T-rex 250,my little bird arrived!Pictures

Marcio.souza

Im so happy today,my t-rex 250 arrived today.I just want to share the pictures and show the size of the bird.I will use stock ESC and motor,pinion 16t,Carbon blades 205mm align,gyro 401 futaba,Futaba 9257 on the tail,3 DS 410 align on the cyclic,Lipo Kongo power 850mAh 3s.HS about 4600rpm







Look how tiny it is,compared to T-rex 600 main gear,blades and tail boom.

fallaci

Did you sell your 600?

Marcio.souza

fallaci wrote: »

Did you sell your 600?

Not yet,im still selling the t-rex 600

syl77

Hey Marcio.souza, good photo comparing 250 Vs 600, best of luck flying it, let us know how it handles. Have you seen the new walkera 4G3 with CCPM and metal head, they are tiny, Im very close to buying one.
I just got my new Logo 500 flybarless kit yesterday. looking forward to getting it up an running.

workaccount

I'm thinking of getting something smaller to pracice on because I'm a little anxious about my 600 in that it's so expensive if you crash. Blades cost about 40 or 50 euro and I don't have a massive place to practice right now. I haven't done much damage yet (just on the 2nd set of blades and had to replace the tail boom but sooner or later it's gonna happen as I try more advanced things.

I would like something smaller and even something I could fly in the house when the weather is bad. I heard these 250's are not beginner friendly at all though. Would it be a bad idea to get one do you think?

I was thinking of spending about 250 for new batteries for the 600 but I could just get one of these for around the same price and get more time flying.

Right just spent some time looking into the 250 and see that it's not really beginner friendly. The headspeed is about 4k rpm which makes it very responsive. Wonder how it behaves if you turn down the headspeed.

Bruthal

Trex 250, i would,t mind one of them myself, i think the trex choppers are great,

Marcio.souza

workaccount wrote: »

I'm thinking of getting something smaller to pracice on because I'm a little anxious about my 600 in that it's so expensive if you crash. Blades cost about 40 or 50 euro and I don't have a massive place to practice right now. I haven't done much damage yet (just on the 2nd set of blades and had to replace the tail boom but sooner or later it's gonna happen as I try more advanced things.

I would like something smaller and even something I could fly in the house when the weather is bad. I heard these 250's are not beginner friendly at all though. Would it be a bad idea to get one do you think?

I was thinking of spending about 250 for new batteries for the 600 but I could just get one of these for around the same price and get more time flying.

Right just spent some time looking into the 250 and see that it's not really beginner friendly. The headspeed is about 4k rpm which makes it very responsive. Wonder how it behaves if you turn down the headspeed.

If you start now flying,i dont think the 250 is good for you,its pretty fast,hard to handle,but depends your settings.You can run the headspeed very high and put swashmix very low,will be very easy to handle.I learned to fly on my t-rex 600.Now i have the 600 and 250.Im trying to sell the T-rex 600 to buy a glow helicopter.The cost of the batteries for the t-rex 600 is too high.

Where do you fly your t-rex 600?

I go sometimes to Marley Park to fly,in the morning,when there isn't nobody over there.Can be dangerous when there are loads of people on the park.

workaccount

Marcio.souza wrote: »

If you start now flying,i dont think the 250 is good for you,its pretty fast,hard to handle,but depends your settings.You can run the headspeed very high and put swashmix very low,will be very easy to handle.I learned to fly on my t-rex 600.Now i have the 600 and 250.Im trying to sell the T-rex 600 to buy a glow helicopter.The cost of the batteries for the t-rex 600 is too high.

Where do you fly your t-rex 600?

I go sometimes to Marley Park to fly,in the morning,when there isn't nobody over there.Can be dangerous when there are loads of people on the park.

I think I will get a 450 instead and park the 600 up for a while. I could fly 450 size in the back garden but it's a little small for 600. I'm nowhere near Dublin myself. There is a place I can go to fly it but I only have 2 batteries at the moment so it's not worthwhile going anywhere for just 10mins of flight.

If anyone is thinking of selling their 450 let me know.

Thanks.

Bruthal

Well the 450 is brilliant i think. It was my second heli. If you have flown the 600 already then 450 or 250 should`t be any problem. But the 450 i find great anyway, very quick and agile, and cheap for batteries compared to the 600.

Where do you live or go flying

workaccount

robbie7730 wrote: »

Well the 450 is brilliant i think. It was my second heli. If you have flown the 600 already then 450 or 250 should`t be any problem. But the 450 i find great anyway, very quick and agile, and cheap for batteries compared to the 600.

Where do you live or go flying

I'm over west in Galway or Mayo.


