How to fix a twisted profile fuse?
12-13-2006 | 10:59 PM
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From: Cedar Park, TX
How to fix a twisted profile fuse?
I had tried one of those 3D flat foamies some time back but didn't really like them. Too flimsy and too easy to break[&o], so I thought I would get a built up balsa and ply equivalent. Some time back I bought a UltraRC Edge 540 which I proceeded to assemble. Once I had glued the rudder etc, there was a note about the fuse could possible be twisted due to the "climate changes". Of course by the time you read this very last additional step, you've glued all kinds of control rod tabs along the fuse making it impossible to lay flat and try to correct the twist as the manual suggested. I wrote to UltraRC and they agreed to send a replacement since the original fuse literally looked like a twisted banana. 2 months later, yesterday, I got the replacement fuse and it's unfortunately not much better. Now, the manual doesn't give any directions on what the best way is to go about removing the twist and hence my post. In the picture you can see that there's about 1/4 in twist in the back when the front is weighted down. How do I use an iron or a heat gun to remove this? What's the procedure?
Any help on this is appreciated. If I were to mount the stab and the wing on the fuse as is, they would not be parallel at all.
Thanks,
tychoc
Any help on this is appreciated. If I were to mount the stab and the wing on the fuse as is, they would not be parallel at all.
Thanks,
tychoc
12-13-2006 | 11:49 PM
#2
RE: How to fix a twisted profile fuse?
I just went through this with a an E-Yak 54 from QuiQue Somenzini's website. These things are designed to be very lightweight. Unfortunately they can twist when they are covered and with changes in humidity. Try gently clamping one end of the fuse to your workbench (I just used a book to hold it down) with the rest of the fuse hanging off. Gently twist the fuselage to slightly past staraight and use your heat gun to re-shrink the covering. Keep holding it until the covering cools. It may take a few trys and it's frustrating but it can be done. Perhaps some others will have additional ideas.
12-13-2006 | 11:55 PM
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From: Mt. Holly,
NJ
RE: How to fix a twisted profile fuse?
ORIGINAL: tychoc
I had tried one of those 3D flat foamies some time back but didn't really like them. Too flimsy and too easy to break[&o], so I thought I would get a built up balsa and ply equivalent. Some time back I bought a UltraRC Edge 540 which I proceeded to assemble. Once I had glued the rudder etc, there was a note about the fuse could possible be twisted due to the "climate changes". Of course by the time you read this very last additional step, you've glued all kinds of control rod tabs along the fuse making it impossible to lay flat and try to correct the twist as the manual suggested. I wrote to UltraRC and they agreed to send a replacement since the original fuse literally looked like a twisted banana. 2 months later, yesterday, I got the replacement fuse and it's unfortunately not much better. Now, the manual doesn't give any directions on what the best way is to go about removing the twist and hence my post. In the picture you can see that there's about 1/4 in twist in the back when the front is weighted down. How do I use an iron or a heat gun to remove this? What's the procedure?
Any help on this is appreciated. If I were to mount the stab and the wing on the fuse as is, they would not be parallel at all.
Thanks,
tychoc
I had tried one of those 3D flat foamies some time back but didn't really like them. Too flimsy and too easy to break[&o], so I thought I would get a built up balsa and ply equivalent. Some time back I bought a UltraRC Edge 540 which I proceeded to assemble. Once I had glued the rudder etc, there was a note about the fuse could possible be twisted due to the "climate changes". Of course by the time you read this very last additional step, you've glued all kinds of control rod tabs along the fuse making it impossible to lay flat and try to correct the twist as the manual suggested. I wrote to UltraRC and they agreed to send a replacement since the original fuse literally looked like a twisted banana. 2 months later, yesterday, I got the replacement fuse and it's unfortunately not much better. Now, the manual doesn't give any directions on what the best way is to go about removing the twist and hence my post. In the picture you can see that there's about 1/4 in twist in the back when the front is weighted down. How do I use an iron or a heat gun to remove this? What's the procedure?
Any help on this is appreciated. If I were to mount the stab and the wing on the fuse as is, they would not be parallel at all.
