GRAB IRON INSTALLATION

[lupo]

L.S.
I want to install grab irons on my H0 walthers rotary snowplow, they tell me to drill out all grab iron locations ( must be around 70 holes) with a no80 drill (that is very thin I think) , what is the best way to drill? electrical with a dremel or by hand, or are there other ways like melting in the irons? Any suggestions by experienced grab iron installers welcome!

[Anonymous]

LS:

Yes #80 is about as small as it gets, .0135 inches, or about 4 sheets of typing paper in thickness.

If you don't have a template I suggest you use a model drill press with as short a drill as you can get into the chuck. The idea is to have a very short shank to flex and break the drill.

Failing that I would use a "finger vise" again with a short shank. This is the less accurate and uniform way to do your work.

I suggest you also use a large needle to "center punch" your work, even if pre-registered on the model. Use a pin vise as a holder. The idea is to give your drill a place to bite into the plastic.

I wouldn't use a power tool, it is apt to create too much friction heat and either melt or bind the drill. Others may think differently.

Final hint: BE VERY VERY PATIENT. 70 holes is a large number to drill out in
registration.

Good Luck

Randy

[lupo]

thanks Randy,
I think I don't need a template or centerpunch, they put "dimples"on the carbody where irons must go

[BentnoseWillie]

Even with the molded dimples, it's a good idea to punch them with a needle or awl. The molded dimples aren't always as concave as they look, and the drill bit can wander.

I often use a #78 bit instead of a #80 - it's a lot more durable. If you're drilling in styrene plastic, I'd strongly recommend using a pin vise to drill the holes by hand. Power tools will generate too much heat and can melt the plastic.

[Sperandeo]

I'm going to disagree with Randy and Will. I prefer to drill small holes using power tools, either a minature drill press or a hand-held motor tool. However, I do use speed controls with both of these power tools so I can work at speeds that won't melt the material I'm drilling.

With my drill press I use a Dremel dial control that sits on top of my workbench. When drilling something that's awkward to secure under the drill press, I use a Dremel motor tool with a pedal speed control. (I don't recommend the motor tools with built-in speed controls, because they don't allow very slow speeds and are hard to adjust while drilling.) Either way, the power tool provides a much steadier turning motion than I could possibly achieve by hand, and I break many fewer bits than I do when hand drilling.

When you have lots of small holes to drill you can really appreciate the power assist.

Happy New Year,

Andy

[BentnoseWillie]

Interesting - I was aware that power tools give steadier rotation, but hadn't considered the use of external speed controls, and I can see where the power drill would be easier on the hands when you're drilling 70 holes!

I guess that'll learn me - there's always a way. Maybe I'll have a look at an external speed control for my Dremel.

[Anonymous]

I use a 3 jaw chuck that fits into my cordless screwdriver to power drill small holes. It turns slow so heat's not a problem. Its weight is just right so it's gravity feed. It's easy to control and the chuck allows you to clamp onto the bit with little sticking out to keep from breaking the bit. It's cheap as the chucks costs less than $10 at the hardware store and most people already have a cordless screwdriver. FRED

[Anonymous]

Fred:

I hadn't thought of using a cordless screwdriver. Its an obviously good idea. Thanks for the tip.

Randy

[lupo]

QUOTE: Originally posted by rda1964


Fred:

I hadn't thought of using a cordless screwdriver. Its and obviously good idea. Thanks for the tip.

Randy

[#ditto][bow]
LUPO

[dknelson]

I use the same system as flee -- you can get special chucks that fit right into a cordless screw driver, the speed is slow so the plastic does not melt. You do need to mount the drill bit so relatively little of it is sticking out of the chuck, however, or it tends to twist or distort (and could break). Be patient, take your time .... it can be done. Oh and by the way -- have a few spare drill bits of the necessary size handy.
I also have a set of very small reamers that I bought at a swap meet -- like very very tiny rat tail files.
Dave Nelson