How do you use a #79 Drill Bit?

Discussion in 'Getting Started' started by TruckLover, Aug 30, 2008.

  1. TruckLover

    TruckLover Mack CH613 & 53' Trailer

    Hoping someone can enlighten me here. I got a bunch of tiny drill bits from walthers. I need to use the #79 Drill Bit for a Walthers Red X Cement Kit to install the brass handrails and walkways ontop of the silos.

    Problem is, the TINY bit does not fit in my drill. What are you supposed to use to drill with those TINY bits? :confused:
  2. ezdays

    ezdays Out AZ way

    You can get chuck adapters for Dremil and other mini-drills that have a zero cutaway. By that I mean the three sections come together tight in the middle and it will chuck down on the smallest drill bit. I found one a few years ago at a local Ace Hardware store.
  3. cdavenport

    cdavenport Member

    Chuck a toothpick in the drill. While the drill is turning, use a #11 hobby blade to cut the pointy end off and, at the same time, make a small concave depression in the middle of the toothpick.

    Again, while the drill is turning, hold your #79 in your finger and gently guide it into the toothpick. It will automatically find center. Drill perhaps 1/4 to 3/8" into the toothpick as parallel to the shaft of the toothpick as possible; remove the bit, shut the drill off and remove your "drill bit holder."

    To make the drill bit stay in its holder, lay the bit on a hard flat surface. Place a fine ******* file over the shank, a needle file will work just fine, and roll the bit under the file. As you move the file back and forth, it will cut some fine grooves in the shank which is not hardened like the flutes.

    Finally, assemble the bit and holder using a bit of epoxy to hold it all together.

    To use the drill bit, you merely twirl it between your fingers.
  4. cdavenport

    cdavenport Member

    EZDays is correct; I have several zero clearance chucks. The downside is that the #79 is so small in diameter that the least variation from horizontal will cause the bit to snap. In addition, the weight and torque of the rotary tool makes it difficult to to control the bit resulting, again, in an easily broken bit.

    Unless you have a lathe or a precision drill press, don't risk it. I speak from experience.
  5. ezdays

    ezdays Out AZ way

    There is an article in this month's issue of Model Railroading where the writer gives his method for using a small bit to drill out grab iron holes in a heavyweight car. As I recall, the guy that wrote in asking the question said he went through about a dozen bits per car. You can't use that small a bit without securing the drill, that's for sure.
  6. nachoman

    nachoman Guest

    you can also use a small pin vise.

  7. TruckLover

    TruckLover Mack CH613 & 53' Trailer

    WOW Thanks a million guys Don, cdavenport, and Kenin!!!! :mrgreen: :mrgreen:

    im going to try out cdavenport's method right now!!! Thanks again guys, This is why i simply couldnt live without this amazing forum!!! :thumb: :thumb: :thumb:
  8. steamhead

    steamhead Active Member

    A pin vise is the best tool...and twirl it with your fingers...
    If you NEED a power tool to do the job, insert the pin vice into the PT and go to it. When using a PT, insert the bit waaayyyy into the pin vise and leave just the length necessary out of the pin vise to drill through the material. This will lessen the chance of snapping the bit.
    Also, use a low drilling have better control of what you're doing if you take it slow....
  9. TruckLover

    TruckLover Mack CH613 & 53' Trailer

    Thanks Gus :mrgreen:

    I have yet to try cdavenport's method, i got caught up in building another Walthers backround building lol

    Where would i find a Pin Vise?
  10. Dave Harris

    Dave Harris Member

    You can find a pin vice at most any hobby shop, Walthers, Micro Mark & many other places.
    However, drilling with a pin vice is a slow , tedious process.
    A better soultion would be to get a chuck adaptor as Ezdays suggested and use it in a drill press. Properly used even a # 80 bit will hold up fine in a drill press .
    When I built my 4 brass Climax engines there were 20 holes # 76 ( .020) size in each of the sideframe pieces for the truck side frames , thats 16 side frames in all. Thats 320 holes in brass! If I had done them with a pin vice I'd not be done yet & I built them in the early 90's! I broke about 5 or 6 by being careless.
    My drill press is a cheap Tiwain import but the chuck goes to "0". I thought I'd get fancy once & bought a Craftsman drill press --- it's now out in the Garage because that chuck won't close farther than 1/8 inch!
  11. TruckLover

