PDA

View Full Version : TREX250 Tail analysis, spacer upgrade and Chinese weights


Pages : 1 2 3 4 5 6 7 8 [9] 10 11

HEIM JOINT
07-06-2010, 06:35 AM
I am making Chinese weights the weighted SE grip. They will be adjusted so the tuning is the same as the old grips with my oirginal weights. Should be ready in about a week.

HJ

Justin Stuart
07-06-2010, 06:41 AM
HJ, Will your Chinese weight modification to the SE grips offer a significant improvement in performance over the stock SE grips?

HEIM JOINT
07-06-2010, 08:22 AM
HJ, Will your Chinese weight modification to the SE grips offer a significant improvement in performance over the stock SE grips?

The weights I am making for the SE weighted grips will have the exact same tuning as my stock 250 weights on the stock grips.
I do not make performance claims. I show people my testing and they decide. I think most people believe the stock grips with my weights perform better than the weighted grips. This is my testing of my stock weights on stock grips versus the original align weighted grips. The SE weighted grips have a larger weight than the grips in the test
http://www.youtube.com/watch?v=wVhit93JrWE
but in my opinion they still need my chinese weights for optimum tuning.

HJ

aussiemick
07-06-2010, 08:58 AM
I think most people believe the stock grips with my weights perform better than the weighted grips.
HJ


I am one of those people that know the 250 stock V1 twin bearing grips are much better with HJ's Chinese bolts than without them.

Got them on all my helis :thumbup:

Mick

Justin Stuart
07-06-2010, 10:02 AM
I think I'll definitely need to pick up some of these weighted mods for my 250SE grips.

s0laris
07-06-2010, 11:57 AM
I threw on an ino lab 30$ tail servo on my se. After 300+ flights tail is solid. I fly it hard. Doing very very fast backwards routines

precV
07-07-2010, 07:54 PM
I am making Chinese weights the weighted SE grip. They will be adjusted so the tuning is the same as the old grips with my oirginal weights. Should be ready in about a week.

HJ

That's great to hear!

Now I wish I had waited for an answer before ordering a set of the original grips. I have a set coming this week...doh!

-John

HEIM JOINT
07-09-2010, 11:59 AM
I threw on an ino lab 30$ tail servo on my se. After 300+ flights tail is solid. I fly it hard. Doing very very fast backwards routines

That servo will run cooler with the weights even if you dont notice any performance improvement.

HJ

s0laris
07-09-2010, 01:28 PM
Heim I believe you.. just saying after 300+ flights I am still fine. The SE tail grips are def better.

My servo shows no sign of wear. and I fly the snot out of the 250 lol

HEIM JOINT
07-12-2010, 08:13 AM
Chinese weights for the weighted grips are in stock. These new weights used with the H250095A weighted grips will give the exact same tuning as the stock grips with my original 250 weights. They will also work with the H25095 weighted grips with just slightly higher pushrod force.

Pm me for info. HEIM JOINT

BTB
07-25-2010, 07:40 PM
Hey Kevin I see you have a weight mod for the 250se, can you give me some info on the price of the grips. One other thing I have a lot of in and out and side to side play with my current tail is there any way to reduce that problem.

HEIM JOINT
07-25-2010, 09:50 PM
Hey Kevin I see you have a weight mod for the 250se, can you give me some info on the price of the grips. One other thing I have a lot of in and out and side to side play with my current tail is there any way to reduce that problem.

If you actualy were addressing this to Kevin, my apologies. But I think you were after the stuff I make. I have Chinese weights for both the stock 250 tail blade grips and also for the weighted Se grips. I will PM you with purchase info. You want the preload spacer set I make for the 250 to get rid of the bearing slop in the tail blade grips. here are videos on the chinese weights and the preload spacer set
(part 1) http://www.youtube.com/watch?v=gP2OYVEjU0Y
and (part 2) http://www.youtube.com/watch?v=8IOXbuMOJfU
and here are just the video instructionsffor the preload spacer set. http://www.youtube.com/watch?v=YFhjuo6tP1s

HEIM JOINT

Cfarrell2
08-03-2010, 10:43 AM
HEIM JOINT can you PM I am would like to order a set for weighted Se grips
Thanks

Cfarrell2
08-03-2010, 12:41 PM
Thanks

jimgior
08-16-2010, 11:07 PM
Please PM me - thanks Jim

Luvlite
08-26-2010, 12:21 AM
HJ, apologies if you explain this elsewhere but I had a question about your test bed. Have you calculated what the increased force on the tail servo would be when fighting the torque of the main blades? On the bench it is symmetric because the setup is static. On a flying heli it should be reduced with torque and higher against. The interesting implication here is that the unmodified tail is going even closer to the servo's red zone while flying and fighting torque.

HEIM JOINT
08-26-2010, 06:46 AM
HJ, apologies if you explain this elsewhere but I had a question about your test bed. Have you calculated what the increased force on the tail servo would be when fighting the torque of the main blades? On the bench it is symmetric because the setup is static. On a flying heli it should be reduced with torque and higher against. The interesting implication here is that the unmodified tail is going even closer to the servo's red zone while flying and fighting torque.

Torque from the main rotors has no virtualy no effect on the tailrotor pushrod force. The only effect it would have is the very minor change in the tail blade grip bearings drag torque from higher or lower moment loading from the tail blades lift forces.
The tail rotor blades feather around the aerodynamic center. Aerodynamic center is the location on an airfoil located of the chord back from the leading edge. If the airfoil is symmetrical and pivoted on the aerodynamic center it takes no torque to move or hold the airfoil at any angle of attack. Go to http://www.grc.nasa.gov/WWW/K12/airplane/ac.html (http://www.grc.nasa.gov/WWW/K-12/airplane/ac.html) for more detail on aerodynamic center.
With all that said, main rotor torque and aerodynamic forces on the tail blades have nothing to do with pushrod force.
Pushrod force has 2 causes, tennis raquet effect (major contributor) and all the frictional drags in the entire tail system (every link, pivot, bearing, slider, etc.) which are minor.

Hope that helps, HJ

Luvlite
08-26-2010, 02:46 PM
I guess I can see that. Net-net: forces experienced by the tail servo are basically due to the dynamics of the rotating blade system and not the force that system is supposed to overcome.

fxd0h
08-31-2010, 02:34 AM
HJ , I would like to order a tail upgrade combo for my trex250se 2010 , weights , spacers , etc.

Frequentyflyer77
09-06-2010, 06:43 PM
Also interested in the Chinese weights.

kdhunter
09-08-2010, 08:47 AM
HEIM JOINT

Tried to PM you, but as a newly registed user the system would not allow me. Please contact me as to the order info on the preload spacers and weights. I have the SE grips.

Thanks Keith

sazunike
09-21-2010, 07:48 AM
Hello, are you still shipping the upgrade?.. Could you tell me how much is it with SH?
Thanks!

sazunike
09-21-2010, 07:49 AM
Also, if you're not including the replacement bearings, could you tell me where to get a set of good ones?..
I'm sending you a PM now.

Thanks.

HEIM JOINT
09-21-2010, 07:58 AM
Also, if you're not including the replacement bearings, could you tell me where to get a set of good ones?..
I'm sending you a PM now.

Thanks.

these guys carry the Gaui 203250 bearings http://www.allerc.com/index.php

ahahn
09-22-2010, 08:40 PM
Just need to get to three posts to make the PM quota!

I know you posted your e-mail address here in this thread, but for some reason I'm not finding it right now.