HK 250GT Build

[JamesPal]

My order has shipped from HK and I want to get going on it asap. The Align 250SE manual refers to a R48 (Green) to install the pinion on the motor. What is this stuff? Is there a comercial equivalent?

What is a good grease to use?

[walkera4g3]

Originally Posted by JamesPal

My order has shipped from HK and I want to get going on it asap. The Align 250SE manual refers to a R48 (Green) to install the pinion on the motor. What is this stuff? Is there a comercial equivalent?

What is a good grease to use?

the green loctite, you'll get it with your HK kit.

I just oil all my bearings prior to flight, i don't use grease

[rseegers]

I use this for screws.

http://www.hobbyking.com/hobbyking/s...Strength_.html

And the red high strength one on the motor pinion (although the green one would probably work) For grease I use a dry teflon bike lube.

[rseegers]

Originally Posted by walkera4g3

the green loctite, you'll get it with your HK kit.:

Not anymore, although you do get a spare bag of screws.

[butterfingers]

You can get the green loctite at the autoparts store.

[JamesPal]

Thanks for the info on the green locktight. I picked up the permatex green. It is a penetrating grade thread locker. The Align 250SE manual says to use this on the bearings. I will need to be careful around the bearings.

The shipment from Hobbyking arrived. It was shipped via UPS 3 day express. Included was: the HK250GT kit, carbon fiber rotor blades, Assan GA250 Gyro, the Turnigy 2508 3500Kv (200w) brushless motor and a HK-190 fixed pitch Helicopter. Shipping cost was $25.24. I will post the rest of the build setup later. This was about $5 more than other shipping methods; but it got here quickly. This makes it worth it.

First impressions:
Not knowing what to expect, I was surprised how small the 250GT box was. Like usual, it arrived in good condition. More surprises included how tiny the copter is. I have a Nine Eagles 100D 3D and the GT250 appears to be about 30% bigger. A lot has been said about the quality of this kit. I am not disappointed and I second everything I have read in this forum. One this I noticed is the swash plate does not slide smoothly on the main shaft. I’m thinking this is just contamination or some kind of preservative. If it doesn’t clean up, I will get the Align 250SE shaft.

I was very concerned about the Pinion fitting the Turnigy 2508 motor. Hobbyking says this has a 2.3 mm dia shift. I will confirm this information is incorrect. I have a total of 31 years experience in Boeing QA and I can say I know how to measure. I have mic’ed the shaft at .097”; this converts to 2.4623mm. I’m certain that is well within the tolerance band (2.5mm = .0984”). This has been submitted to Hobbyking’s customer support center.

The Assan GA250 Gyro is still in the box. It sure looks nice.

The plan forward:
I can’t wait to get this into the air. Before I start I need to clear the workbench. My Honey Bee ccpm v2 needs the center hub shaft replaced. After that is out of the way, I will start on the HK250GT build. The plan is to follow the Align 250SE assembly instructions. I will try to post progress with as many photos as possible and ask many questions.

[walkera4g3]

don't waste your time on the assan ga250, what a load of garbage that is. Get the Tarot GY550 for $20 it's worth it.

[youturnjason]

Yeh hobbyking's shaft diameter for that motor is wrong. I bought some 2.3mm pinions which were too small but the 2.5mm pinions that came in the kit fit so it was alright.

[Bunliong]

becareful with the tail case mine broke on maiden. Bought second one and it face the same fate. Finally I ended up with align tail case and its rock solid.
Good luck with that because you'll need it.....alot hehehe

[JamesPal]

Last night I finished up the structure, rotor heads and mounted the servos. Up until now I have been flying RTF helicopters. So this is my first build and it went well. I was able to disassemble all of the metal to metal screws and apply thread locker; without losing a single screw. The only additional parts needed were 2mm bullet connectors for the motor to speed control, the tail rotor servo mounting screws were short for the servo I chose and one of the canopy mounting grommets was missing. The bag had one grommet and one feathering shaft isolator. The included tail servo screw is 2 x 8mm and I sourced some 2 x 10mm at the local hobby store.

I tried to follow the Align TREX 250SE assembly manual. The only departures were for servo mounting, screw head types and the rotor head link lengths. It seems the Align version uses a much easier to install servo mounting system. I completed the main body before installing the servos. This turned into a mistake by making the servo mounting a very tedious process. I wound up taking about 4 hours for this part of the job. It would have been much easier to pull one of the upper frame sides off, mount the servos and then proceeded with the build. I think this would save about 3 hours of frustration.

The HK version uses Torx 1.5 bolt heads. This is good because they will take a lot of torque. It is easy to break dried Loctite. The downside is they used Torx in the rotor head. They included one wrench with the kit. It takes two to get the feathering shaft out. Please let me know if you know where to find the Torx wrench.

Next up will be getting the servos and rotor head setup. I should be running the radio from a receiver battery. Starting from the bottom up, square up the servo arms, level the swash plate, set the rotor head and rotor pitches. Then into the Tx setup. I have more to learn.

HobbyKing currently has a lot of spare parts available. Check it out.

[youturnjason]

You should be able to install/remove all the servos even with the frame together. They all sit on the outside of the frame. Make sure you installed them correctly as its gonna be a big pain if you have to take the frane apart if you need to replace a servo.

