Drilling Holes For Sunshades?

[MetroRedLine]

I think we have all been there ..I usually use a large needle to scribe a starter hole before I drill .. it keeps it from floating ..  try to clean up the mess as much as possible around the holes and then try to massage the sunshade to be straight around the front hole using some leverage such as a small pin or very small screw driver .. depending on how the area looks afterward .. maybe weather the area or install the sunshade in a more downward facing position .. that could help hide the blemishes

http://rrpicturearchives.net/showPicture.aspx?id=5187527

Thanks. The hole to the left is fine, the one to the right is not only too large but too far to the right. I tried drilling another hole just barely to the left of it (hoping that the sunshade would conceal the bad hole anyway) but the drill bit slipped and went towards the bad hole, which is why it looks larger than a normal #78 hole.

I have a tube of squadron putty, would that help? If so, how should I go about applying it? I tried applying CA with a needle and even that seemed too large of an object (How do you all apply CA in these situations?).

After sleeping on this, I wonder if I can fill the bad right hole with a speck of squadron putty and after it dries, paint over it with a microbrush (I have a jar of Tru-Scale UP Harbor Mist Grey that I used to paint the sunshades), then drill the new right hole. Would that plan work?

[woodone]

The problem with drilling very small holes is we can not turn them fast enough. A # 80 bit could go up to 80K, but then you will melt the plastic-not drill it. I use my Dremel Styles and I am able to drill most holes. The PC carbide bit are very brittle, any side pressure will break them.  I also use the smallest dental burs I can find. Turing a bit by hand is hard to do without exerting site force and will break them.

[ednadolski]

How do I salvage this? 

Fill the holes with some styrene rod or stretched sprue, trim/sand flush, and try again.

If you have the BLMA shades, then they come with a drilling template.   Alternately, you can make some impressions from your parts onto a small sheet of paper, position it on the model, and mark the hole locations with a sharp tool.

Ed

[ednadolski]

Where do you get your HSS bits in sizes like #95?

Found some here, tho they don't come cheap (the smaller the pricier  ) :

https://allindustrial.com/precision-twist-drill-018695-95-diameter-3-4-oal-118-degree-high-speed-steel-bright-finish-jobber-length-drill-bit/

Ed

[ednadolski]

0.2mm drills have enabled me to use 0.006" and 0.008" wire for hand grabs and other details, which is a win win.

Love to see some pics, can you pls. post some link(s)?

TIA,
Ed

[MetroRedLine]

Okay, MUCH better now!



Looks like the plan worked. I masked the area around the offending hole, put a tiny bit of Testors Contour Putty, sanded, painted a speck of touch-up Harbor Mist Grey and drilled a new right hole in the correct location. It looked much better, the disaster hole was well-disguised, even before installing the sunshade.

Someone on an N scale group on Facebook said for his sunshade holes, he measures the sunshade pin width with a set of digital calipers, marks the holes over the cab windows, and drills appropriately. I was all, "Why didn't I think of that?!?!" So I did the caliper method and it seemed to work out.

The sunshade appears warped, but it's not - the "warping" is caused by dabs of touch-up paint (some paint had scraped off from being handled by tweezers).

[Chris333]

I thought there were a few people here specifically drilling sun shade holes with piano wire. Just grind the end to a bevel and use it like a drill bit.

[wazzou]

I’ve just laid the shade on a piece of masking tape, marked the pin location with a pencil and put the tape on the side of the cab and used the marks on the tape to drill holes in the correct locations.

[James Costello]

The clear "glass" insert on the Kato shells is also harder to drill then the cab/body shell, so you can always disassemble the loco and drill the cab first.

And like the others have said, I always make a dimple with a pin first - an inexpensive sewing pin borrowed from the Mrs works well. Grab a second one to apply your super glue with.

[peteski]

Found some here, tho they don't come cheap (the smaller the pricier  ) :

https://allindustrial.com/precision-twist-drill-018695-95-diameter-3-4-oal-118-degree-high-speed-steel-bright-finish-jobber-length-drill-bit/

Ed

Wow, they are pricey!  Thanks Ed.  Also, since they do not have larger diameter shank, chucking them can become problematic.

