Fun, Learning, Friendship and Mutual Respect START  HERE


Unregistered
Go Back   HeliFreak > R/C Helicopter Support > 250 Class Electric Helicopters


250 Class Electric Helicopters 250 Class Electric Helicopters manufactured by Align, Tarot, SYMA, Airhog, Chaos, HK and similar.


Reply
 
LinkBack Thread Tools Display Modes
Old 05-07-2016, 12:14 AM   #1 (permalink)
Registered Users
 

Join Date: Jan 2015
Default A light weight 250 build.

So here's my take and attempt with a 250. It was mostly inspired by Number's build and finding one on the classifieds cheap. It will under go some refinements as time goes on and I decide on where I like it.

The basics on this heli include,
SE frame with the belted tail
DFC head
Talon 15 esc
Align 250sp motor with 15 tooth pinion
Eflite ds76 servos
Kbar, decased with the sat mounted directly to it
Cheapo florion 800 mah 3s batteries
AUW ready to fly 281g

Future things I still want to get and or work out.
Carbon boom
Carbon tail rod control linkage
Double bearing mod and Chinese weights on the tail
Lynx dampeners
Zeal mains.
Shorten servo wires
Maybe some different servos

Please excuse the crappy pictures I took, they are from a cell cam and I am a horrible photographer. As they say though if there's no pics it didn't happen so here they are.

Hopefully I will get a maiden in soon and get some tuning and tweaking done but the weather hasn't been good for me when I have the time.
Attached Thumbnails
Click image for larger version

Name:	20160506_214535.jpg
Views:	227
Size:	57.4 KB
ID:	651042   Click image for larger version

Name:	20160506_193027.jpg
Views:	264
Size:	75.8 KB
ID:	651043   Click image for larger version

Name:	20160506_214755.jpg
Views:	228
Size:	92.3 KB
ID:	651044   Click image for larger version

Name:	20160506_193323.jpg
Views:	222
Size:	89.9 KB
ID:	651045  
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 05-07-2016, 01:32 AM   #2 (permalink)
Registered Users
 
Posts: 1,643
 

Join Date: Feb 2015
Location: Melbourne
Default

very nice looking 250, let us know how you go with the CF boom
gimbleguy is offline        Reply With Quote Quick reply to this message
Old 05-07-2016, 02:14 AM   #3 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

Thanks for the nice compliment, although I would not consider it a nice looking build by any stretch. I did however finally get a heli that I can fly and start tuning in that met my goal of 280g to 290g flying weight.

I was getting a bit bogged down trying to get this thing built up and it's a bit difficult for me to keep from going too crazy so I had to draw the line where it's at for now until I get some stick time in.

After thinking on the carbon boom for a bit more I may skip it because I'm a bit nose heavy for my liking. If I go the plastic canopy route, double bearings and Chinese weights it may make it a good bit better. I'm still not sure where this heli will end up but I do think it will be fun.

I'm hoping the tail doesn't give too much trouble because the other complaints I have read about being difficult to work on haven't bothered me in the least.

Now the real fun begins though, flying and dialing it in.
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 05-10-2016, 10:01 PM   #4 (permalink)
Registered Users
 

Join Date: Jun 2015
Location: KC MO
Default

What are these double bearing grip mods you speak of?
__________________
Keith - MSH Brain2 Beta Team
Raptor E700 RMJ Nitro | Synergy N556 | Synergy 516 | T-REX 470LP
For FrSky help visit my thread: https://tinyurl.com/y3b3vu3k
https://kc3dprint.com - 3D Printing on Demand and 3D Printed RC Helicopter Upgrades
Number is online now        Reply With Quote Quick reply to this message
Old 05-10-2016, 10:44 PM   #5 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

Check out the 250 mods section. It's for the tail grips to take the slop out, which mine has lots of.
It's the tail analysis thread that has it in there.