[JamesPal]

You are correct about the servos being installed on the outside of the frames. However, the HK kit provides 2 mm bolts and nuts to mount them. Getting the nuts on the inside of the frames was a genuine pain. The Align version has a different profile for the servo cutout. It uses plastic clips; avoiding the painful screws.

[youturnjason]

I used the screws that came with the kit. There were no nuts. They threaded through the cf frame quite nicely.

[JamesPal]

I have been around radio control long enough to remember single channel escapement, kit digital proportional radio sets, 27 Mhz shared with CB and mainstream U-control.

Tonight I discovered the servos I selected are not compatible with my receiver. My choice is to obtain a new receiver or swap out the servos.

I'm using a Hitec Eclipse 7 transmitter with the Spectra Module on 72 Mhz. For a receiver, I chose the Corona RP8D1 synthesized receiver. The installed servos are IND-LAB HG-201HB servos. I have used these receivers with much success on my fixed wing models.

I tried three different receivers and none would bind with the IND servos installed. I could get it to bind without servos. I tried plugging in one Hextronic HTX900 and it worked fine. I wanted a better servo.

My decision is to find another receiver or use the compatible servos. I really like the synthesized Tx-Rx. I works great on my fixed with aircraft.

Besides the HTX900, I found three Corona DS-929MG (digital) and a Blue Bird BMS370DD (digital) servo in my spares box. With these plugged into the receiver, binding and operation was not a problem. I will do a simulated range check before changing the servos.

I guess my issue is finding a receiver that is compatible with the installed servo or bite the bullet and spend hours swaping out the servos.

Any comments or advice would be appreciated.

THX- Jim

[JamesPal]

It turns out the Hitec RCD9500 will interface with these servos. It is a little large, but will fit in the space aft of the motor. I will go ahead with this configuration. It is time to be looking at 2.4 Mhz. technology. More to come on that.

I found the Torx screw drivers at Fys's Electronics. It is the T6 size. I didn't know which one it was, so I bought this set: http://www.frys.com/product/639975?s...H:MAIN_RSLT_PG Here is the individual driver: http://www.frys.com/product/639975?s...H:MAIN_RSLT_PG
I should be able to take apart any small electrical device.

[JamesPal]

Earlier on I promised lots of pictures. Turns out my camera does not make good closeups. The box is maller than you would expect. But I do have a few:

[xpftp]

the RX is bigger then the heli ... lol

[JamesPal]

Good one about the receiver, it is big. I want to look into a 2.4 Mhz module for my Hitec Eclipse. Any suggestions?

Looks like the one-way bearing gave up. It had been running OK without the rotor blades. After setting the link lengths and installing the blades, I ran it up a couple of times. Now it won't lock in the either direction.

Another issue cropped up, I couldn't get the ASSAN GA250 to play with my tail rotor servo. Off it went and I put in a HobbyKing HK401B. It is a little big, but it worked. I will leave it in for now. Walkera4g3 recommends the Tarot GY550. I may need to look into that.

I guess I will try to get the Align parts and see if they will fit. Going into this, I knew there would be quality problems. I will pick up the Align one-way bearing and main gear.

Besides be hung up for needed parts, I’m a little frustrated. It is time to get the parts on order, clean up the workbench and go work on my classic Goldwing. I’m rebuilding a 1981 STD model.

Does anyone have any recommendations for a U.S. located Align 250SE parts supplier?

[xpftp]

Originally Posted by JamesPal

Good one about the receiver, it is big. I want to look into a 2.4 Mhz module for my Hitec Eclipse. Any suggestions?

Looks like the one-way bearing gave up. It had been running OK without the rotor blades. After setting the link lengths and installing the blades, I ran it up a couple of times. Now it won't lock in the either direction.

Another issue cropped up, I couldn't get the ASSAN GA250 to play with my tail rotor servo. Off it went and I put in a HobbyKing HK401B. It is a little big, but it worked. I will leave it in for now. Walkera4g3 recommends the Tarot GY550. I may need to look into that.

I guess I will try to get the Align parts and see if they will fit. Going into this, I knew there would be quality problems. I will pick up the Align one-way bearing and main gear.

Besides be hung up for needed parts, I’m a little frustrated. It is time to get the parts on order, clean up the workbench and go work on my classic Goldwing. I’m rebuilding a 1981 STD model.

Does anyone have any recommendations for a U.S. located Align 250SE parts supplier?

the azz250 gyro is a pain to setup .. i wouldnt give up tryin to get it to work .. set it to defualt for digi i think its 5 red flashs and unplug it then turn heli on .""make sure no servo pluged in"" then plug the azz250 in both wires at same time and hit that gain switch ..and no delay .. i had gottin mines in saturday and had planed to set it up on the 250 .. changed my mind as i think iam done with the 250 for a long time .. and i put it on the 500 .. and i be loving it .. the gy48 and HK clones suck .. i have 3-gy48's and i did the mods and such to them and they still suck ..

as for TX and RX sorry there no clue . i run specturm .. have had good luck with them .. DX6Eye and diff RXs .. all specs no oranges ..

[walkera4g3]

For torx I use these, I filed them down to size, as you know it's slightly bigger, but it's very strong!

http://www.dealextreme.com/p/ie-826-...k-8322?item=42