Large Scale Wing Bolts
05-05-2005, 01:08 PM
#1
Large Scale Wing Bolts
I have had poor luck with wing bolts on large scale airplanes. I am flying Ziroli Bearcats and a 96" P-51. I am using steel bolts. I have had problems such as the wood stripping. I tried blind nuts, they would com loose and spin. I tried brass inserts and they would come out. Ocasionally the bolt would fall out on it's own from vibration. I couldn't dare use any locktight to keep it in.
The solution for me was to bend some metal I had and weld a blind nut onto it:
The plate is then attatched to the block with a srcew:
I know not everyone has access to a welder but this is what ultimately worked for me. By fixing the nut I can now use some mild locktight to keep the bolts from vibrating out or loosening up.
The solution for me was to bend some metal I had and weld a blind nut onto it:
The plate is then attatched to the block with a srcew:
I know not everyone has access to a welder but this is what ultimately worked for me. By fixing the nut I can now use some mild locktight to keep the bolts from vibrating out or loosening up.
05-05-2005, 07:13 PM
#3
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RE: Large Scale Wing Bolts
Yea ,I don't fly large scale planes and still have had problems with blind nuts and screws. [:@] The hidden problem is the spikes are not made long enough and I beleive most people use blind nuts on softish surfaces IE sheet rock. I think you could have gotten away with soldering the metal.
05-05-2005, 08:23 PM
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RE: Large Scale Wing Bolts
It looks like we have come full circle on fasteners. Fifty years ago we soldered nuts to strips of brass or tin can stock to make nut plates for mounting motors to hardwood motor mounts. They were screwed in place prior to slosing up the back side motor mount area with balsa blocks which were then shaped to finish the nose profile.
As an aside the Bearcat pictured uses 5/16 socket head capscrews that mate up in brass inserts installed in 1x1 1/2 maple wing mounts molded into the fiberglass fuselage. This is 55# pulled by a DA-150
As an aside the Bearcat pictured uses 5/16 socket head capscrews that mate up in brass inserts installed in 1x1 1/2 maple wing mounts molded into the fiberglass fuselage. This is 55# pulled by a DA-150
ORIGINAL: gow589
I have had poor luck with wing bolts on large scale airplanes. I am flying Ziroli Bearcats and a 96" P-51. I am using steel bolts. I have had problems such as the wood stripping. I tried blind nuts, they would com loose and spin. I tried brass inserts and they would come out. Ocasionally the bolt would fall out on it's own from vibration. I couldn't dare use any locktight to keep it in.
The solution for me was to bend some metal I had and weld a blind nut onto it:
The plate is then attatched to the block with a srcew:
I know not everyone has access to a welder but this is what ultimately worked for me. By fixing the nut I can now use some mild locktight to keep the bolts from vibrating out or loosening up.
I have had poor luck with wing bolts on large scale airplanes. I am flying Ziroli Bearcats and a 96" P-51. I am using steel bolts. I have had problems such as the wood stripping. I tried blind nuts, they would com loose and spin. I tried brass inserts and they would come out. Ocasionally the bolt would fall out on it's own from vibration. I couldn't dare use any locktight to keep it in.
The solution for me was to bend some metal I had and weld a blind nut onto it:
The plate is then attatched to the block with a srcew:
I know not everyone has access to a welder but this is what ultimately worked for me. By fixing the nut I can now use some mild locktight to keep the bolts from vibrating out or loosening up.
05-11-2005, 11:51 AM
#5
RE: Large Scale Wing Bolts
Gremlin, I have used brass incerts but they cam out onb me with the screw:
http://www.rc-tech.net/gear/f2b.jpg
http://www.rc-tech.net/gear/firsta.jpg
Would you trust solder on something using 1/4 or 5/16 bolt? I have the benifit of a welder so it's no big deal for me but if the solder came off getting the bolt out would be a real problem.
Gary
http://www.rc-tech.net/gear/f2b.jpg
http://www.rc-tech.net/gear/firsta.jpg
Would you trust solder on something using 1/4 or 5/16 bolt? I have the benifit of a welder so it's no big deal for me but if the solder came off getting the bolt out would be a real problem.
Gary
05-11-2005, 02:16 PM
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RE: Large Scale Wing Bolts
I would trust soldering if it is done properly. The average modeler doesn't always have the proper size equipment for heavy duty soldering.
As for 1/4 & 5/16 nuts soldered to a plate as a substitute for tee nuts, yes, I would trust them if properly soldered. After all they are only clamping wood and or fiberglass together. They are not being torqued anywhere close to their limits so the shear load on the solder joint is well within limits.
As for the brass inserts, I have also found them problematic at times. The self tapping types seem to work best if you drill a 1/16th hole or larger thru the brass thread and wood interface and then drive a metal brad in the hole along with some CA.
On my big birds I have found that soldering a flat washer to the socket head capscrew adds enough increase in friction to stop the bolts from backing loose during flight.
It seems every airframe requires something just a little different to make a secure wing connection.
You have a great looking Bearcat. I have thought about doing one up in Corky Fornoff's colors. His bronze and red scheme was a real show stopper.
As for 1/4 & 5/16 nuts soldered to a plate as a substitute for tee nuts, yes, I would trust them if properly soldered. After all they are only clamping wood and or fiberglass together. They are not being torqued anywhere close to their limits so the shear load on the solder joint is well within limits.
As for the brass inserts, I have also found them problematic at times. The self tapping types seem to work best if you drill a 1/16th hole or larger thru the brass thread and wood interface and then drive a metal brad in the hole along with some CA.
On my big birds I have found that soldering a flat washer to the socket head capscrew adds enough increase in friction to stop the bolts from backing loose during flight.
It seems every airframe requires something just a little different to make a secure wing connection.
You have a great looking Bearcat. I have thought about doing one up in Corky Fornoff's colors. His bronze and red scheme was a real show stopper.