[milw156]

Instead of using a pin for starter holes, try a lancet for diabetic blood glucose testing. they tend to be 30 or 31 gauge with very sharp points. because of the shape of the point, might be able to "drill" with it

[robert3985]

Drilling very small holes.  First thing is to know that high speed drilling using micro-sized drill bits is totally wrong, and will cook a bit very quickly. This means DON'T USE A DREMEL TO DRILL SMALL HOLES IN EITHER PLASTIC OR METAL.  It's lowest speed is much too high.

However, drilling micro-sized holes with a pin vice can be problematic because it's very easy to snap bits, both HSS and Tungsten Carbide.

Frankly, I find Carbide bits to be too brittle to trust, so all of my micro bits are HSS, and they're all sharp.

I drill a lot of holes using my HSS .007" bits for installing .007" grab irons or inserting .003" suture silk for caboose smokejack supports.

In plastic, I always start the holes with a sharpened tool steel round boring bar on to which I've ground a very sharp, concentric tip.  If that happens to be too large in diameter, I use a large needle to prick a starting dimple. I don't need a big dimple, just big enough so the bit doesn't wander.

Then, using a quality pin vice, such as my Starrett pin vice, I chuck my $10.00 .007" HSS bit into it with a little less than 1/4" of it sticking out.  This makes a small bit much stiffer and less likely to snap under excess pressure.

I apply a small amount of pressure...SMALL... and twist the pin vice as smoothly as I can, and the plastic comes curling out.  I keep doing this until I'm through the plastic.  Easy. 

I use this technique for holes up to about .020" and I never break a bit.

For brass, it's a different technique.  I use a precision adapter chuck, which has a 1/8" shaft on the back and goes to zero, which I chuck in my Foredom Tool handpiece. 

I also make a starting dimple in brass, usually with my tool steel boring bar that I've ground a sharp tip on, tapping on it lightly with my jeweler's hammer. 

I chuck my micro bits in this small adapter chuck again with about 1/4" sticking out, then I spin the bit in my waxy drill lube...jeweler's often use beeswax for this.  NEVER drill metal without lube on the bit.

Then, I press on my foot pedal speed control so the chuck is ticking over about 3 revolution per second (NOT rpm...revolutions per SECOND), then lightly position the bit in the starting dimple and apply very light pressure.

If the brass curls out of the hole, I know I'm applying the right amount of pressure.

I usually re-lube the bit at least one more time depending on the depth of the hole.

Instead of investing in a Foredom Tool, there are precision adapter chucks that can be attached to small, battery powered screwdrivers that will work well also.  I don't have a recommendation because I haven't decided on what powered precision screwdriver I'm getting yet.

Using these techniques, out of the dozen $10.00 .007" bits I bought 30 years ago, I've broken two (one from not lubing and one from applying too much pressure) and dropped one...which disappeared forever.  The rest are still sharp, unbent and ready for use in their little blue envelope.

The same technique works for other, slightly larger bits when drilling brass, zamac, ns or bronze.

I learned this from Ralph Gochnour, who designed and cast the detail parts for the first Overland HO scale GTEL Turbine dealing with drilling micro-sized holes to insert brass wire into to simulate rivet heads.

Cheerio!
Bob Gilmore

[ednadolski]

I drill a lot of holes using my HSS .007" bits for installing .007" grab irons or inserting .003" suture silk for caboose smokejack supports.

@robert3985  could you please share your source(s) for HSS bits and the 0.003" suture silk?

Thanks,
Ed

[robert3985]

@robert3985  could you please share your source(s) for HSS bits and the 0.003" suture silk?

Thanks,
Ed

@ednadolski  Ed, I haven't bought miniature drill bits for a couple of decades, but...I have a friend who needed to know where to buy 'em a couple of weeks ago, so I did a little research and came up with two places that look like they might be good.