I tried to get a maiden in yesterday, but still have some things to sort out better. In the end I ended up busting a tail blade. I also need to get my OWB and and main gear straightened out better. It's warped and is not very smooth.
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 05-10-2016, 10:55 PM   #6 (permalink)
Registered Users
 

Join Date: Jun 2015
Location: KC MO
Default

Don't bother trying to straighten the main gear. You will never get it perfect. And there is zero benefit even if you could. Just fly it
__________________
Keith - MSH Brain2 Beta Team
Raptor E700 RMJ Nitro | Synergy N556 | Synergy 516 | T-REX 470LP
For FrSky help visit my thread: https://tinyurl.com/y3b3vu3k
https://kc3dprint.com - 3D Printing on Demand and 3D Printed RC Helicopter Upgrades
Number is online now        Reply With Quote Quick reply to this message
Old 05-10-2016, 11:11 PM   #7 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

Lol, that was the original plan, just fly it and tweak it in as I went, sorting out the less than perfect stuff.

Hopefully I have a spare set of tail blades and I can give it another go this weekend. The weather here has been stupid windy but it should be over soon.
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 05-11-2016, 12:02 AM   #8 (permalink)
Registered Users
 

Join Date: Oct 2010
Default

Quote:
Originally Posted by Number View Post
What are these double bearing grip mods you speak of?
Check out the Heim Joints double bearing mod - he has the spacers and torx screws and sells them as an upgrade, but you do have to get the zz bearings on your own - which are slightly thinner versions of the normal tail grip bearings. It's under the aftermarket upgrades at the top of the 250 class forum:

https://www.helifreak.com/forumdisplay.php?f=183

I did have to sand down the batwing blades a touch on the bottom side due to the size of the head on the torx bolt - and you'll need a tool for the bolt. I found the correct torx size in one of those multi-tools with the miscellaneous bits in the grip in the Home Depot tool section. I did overtighten one screw and it broke in flight - which was my fault. I bought two kits knowing I would drive'er in and break it at least once. I haven't broken a bolt since.The mod definitely tightens up the tail grip slop.
__________________
Agile 5.5, Logo 550sx, X5, Oxy 3, Trex 450proV2, 250DFC #309
nflanagin is online now        Reply With Quote Quick reply to this message
Old 05-19-2016, 01:04 AM   #9 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

I finally got to get a maiden in on my 250 today. There wasn't much excitement to be had with it, mostly just some hovering and checking things over. It was fairly windy and raining off and on. I did mange to get a couple of packs through it and start to get an idea of what I have left to do.

I was surprised at how stable and how good the heli felt in the air despite a few minor tweaks that need to be made stil.

Mainly I need to get the servo linkages shortened up, I am thinking I will probably get some from the 250 dfc and that will fix the linkage length issues that I'm having. Also I have a ball link end that's a bit sloppy. I think a new swash will also be on the list as well but that can wait for a bit.

A few other issues that seem to need to be dealt with are slop in the tail grips, shim the main shaft, and get the pinion set on the motor shaft for a better alignment with the main gear.

So far as I can tell so far I think I am going to really like this heli. After having a few set backs getting it rebuilt and setup, it's looking like it will be lots of fun.

Hopefully I will get a chance to get a few more things dialed in and straightened out in the up coming weekend and start to get to enjoy it.
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 05-19-2016, 01:10 PM   #10 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

Well I finally got to fly a few packs through this heli flying some upright circuits. I am really liking how it feels in the air so far and am getting a feel for what I needs adjustment to get it in the sweet spot.

So far it looks like I am going to want to raise the collective pitch to 14 degrees instead of 12 and crank the HS up a bit.

I had a minor mishap on the first flight, I forgot that I made a few adjustments last night and forgot to tighten the motor screws down. Needless to say 30 seconds into my flight the motor pinion and main gear were not meshed anymore. I managed to get to the throttle hold and and get a sloppy auto from about 10 feet in the air. The only casualty was a broken landing gear strut. Had it been the align one instead of the HK mount it wouldn't have broke at all I don't think.
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 05-20-2016, 10:22 PM   #11 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

I've managed to get a few more flights on the 250 and am starting to get comfortable with how it's flying in its current state. Everything has been working great on it so far and I'm starting to figure out what's going to be needed as far as tuning goes.

