Jozef
Well-Known Member
- Joined
- Aug 25, 2014
- Messages
- 350
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Mike, what's your refund policy?
Would be interesting to know your preference for conformal rail guides over rail buttons. Have you used them before?
Mike, what's your refund policy?
Would be interesting to know your preference for conformal rail guides over rail buttons. Have you used them before?
I've used them on 2 other rockets and won't go back to lugs. You really need to score the surface before bonding, but it's lower drag and easy to mount. The previous pic was a spoof (I just put them down and took the pic) so I'll take a pic of the scoring before mounting.
OK, you said reduced drag compared to lugs, but my question was relative to rail buttons. Delrin rail buttons have less surface contact are than either lugs or conformal rail guides.
To my eyes there's less frontal area with rail guides than with buttons, and I have an assumption that the air would have a cleaner entrance/exit with two skinny appendages vs one much larger one. Absolutely nothing scientific about it, other than the marketing hype matching what I think makes sense.
One benefit I’d see is that rail drag is during a short time of very high thrust.
Maybe. No way to measure it. I cannot imagine that either system makes more than an insignificant difference in flight performance or altitude. The only identifiable difference boils down to drilling and tapping holes vs sanding prep and epoxy....and appearance. Not sure why they need to be so long... unless it is for bonding concerns. They appear large enough to be cut in half.
If the conformal rail guide was say maybe .25% (arbitrary number) of the length that it is would it still not do it's job and would it also cause less drag? Why does it have to be the length that it is, is there a technical reason? Being made from aluminum it would be easy to cut them down to another size and re-angle the cut edge.
id wager there’s an aerodynamic drag difference between buttons and guides. There’s ways to measure it, but which are practical and available to us?
Agree, David ...and you would win that wager. There has to be a difference. Might be interesting to chat one evening during URRF5 over a beer
Or... buy a kit and build it with it with buttons. I'll be at URRF. We could put the same motor in both and drag race. Pitfield too to increase the sample size.
If I get my 4" built in time then I am in. I will do a fly-away rail guide, you do the conformal and Dave can do buttons. I say we use the K-960-LW as the motor
Deal... now mine is getting close... so get yours done...
Internal fillets and some internal support. Compared to full scratch, I'm loving this kit.
id wager theres an aerodynamic drag difference between buttons and guides. Theres ways to measure it, but which are practical and available to us?
Build a couple of identical GD29's: on one put three sets of A, on the other put three sets of B.Agree, David ...and you would win that wager. There has to be a difference. Might be interesting to chat one evening during URRF5 over a beer
id wager theres an aerodynamic drag difference between buttons and guides. Theres ways to measure it, but which are practical and available to us?
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