Thanks,
tychoc
All you have to do is give me a call. I will gladly explain the process to you. I believe I have already explained once via email, but I will be more than happy to explain again by phone. It is a fairly simple procedure. Also, to clarify, the second sentence on the first page of the instructions state "Please read through the instructions thoroughly before attempting to assemble this model. " I am sorry about the time it took for the replacements, but as I stated, this plane has been sold out for many months. It took some time for the parts to be made and return to "in-stock" status. You can reach me tomorrow anytime between 10am and 5pm at 609-714-0040.
Sincerely,
Ultra-RC
Brian
12-14-2006 | 09:53 AM
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From: Cedar Park, TX
RE: How to fix a twisted profile fuse?
Brian,
I believe I spoke to a guy named Jim on the phone last time I tried to remove the twist. If I remember, he told me to lay it flat and go over it with an iron. I did do that. I took a ceiling tile and dug out holes for all the tabs already glued to the side so that it could lay flat an tried to re-shrink, but the last fuse not only had a twist but also a bend to it and I was not successful.
I guess I don't know what covering is used hence not what temperature to use to achieve maximum shrinkage.
I do appreciate you getting me a replacement fuse and understand that the delay was due to having it shipped from Asia. Part of my frustration was what I perceived as a lack of communication on why it took so long.
I will give you a call later today to have you walk me through the steps so that I can get it right this time.
Regards,
tychoc
I believe I spoke to a guy named Jim on the phone last time I tried to remove the twist. If I remember, he told me to lay it flat and go over it with an iron. I did do that. I took a ceiling tile and dug out holes for all the tabs already glued to the side so that it could lay flat an tried to re-shrink, but the last fuse not only had a twist but also a bend to it and I was not successful.
I guess I don't know what covering is used hence not what temperature to use to achieve maximum shrinkage.
I do appreciate you getting me a replacement fuse and understand that the delay was due to having it shipped from Asia. Part of my frustration was what I perceived as a lack of communication on why it took so long.
I will give you a call later today to have you walk me through the steps so that I can get it right this time.
Regards,
tychoc
12-15-2006 | 09:59 AM
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From: Cedar Park, TX
RE: How to fix a twisted profile fuse?
After talking to Brian at Ultra-RC he gave me the following steps which basically are the same as what ChuckW suggested.
1. Clamp down one end of the fuse at the table with the remainder hanging over the edge. I used my wife's dictionary.
2. Brian feels it's better to use an iron set at around 225-250ºF as opposed to the heat gun. The covering is a a very light Oracover (Ultrakote).
3. Twist the fuse in the opposite direction of the original warp. In my case I had a 1/4 in warp, so I twisted past neutral to about a 1/4in twist in the opposite direction.
4. Then using the iron at around 230º, I went over and reshrunk the covering where that was needed and loosen it in other places on both sides of the fuse. Then using a clean rag soaked in water, I quickly cooled the covering while holding the twist. This can be a little tricky.
5. Now, I would recheck the twist by placing the fuse on a flat surface.
Using this method, I was able to get almost all the warp out after a few rounds of the above steps. I now have about a 1mm "warp" which is as colse as I'm going to get.
So, now I'm hoping to try out this parkflyer this weekend. I'm almost done.
thanks,
tychoc
1. Clamp down one end of the fuse at the table with the remainder hanging over the edge. I used my wife's dictionary.
2. Brian feels it's better to use an iron set at around 225-250ºF as opposed to the heat gun. The covering is a a very light Oracover (Ultrakote).
3. Twist the fuse in the opposite direction of the original warp. In my case I had a 1/4 in warp, so I twisted past neutral to about a 1/4in twist in the opposite direction.
4. Then using the iron at around 230º, I went over and reshrunk the covering where that was needed and loosen it in other places on both sides of the fuse. Then using a clean rag soaked in water, I quickly cooled the covering while holding the twist. This can be a little tricky.
5. Now, I would recheck the twist by placing the fuse on a flat surface.
Using this method, I was able to get almost all the warp out after a few rounds of the above steps. I now have about a 1mm "warp" which is as colse as I'm going to get.
So, now I'm hoping to try out this parkflyer this weekend. I'm almost done.
thanks,
tychoc
