Need to cut holes in ribs of a wing that is already put together.
#4
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Find a long brass or aluminum tube slightly larger than the servo leads, take a file and notch some teeth in it, then use some needle nose plies and stagger them.
use a regular drill in the light ply root rib, then slowly rotate the tube back and forth, it will go through balsa without cracking it, as long as you don't put too much pressure.
this will work if the halves are not joined.
use a regular drill in the light ply root rib, then slowly rotate the tube back and forth, it will go through balsa without cracking it, as long as you don't put too much pressure.
this will work if the halves are not joined.
#6
If the wing is fully sheeted with balsa, I'd cut an oversized slot along the bottom with a Dremel, install something to use as a channel and then cover the slot with new balsa. If you do this, you need to make sure the channel is smaller than the slot so you have structure to glue the replacement balsa to
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I did the same thing. I used a copper pipe 1/2 union. Or 1/2 copper pipe. Sharpened by cutting an INSIDE taper then used a cut-off wheel to cut notches in it. I think I did 8 notches. This worked, but warning, not well. Turning by hand left me with blisters after a cpl holes. Perhaps as NH4CLO4 said, if I'd staggered them it may have worked better.
I ended up sharpening it more in a metal lathe but you may not have that option. Also held a backer on the rib so I didn't apply so much pressure as to crack the rib.
I feel your pain. It sucked.
I ended up sharpening it more in a metal lathe but you may not have that option. Also held a backer on the rib so I didn't apply so much pressure as to crack the rib.
I feel your pain. It sucked.
Last edited by Therapy; 08-24-2017 at 10:54 AM.
#9
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All the ideas so far require straight-in access to the center of the wing. I used a large ball-end cutter in a Dremel tool going in perpendicular to the wing and cutting on the side of the cutter. Holes don't look so great but no one will see them after the wing is covered. Remember to put in a string to fish the wires through.
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Actually, I did mine after wing was joined. Hence the blisters on the copper tube joiner.
But hey, point made! Or insert a paper tube as I did. I fished it between ribs. It crushed but was able to reform it in the wing.
I should have tried your method RC.
But hey, point made! Or insert a paper tube as I did. I fished it between ribs. It crushed but was able to reform it in the wing.
I should have tried your method RC.
#11
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Hey it is not covered. Don't overcomplicate or over think this. Sharp knife to cut letterbox holes making the long cuts from LE to TE first in the balsa ribs. Light ply will need a drill about 5/32 and make 5 holes in a row. Use the sharp knife to join them up.
#13
Exactly. Putting holes in an uncovered wing is a simple process. When in the OP's position, I've used everything from a paper punch to a sanding drum equipped Dremel tool.
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I have even used a piece of tube cut to fit between the ribs and roughened up to cut. It takes a little while and can be hard on the fingers just make sure to hold a piece of light ply or whatever on the other side of the rib so you don't break it.
Calvi
Calvi
#16
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I've taken a larger brass tube (3/8" I think.... big enough for a servo plug anyway..) and cut a piece down to length that fit between the rib spacing... Take an X-acto and sharpen the ID (inside diameter) of the tube, and/or take a Dremel and cut some teeth into the end of the tube. Then place the tube between the ribs and start sawing. The principle is to fabricate your own hole-saw out of the brass tube..to a custom length to fit your application... whether it has teeth, or a sharp ID in the tube, or both.. (which a sharpened brass tube works VERY well to cut angled holes in balsa..extreme angles if you need, that's another story though...). If you need to grip the tube to get it cutting/sawing.. just put a small rubber band around it, and that will provide a grip.
I just did this exact thing a few years back to install dual-aileron servos into a plane I was restoring that originally had one single servo.. so I had to run wires through a wing that was already built. I cut teeth into the tube... and it worked really well for me. So.. that's my 2 cents. Good luck with it.
I just did this exact thing a few years back to install dual-aileron servos into a plane I was restoring that originally had one single servo.. so I had to run wires through a wing that was already built. I cut teeth into the tube... and it worked really well for me. So.. that's my 2 cents. Good luck with it.
