Grab irons, wire or etched?

[Sokramiketes]

Just a random thought--perhaps using a steel sewing pin as a (literal) pin punch, to create a divot in the plastic before drilling, would help with the wandering issue?

It would also be interesting to see if heating a pointed bit of wire and melting through the plastic, rather than drilling, might produce useful results.

(I'd try it myself, but I don't have any projects that need ultra-tiny holes at the moment, and enough other hobby things on the fire that research for its own sake isn't practical right now.)

Yes, the pin prick is useful.  You don't even need heat for the pointed wire.  You can push a stubby bit of .004-.006 wire straight into a Kato shell for a perfectly sized hole.  It's even more accurate than twisting a fancy drillbit!

[DKS]

It's even more accurate than twisting a fancy drillbit!

Although I have my doubts about this assertion, I have neither the time nor the inclination to do any exhaustive testing. So, I'll just let Skibbe think he's won. 

[PJPickard]

Chris,

By stainless bits do you mean for drilling stainless material?  You would need a carbide or high speed steel bit for that.

Paul

[Sokramiketes]

Although I have my doubts about this assertion, I have neither the time nor the inclination to do any exhaustive testing. So, I'll just let Skibbe think he's won. 

The credit goes to Vince Kotnik of our Modutrak group.  Not me.  So you don't have to hate it "just because".  His .004" drop grabs installed in puncture holes look fantastic.  I didn't think it was such a great method until trying it.

It might even be good for older modelers with arthritis who might not be able to handle the small twisting action anymore.

But, if you don't want me to share alternate techniques anymore, keep bagging on them. 

[DKS]

The credit goes to Vince Kotnik of our Modutrak group.  Not me.  So you don't have to hate it "just because".  His .004" drop grabs installed in puncture holes look fantastic.  I didn't think it was such a great method until trying it.

It might even be good for older modelers with arthritis who might not be able to handle the small twisting action anymore.

But, if you don't want me to share alternate techniques anymore, keep bagging on them.

Back off, Mike. First, if you'll note a few posts back, I commended those people who use these techniques. I do not "hate it just because" (note the smilie in my last post, you silly boy!). I've described my experiences making and using custom wire tools and similar techniques; most don't work for me in large part because I am indeed "older modeler with arthritis." Anyway, I mostly use my "fancy" bits in a drill press, which makes things quite a bit better all around.

Tell Vince thanks. Invite him on board to make a tutorial.

[peteski]

I wonder if all the recent animosity in TRW, which seems to have started right at the beginning of the year, has something to do with the fact that this is the year 2013 ? 

[DKS]

I wonder if all the recent animosity in TRW, which seems to have started right at the beginning of the year, has something to do with the fact that this is the year 2013 ? 

Nah, some of it's been around a loooong time.

[Chris333]

Chris,

By stainless bits do you mean for drilling stainless material?  You would need a carbide or high speed steel bit for that.

Paul

Naa just mean stainless #80 or smaller drill bits. Or just #80 or smaller bits that are indestructible.

[peteski]

Naa just mean stainless #80 or smaller drill bits. Or just #80 or smaller bits that are indestructible.

Chris, this is a now one on me. I never heard of stainless steel drill bits!  Maybe you mean high speed steel?  Also, there is no such thing (especially in that size) as an indestructible drill bit!  If you can develop an indestructible drill bit, you will be a very rich man!

[Chris333]

Awww crap talking about stainless etchings being strong and then switched to drill bit talk and somewhere I though there were stainless drill bits   

[robert3985]

Haha...enjoying this thread!   As to drilling holes, I've found the HSS micro drills are more durable than the resharpened tungsten ones.  I am near certain that when drilling plastic or wood, they are gonna last about the same amount of time 'cause they're not going to get dull in those soft materials.  I've also found that creating a small center-punch with a needle or some other really pointy instrument like a sharpened dental pick will ensure your drill bit doesn't wander.  My center punch is made from a small tungsten-carbide rod, which creates a pilot indentation in plastic very easily.

For those of us who decide to not use a miniature drill press to drill holes in plastic as DKS does, investing in a small battery screwdriver that has a chuck to accept a small, precision "ought" chuck will go a long way towards making drilling your holes manually really easy.  Drilling out a lot of grab iron holes will definitely tire old, arthritic fingers (ask me).  If you want to spend more money and get more versatility, a Foredom Tool with its foot pedal will go from zero to whatever, and allow you to precisely drill holes with the chuck barely ticking over.

Using a Dremel will cook the mini drills, especially in metals.

I bought several dozen mini drills of varying diameters a couple of decades ago at my local machine supply store at ten bucks apiece.  I have yet to wear one out or break one.  Just be careful and always lube your bit and keep the drilling speed slow (like 10 rpm), and your investment will last a loooong time.

