This Weeks Stupid Award Goes To Me!!

[Bill D]

After painstakingly fitting and trimming my RHD headlamp cover, I broke the cover while drilling the mounting holes. I apparently put too much pressure on the drill while drilling the hole and it went "SNAP"!

This is to alert others who have not installed theirs to press "lightly" to avoid ruining their parts.

Now I have to get another cover from Fran and start over. I'm really pissed at myself.

Bill D

 

[Lynn Larsen]

Bill,

Don't feel like the lone wolf! Luckily, my cracks didn't go that far. You'll want to be careful when tightening the screws upon mounting as well; I cracked a couple of mine doing that.

Lynn

 

[Chris Martino]

Bill - it's VERY easy to crack these, the last hole I drilled in the passenger side headlamp cover produced a 1/2" long crack, almost not worthy of replacing but definately enough to piss me off.

I found that drilling the holes in the covers just slightly larger than the screw worked best.

I bought another...

Chris

 

[Fran Hall RCR]

I guess I had better stop off at FedEx on the way home then......

 

[Alex Hirsbrunner]

One alternative to drilling is to find a thin wall brass tube (either from a hobby shop or Ace Hardware's K&S tubing display) that is the diameter of the hole you need. Sharpen the edge (the inside edge ideally, using a jewelers file), attach to a soldering iron (a 15 watt one for electronics) with a couple of hose clamps and you can then gently "hot bore" out the holes you need. Adjust the heat as required by shortening or lengthening the tube to suit your soldering iron.

This generally leaves a pretty clean hole, with some flash on the bottom that can be cleaned up (or left as is if you are using a foam gasket). If you want it to be perfect, you can start with an undersize tube take a small dremel burr to get to the final dimension - @ low rpms.

Regards,

Al

 

[Dutton]

Bill,

There's NO way you're the first one down this path and, before reading Al's comment, I knew I was destined to the same results!

An oversize bore using heated tubing sounds like just the ticket. Great suggestions, guys.

Best,

T.

 

[Mark Charlton]

Anyone who has drilled enough holes in plastic has had that happen eventually.

One thing that helps is to use a plastic drilling bit. There are lots around and although it doesn't guarantee a perfect result, it helps a lot. You may have already known about or indeed used these already, but in case you didn't:

http://www.rplastics.com/plasticdrill.html

 

[Bill D]

Thanks (sniff, sniff)

 

[JimmyMac]

Bill.
Try a hand tapping chuck with the drill bit - slower but without the pressure ?
All the best,

 

[Lynn Larsen]

Get a plastic bit or take a dremmel grinding wheel and flatten the "bite" out of a regular twist bit. If you look closely at a plastic bit, you'll see that it is somewhere between a twist bit and a paddle bit.

If you can do it without electrocuting yourself, you might try a tiny water stream to keep everything cool so that the bit can't bite. But I think if you'll use a slow speed on a variable, you'll be OK.

There should be a thread on this that I started back when I was doing mine as well.

Lynn

 

[Bill D]

I have the correct drill bits to do the job. However, I wasn't paying attention to the amount of pressure I was applying to the drill.

 

[Scott Calabro]

Hi Bill,
Check out this site, they can supply all your drill/lens/window/cleaning needs.
www.lpaero.com
Regards,
Scott

rockonsmile

 

[Jools]

I think we all empathise with you Bill.
I was so pleased with myself when I managed to drill all the covers without incident when I re-built my 40. Accurately making card templates as I had to match the new covers and their respective holes to the existing holes in the painted body, gently warming the plastic , and ever so carefully guiding the drill bit through .....only to crack one the minute I tightened that final turn of the screw !!!
Note to self : Use Nut/Screw lock everywhere !!

 

[Sandy]

Hi Bill,
Check out this site, they can supply all your drill/lens/window/cleaning needs.
www.lpaero.com
Regards,
Scott

rockonsmile

We should get these type of resources added to the links page. The are very useful and often a pain to find via the search.

Ron - What's the best way to get new links up?

Sandy

 

[Paul Butvila]

Bill, if that cover was acrylic then you need to use either a dull drill bit or have it sharpened much diff. than you would say one for metal. The problem is when you are "breaking" through the other side, the drill bit tends to grab. The other thing is to keep pressure around the drill bit as it breaks the opposite surface. I;'v been working with plexiglas for about 25 years. It's happened to me to.