Yeah I think it will be much easier to pay for mistakes aswell on the 450 than the 600.

Bruthal

yes the big cost in 600 is the main blades, did you fly the 600 much yet,

workaccount

robbie7730 wrote: »

yes the big cost in 600 is the main blades, did you fly the 600 much yet,

Not alot at all. I only have it since last August and only have two batteries - limits the amount of time you can go out on the limited decent days we have.

I really want to learn how to fly this year though. Buying a 450 will cost me either less or about the same as getting more batteries for the 600 and repair costs. I'll park the 600 up until I'm better experienced.

How long are you flying? I see that you have about 300 flights up on the 600 at the time of that video.

Bruthal

Im flying fixed wing since about 1988-89, heli`s i started in nov 07 so just over a year at them, the 600 has 348 flights on it now, i only have 2 batteries for it myself and could do with new ones now. There is other fella in other video with the nokia n95 onboard, he learned last year from scratch, we hooked the radios up, its a great way to learn. Pity your not nearer and we could of flew your 600

What radio are you using

workaccount

robbie7730 wrote: »

Im flying fixed wing since about 1988-89, heli`s i started in nov 07 so just over a year at them, the 600 has 348 flights on it now, i only have 2 batteries for it myself and could do with new ones now. There is other fella in other video with the nokia n95 onboard, he learned last year from scratch, we hooked the radios up, its a great way to learn. Pity your not nearer and we could of flew your 600

What radio are you using

That's alot of flights for 2 lipos. You must be looking after them well. Have you heard of these - supposed to be as good as more expensive thunder powers etc. http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6353&Product_Name=ZIPPY-H_5000mAh_6S1P_20-30C_Lipoly_Pack


No plans to move up to Dublin anytime soon I'm afraid.
I have a Spektrum DX7 for it.

Bruthal

Yes one of the battery packs has about 230 and the other about 120, the 230 one is performing better than the 120 cycled one, so its the luck of the draw as much as lookin after them. I think if i had 2 new ones id get more out of them, I started off at 7 and half minutes flight time and reduced to 6 and half as the batteries took on less charge over time, but new ones i`d keep to 6 and a half minutes from the start. I use the TP1010 charger which is great, with 210 balancer. DX7 is great, i got my one in dec 07, not once have i had a single glitch, before it i would have at least one in most flights,

I did see the zippy ones before but have never tried, I will get one for the 450 id say.

workaccount

robbie7730 wrote: »

Yes one of the battery packs has about 230 and the other about 120, the 230 one is performing better than the 120 cycled one, so its the luck of the draw as much as lookin after them. I think if i had 2 new ones id get more out of them, I started off at 7 and half minutes flight time and reduced to 6 and half as the batteries took on less charge over time, but new ones i`d keep to 6 and a half minutes from the start. I use the TP1010 charger which is great, with 210 balancer. DX7 is great, i got my one in dec 07, not once have i had a single glitch, before it i would have at least one in most flights,

I did see the zippy ones before but have never tried, I will get one for the 450 id say.

After thinking over the weekend I decided to put the 600 up for sale on adverts to fund this 450. I'll probably buy one again in the future but with the way things are economy wise I don't want to have expensive things around not being used.

Marcio.souza

I finished the heli,i just have problem,a huge tail wag,because i have slop on the tail,i tryed different things,that didn't work really good.Gain,different push rods,gyro,servo,now i will buy a Micro heli tail set for the 250,there isn't no slop at all.

Bruthal

Tail wag is usually caused by too high a gain on the gyro, because the gyro is then too sensitive, also if battery is low the tail wags because the esc pulses the main motor to tell you to land,

Marcio.souza

Its not eletronic problem,i set the gain to 5,huge wag,the problem is mechanical because there is a huge slop on the tail.I will post videos soon.

syl77

gain is measured as a %, are you saying its 5% (which would be very low) what Gyro are you using and where is it placed on the heli. Check to see if the belt is not to tight or loss.

Bruthal

If its gyro gain the wag is usually in perfect timing, as in wag from one side to other in even strokes, if its mechanical slop its usually erratic movements of the tail then, i fly with tail belts fairly loose and seems grand, if its an even uniform wag id say its gyro problem, what gyro and radio might give us a clue, or a video like you suggested.

