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jombo
04-13-2010, 07:17 PM
i have been looking for something smaller than the 450 and didnt want to spend a whole bunch if i didnt like it so i gave the hk250 for 30.00 a shot. this thing is almost all metal except the head and the part of the seasaw. the tail is plastic but the tube has a hole in it and the tail locks into it. from what i have seen it has all bb everywhere in the head and tail.
but now for the twist , i have some fixed pitch blades so i dont need the ccpm radio just a basic computer radio and save the 7c reciever for the 500 and 450. has anyone else tryed this , i hate the 4 channel fp with the motored tails and they always died at the worst time. this way i can run a lower head speed and bring it to the park with me. i am hoping to get this thing built by next week to try it out, not heavy in 3d so that is not a problem, i just want something to have fun at the park with the kids and maybe have others here (if they show up at the field with there planes) a try.

jombo
04-29-2010, 03:21 PM
been slacking on this as i havent had alot of time, here it is about to put the arms on and to level the swash , and some pics with the fixed pitch blades

miamiheli
04-29-2010, 03:26 PM
That's kind of an interesting idea.

jombo
04-29-2010, 05:05 PM
Thank you but it's not a original idea. Someone on rc groups made one already and flys great , I wish I googled searched it first as I could of saved some time looking things up . I needed to use a low kv motor for the blades so I needed to know what watts a brushed 380 motor does and the rpm, I ended up using the same 2400 kv motor on 7.4 v lipo lol .

jombo
05-10-2010, 01:50 PM
i got it almost done , i tryed the falcon 40 blades but since they use a plastic spacer for the mounting hole i used some plastic spacers i had and fit perfectly. set the swash, servos , esc , head , and had to test it out :YeaBaby: . i only had 1/5th throttle just enough to spin it up ,wow this will take off for sure at 1/3 throttle sweet

jombo
05-13-2010, 02:00 PM
got a small problem with the setup , it will take off on 2 cells but it spins like there is no tail :DOH . i lowerd the pitch on the blades to 0 but it still spins , alot less though. this is with no gyro installed i am using it old school :thumbup: and i dont have a gyro avalable yet :o . anyway just asking questions because right now not sure what to try........ lower the pitch more , up the motor to a 4400kv instead of the 2400kv should i clip the falcon 40 blades alittle as it may be too much for the tail to handle ? not giving up yet as i still have a spare kit on hand just in case this gets trashed in the testing stages.
anyone got any suggestions i can try :hug:

miamiheli
05-13-2010, 02:41 PM
I was wondering how that would work but thought maybe a gyro would sort it out.

Is the tail overpowering and spinning the heli? or underpowered due to lack of speed at the tail.

If walkera can have a fixed pitch heli (4#6) with a tt driven pitch tail, then there has to be an answer for getting this to work.

jombo
05-13-2010, 03:56 PM
it seems under powerd , i have the stick all the way to the left and on startup its fine then about 1/2 throttle it starts to spin , i can get it off the ground on the spin but i dont think it will fly well :rolling. i neet to try the faster motor , i will see if that helps or make it worse

miamiheli
05-13-2010, 05:45 PM
it seems under powerd , i have the stick all the way to the left and on startup its fine then about 1/2 throttle it starts to spin , i can get it off the ground on the spin but i dont think it will fly well :rolling. i neet to try the faster motor , i will see if that helps or make it worse

Seems like it would make it worse or no real change. The tail will still be geared the same.

I think you were on the right path on trimming the main blades, don't think you could get much larger on the tail.

jombo
05-13-2010, 06:41 PM
i will give that a try , it came with 2 sets of tail blades , a lonf set and a shorter wider set . i will change them out and see what that does:thumbup:

Inverse
05-13-2010, 06:48 PM
Cut your main blades down, they are far too large.

jombo
05-13-2010, 07:12 PM
you are right the blades are too big, i just tryed the heli with the stock blades and it hoverd fine and the gyro i put on for the time being off the 450 is wagging hard , before it would just spin lol . i think i spent too much time today on it tomorrow is another day . i will cut about the size of the stock 250 blades and go from there, also the bigger tail blades made a small difference too .thanks guys for the help :hug::thumbup:

Inverse
05-13-2010, 07:46 PM
I'd personally cut the blades a few mm at a time until you get the desired mass and headspeed.
It's pointless cutting them to the same size as the stock blades as the lift characteristics will be totally different.

jombo
05-13-2010, 09:07 PM
i got them cut right now to almost the lenth, width of the stock 250 blades and its still spins , i think this ia a lost cause. i just checked the size of the falcon 40 tail and its big compared to the 250 tail , almost the size of the 450 tail. and now the belt broke , i dont see this working with a 250 size maybe a 450 but not 250 .

miamiheli
05-13-2010, 11:28 PM
i got them cut right now to almost the lenth, width of the stock 250 blades and its still spins , i think this ia a lost cause. i just checked the size of the falcon 40 tail and its big compared to the 250 tail , almost the size of the 450 tail. and now the belt broke , i dont see this working with a 250 size maybe a 450 but not 250 .

The 4#6 walkera is a 125 size heli with the same set up.

