I was drilling a hole for one of the nose door handrail in one of my RF-16’s noses using a #80 bit and a pin vise. I didn’t realize the plastic at that point was about a half-inch thick and I broke the bit. I then tried to use a second #80. That broke too, and now part of that bit is stuck in the nose. It’s too deep for me to get out with tweezers and I can’t push it out from the inside of the shell because it didn’t go all the way through. Any ideas on how I can get it out?
Could you carve away some of the material from the back side to expose the end of the bit? Without messing up the front of the shell there is no way to extract the bit from the front.
Dan Pikulski
I have had the exact same problem with Walther’s passenger cars in the past. I did exactly what was suggested above, and carved. or drilled another hole form the backside and pushed the broken bit through. Worked like a charm.
Dan’s recommendation of removing the bit is about the only way to remedy the problem.
Many times when the directions call for using a #80 bit, this hole is generally too small in the first place. As you have found the very small #80 bits are very fragile. I find that using a #76-78 will work better. These are still brittle but you will find that using a good pin vise and even control the bits will last for many hundreds of holes. The slightly larger hole will allow for some added clearance for CA and also any minor adjustment of the detail part as you glue.
<><>I’ll try that carving technique, but there is a lot of plastic in that area. I just had an idea, though: What if I drilled an adjacent hole to extract the bit, puttied it up, sanded it, then redrilled the hole? The hole is on a flat part of the nose. CA will stick to dried Squadron Green putty, right? I know puttying up mistakes isn’t the best way to go about making a model. Speaking of sanding, what grit sandpaper do you guys use for finishing?
I’m fresh out of #76-77-78 bits, so I’ll skip the upper hole of the front door grabirons until I can get some. I have one more #80 bit that works fine everywhere else on the model and all the grabs and NBW castings fit.
You could try that, but the putty being softer than the plastic will cause the drill bit to wander. If you do try that method, you could putty it up with a piece of wire in the good hole to keep the putty out of it. Then when the putty dries, remove the wire and sand leaving the hole where you want it.
Why not just leave the busted bit inside the model and make the necessary cosmetic repairs.
Bits are cheap.
You can letter the model “Spirit of the two bits”
Now that’s funny![(-D]
Use plastic rod to fill the hole, then its a good strong bond.
Art, just leave the broken bit in the hole and trim the end of the handrail that goes in that hole shorter. Also agree with other posters about #80 bits being to small for handrails and grabirons (for HO scale).
To add, if the bit is just below the surface not allowing enough depth to anchor a cut down grab, redrill a hole just above or below. By drilling at a slight angle the grab can be cut to size if hole isn’t deep enough and the grab itself can be bent to level or fit (horizontal drop step or vertical?) When installing the drop step grabs that form a ladder, I do this all the time. Not every model will give the dimples for the exact location of the part. Stewart Fs nose grabs in particular can be a real pain. Nose plastic is very thick here and the parts are sometimes mounted at a slight angle. Reshaping the part may be nec to assure exact, proper fit.
Just a suggestion here to keep from breaking bits. Chuck the bit in a Dremel tool. Trying to turn a pin vise is too wobely. And is easier to control this way. Ken
Ken,
I feel that using a dremel can cause more problems for those not as experienced with the tool. Lack of very low speed control and bit walking can really make a mess if not careful. I see what you mean about a wobbly bit, however that is only if you don’t choke up on the very tiny bit in the chuck. For drilling through such thin plastic I will only allow about 1/4 to 3/8" of the bit extend from the collet of the pin vise.
An added hint to drilling for grabs, whether the surface is dimpled or not is to use an Xacto blade as a locating center punch- a quick twist and the hole to be drilled is perfectly located for drilling. This is especially helpful if adding NBW castings so close to the hole for the grab.
Second this advice! A dremel tool with a #80 bit = broken bit in like 20 seconds in my humble opinion… maybe with wood it works, but with plastic…yikes! Using a sharp Xacto knife to mark the hole is a great trick.
Brian
Being an orthopaedic surgeon myself I use pneumatic high velocity drills in bone for plate fixation.
One thing I have learned is to keep my hand still and not move the drill whileproducing guide holes/ taps in bone, the bits break easily if that is done…also don’t put weight on your drill because it will bend and break the bit, and also make sure that your bits are sharp.
I hope this helps.
That’s what I do.
But if you are real careful, you could take a #60 and drill from the back side. The extra width will help make sure you hit your drill bit. (I’ve broken off more bits than I care to count). If the plastic is 1/2" thick like you say, make sure you put tape about 1/4" up the bit to make sure you don’t drill all the way through!
I can’t remember where I saw it, but there’s a planetary reduction gear that replaces the collar and attaches to the collet also. I think the reduction is something absurd like 25:1. If I can find it, I’ll post the link.