, I've bought them. I've also thrown out a lot over the years, too.
These from Otto Frei Jewelers are my everyday bits of choice nowadays. High quality and affordable, start nicely and right combination of temper and flexibility for resin and brass.

https://www.ottofrei.com/High-Speed-Steel-Twist-Drills-Sizes-80-to-50
--
-------------------
RJ Dial

Mendocino, CA


radiodial868
 

As I mentioned, the nicely made Otto Frei bits at $0.60 each are my standard now.  If you only want to use the best of everything, USA made precision ground bits from Gesswein at $3 each are also available. I have some in the smaller sizes, but I find they are way overkill for resin and brass.  When the pin vise with a Gesswein bit rolls off the workbench onto the floor, the pain is real...
https://www.gesswein.com/burs-drills/drills-taps-reamers/twist-drills/blue-ribbon-high-speed-twist-drills/

BTW, I too use #79 & #78 bits in most cases. I find the CA fills in that tiny little gap perfectly and takes most of the frustration out of installing grabs and the like.
--
-------------------
RJ Dial

Mendocino, CA


Curt Fortenberry
 


I buy these on ebay, and have never had a problem with them.  

https://www.ebay.com/itm/165010445835

Some sellers have sets.

Rule 1:  lubricate.  I keep a wax block handy and just touch the bit to the wax.  I've never broken a bit in plastic, but have with resin as it's sticky and soft. 

Curt Fortenberry


Kevin Macomber
 

What sizes are generally required.  How do you match up with the item to be inserted as it is so small.  My knowledge of these sizes of drill bits is low and appreciate the assistance.  Kevin


Fran Giacoma
 

I have been happy with the quality/cost of the drill bits and excellant service from Drill Bit City: https://drillcity.stores.yahoo.net/highspeedtools.html

Fran Giacoma


Dennis Storzek <dennis@...>
 

On Thu, Jul 7, 2022 at 09:17 AM, Kevin Macomber wrote:
How do you match up with the item to be inserted as it is so small.  My knowledge of these sizes of drill bits is low and appreciate the assistance
Google "number drill size chart". That will give you the size of number drills in thousandths of an inch, which is the same units of measure used by most hobby wire suppliers. Most pre-forrmed HO grab irons are .012" diameter wire, so a #80 drill at .0135" is just right, leaving some room for glue to surround the wire.

Dennis Storzek


George Hollwedel
 

Excel work good for me

Prototype N Scale Models (TM)
by George Hollwedel
2108 Buffalo Tundra Dr
Austin, TX 78754-5960
512-796-6883
proto.nscale@...





On Wednesday, July 6, 2022, 02:18:38 PM CDT, Chuck Cover <chuck.cover@...> wrote:


Group,

I know various drilling methods have been discussed before, however, I have not found recommendations for the actual drill bits themselves.  I like to hand drill for grab irons, etc. and will continue to do so.  I have tried several brands of drill bits such as Jobber, Mascot, and Gyros.  I have found the Gyros to be more fragile than the other two.  Are there any suggestions for favorite drill bits from other modelers?  Thanks

Chuck Cover
Santa Fe, NM
PRR's Shamokin Branch


Nelson Moyer
 

I’ve used Walthers, Gyro, Mascot, McMaster, Drill Bit City. For the smallest sizes, the ones I got from McMaster lasted the longest and were reasonably priced. Otto Fry is too pricy.

 

I attached a conversion table.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Kevin Macomber
Sent: Thursday, July 7, 2022 11:18 AM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] maker of small drill bits (#78, #80) for hand drilling resin kits

 

What sizes are generally required.  How do you match up with the item to be inserted as it is so small.  My knowledge of these sizes of drill bits is low and appreciate the assistance.  Kevin


Nelson Moyer
 

Here’s my bit size information.

 

Nelson Moyer

 

From: main@RealSTMFC.groups.io <main@RealSTMFC.groups.io> On Behalf Of Kevin Macomber
Sent: Thursday, July 7, 2022 11:18 AM
To: main@RealSTMFC.groups.io
Subject: Re: [RealSTMFC] maker of small drill bits (#78, #80) for hand drilling resin kits

 

What sizes are generally required.  How do you match up with the item to be inserted as it is so small.  My knowledge of these sizes of drill bits is low and appreciate the assistance.  Kevin


Bruce Smith
 

Folks,

 

I also keep a digital caliper on my bench to check the size of wire, etched parts, or other parts, so I know which drill to select. As you note, a little wiggle room can help.

 

Regards,

Bruce

Bruce Smith

Auburn, AL

 

From: <main@RealSTMFC.groups.io> on behalf of Dennis Storzek <dennis@...>
Reply-To: "main@RealSTMFC.groups.io" <main@RealSTMFC.groups.io>
Date: Thursday, July 7, 2022 at 11:58 AM
To: "main@RealSTMFC.groups.io" <main@RealSTMFC.groups.io>
Subject: [EXT] Re: [RealSTMFC] maker of small drill bits (#78, #80) for hand drilling resin kits

 

CAUTION: Email Originated Outside of Auburn.