Try trimming more blade but not just length.
Maybe you can find a different blade with less pitch. Sounds like you just need to find the right balance of headspeed and lift to allow the tail to work.

jombo
05-14-2010, 11:22 AM
here is where i am at, i started with and i have cut the blades down alot and it still spins . the 450 tail hits the ground so thats a no, and faster motor is also a no since with the 2400k i can hover and fly with the stock blades:confused: . i have alot of fixed pitch blades from coax helis and will try them out , or look into the walkera 180 d blades . first things first new belt.

jombo
05-18-2010, 05:52 PM
got the new belt from amain and i think it was the belt slipping before , now the tail holds perfectly . now for the bad news , i must of cut the blades too much as now it wont take off . well no worries i got plenty of fixed pitch blades to try .

stay tuned........

jombo
05-18-2010, 06:52 PM
put the new blades on new belt , got the green light to go for it and found a few things out .
1- low head speed will give me less tail authority
2- a higher head speed makes the tail locked in with no input from me
3- to achieve more head speed i need to give it -9 pitch instead of 0 , if in the + it will be too slow and will spin .
4- it needs more motor , got the 4200kv comming soon or could probably go with a 3 cell lipo :dontknow
the video is a bit dark but you can make out the pitch i put in the radio
http://i120.photobucket.com/albums/o168/jombo01/th_MOV00404.jpg (http://s120.photobucket.com/albums/o168/jombo01/?action=view&current=MOV00404.flv)

jombo
05-21-2010, 10:17 AM
i am giving up on this for now , i got the new motor in and it did fly but i also stripped the main gear because of the motor mount . i used a GT metal motor mount, the plastic version 250 will not work with it sio i used 4 screws instead of 6. then i forgot to lower the pitch on the radio to -18 and left it at+5 :arggg: so it spun but was controllable so if i lower the pitch and to -18 or -11 it may work . so right now the weather is beutiful and dont want to waste anymore time fiddling with it , time to go to the field and have some fun.

miamiheli
05-21-2010, 10:38 AM
i am giving up on this for now , i got the new motor in and it did fly but i also stripped the main gear because of the motor mount . i used a GT metal motor mount, the plastic version 250 will not work with it sio i used 4 screws instead of 6. then i forgot to lower the pitch on the radio to -18 and left it at+5 :arggg: so it spun but was controllable so if i lower the pitch and to -18 or -11 it may work . so right now the weather is beutiful and dont want to waste anymore time fiddling with it , time to go to the field and have some fun.

Maybe an Align gear will be stronger?

You'll get it eventually, taking a break can be a good idea.

jombo
07-30-2010, 05:19 PM
gave up on the fixed pitch , i am glad i did :YeaBaby: . i just almost finished setting up the 250 , maidened the hover only to have something go wrong with the tail :confused: . after taking it apart i found the grub screw loosened up and wasent spinning properly . i fixed it and second flight, slowly raised the pitch setting and up it went . that lasted 2 min before i needed to bring it down fast . nothing broke but my pride:lol: . found a second thing wrong , the tail twisted down, the plastic pin holding it broke , drilled a hole and pinned it with a screw. i havent tryed it yet but i am hoping that should be the last of the surprises :dontknow worst case since this is a find all the quarks of this bird , i might just take what i found and build the second one and use this as parts:banana

jombo
08-02-2010, 05:38 PM
broke the skids on this thing after 3 flights :thinking , the things are super fragile and didnt even land that hard. they do flex alot when holding them so i guess it was inetable of them breaking , maybe using some braces inbetween them would make them less bouncy . i think i like the 250 more than the 450 :YeaBaby:

rcjames
09-29-2010, 04:56 PM
broke the skids on this thing after 3 flights :thinking , the things are super fragile and didnt even land that hard. they do flex alot when holding them so i guess it was inetable of them breaking , maybe using some braces inbetween them would make them less bouncy . i think i like the 250 more than the 450 :YeaBaby:

See you are going through frustration, just built ur 250 with eccpm go by trex 250 manual, get the right esc, motor, get a telebee, xmhobbies g401b or dynam gyro the one with red metal case and the right blades and all replace the mainshaft, tail shaft, feathering shaft with align and tail slider and god knows what and fly that sucker. Don't experiment it only brings frustration then once you become more advance then experiment. I love these 250 i have a 250 and they fly well and crash only cost less then 20 bucks or so. Get a good .09 servo for tail. Decent cyclic maybe tower pro sg50 for cyclic and tail since their pretty fast .09 or .08 sec but dont' have much oz of torq but its decent. Fixed pitch, does not work well as eccpm. Eccpm is a upgrade and latiest right now. MCCPM is old school and for sure the fixed pitch helis too. Fixed pitched first came out on the late 70's and 80's.

jombo
09-29-2010, 05:50 PM
LOL, rc james i gave up making it fixed pitch, i had some issues with the plastic version so after i saw the GT was 10.00 more i went that route. i have 0 binding in the head and it seems to be built alot better . it is still on the bench being put together and i have only to set the gyro . i have the 450 waiting for a US Coast Guard body with lights i got from bills custom lighting and i havent even finished that :arggg:

rcjames
09-29-2010, 06:00 PM
LOL, rc james i gave up making it fixed pitch, i had some issues with the plastic version so after i saw the GT was 10.00 more i went that route. i have 0 binding in the head and it seems to be built alot better . it is still on the bench being put together and i have only to set the gyro . i have the 450 waiting for a US Coast Guard body with lights i got from bills custom lighting and i havent even finished that :arggg:

Post you're built information here :). I built my own helis but i had to try out the dynam 250 seriously i love it, it has some bugs but 250 are so cool. Heh if i fly my 50 here where i live i will fill up between the building smoke. 500 is a bit big, 450 is still big, 250 perfect but looks like toys after all all these are toys for grandup. LOL. I would like to see pic of the gt. I wunder if they safe though being small heli spining 3000 rpm damn. Scary shit. Show some pic.