As i said before, when i first flew trex 450 the battery low warning came on, and tail wagged because the electronic speed controller pulses the motor to warn of battery low. If i fly the trex 600 in cold weather with cold batteries the low warning wag comes on in tail even when batteries just charged until they warm up in flight,

Myself and other lad found the trex 500 tail wagged at high head speed at times for some reason we never really found, and it seemed it was a known issue with them sometimes,,,, maybe the high head speed at fresh charged batteries and higher tail rotor speed made gyro that bit more sensitive or the tail more responsive etc.

syl77

robbie7730 wrote: »

As i said before, when i first flew trex 450 the battery low warning came on, and tail wagged because the electronic speed controller pulses the motor to warn of battery low. If i fly the trex 600 in cold weather with cold batteries the low warning wag comes on in tail even when batteries just charged until they warm up in flight,
.

This refers to a setting on the ESC, a voltage cut off setting that can be set to high, medium or low. when the batteries reach a certain voltage it starts pulsing the voltage to the motor, you will hear the motor speed up and down, this cause the pulsing also in the tail. I usualy set it to low but time my flights so as not to discharge the batteries to much.

Myself and other lad found the trex 500 tail wagged at high head speed at times for some reason we never really found,

Is this at high speed FF. usualy means the gyro gain is a little to high.
Had a similar issue with my 600n and lowering the gain by 2% sorted it.

Marcio.souza

robbie7730 wrote: »

If its gyro gain the wag is usually in perfect timing, as in wag from one side to other in even strokes, if its mechanical slop its usually erratic movements of the tail then, i fly with tail belts fairly loose and seems grand, if its an even uniform wag id say its gyro problem, what gyro and radio might give us a clue, or a video like you suggested.

As i said before, when i first flew trex 450 the battery low warning came on, and tail wagged because the electronic speed controller pulses the motor to warn of battery low. If i fly the trex 600 in cold weather with cold batteries the low warning wag comes on in tail even when batteries just charged until they warm up in flight,

Myself and other lad found the trex 500 tail wagged at high head speed at times for some reason we never really found, and it seemed it was a known issue with them sometimes,,,, maybe the high head speed at fresh charged batteries and higher tail rotor speed made gyro that bit more sensitive or the tail more responsive etc.

I'm running Gyro futaba 401 with tail servo futaba 9257,its not eletronic problem or setting problem,it's a problem that came from the factory,Align have said before there is a problem on the tail of the t-rex 250,just go to helifreak.com and sub forum t-rex 250.You see loads of people complaining about the tail.Im trying my best to hold the tail when i pump the colective.

Bruthal

yes thats a strange one, usually if the tail swings when pump collective its because the gyro gain is too low, if you pump collective up and gyro is set too low a gain then the tail would swing to the right (nose to left). So tail wag is a problem with the 250 tail itself like your saying. Thats what i was saying about the 500 in last post, there seemed to be a problem with that too which was`t caused by gyro. Put a video up if you can

Marcio.souza

robbie7730 wrote: »

yes thats a strange one, usually if the tail swings when pump collective its because the gyro gain is too low, if you pump collective up and gyro is set too low a gain then the tail would swing to the right (nose to left). So tail wag is a problem with the 250 tail itself like your saying. Thats what i was saying about the 500 in last post, there seemed to be a problem with that too which was`t caused by gyro. Put a video up if you can

Two videos:

http://www.youtube.com/watch?v=XuTxmTKsbbM

https://www.youtube.com/watch?v=

http://www.youtube.com/watch?v=93gC-o12rBQ[/YOUTUBE]

http://www.youtube.com/watch?v=93gC-o12rBQ

Marcio.souza

robbie7730 wrote: »

yes thats a strange one, usually if the tail swings when pump collective its because the gyro gain is too low, if you pump collective up and gyro is set too low a gain then the tail would swing to the right (nose to left). So tail wag is a problem with the 250 tail itself like your saying. Thats what i was saying about the 500 in last post, there seemed to be a problem with that too which was`t caused by gyro. Put a video up if you can

Two videos:

http://www.youtube.com/watch?v=XuTxmTKsbbM

http://www.youtube.com/watch?v=93gC-o12rBQ


Tomorrow i will be working on the t-rex 250 and my t-rex 600.

Bruthal

First video doest look like tail wag, it looks like gyro gain is set way too low, i had some helis with very sloppy tail links and still nothing like as bad as that, what settings have you got on radio for the gyro gain,

I actually just use the Gear channel with the travel at -75 for head lock
and +65 for the heading rates mode. So its 75% one way and 65% with the gear switch the other way, and the gyro gain plugged into the gear channel


Where did you say you live,

Send your exact gyro settings you have in radio, but either way you should have at least 60 - 70% gyro gain to hold it steady.

Second video does look like tail wag though, did you adjust settings between videos at all?