So far the only real issue that I am running into is that it has a bit of tail wag. It's not real crazy or anything maybe only 2 inches or so. At my lower head speed (3700 I think) it's non existence but once I go to 4200 is wheen it happens. It's not bad enough to stop me from flying at 4200 and the tail holds good in backward circuits.

I have been flying without the canopy so far and am not sure if I will even bother at this point. Also I have been running plastic blades while I get the bugs worked out. I will be switching those out for the carbons soon enough and eventually a set of zeal's on down the road.

I have been running some cheap flourion 800 mah batteries on it and flying for 4 minutes and the packs are coming down at over 50% charge still, 11.6 V. Although I haven't really been tossing it about much yet and just doing fast circuits.

I still have lots of work to do yet to get it dialed in and am doing a little each night as I have a bit of time, but I'm liking it enough right now that I'm trying to get as many flights in on it while I can.
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 05-22-2016, 02:46 PM   #12 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

Got some more packs through the 250 this weekend and still am really liking this heli. I haven't got much work done on it, I've just been flying it. It has been flying great and all the work to build it up light has payed off great.

With every flight it gets to feeling better, I have been trying not to push too hard with it before I get everything worked out with it, but it just begs to be thrown around and flown. Today I broke down and started flipping it, flying inverted, piro circuits and lots of big air. I can see that this heli is going to quickly become one of my favorite take anywhere helis to beat on.

The only down side to it right now is that it doesn't like wind too much and doesn't carry a lot of momentum.
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 05-23-2016, 10:04 AM   #13 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

Well fate caught up to me this morning on my second flight for the day and the 250 took a dirt nap. After my first run and having a good time I had noticed that one of my tail rotor blades had been put on backwards after I balanced them. I was thinking that after I flipped it around the right way I would see the little bit of tail wag I had been experiencing would disappear.

Unfortunately that was not the case the wag did get a bit better but in the end the tail blew out on a fast loop.

So far the damage looks to be the motor mount, a main blade, main shaft and a feathering shaft.

I'm sure that I will find a few other things as well as I disassemble and rebuild. The big surprise to me is that it doesn't appear that I stripped the servo gears out. The carnage is certainly much less than I figured it would be with as hard as it hit. Now I have a good reason to fix up a few of the issues it was prior to this.
Attached Thumbnails
Click image for larger version

Name:	20160523_075803.jpg
Views:	99
Size:	55.3 KB
ID:	653523  
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 05-23-2016, 05:51 PM   #14 (permalink)
Registered Users
 
Posts: 1,643
 

Join Date: Feb 2015
Location: Melbourne
Default

sorry to hear of your crash, hope you get her back in the air soon
gimbleguy is offline        Reply With Quote Quick reply to this message
Old 05-24-2016, 01:49 AM   #15 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

All back in the air now with a minor tuning adjustment. The best part is I didn't have to buy any parts and even came out a little ahead.

So I ended up straightening out the motor mount and the main shaft. The motor mount was pretty easy with needle nose pliers and a good eye. The main shaft was a bit more involved, but turned out good using a lathe and a dial indicator and a bit of patients with a brass hammer.

While I was at it I also drilled and shortened 2 SE main shafts to fit nice with the dfc conversion. I did this so I could use the SE main shaft and collar. Also it makes it easy to adjust fit for the bearing blocks with out having to deal with shims. I ended up making them a little longer as well to help with the servo geometry so I don't have shorten my links down now.

Its all put back together now like it never even happened and the only casualty was a plastic main blade. I even managed to come out with 2 more main shafts that fit my build better.


I also cleaned the bearings, swapped out the swash and OWB with extras that I cleaned up good.

I will have to do a few tweaks to the FBL before I fly again but it's all fixed up.

Next I'm going to try to get some Chinese weights made up, pin the boom clamp and put a carbon tail boom on.
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 06-01-2016, 12:01 AM   #16 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

Got some new parts in today and installed. It's almost ready to go.