On Thu, Jul 7, 2022 at 09:17 AM, Kevin Macomber wrote:

How do you match up with the item to be inserted as it is so small.  My knowledge of these sizes of drill bits is low and appreciate the assistance

Google "number drill size chart". That will give you the size of number drills in thousandths of an inch, which is the same units of measure used by most hobby wire suppliers. Most pre-forrmed HO grab irons are .012" diameter wire, so a #80 drill at .0135" is just right, leaving some room for glue to surround the wire.

Dennis Storzek


Rick Jesionowski
 


Philip Dove
 

To get the right size drill for a task such as installing grab irons l first look on the packet for recommendations as to what size to use. I visually compare the two then drill a hole in scrap material and see if it works. Slightly oversize holes help as others said. For grab irons l drill right through the piece glue from the reverse and if neccessary then cut and file the reverse side of grab off if it's going to get in the way. 
To ensure the grabs are all protruding a uniform amount l put a small sliver of some unglueable plastic under the grab so they don't go in too far. I use resharpend Carbide drills because they are the only drills l have in US sizes. I don't drill unless l a relaxed and fresh because l use a pin vice, and breakages are three times as high if l'm tired or tense. 


Ken Adams
 

My recent experience with the Gyros #78 drill bits I bought through Amazon was not good. They broke on the second hole I drilled with each bit. Earlier purchases of Gyros drill bits were ok as they would last 15-20 uses.  Even buying a recommended Starrett pin vise did not help.  It works much better with some older #78 Gyros I had on hand.

I used to buy from Otto Frei (ouch that rhymes) before the Pandemic as they are local in Oakland and I could order and they drop by for pickup avoiding shipping costs.  The drill bits were fairly long lasting.  

The thicker shaft on the GMAUVAIS bits at MSC looks like a possible solution to constant breakage.  I will put together an order in the near future for 10 packs of 77/78/79 bits and see if shipping is not prohibitive. 
--
Ken Adams
Omicron BA2.2 may come and go but I still live mostly in splendid Shelter In Place solitude
Location: About half way up Walnut Creek
Owner PlasticFreightCarBuilders@groups.io


ed_mines
 

I've been using these carbide bits but when I bought them from e bay a few years ago they were much less expensive. They are brittle as h... and if they break off you better drill another hole.


Philip Dove
 

Yes l would have to agree the carbide bits are very brittle. Another modeller was surprised l'd managed to drill any holes without breaking them. 


Chuck Cover
 

Thanks to everyone who has responded.  It has been a big help.

 

Chuck Cover

Santa Fe, NM


Owen Thorne - owen at udel.edu
 

I have enjoyed this discussion, but one question remains unanswered for me. I too have had trouble finding reliable affordable bits for hand-drilling plastic and resin and I remain unsure if I should be shopping for high-speed, carbide-tipped, carbon or another. For me, skinny bits from the hobby shop or Amazon suppliers break too easily and are often dull from the start. These bits rarely last long enough to dull, maybe because I am increasingly fumble-fingered and visually challenged with age but maybe because I am choosing the wrong drill-bit material. The expensive Otto Frei and Gesswein products RJ Dial discussed above are "high-speed" so is this the correct material to choose or are those just better quality (and pricier?)

I agree with folks who like the style of bit that has a 1/8th inch shaft and necks down to the bit. The collar with size info is convenient. Chucking them in and out, and sizing or keeping track of loose bits is so easy. Drill Bit City bits have been pretty good lately, but they still break for me, and they are more expensive to replace.

McMaster-Carr has provided me excellent tools and materials in the past, so I trust them. They write about bit materials here: https://www.mcmaster.com/drill-bits/

Quoting from their site:


"A number of factors determine which drill bit will be best for an application, including the type of material to be drilled, drilling speed, and desired number of holes per bit. Select a drill bit with the combination of material, finish, length, and style that will be best-suited for your job.


“Material

  • High-speed steel bits are for general purpose drilling in most material.
  • Cobalt steel bits have better heat and wear resistance than high-speed steel bits, so they can run up to 25% faster and have a longer tool life.
  • Carbide-tipped bits are more wear resistant than high-speed steel and cobalt steel bits, so they maintain their sharp edges longer for excellent performance on abrasive material, such as plastic. Because they aren't as brittle as solid carbide bits, they can be used in less rigid setups, such as a hand-held drill.
  • Carbide bits are harder, stronger, and more wear resistant than high-speed steel, cobalt steel, and carbide-tipped bits for the highest accuracy and longest tool life. They retain a sharp, hard edge at high temperatures for the best performance on hard and abrasive material. Made of solid carbide, these bits require rigid toolholding to prevent breakage and should not be used in hand-held drilling applications."

So, while choosing high-speed bits for hand-drilling plastic and resin seems counterintuitive, the commonly available carbide bits are specifically NOT recommended, as per above. Does anyone have experience with cobalt or carbon-tipped bits? Or is there another material, tip shape, angle, or coating we should be using for resin or plastic?

p.s. One key for me is lubrication, as Curt Fortenberry mentions above. I keep a hunk of beeswax on the bench and poke the bit into it each time I start a hole or clear the chips. And as Hudson suggests above, chucking the skinny bits really short also helps prevent breakage while using a smaller, finer pin vise has helped me to avoid lateral stresses that can break a bit.

Thank you, all,

--
T. Owen Thorne
Cecil County MD USA
owen at udel dot edu