T-REX 500 pinion question

[ROGER G]

On a Rex 500 ( their cheapest, basic FB kit ), what would be better to use, the 13T pinion, or the 12T pinion ? I don't want real high head speed, just for sport flying, so want headspeed I think in the 2500 to 2600 range, but want to run maybe a flat 85 or 90 percent throttle curve with the governor in the align ESC. Which is the other question, does the governor work ok on the align esc ? Waiting on delivery of the kit, so doing a little pre-planning.

[wanderer56]

Don't bother with the Align Govenor, as they do not work very well. I ran the 13T @ 100% Flat TC before I converted mine to FBL and was getting 5:00 min flight times.

The closer you can run to 100%, the more effecient and cooler the motor will run. If you have to drop the TC down lower than 85%, I would drop a tooth on the pinion gear and then raise the TC back up a little.

[StatiC]

Originally Posted by wanderer56

Don't bother with the Align Govenor, as they do not work very well. I ran the 13T @ 100% Flat TC before I converted mine to FBL and was getting 5:00 min flight times.

The closer you can run to 100%, the more effecient and cooler the motor will run. If you have to drop the TC down lower than 85%, I would drop a tooth on the pinion gear and then raise the TC back up a little.

I see comments like this every once and awhile and I just wonder why their experience is so much different than mine. I fly flybar helis only.

I have had nothing but good things to report with the Align governors as long as you are somewhere around 75 to 85% straight line gov throttle in my experience. There is a sweet spot range where it governs very well. If you try to use 50% throttle or 95% the headspeed is not as consistent as other ESCs. I have had very consistent headspeeds with mid-throttle-response and mid-timing on the Align ESCs in gov mode. I have owned a few Kontronik Jazz on a 450, 2 Kontronik Jive on an Align 700e (12s), and a Castle Creations on my 600e (6s) and 700e (12s) over the years.

Most of my experience is from before 1.5 years ago (except the BL70G which I am using now) so I am not up on any new models from CC or Kontronik since then but from my experiences every time I have compared them side by side on the same setups the RPM graphs of the Align have come out on top when you are talking about headspeed consistency. CC felt the strongest in flight but less consistent headspeed. Kontronik Jive and Jazz felt more subdued (it felt it didn't adjust to motor RPM as quickly as the others) and was close to the Align in headspeed consistency. Yes I spent a lot of time trying all the settings too and viewing the RPM graphs. The Align seems to have a good balance between the two with power and at the top for headspeed consistency.

I realize that is not what everyone has been lead to believe and maybe for some setups the Align doesn't work well but for the stock motor in the kits the Align ESC works very well. Kontronik was the easiest to setup once you know how it works but the way it adjusts it's timing on every startup can cause some variation to the headspeed depending on how consistent your startup routine is. The Kontronik adjusts itself every time you start up so if you have different pitch when you startup or your throttle ramps up slower than the previous time your average headspeed can be different. The CC and Align ESCs are not affected by that anywhere near as much.

Now as far as reliability I have never had any of the ESCs fail on me personally unless I put them in the pond or I did something stupid like reverse the battery leads on the Kontronik . There have been lot of reports of Align ESC not working, CC ESCs not working, and there are some Kontronik failures too. You have to take into consideration how many of each is in the field though. For me personally they have all have been reliable.

With all that said though...

If you want the most performance out of your ESC for 3D then don't let any governor waste any of the power trying to maintain the RPM. There is a noticeable difference between a governed heli and one using 100% straight throttle curve without gov mode.

If you want to have slightly longer flights, slightly reduced motor temp (and slightly increased ESC temp), and/or just like a constant headspeed for all maneuvers and don't mind not getting 100% of the performance out of the motor then using the Align gov mode on their ESCs have proven itself to me over and over as a great option.

That is my experience anyway.

[Russell Harding]

Same here. I use the Align Gov on my 70A and it works.

I won't say works great, but it works well.

With the gov OFF and stock servos w/ AR7200BX (I'm not an expert tuner, but have put a lot of work into tuning it), I get some tail jiggle (less than an inch) on full pitch pumps. But, I fly pretty hard and the heli bogs badly on tic-tocs, etc without the gov. I tried various V curves, but still had bogging.

With the gov ON, the tail performance is not quite as good in a pitch pump. I get about 1.5 inches of kick. However, tic-tocs are rock solid (even on the tail) and there is very little bogging unless I over do it. I really couldn't fly like I want to without the governor enabled. I have it set at 85% and am at 2700rpm with a 13T pinion.

I've found the key is to set the throttle response speed to "normal" (lowest setting). If this is set at the higher settings, the throttle seems to oscillate rapidly and violently, causing the tail to jitter badly, exactly like in this video:

Trex 500 with tail jitter in governor mode (0 min 56 sec)

[bcflyer]

Originally Posted by ROGER G

On a Rex 500 ( their cheapest, basic FB kit ), what would be better to use, the 13T pinion, or the 12T pinion ? I don't want real high head speed, just for sport flying, so want headspeed I think in the 2500 to 2600 range, but want to run maybe a flat 85 or 90 percent throttle curve with the governor in the align ESC. Which is the other question, does the governor work ok on the align esc ? Waiting on delivery of the kit, so doing a little pre-planning.

Up front, I don't have a lot of experience. I have the 500E flybar heli. Built it during the winter. I originally had the 13 tooth pinion gear. I wanted lower headspeed as I lean toward scale and the high headspeeds are a little daunting to me at this point. I went with the 12 tooth after the 13 so I could lower headspeed and still let my motor spin where it likes. I run 85% throttle and am around 2200rpm according to my app on my phone. I bought some SPIN Semi Symetrical blades and it flys great with those. I currently have the Align blades on and it flies great as well with those, mind you I am just doing basic beginner sport type flying. I love just seeing the machine fly and all the mechanics of it so sport/scale is where I'm at at this point in time. Awesome helicopter imo. Hope this is of some use to you.

I have consistent 8 minute flights with a 2700 TP battery 25C. About 20-25% left in battery

[Dylan Hudock]

I would also watch how high you go with the head speed on that 500. It has the old grips with slop and the higher tail ratio, which could cause a tail bolt failure. The new 500 pro grips have almost no slop at all and really reduce the chance of the bolt failure.