Lookin at both videos the gain looks too low in first one and slightly too high in second,

www.youtube.com/user/robbie77300

Bruthal

syl77 wrote: »

This refers to a setting on the ESC, a voltage cut off setting that can be set to high, medium or low. when the batteries reach a certain voltage it starts pulsing the voltage to the motor, you will hear the motor speed up and down, this cause the pulsing also in the tail. I usualy set it to low but time my flights so as not to discharge the batteries to much.



Is this at high speed FF. usualy means the gyro gain is a little to high.
Had a similar issue with my 600n and lowering the gain by 2% sorted it.

No was at hover also, but was really only at the initial surge of head speed from fresh battery, the gyro is probably that bit more sensitive since its controlling a now faster tail rotor, so a couple of percent drop in gain would probably have sorted it, i thought we tried that, i forget now, but anyway its seemed to settle after a couple of flights

I set battery warning on ESC to high, the high setting on the trex 600 ESC is actually a bit too low, the batteries have already passed the recommended low at that high setting, I use timer as well, but if the heli is flown hard it might reach the low voltage setting before the timer runs down, my batteries are near their end id say now anyway, although still going

syl77

I have to say thats not really tail wag, it looks like gyro gain is set way too low, i had some helis with very sloppy tail links and still nothing like as bad as that, what settings have you got on radio for the gyro gain,

I tend to agree but only in relation to the first video (the gain maybe to low on testing), I think the second video is where he is having a serious tail wag with the correct gain rate. looks to be mechanical for such wag. May try different size tail blades.

I actually just use the Gear channel with the travel at -75 for head lock and +65 for the heaing rates mode. So its 75% one way and 65% with the gear switch the other way, and the gyro gain plugged into the gear channel

Same here, I use the gear switch also for gain rates, however the settings on the gear switch isn't your gain%, they are just settings that adjust your %gain at the gyro. This is more clearly seen when you use gyros like 601/611 or solid G where you can see the % gain go up/down at the Gyro via the gyro screen when you adjust your switch end points. This is your true % gain.
When talking about % gain, this is the setting you should be talking about. However, this true value can not be obtained from a 401, so becareful when talking about switch endpoints as radios differ...

A note on Gyros: you pirouette rate should be at confortable speed to fly with (say 360degress/sec). To achive this you need to try and have your rudder endpoints near to 100% and adjust you ball link position on the servo arm. It is not crucial to have your rudder end points as close to 100% (like with throttle govners) but the closer to 100% it is the less work the gyro will have to do, thus your rudder servo will live longer. Once that is correct, adjust your true % gain to its highest value where no taill wag is seen either in hover and then in flight. Finally I adjust the servo link at the tail end so no drift is seen when taken out of head hold.

Bruthal

syl77 wrote: »

I tend to agree but only in relation to the first video (the gain maybe to low on testing), I think the second video is where he is having a serious tail wag with the correct gain rate. looks to be mechanical for such wag. May try different size tail blades.


Same here, I use the gear switch also for gain rates, however the settings on the gear switch isn't your gain%, they are just settings that adjust your %gain at the gyro. This is more clearly seen when you use gyros like 601/611 or solid G where you can see the % gain go up/down at the Gyro via the gyro screen when you adjust your switch end points. This is your true % gain.
When talking about % gain, this is the setting you should be talking about. However, this true value can not be obtained from a 401, so becareful when talking about switch endpoints as radios differ...



A note on Gyros: you pirouette rate should be at confortable speed to fly with (say 360degress/sec). To achive this you need to try and have your rudder endpoints near to 100% and adjust you ball link position on the servo arm. It is not crucial to have your rudder end points as close to 100% (like with throttle govners) but the closer to 100% it is the less work the gyro will have to do, thus your rudder servo will live longer. Once that is correct, adjust your true % gain to its highest value where no taill wag is seen either in hover and then in flight. Finally I adjust the servo link at the tail end so no drift is seen when taken out of head hold.

I dont think that much about it, just fly it and see what happens, I could actually do with adjusting the endpoints slightly, its slightly slower one way than another so a slight increase in one direction than the other needed, but it flies grand so it will do for now

Bruthal

syl77 wrote: »

. Finally I adjust the servo link at the tail end so no drift is seen when taken out of head hold.

Id agree with that one, I seen a video of a fella askin why t rex tail was sticking, he was diving rapidly sideways toward ground and tail would`t turn into direction of dive, which is`t something id try anyway, but he was just trying to get out of dive but tail was stuck due to the weather vane thing, just for an instant, but he was convinced it was control sticking, in reality it was obvious the tail was`t set at a neutral point in rates mode and had much more authority one way than the other in head hold mode.

He did`t seem convinced when explained though, .