On brass models, I don't drill holes to mount my grabs.  I shape the grabs, flatten the ends (just like most prototype grabs), tin the flats and solder them to the brass body using my probe in my resistance solderer.  You can see that on my photos of the Hallmark caboose.  It works great and looks very nice too.

Ed, you are probably correct to use .005" wire as most prototype grabs are less than 1" in diameter.  Add paint to .005" and you're gonna be really close.  It is totally amazing that the naked eye can really see a difference of two or three thousandths of an inch!  Really gives the lie to that stinking "three foot rule" doesn't it?

As far as materials go for making intricate caboose end-platform details brass is the best if you're gonna solder things up.  Some parts really don't need to be soldered and will stay in place after inserting in several holes and bending the ends, so SS or phosphor bronze will work great.  HOWEVER, for those of us who are detail oriented but don't have any of the specialized tools needed for bending up and shaping tiny metal parts, I've used a technique that works quite well for a modeler who just has sharp #11 blades, a straight edge, a dial caliper, a pin vice, precision scissors and knows how to use runny CA.

I call it "paper prototyping" and I've used the technique several times when mocking up structures that would eventually be fabricated from brass, such as my U.P. cantilever signal bridges.  It's pretty simple, and basically involves cutting the parts out of different thicknesses of paper (measure the thickness with your dial calipers), bend the parts if needed, and drill holes where required, then soak the paper parts with runny CA, breathing on it to set the CA off.  Make sure you soak-off any runny CA that might be dripping 'cause you don't want the big drops to become part of your structure.  After the pieces are cured, you can file, sand and drill them.  They will be surprisingly durable, and you will be able to insert any metal rods into the holes you drill, such as ladder rungs or end railings.  You can apply rivet decals to them for added detailing, or little squares of paper for joiner plates or gussets, then use little dabs of runny CA to cement the whole thing together.

No, it won't be as durable as brass, but it will be fairly durable and if you bend it, you can apply a little runny CA to it again to stiffen it up.

I'm thinking seriously about trying this out on my kitbashed CA-1 that's on my bench right now for the ladders, cutting the ladder sides to the proper profile, drilling the holes and inserting .005" (thanks Ed) wire into the holes and gluing it all together with runny CA.  It'll work, and won't be nearly as tedious as making the ladder sides out of brass.  I might even try it for the vertical brakewheel base, which would really cut my time down as opposed to making that piece out of brass.

I'll post some pics when I get to doing that in the next couple of weeks.

[peteski]

Haha...enjoying this thread!   As to drilling holes, I've found the HSS micro drills are more durable than the resharpened tungsten ones.  I am near certain that when drilling plastic or wood, they are gonna last about the same amount of time 'cause they're not going to get dull in those soft materials.  I've also found that creating a small center-punch with a needle or some other really pointy instrument like a sharpened dental pick will ensure your drill bit doesn't wander.  My center punch is made from a small tungsten-carbide rod, which creates a pilot indentation in plastic very easily.

Bob, you are absolutely correct. The small TC bits are very fragile.  HSS bits are much more durable (breakage-wise).  There is absolutely no need to use the TC bits in the materials we use for model trains (wood, plastic, brass, Zamak, etc.) as HSS bits are plenty hard enough to stay sharp for a long time.

But there is one feature that the TC micro-drill bits have which makes me willing to put up with all the negative properties they have:  it is their split point.  That lessens the "walking" and makes drilling (even by hand) very easy.  Here is a brief explanation: http://www.mycncuk.com/forums/tool-tooling-technology/233-split-point-drill-bits.html These bits go through plastic like butter!  I also like that they all have 1/8" shanks - makes it so much easier to change the bits in your power tool and it makes it possible to just drill holes while holding the bit in your hand. I do do that quite often.  Can you use your fingers to manually drill using a HSS #80 bit?  I can with my #80 TC bit.

If you have a source of small HSS bits with a split point, I'll use them in a heartbeat! 

[robert3985]

I also like that they all have 1/8" shanks - makes it so much easier to change the bits in your power tool and it makes it possible to just drill holes while holding the bit in your hand. I do do that quite often.  Can you use your fingers to manually drill using a HSS #80 bit?  I can with my #80 TC bit.

If you have a source of small HSS bits with a split point, I'll use them in a heartbeat! 

Peteski, uhhh...nope, I've never tried that, nor even thought of it!  Hmmmm...it'd work in plastic, that's for sure.  I have, however, used my "ought" chuck with its 1/8" shank to drill holes in plastic w/o putting a motor on it with a chucked-in .007" bit.  I like how fast I can spin a 1/8" shaft as opposed to my normal pin vice.

As to needing a split point, I've never had a problem drilling precise holes using my tungsten carbide center punch to form a pilot indentation, so...since I still have all of my 20 year old HSS drills (at ten bucks each), I'm probably not gonna go with TC in the near future.  However, somebody who doesn't have my investment in drills should take your experience into consideration before purchasing a big batch of micro drills.