This place looks to have bits down to #97 (.0059") in stock at a pretty good price.  They've also got metric sizes which may go smaller (I haven't checked).  When looking for your drill sizes in their search engine, just type in #94 or #97...the drill number.  Here they are: https://www.msdiscounttool.com/catalog/index.php?cPath=3437_1_2_57_989_990_992&page=6   which is the size chart page that has the micro drill sizes.  Clicking on the size you're looking for takes you to the appropriate order page. However, the smallest they have is #97 (.0059")

Here's another place that sells "miniature drills" but they have minimum orders.  Although it isn't clear on their page, it appears as if they're selling the bits by "package" which is 12 drills, but ya gotta buy a minimum of 3 packages per drill size.  Maybe calling them and seeing what they'll do for you would be a good Idea, because less than 20 bucks for a package of 12 "miniature" HSS drills is a good deal.  Here's the link:  https://imsbolt.com/alfa-tools-96-hss-alfa-usa-miniature-drill/  Use "miniature drills" as the search parameter.

I was having trouble finding sizes for micro sized bit in both ANSI and ISO so, I found this handy chart:  https://www.custompartnet.com/drill-size-chart

For lube, I use a tube full of a waxy lube I got at the machine shop in SLC when I bought my bits a loooong time ago and I'm running out of it.  Synthetic beeswax is used by jewelers as a drill lube, but maybe there's something better. After a little research, I came upon an advanced machining lubricant that might be the best.  Called Boelube...invented by Boeing and the paste version being just right for drilling small holes.  Here's the link at Amazon: https://www.amazon.com/BOELUBE-Machining-Lubricant-70302-12-Container/dp/B00DHMGWFK/ref=sr_1_3?hvadid=580937724925&hvdev=c&hvlocphy=9057531&hvnetw=g&hvqmt=e&hvrand  Some cutting fluids will probably work just as well, maybe even synthetic beeswax, but...I want something that's easy to remove and doesn't run everywhere like some cutting fluids I've used for other machining projects over the years.

Non-sterile, braided silk suture thread, black is hard to find at a decent price.  The 100yd spool I have is from a company called "Ethicon" out of Somersville NJ and is 6-0, Silk, Black, Braided, Code A-51

I found a company that will sell to non-physicians, but they're a little pricey and offer their black silk braided non-sterile thread in either cut lengths or 25 yards on a spool.  Different diameters are priced differently, but they have silk down to 7/0 which is .05mm or .001969" in diameter.  Go here:  https://www.fishersci.com/us/en/catalog/search/products?keyword=silk%20suture%20thread%20braided%20silk&page=1    Specs on their stuff doesn't say if there's any wax coating but the 7/0 thread would be 0.315" in N-scale.  However, it's expensive at almost 100 bucks for 25 yards. Their 6/0 stuff at 0.003.1" is almost half that price.  Still pricey.

Here's another place.  I didn't check to see if they sell to non-physicians, but their prices are considerably lower and they offer 100 yards of suture silk on spools down to 6/0.  Go here: https://www.net32.com/ec/look-6-0-100-yards-silk-black-d-82859

Another option may be to try fly-tying threads.  I see they're offered down to 18/0...or 30D (denier) but I can't find any charts that give an actual diameter as opposed to suture silk.  I'm not sure, but the company "Semperfli" seems to have a really good reputation and offers some threads in "waxed"...but none of them are braided as is all silk suture thread as far as I can determine.  HOWEVER, the prices are very low...like six bucks for 100 meters of the 18/0 Nano Silk, and in various colors too.

Fly tying threads of different sorts are available...along with various metal fine wire...online everywhere or at local fly tying stores or big sporting goods stores like Cabellas and Sportsman's Warehouse.  I think I'm gonna go look with my digital calipers in hand to see just what the diameters really are in inches.

That'll about do it!  Have fun and good luck!

Cheerio!
Bob Gilmore

[Ed Kapuscinski]

Seeing this topic made me think how handy it might be for someone to design up some fixtures to do these accurately to be 3D printed.

Like, "hold this piece against an Atlas cab flush with the front and located by the contours of the roof, then drill in these spots".

I made a ghetto version of that when doing holes for the horns for my SD40-2s. Worked ok, but something better than paper would likely have been far better.