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Post by john66 on Mar 22, 2012 13:40:26 GMT 1
So gentlemen, contraceptive/climax based jokes aside.....Does the flexibillity of the rubber not compromise the flight characteristics in any way, alot, slightly, negligible or not at all?
John
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Post by larkshead on Mar 22, 2012 14:01:31 GMT 1
The motor mount seems solid. No noticeable difference from a standard installation. No detectible movement on the bench under power. Air trials this weekend, weather permitting.
-Peter
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Post by flydiver on Mar 22, 2012 16:47:12 GMT 1
I think folks seriously underestimate the forces involved with crashing or even a prop strike. So you could have a pretty firm rubber pad that would be stable under normal forces but maybe give a bit with some impact.
Doubt it will do any good at all in a hard crash, very little does.
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Post by geoff2474 on Mar 22, 2012 19:05:02 GMT 1
So gentlemen, contraceptive/climax based jokes aside.....Does the flexibility of the rubber not compromise the flight characteristics in any way, alot, slightly, negligible or not at all? John Sorry John, but when you say "Does the flexibility of the rubber not compromise.............." I assume you have not used that particular brand before!!!!!!!!!!! |
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Post by geoff2474 on Mar 22, 2012 19:15:22 GMT 1
I think folks seriously underestimate the forces involved with crashing or even a prop strike. So you could have a pretty firm rubber pad that would be stable under normal forces but maybe give a bit with some impact. Doubt it will do any good at all in a hard crash, very little does. I must say I am with you on this one Fly. If you crash head-on into anything solid, then a rubber engine mount is not going to protect anything. You already have a built in shock absorber with the SC it is called 'foam'. Any of you that have had a serious coming together with mother earth will have noticed how the foam has compressed at the point of most impact, yet remains relatively unharmed away from the stress area. This is one of the reasons it is an ideal material for the job, as it is able to absorb these impacts with a cushioning effect. By the way, if you have not tried it, very hot water over the impacted foam will nearly always restore it to its original shape. Geoff |
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Post by flydiver on Mar 22, 2012 19:43:07 GMT 1
This could easily drift off into discussions we've had before. I argue for keeping it light to fly right.
Newbies tend toward serious reinforcement, duct tape, and more power to save them from their dumb thumb foibles.
Not much can be done to save a plane with an engine on the front when it augers in with any force.
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Post by larkshead on Mar 22, 2012 20:21:17 GMT 1
I don't think the OP is talking about augering in or direct impact. I think he is just talking about those tip-overs and less-than-gentle landings that tend to crack the firewall without doing much other damage.
Also, from my comparison before and after the upgrade from the stock motor w/o the rubber cushion to the brushless with the rubber cushion, the stock CoG was maintained.
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Post by renard80 on Mar 23, 2012 0:20:37 GMT 1
I don't think the OP is talking about augering in or direct impact. I think he is just talking about those tip-overs and less-than-gentle landings that tend to crack the firewall without doing much other damage. Also, from my comparison before and after the upgrade from the stock motor w/o the rubber cushion to the brushless with the rubber cushion, the stock CoG was maintained. As the OP, many thanks to larkshead for his post, which summarises my position exactly. Yes, not much will survive a full blown head-on at max throttle. (I have had more than my fair share of those!) But I am fed up with the pathetic firewall cracking under fairly minor impact with Mother Earth. Once cracked, it is virtually impossible to repair satisfactorily. That is why I am trying to dampen such impacts with the rubber cushion. Since installing it, I have had one head-on with a brick building at moderate speed. The firewall survived. ;D Did the rubber absorb the stress, thereby saving the firewall? Dunno, but my gut feeling says Yes. JOHN: my piece of inner-tube rubber is quite light and does not appear to have affected flight characteristics at all. LARKSHEAD: I do like your rubber washer idea, which is far prettier than mine.  EVERYONE: So, does using some rubber mean Safer Flying? ;D |
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Post by flydiver on Mar 23, 2012 2:21:59 GMT 1
Since installing it, I have had one head-on with a brick building at moderate speed. The firewall survived. ;D OOOooooo.....ouch! But did anything else survive? ;D I'm in favor of experimentation like this. Minimal weight, some possible benefit. But these 'field experiments' are so completely uncontrollable that the results are questionable. Plus it takes a lot of 'rats' to figure out the effectiveness out on a larger scale. One-off crashes don't tend to tell you much, too many other things can be involved. That's just chaos. 100 crashes of a generally similar nature can be pretty useful and statistically significant. THEN we learn something. So....I suggest a bulls-eye on that brick building and an unqualifieded donation of time, foam, parts and money to raise the educational level for this ignorant lot.  We humbly await your input, indeed, we do. fly |
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Post by renard80 on Mar 24, 2012 0:00:41 GMT 1
So....I suggest a bulls-eye on that brick building and an unqualifieded donation of time, foam, parts and money to raise the educational level for this ignorant lot. We humbly await your input, indeed, we do. fly Sorry, fly. I regret that neither my desire to further the cause of science nor my innate curiosity are strong enough to launch such an experiment. I only appear stoopid . . . Oh, and the only apparent damage from that head-on was a chunk out of the prop . Fortunately, I had throttled right back for landing so she wasn't going full belt when that stupid building jumped into her path. |
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Post by flydiver on Mar 24, 2012 16:30:36 GMT 1
Ah, well, seemed like a good idea at the time. Hard to rally committed volunteerism and community spirit in 'kids' these days.... ;D
So, what about that slope idea?
And what did you do about the battery/charger/storage issue? Feel free to take that question back to the original thread.
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Post by larkshead on Mar 28, 2012 14:14:07 GMT 1
Flew my version yesterday in a pretty rough field. Several tip-overs and one cartwheel landing. Minor damage to other parts, but none to the firewall. Can't say the rubber washer helped, but it didn't hurt. Flight characteristics seemed OK, but I'm too new to really tell.
regards,
-Peter
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Post by larkshead on Apr 20, 2012 11:59:41 GMT 1
I decided to take your challenge, flydiver. After a near-auger encounter with the turf, my fuselage snapped completely in half at the front corners of the electronics compartment. But...no damage to the firewall!
regards,
-Peter
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Post by flydiver on Apr 20, 2012 16:54:27 GMT 1
Aw, that's sweet! You shouldn't have done that just for me! I'm flattered.
Only 99 more to go! Make it so.......
Renard80 - feel free to join in any time.
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Post by larkshead on Apr 20, 2012 18:08:27 GMT 1
btw - White Gorilla Glue is truly amazing. I believe the fuselage will fly again. All of the electronics survived.
-Peter
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