It's not a crash... it's an upgrade opportunity.
16/05/10 14:05 Filed in: Hobby
I’ve been working with my Hirobo Sceadu Evo .50 for the past several weeks, trying to get it to work “just right.” It was wasted effort, apparently.
You see, I’ve been having vibration trouble with the machine (always a bad thing), and the Gyro wasn’t behaving. I finally got it working properly just before the season started. I was very pleased – the tail was rock solid for a change.
Then, I bought the new transmitter out of necessity. Part of the process was manually copying the settings over from one machine to the other. Suddenly, my gyro wasn’t working well at all. The machine would continue to yaw for seconds after the last command input. This is distressing, as you can imagine.
I went back to the bench, and started working on getting all of the little vibrations out. I found I had to re-balance the tail hub & grips, but that wasn’t much of a problem. I was ready to give it a go - and I was feeling pretty good about the whole situation. Good enough that I dared to do the test hover in my backyard (which is huge).
I started the engine, spooled it up, and started hovering. I gave it a quick stab to the right, and it still behaved poorly. Then I gave it a stab to the left, and it just… kept… spinning… The machine was also moving distressingly close (about 4-5 feet) from the house. In a panic, I decided to plant the machine.
I chopped the machine’s throttle to send it down. The thing is that I have the collective pitch set so it’s at full negative when the engine is at idle. The end result: The machine shot downward rapidly, hitting the concrete below. Parts broke off and flew in about every direction but towards me. (The tail was pointed away from me - so the tail shot away from me, and ended up behind a tree about 50 feet away.) The machine bounced fairly high, and came back down.
I shut the engine off, and started to survey the damage. As far as the airframe goes, the only thing left that was still good was the (nice) SD-G aluminum rotor head. Everything else – frames, tail, canopy, boom and brace, skids, blades – was damaged and needed replacement. The radio gear and engine/exhaust were still undamaged (thank goodness!), but there was a lot of replacement to do.
I made a spreadsheet with the parts I needed and their costs. It turned out that the repair cost would be about the same as buying a slightly used Hirobo SDX from a friend in the UHA club, Jim Innes. That particular SDX had been featured in RC Heli Magazine (twice!). The SDX is Hirobo’s updated Sceadu - the timeline is something like Sceadu → Sceadu Evolution → SDX.
The SDX has an upgraded head, which allows for much more responsive flight. It also has an upgraded tail assembly & tail grips, and a new radio tray. I’m a bit torn between using my nice (but expensive) SD-G head, or use the newer/better design of the plastic SDX head. All things told, Hirobo does plastic very well — you don’t have to have the metal head unless you want the bling. It doesn’t really fly any better. Still, I don’t want to waste the investment in the SD-G head. I might try putting it in my Raptor .50, replacing the Raptor’s plastic head.
Either way, I’m excited to have an SDX, and am looking forward to being able to “stuff” the airframe with my radio gear & engine.
You see, I’ve been having vibration trouble with the machine (always a bad thing), and the Gyro wasn’t behaving. I finally got it working properly just before the season started. I was very pleased – the tail was rock solid for a change.
Then, I bought the new transmitter out of necessity. Part of the process was manually copying the settings over from one machine to the other. Suddenly, my gyro wasn’t working well at all. The machine would continue to yaw for seconds after the last command input. This is distressing, as you can imagine.
I went back to the bench, and started working on getting all of the little vibrations out. I found I had to re-balance the tail hub & grips, but that wasn’t much of a problem. I was ready to give it a go - and I was feeling pretty good about the whole situation. Good enough that I dared to do the test hover in my backyard (which is huge).
I started the engine, spooled it up, and started hovering. I gave it a quick stab to the right, and it still behaved poorly. Then I gave it a stab to the left, and it just… kept… spinning… The machine was also moving distressingly close (about 4-5 feet) from the house. In a panic, I decided to plant the machine.
I chopped the machine’s throttle to send it down. The thing is that I have the collective pitch set so it’s at full negative when the engine is at idle. The end result: The machine shot downward rapidly, hitting the concrete below. Parts broke off and flew in about every direction but towards me. (The tail was pointed away from me - so the tail shot away from me, and ended up behind a tree about 50 feet away.) The machine bounced fairly high, and came back down.
I shut the engine off, and started to survey the damage. As far as the airframe goes, the only thing left that was still good was the (nice) SD-G aluminum rotor head. Everything else – frames, tail, canopy, boom and brace, skids, blades – was damaged and needed replacement. The radio gear and engine/exhaust were still undamaged (thank goodness!), but there was a lot of replacement to do.
I made a spreadsheet with the parts I needed and their costs. It turned out that the repair cost would be about the same as buying a slightly used Hirobo SDX from a friend in the UHA club, Jim Innes. That particular SDX had been featured in RC Heli Magazine (twice!). The SDX is Hirobo’s updated Sceadu - the timeline is something like Sceadu → Sceadu Evolution → SDX.
The SDX has an upgraded head, which allows for much more responsive flight. It also has an upgraded tail assembly & tail grips, and a new radio tray. I’m a bit torn between using my nice (but expensive) SD-G head, or use the newer/better design of the plastic SDX head. All things told, Hirobo does plastic very well — you don’t have to have the metal head unless you want the bling. It doesn’t really fly any better. Still, I don’t want to waste the investment in the SD-G head. I might try putting it in my Raptor .50, replacing the Raptor’s plastic head.
Either way, I’m excited to have an SDX, and am looking forward to being able to “stuff” the airframe with my radio gear & engine.