I have to run through the head geometry again on the FBL setup because I changed main shafts and now am running shortened FB shafts with the collar. I did this so I don't have to mess with shims and it makes shaft replacements easier. It also gets my servo arms closer to 90*, the FB servo links are a bit on the long side for the dfc head. Later I will make some turn buckles for it that get it there.

I also put some new tail grips on with the double bearing mod and Chinese weights. It has tightened up the tail considerably and hopefully with the Chinese weights the tail servo won't have to work as hard.
Attached Thumbnails
Click image for larger version

Name:	1464753548072-1127149928.jpg
Views:	82
Size:	62.5 KB
ID:	655181   Click image for larger version

Name:	14647536216231177685942.jpg
Views:	79
Size:	48.4 KB
ID:	655182  
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 06-01-2016, 11:31 AM   #17 (permalink)
Registered Users
Thread Starter Thread Starter
 

Join Date: Jan 2015
Default

I got a couple flights in this morning and the tail is still a bit of an issue. The first flight had a good bit of tail wag going on and didn't feel good at all. The second was a bit better after making a few adjustments but it's still there.

I was a bit lazy setting it all up and didn't really put much effort into making sure it was smooth enough. So this evening I will have to go through it better and see if I can get dialed in. It's also a posibily that I'm running the ds76t servo to hard, I noticed that my bec is set to 5.5v and the ds76t is only rated at 5, so it maybe burning up in a slow death. If it craps out I will grab up another and run a diode on it to drop it down a bit.

I'm a bit curious about why it was flying better with one of the tail blades on backwards and now not so much.
__________________
Helis: Trex 250, Oxy3 +, 450 se v2, 450 pro, 470, 480N, 500 ESP, 600N, 700N
HeliLust is offline        Reply With Quote Quick reply to this message
Old 06-01-2016, 11:59 AM   #18 (permalink)
Registered Users
 

Join Date: Apr 2013
Default

Shouldnt be a problem, I'm running DS76t and a Talon 15 which I'm sure is fixed at 5.5V, it's had hundreds and hundreds of flights without issue, and I'm pretty sure a lot of that is down to the Chinese weights.
__________________
Helis: Oxy2 FE, Oxy2 Sport, Protos 380, Oxy 4 Max, Gaui X3 stretched
Electronics: Spartan Vortex, MSH Brain, Jeti DS-14
Sims: RealFlight & AccuRC
Other: Team rep for Lynx/Oxy, Founder of NightWave Systems
myxiplx is offline        Reply With Quote Quick reply to this message
Old 06-01-2016, 12:56 PM   #19 (permalink)
Registered Users
 

Join Date: Jan 2012
Default

for a quick test grab the tail blades and try to wiggle them to change the pitch. if the pitch changes more than a degree or so then you will have to get the slop out first.
you servo will be fighting this all the time.
Crashtestheli is offline        Reply With Quote Quick reply to this message
Old 06-01-2016, 03:25 PM   #20 (permalink)
Registered Users
 

Join Date: Apr 2013
Default

Mine wiggle like crazy, but still hold fine in flight.
__________________
Helis: Oxy2 FE, Oxy2 Sport, Protos 380, Oxy 4 Max, Gaui X3 stretched
Electronics: Spartan Vortex, MSH Brain, Jeti DS-14
Sims: RealFlight & AccuRC
Other: Team rep for Lynx/Oxy, Founder of NightWave Systems
myxiplx is offline        Reply With Quote Quick reply to this message
Reply




Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the HeliFreak forums, you must first register.
Please enter your desired user name, your REAL and WORKING email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself. Use a real email address or you will not be granted access to the site. Thank you.
Email Address:
Location
Where do you live? ie: Country, State, City or General Geographic Location please.
Name and Lastname
Enter name and last name here. (This information is not shown to the general public. Optional)
Helicopter #1
Enter Helicopter #1 type and equipment.
Helicopter #2
Enter Helicopter #2 type and equipment.
Helicopter #3
Enter Helicopter #3 type and equipment.
Helicopter #4
Enter Helicopter #4 type and equipment.

Log-in


Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On




Copyright © Website Acquisitions Inc. All rights reserved.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.

SEO by vBSEO 3.6.1