 

[Phil]

Bill
Not stupid on your part...I think every method could produce cracks, and if your like me a little diversion can produce drastic results...so carry on and call it experience. By the way I only make one mistake a year...I am up to the year 2700 or so by now.
Cheers
Phil

 

[Chris Kouba]

Oh Bill...

I believe I take the stupid award of the week. I was mountain biking with a buddy on a technical trail with some large exposures and we got through the tricky parts (most of them...). I pulled off a really cool move down a little technical step and was yapping to my buddy about it when my front wheel got wedged into a rock. I was stopped instantly and immediately started losing balance. Also, I had paid too much attention to the conversation to notice the 8' cliff (that's about 2.5m to you metric people) that I proceeded to fall over.

I ended up tumbling around 20'-25' (call it ~7m) with the roll-out at the end, landing (MIRACULOUSLY) on a sloper rock, missing an old tree trunk and the majority of sharp rocks, sliding right onto the trail which switched-backed below us. Got a gash on my right wrist, charlie horses on my right quad and left calf, and a bit of rock rash on my back, shins and knee. I also took a hell of a direct shot to my helmet (which will now be replaced) and knocked apart my front derailleur shifter.

I walked away and everything was functional. I was in awe. I had been thinking about broken legs, head trauma, internal bleeding on my way to the ground but I came out (relatively) unscathed. Since all was good, we made quite light of the situation with a bunch of pics. It could have been MUCH worse.

The moral- don't get distracted, don't lose focus, wait til you're done to shout out your triumphs, and if you're gonna stack it, make sure you have a soft place to crash.

The other moral- Make sure you're riding partner is an ER doc

staged aftermath

top looking down

bottom looking up

(I'm the genious in the bright jacket, and my apologies for thread drift)

 

[Dutton]

Bill,
Chris has clearly outdone you. Nice try but no cigar.

Chris,
I've known you long enough to say "what the HELL are you thinking!?!"

I've been with you off-road and remember being impressed with your ability (and a large right foot) but this is way, WAY past that. Very glad to learn you're okay but will be more pleased to find out that your mom has taken you over her knee and given you the walloping you so clearly deserve.

Note to all: Watch out for those sharp drill bits - and rocks, too.

T.

 

[Howard Jones]

I did mine by using a small pilot drill first, about 1/16. I then started a chamfer on the back side with the larger bit and then drilled through from the front with a bit two drill index sizes larger than the screw shank diameter. The chamfer on the back side helps prevent the bit grabbing as it passes through.

This is very important. The hole MUST be larger than the shank of the screw. I also used a nylon washer under the head of each screw. You can use a power drill, I did, BUT a nice slow hand cranked drill might work. Cont ant speed is what is important. The hand drill might be hard to maintain drill speed AND equal light pressure at the same time.

I used a piece of wood as a working surface so that I could drill completely through the piece in a complete stroke. Slowing down just as you punch through will crack the back side. Just continue with SLOW constant LIGHT pressure into the wood. Also work in a place where you can lay the piece flat on the working surface. The front room carpet is the best place. Hence the wood working surface. Knee along side the piece and press straight down. On the small stuff have someone help hold it. And on the big one, pillows should be used to support the piece so that the point at which you are drilling is completely flat against the wood backing. I also used duct tape on the wood so as to not scratch the lexan.

DONT FORGET THE TAPE ON THE BACK SIDE. I used that blue painting tape.

Put the piece to be drilled out in the sun or under a electric blanket and warm it up. The small stuff can be run under hot tap water. The temp of your hot water is about right. On the big pieces remember to re-warm.

DO NOT use new sharp metal bits. If you have to, take one of yours to some sand paper to dull it up.

Practice on your cracked piece...... ALOT!

Unless you want to try and save it. You could try the lexan cement. Wick in into the crack. You can get this stuff from Tap Plastics. It would be interesting to ask them what they think about this idea. By the way they can make you a new piece on the spot. You can form them by hand with a hair dryer. Not all that expensive really. The side windows are about a $100 each with the flip out window holes cut into them for you. The back was about $150. I might be off on prices. It's been awhile.

Oh and don't feel bad......wait until you F U the rear window....to feel bad.

Easy big fella......easy....