Drilling Holes For Sunshades?

[MetroRedLine]

I just got finished painting a set of Trainworx sunshades from some locos in my fleet.
The instructions call for a #80 bit, but when I drilled them above the side cab window using a pin vise into a Kato SD70ACe, I couldn't get anything more than a shallow dimple.  I've drilled and drilled and drilled for over 20 minutes but no luck. I've even tried more downward pressure, but these drill bits are tiny and delicate.

I've even switched to a #78 bit with more pressure, and just my luck, the bit slipped and snapped off. 

How do you guys do it?

[nickelplate759]

I just got finished painting a set of Trainworx sunshades from some locos in my fleet.
The instructions call for a #80 bit, but when I drilled them above the side cab window using a pin vise into a Kato SD70ACe, I couldn't get anything more than a shallow dimple.  I've drilled and drilled and drilled for over 20 minutes but no luck. I've even tried more downward pressure, but these drill bits are tiny and delicate.

I've even switched to a #78 bit with more pressure, and just my luck, the bit slipped and snapped off. 

How do you guys do it?

Sounds like your drill bits are dull for some reason.  #80 is delicate (so is #78, as you found out), but shouldn't need much pressure to cut into styrene.  Just the weight of the pin vise and maybe your finger on top.

[MetroRedLine]

Sounds like your drill bits are dull for some reason.  #80 is delicate (so is #78, as you found out), but shouldn't need much pressure to cut into styrene.  Just the weight of the pin vise and maybe your finger on top.

They all came from an Enkay 20-piece mini drill bit set (a dispenser that has multiple bits from #61 to #80). To my knowledge, I have never used those bits before, and if I have, only sparingly.

I've successfully drilled sunshade holes into a Fox Valley and Intermountain loco before with no issues.

[ednadolski]

I like to use a sharp machinist scribe to make a dimple in the plastic to help start the bit.
Ed

[peteski]

Yes, most small size HSS drill bits are rather dull.



If you had some of these" PC Board" Tungsten Carbide bits with split point, you would have no problem drilling holes in pretty much any material.  These bits are extremely sharp and hard, but they are fragile, so they need to be handled with care.  I'm addicted to using them for most of my drilling tasks (and yes, I have many spares for when I snap them).

[ednadolski]

but they are fragile, so they need to be handled with care.

Quite an understatement esp. for anything smaller than #80.  I've had #94 carbides that easily broke just barely getting started on a single hole, so I prefer the HSS ones. In any case, it still calls for a pretty light touch.  I try to brace my hands against the bench as best I can.

All that being said, the Kato plastic is pretty soft and should not really need carbide like for PCB material.  Perhaps your bits were broken off at the tip, or if you got them on Amazon or such then they could have been pre-used.
 
(Edit: the reviews of those on Amazon seem quite mixed.)

Ed



 
 

[peteski]

Quite an understatement esp. for anything smaller than #80.  I've had #94 carbides that easily broke just barely getting started on a single hole, so I prefer the HSS ones. In any case, it still calls for a pretty light touch.  I try to brace my hands against the bench as best I can.

Very true.  #85 is the smallest one I can use without it  breaking (too often). I buy the smaller size bits in boxes of 50 (if I can find bargains).  I acquired few #95s (shown in my photo) but like you mentioned, those are just too fragile for hand drilling.  Where do you get your HSS bits in sizes like #95?

[MetroRedLine]

Okay it turns out the drill bits in the set I had were really weak. I found a #78 I bought from a hobby shop that worked without much pressure.

So I installed another set of sunshades into a Kato AC4400CW. But for some reason the holes wouldn't cooperate. I'll drill them in the right places, using the rivets in the window frame as a reference, but when it came time to fit them, they're either too wide or too narrow. For the SD70ACe, I was barely able to get away with it as the width allowed more friction for the sunshade pins, but for this one side, I clearly failed at drilling. How do I salvage this? 




I'm almost too embarrassed to show this to you all.

(If you want me to delete my account, I'll leave this site)

[John]

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

[davefoxx]

^ What John said.  The sunshade, if you get it installed straight, should hide the worst of that.

DFF

[JeffB]

Yes, most small size HSS drill bits are rather dull.



If you had some of these" PC Board" Tungsten Carbide bits with split point, you would have no problem drilling holes in pretty much any material.  These bits are extremely sharp and hard, but they are fragile, so they need to be handled with care.  I'm addicted to using them for most of my drilling tasks (and yes, I have many spares for when I snap them).

I will second this...  I've stopped using standard drill bits below #76 and now use these relatively inexpensive 3mm or 1/8" shank carbide drills.  You can buy them off Amazon for $8-$10 per set of 10 (metric sizes).  Been successfully using down to 0.2mm (about 0.008") in wood and resin.   

While they break fairly easily, they are more resilient than you'd expect for very small carbide drills...  I don't break many actually drilling holes.  Most of the ones I've broken were because I dropped them, or hit the drill bit (when in the drill press chuck).  If you're careful while drilling out holes, they'll last quite a while.

IMO...  Much better than the standard HSS or carbon steel numbered drill bits.  The 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.

Jeff

[Maletrain]

Are you guys with the tiny carbide bits using them in a pin vice, or a small drill press?

If a drill press, what rpm do you use when you need to make tiny holes in brass?

[JeffB]

Are you guys with the tiny carbide bits using them in a pin vice, or a small drill press?

If a drill press, what rpm do you use when you need to make tiny holes in brass?

Mostly by hand, without a pin vise.  They're a little tricky that way, but I prefer the feel/control of doing it like that.  It's also the main reason why I drop them (and they break). 

The 3mm or 1/8" shank is a down vote though.  There are pin vises that have a collet that'll hold 3mm or 1/8", but the size of the pin vise makes them cumbersome to use.

In the drill press, speed depends on material being drilled.  I'm almost always using them to drill out 3D printed resin (very occasionally basswood), so the speed is on the slow side.  Can't give you an exact RPM, because my drill press (Micro Mark) doesn't have a readout for RPM's.

Jeff

[peteski]

Same here. For the sizes of about #77 and smaller I just hold the 1/8" shank in my fingers.  Yes, it is a bit awkward, but it gives me the best control and feel of the drilling process.  Holding the bit close to its cutting end is also a plus for gentle precision drilling (especially with shaky hands). Pin vise makes the setup too heavy and imbalanced.

Of course, if feasible, using a drill press and immobilizing the item being drilled is the best option.

[Spades]

Okay it turns out the drill bits in the set I had were really weak. I found a #78 I bought from a hobby shop that worked without much pressure.

So I installed another set of sunshades into a Kato AC4400CW. But for some reason the holes wouldn't cooperate. I'll drill them in the right places, using the rivets in the window frame as a reference, but when it came time to fit them, they're either too wide or too narrow. For the SD70ACe, I was barely able to get away with it as the width allowed more friction for the sunshade pins, but for this one side, I clearly failed at drilling. How do I salvage this? 


I'm almost too embarrassed to show this to you all.

(If you want me to delete my account, I'll leave this site)

Every modeler has seen or done worse. If the shade doesn't cover the damage. remove the cab window glazing. Remove unwanted plastic shaving. Take masking tape and tape around and as close to the craters as you can. Use filler of choice, let dry.  Sand. Remove tape do any finish sanding. Touch up paint.

If you install the shade and than repair, do the same just tape everything that is not a hole.

Removing my anal cap now



I use a pair of dividers to mark my holes on the cab.