Archive for the ‘ T-Rex 250 ’ Category

Bank Holiday Weekend

Just a quick update today. Been out flying as the weather and the wind has finally calmed down to allow such things. I have been out practising the aileron tic-tocs and I’m getting there. I had a good session on the simulator on Saturday and watched a few videos off the internet on how to do it. This helped but I need to work at it.  Still it’s like when I started learning the elevator tic-tocs and they were a bit random but now there much better.

After today’s flying I need to change the main gear on the 250 after a little crash, and the Mini-Titan has a horrible wobble in the head when in Idle-Up. Strange as I haven’t really flown it so I’m not sure where that has come from.

My squadron: T-Rex 550E, MSH Protos, Mini-Titan, T-Rex 250 3G

My squadron: T-Rex 550E, MSH Protos, Mini-Titan, T-Rex 250 3G

btw I  did go to the BMFA nationals at RAF Barkston Heath on Sunday but the weather was awful and there wasn’t much flying.  I saw some bits and pieces, F3C, pylon racing and some aerobatics but not any jets. It was a bit of a shame but at least I tried.



Went for a fly this evening, but really I should of headed home.  It was nice to get out with some friends and have a fly (and I didn’t crash), however I have had a very busy and chaotic week so far at work and I wasn’t quite as smooth as I could/should of been. It left me feeling a bit disappointed if I’m honest.

Still onward and upward, the weekend is coming and I might head off to the Nationals on Sunday if the weather is kind. Also the super hard TrueBlood head dampers have turned up for the 250. (See the T-Rex 250 Flybarless Conversion page for more info)

T-Rex 250 goes all 3G..

It’s happened.. T-Rex 250 Flybarless Conversion. Only a matter of time after the 550E findings.. Check it out by following this link or by selecting it from the page directory at the top right.

T-rex 250 SE Manual

Found this on the web and thought it might be useful to post here.  Align T-Rex 250SE manual

Useful pinions for T-Rex 250

Just found this and though it might useful for people with T-Rex 250’s, it’s a pack of 14t, 15t and 16t pinions with grub screw holes.  It’s for Scorpion motors but fits the stock one.

Hyperion Destiny for the T-Rex 250

After having some immense fun with the pocket sized T-Rex 250 I decided to upgrade/replace the motor with a Hyperion.  Technically the same as  a Scorpion motor (as they are now owned by Hyperion) I’m expecting the performance to be slightly better than the stock motor (3200 kv) as it’s a 3900 kv but I also think it will run cooler.   When I changed the motor in my Mini-Titan for a Scorpion it was significantly cooler.

Hyperion HS2206 as supplied

Hyperion HS2206 as supplied

Anyway this now brings me on to head speed and throttle curves.  I run a 16t pinion on the T-Rex which is not listed in the manual but gives me (in theory) a head speed of 5411 at 100% throttle curve ( or 4329 if you believe a popular used spreadsheet.  As you can the differences are huge so I tried using these two calculators to match the figures given in the 250 manual. There was still huge differences, so if anyone knows a decent head speed calculator then let me know.  In the mean time the only conclusion is to try the 250 with a 90% throttle curve and see..

Hottest Day of the Year – so far…

Well I have been quiet for the last few weeks on here. This is mainly due to the fact that I have been busy in my working life.

Nevertheless I did eventually get the spare parts for the Protos and managed to build it back up again. Along the way I noticed several problems and had to buy new parts.  This was generally caused by all the flying that the Protos has taken over the last year. Still it was all fixed and ready for today’s flying!

Today was, I think, the hottest day of the year so far so I have spent all afternoon in the field with the 3 helis. Fortunately there were no crashes but they all came home with problems:

  • Protos – the new 14t pinion looks like it will be okay.  Still has a high head speed but I think it will be good.  However didn’t get time to really fly her as the cir-clip holding the pinion came.  Also a bolt had come out of the head that forms part of the flybar cage so the Protos was back in the car fairly early. I just have to find a cir-clip that fits now..
  • Mini-Titan – The glued undercarriage snapped again on the first landing of the day.  This didn’t really stop me but as I have had to resort to wooden blades they don’t really cut it.  Too much flex means I couldn’t get into my tic-tocs and various tricks. A bit disappointing but predictable.  I have just ordered some new Align 325 carbon blades so this should be sorted for net weekend.
  • T-Rex 250 – Well the work horse of the day.  Flew hard all day and worked flawlessly.  This was of course until the last flight where, some how, the bolt that secures the main gear to the main shaft came loose.  This meant that upon landing I could pull the main gear straight out.  I was very lucky this didn’t cause a crash.  I thought something was up as the collective was getting very spongy towards the end of the flight. Anyway this is now been fixed and the bolt secured with thread lock.

The other interesting issue of the day was that due to the high heat the batteries were all coming back red-hot. Not much I could do about this but worth noting for the future. Will keep the cool in the shade before use next time.