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| Scale Helicopters Discuss scale helicopters, tips, tricks and scale construction threads |
Topic Review (Newest First)
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| 11-04-2012 10:36 PM | ||
| jackheli |
Re: My almost Hughes 500 TOW That's right! Old Century Falcon converted to electric. You can still get it from Century as they now sell it as "Scale Mechanics", which are nice as they come ready for both nitro and electric plus you can get it with any head you want (5 bladed head inclusive). I've used several different mechanics for scale, Align inclusive, and nothing beats this setup. |
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| 11-04-2012 08:08 PM | ||
| Phil Noel |
Re: My almost Hughes 500 TOW Quote:
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| 11-04-2012 01:47 PM | ||
| Phil Noel |
Re: My almost Hughes 500 TOW Quote:
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| 11-04-2012 12:57 PM | ||
| jackheli |
Re: My almost Hughes 500 TOW well, there you have it... Points of interest: 1-I am using a FBL command module: a very old sjgd 2-to check for the correct phasing, line up a blade with the boom and make sure it doesn't move when applying elevator input 3-the align 780 is a sub par gyro in my opinion. Pure garbage. 4-lowering the head speed may be a mistake as you also lower the tail rpm which loses its "bite". There is only so much you can go low... |
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| 11-04-2012 09:20 AM | ||
| Keyrigger |
Re: My almost Hughes 500 TOW Gary: I have a four blade head A109 that when setup so the mechanics flew perfectly, in the body it flew like a garbage truck, nearly crashing every time it went in the air. I have scale blades on it from SmartModel in HK. They are very flexible and have weights on the end. The head is an out of production unit from RC Aerodyne in WA, USA. The head is mechanically phased spot on and the original tail gyro was the Align GP780. The motor is a Scorpion 2580kv unit with a 13t pinion turning the stock 150t main gear. I tried different tail blades ranging from stock to cut-down mCPX blades. They didn't work. I was about to give up so I had an unused Align 3G system that I refused to use in the 550 I had just built. I installed it in the A109 and it finally flys properly. I ended up using KBDD 61mm tail blades which are longer than stock and wider, too. The gyro is set to default with the only adjustment being done to the tail component in the system. Many have said that any flybarless helicopter can be flown if you put enough time into it to learn how to control it. I also got fed up with the stupid antics the helicopter would give me so the FBL system was the answer to my problem with it. There are many cases of guys flying multi-blade helis with standard blades but they do add significant torque to the body. Lowering the head speed can help as less torque will be produced so the tail gyro may be able to keep up with it. The pundents said that in my heli, unweighted blades would be a mistake but that may gave been the problem all along. There are some smaller "under 315mm" blades available but they are few and far between. Look on RC Areodyne's site and you can find the blades I am using. If you have a flybarless system at your disposal, use it and the unweighted blades. If you want to try the non-3axis route, go with the weighted blades but keep the headspeed down a bit. As a last bit of advice from experience, make sure that you have: the head phased correctly, the blade grips set so the blades are moved on the leading edge (not the trailing edge like on a flybar head), lower your pitch curves so you only have about 8 degrees of pitch and 6 degrees of collective, and keep the headspeed down. The more pitch you apply after that, the more torque is created which will blow out the tail. A tail gear that speeds up the tail will also help if you can find or make such an animal. Take care. Don |
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| 11-04-2012 12:15 AM | ||
| jackheli |
Re: My almost Hughes 500 TOW Normally when you increase the number of main blades you reduce their size. For example, 530s on a 600 5-bladed heli. Try getting a set of 5 shorter main blades. I saw some 253s somewhere. |
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| 11-03-2012 09:49 PM | ||
| Cougar429 |
Re: My almost Hughes 500 TOW On my friends I had tried to match a set of regular blades. From some other advice scale blades may not have worked as well, but cannot say. Don't know if FBL blades would make any difference as the total drag would still be considerably more than a stock setup. I realize I could reduce the drag by dropping the head speed as the disc loading would now be shared by the greater number. Unfortunately due to standard gearing the tail RPM would also drop, the worst combination. One option was to fit a set of 500 size tail blades. That took considerable shaving of the grip thickness and I found it difficult to be consistent. Another idea was to mount another brushless to drive the tail with a governed 250 size ESC. Along the way, to remain closer to scale I also carved out a mirror image tail pitch bellcrank to move the blades to the left side. Still have to fab up another alloy side plate to be able to mount the pitch arm bracket. Interested to try this out on my stock 450 first to see if it alters the tail behavior. Again, this sits in storage until I have a reliable method for a controllable tail. Also, there is a wonder if the common HS-65 swash servo would handle the pitch loading or be fast enough to work with a stab system. |
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| 11-03-2012 09:20 PM | ||
| jackheli |
Re: My almost Hughes 500 TOW Quote:
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| 11-03-2012 09:05 PM | ||
| Cougar429 |
Re: My almost Hughes 500 TOW I have to ask your advice on this one as I have been searching for quite a while on my own 450 size MD500 to get the tail to compensate for the drag of the 5-blade head. I assembled one for a friend and measured 47A on quick spool up alone and with dropping the head speed I would lose tail effectiveness as well. To my knowledge his never flew. This project has sat for quite a while due to no adequate solution. |
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| 11-03-2012 08:44 PM | ||
| Keyrigger |
Re: My almost Hughes 500 TOW Nice. Are you using the scale mechanics from Century? Head speed looks very realistic. Take care. Don |
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