    TruckLover Mack CH613 & 53' Trailer

    Thanks Dave for all the advise

    Ive always wanted to get a drill press lol, maybe its time to get one lol :mrgreen:
  12. Dave Harris

    Dave Harris Member

    If you plan do do much modeling it will be a GOOD investment. You can buy one at harbor freight & places like that for 60 -70 bucks that will be fine for it. Take along a # 80 bit & see if you can find a chuck that will hold it , some do.
  13. cdavenport

    cdavenport Member

    As a former precision machining instructor, I would be very careful about what I buy in the way of a drill press. If you are into railroading and wish to scratchbuild, you may want to consider a tabletop mill, more expensive than a drill press, but infinitely more accurate.

    In your research, I can recommend Sherline tabletop products though there are many other competing products. Check out EBay.

    As far as drill presses go, I really like Powermatic products; definitely not cheap but they will last more than a lifetime. My class refurbished one that had been in use since the 60's and is still in use today. It is in the automotive program now at my previous school.

    Second are Delta and Home Depot's "Rigid" line of tools which are excellent products for the money. In fact, the company makes its tools right here in the good ole US of A. That company now making Rigid once made Sears Craftsman power tools until Sears switched to off-shore production.

    Well, here's more information than you likely need. Good luck!
  14. steamhead

    steamhead Active Member

    CT....Are the Rigid power tools AND their batteries made in the US..? I've had it with the stinkin' Craftsman line of made in China garbage....
  15. doctorwayne

    doctorwayne Active Member

    For the little bit of drilling you need to do, a pin vise will work just fine. While it's nice to have all of the power equipment, do you think that you'll get your monies worth out of a drill press?
    I did all 78 #79 holes in this boxcar with a single drill bit in a pin vise, then did another 4 similar cars and an additional 75 holes in a sixth car with the same bit. For the last 3 holes, however, I used 2 more bits. wall1:eek: :eek: :eek:

    I've purchased two or three pin vises over the years, and find that those from the hobbyshop don't seem to stand up too well, with the jaws eventually wearing enough that they won't hold the smaller bits. A couple of years ago, I got a set of four from a tool supply store, for about $12.00. They're of surprisingly good quality, and will hold my entire range of bits, from #80 all the way up to #1.

  16. Nomad

    Nomad Active Member

    I have had good luck using rosin core solder for a adapter. Put the drill bit inside the solder where the flux was.

  17. cdavenport

    cdavenport Member

    A couple of comments:

    DoctorWayne is correct; purchasing a drill press to drill #79 holes is a bit of overkill, sort of like hunting quail with a 105 howitzer!

    Secondly, I am not sure about Rigid's batteries. But, I share your sentiments about Craftsman power tools!
  18. Russ Bellinis

    Russ Bellinis Active Member

    The best thing you need to remember is to buy at least 5 or 6 of the smallest sizes of drill bits at a time. As Dr. Wayne said, you can sometimes get a surprising number of holes out of a bit before it breaks (I think Wayne's number quoted above is probably a record), but they will also tend to break very easily and often. What works better than the small bits if they are the right size for your needed holes are hypodermic syringes. The problem is that there are laws on the books about drug paraphenalia. One of the presenter's doing a clinic at the recent NMRA convention on scratch building supplies mentioned that when she wanted to buy a syringe, she took a model boxcar body into a drug store, and showed the pharmacist how she used the syringe to drill small holes in the body to mount grab irons. He was so impressed because he was trying to figure out how to drill small holes in ship models to mount rigging, and hadn't thought of a syringe. She is now on a first name basis with that pharmacist, and has no problem buying syringes from him. If you are able to get syringes, you need to get a "sharps box". Even if they are not used for medical purposes, syringes are considered "medical waste" and must be disposed of correctly.
  19. Nomad

    Nomad Active Member

    Russ, I thank you. As a diabetic and a former janitor in a hospital, medical waste and "sharps" are not something to take lightly. Proper disposal is a must!

  20. TruckLover

    TruckLover Mack CH613 & 53' Trailer

    Thank-you everyone for all the help. Im still going to try out cdavenport's method, and im also going to pick up a pin vice next time im at the hobby shop or i might just order one online somewhere :mrgreen:

    I am considering saving up for a nice drill press and lathe too :thumb: :mrgreen:

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