#17
I had this problem on one build. I cut a piece of EMT electrical tubing, sharpened and cut teeth in the edge. Then I just rotated back n forth to cut the rib. It was just on balsa ribs so easy task. Plywood would be a bit harder. I drew a line on top of the ribs to keep the all holes straight. Then measured down to the top of the hole. Worked quite well. I still have that piece of tubing.
#18
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You can make it easier on yourself by not sharpening the inside of the tube first. Just cut angled teeth into the end of the tube and leave then a bit rough. That gives you a kerf wide enough for the thickness of your tubing.
#19
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Hi!
If the wing is covered with balsa the easiest metode is to make a slot on the underside of the wing with a router in a Dremel!
This is how it's done!
1. Draw a line on the balsa planking with a ruler. From the base rib to where the aileron servo is to be.
2. Hold the dremel in your hand and cut by free hand a deep slot in the wing, how deep doesn't matter but not through the upper planking...!
3. Put the servo leads in the slot in the wing and mount the servo!
4. Cover the slot with a long (or several short pieces of balsa.
If the wing is covered with balsa the easiest metode is to make a slot on the underside of the wing with a router in a Dremel!
This is how it's done!
1. Draw a line on the balsa planking with a ruler. From the base rib to where the aileron servo is to be.
2. Hold the dremel in your hand and cut by free hand a deep slot in the wing, how deep doesn't matter but not through the upper planking...!
3. Put the servo leads in the slot in the wing and mount the servo!
4. Cover the slot with a long (or several short pieces of balsa.
Last edited by jaka; 08-30-2017 at 06:54 AM.
#20
Hi!
If the wing is covered with balsa the easiest metode is to make a slot on the underside of the wing with a router in a Dremel!
This is how it's done!
1. Draw a line on the balsa planking with a ruler. From the base rib to where the aileron servo is to be.
2. Hold the dremel in your hand and cut by free hand a deep slot in the wing, how deep doesn't matter but not through the upper planking...!
3. Put the servo leads in the slot in the wing and mount the servo!
4. Cover the slot with a long (or several short pieces of balsa.
If the wing is covered with balsa the easiest metode is to make a slot on the underside of the wing with a router in a Dremel!
This is how it's done!
1. Draw a line on the balsa planking with a ruler. From the base rib to where the aileron servo is to be.
2. Hold the dremel in your hand and cut by free hand a deep slot in the wing, how deep doesn't matter but not through the upper planking...!
3. Put the servo leads in the slot in the wing and mount the servo!
4. Cover the slot with a long (or several short pieces of balsa.
#22
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Well,there is one last option you can try,, Instead of drilling holes and hoping your going in a strait line,which you will probably end up hitting other parts of your plane. Then you will wonder ,Was It Worth screwing up a perfectly good plane, Maybe you can incorporate the servo wires into the outside shell of your plane. Use your imagination and enclose them in something and maybe cover them in a different colour.,Who Says That you can't do this, If you do,it will be special to you and unique!
#23
RC Fanatic in post 9 suggests what I would do...use the ball sander in the Dremel. Quick and easy.
If I didn't have a Dremel I'd use the tubing technique, making the tubing short enough to fit in between ribs, and backing up the rib with a small block of wood on the other side so the rib is sandwiched between the tubing and the backup. A bit laborious; I never regretted buying a Dremel.
If I didn't have a Dremel I'd use the tubing technique, making the tubing short enough to fit in between ribs, and backing up the rib with a small block of wood on the other side so the rib is sandwiched between the tubing and the backup. A bit laborious; I never regretted buying a Dremel.
#24
RC Fanatic in post 9 suggests what I would do...use the ball sander in the Dremel. Quick and easy.
If I didn't have a Dremel I'd use the tubing technique, making the tubing short enough to fit in between ribs, and backing up the rib with a small block of wood on the other side so the rib is sandwiched between the tubing and the backup. A bit laborious; I never regretted buying a Dremel.
If I didn't have a Dremel I'd use the tubing technique, making the tubing short enough to fit in between ribs, and backing up the rib with a small block of wood on the other side so the rib is sandwiched between the tubing and the backup. A bit laborious; I never regretted buying a Dremel.
The rotary tool knock offs are reasonable in price, so every modeler who wants one, should be able to afford one. .