HK 450 CCPM carbon fibre pro Question

[Ash1]

Help required please if you have built one of these.I have Kelvin Wilson's build log as a guide but the CF version differs slightly. Firstly,is there a build log anyone knows of for the CF pro version?
My issue is with the cyclic servo's placement. On the other versions of this heli as per build log, the servo slots appear to be horizontally laid out on the body, with slots cut out not directly opposite each other on each frame side, but one above the other. This so that the servo bodies do not hit each other when attached to the frame.
On my CF kit, each frame side is the same. Even the smallest servo's hit each other in the middle if placed into the slots. I cannot find anyway of placing the servo's so that all three cyclic pushrods are directly in line with the servo arms. There are really only two servo slots, vertically mounted rear of the main shaft, too far away to drive the two front cyclics with standard servo arms. If I use these, there is nowhere to mount the servo to drive the rear (elevator) cyclic. It appears to be a complete cockup.
Any help from anyone that has built one would be appreciated, especially if you could post a few photo's.
I was extremely impressed with this kit when I opened it up, but now not so sure. I would have expected slots for three servo's, in the right places for servo arm stnd length's. Doesn't look thought out at all. Or am I missing something???

I have built/rebuilt several Heli's before including a Belt CP and an Align Trex 250, but this has foxed me.

Servo arm length not reaching pushrod

[Ash1]

Having posted the thread and photo's, caused by the frustration in trying to follow the instructions for the other version, had a cup of tea, went away and had a rethink.

All became clear when I downloaded the Trex 450 Pro manual. The two front cyclic servo's go inside the body at the front. Obvious now.

Feel a prat!!!!!!!!!!!!!!!!!!!

Problem solved. Thanks to anyone that looked.

Ian.

[Bad Raven]

http://video.align.com.tw/mpeg/manuals/ ... 450PRO.pdf

Page 11....................

[Keith England]

Ian,

Just about to send you the 450 Pro link myself. This is the best copy I found http://www.heliguy.com/i/T-Rex-450-Pro-Super-Combo-Manual.pdf and, yes servos go inside frames - note your rear elevator servo which you have fitted outside also has to be inside see page 9.

Keith.

PS watch out for the tail a torque tube is going to be very prone to stripping gears if the tail rotor touches the ground. Strangely enough on my TREX 600 CF it is the gears at the front of the tube that strip - at the slightest tail contact with the ground - finally fitted a TREX 700 Fin and hardly ever break one now!

PPS let us know how you get on with it and what power train you fit?

[Ash1]

Bad Raven, Keith,

Thanks very much for your help again. Was just against a brick wall with Brain failure. Couldn't see the woods for the trees!!

Hadn't fixed any servo's or started, just setting out my stall in readiness to start, when the servo placement confusion set in as I loosely placed servo's.

Really was obvious when I downloaded the 450 Pro manual and spotted servo screw holes in the cross bars within the body.

Yes the rear servo needs to go inside the body. Using MG90's with a DS520 for the tail and am going to try the 401b see what happens. I have genuine GY401 or Align gyro's on my others. Thought I would give the HK401b a try for the price. Many saying its good, others saying its tosh.

Thanks for your advice regarding the potential for tail gear stripping. All my other heli's are belt driven, will see how I get on, may change to belt, I did think about crashes and the bending of the drive shaft as well. (And I have been known to crash now and then!!!!)

Never had an issue with a belt driven Heli, fancied a change and try a shaft driven tail.

As for the HK450 Pro, pretty impressed with the quality and price. I built an Align Trex 250 (super Combo), and I have to say, cant tell the difference in quality of the parts between that and the HK 450. Very impressed for the money. It appears as if the major issues/complaints are the quality of the screws etc. But for £45.00 you do get a lot. Up to now, well done to GShark for getting this in.

Thanks to all again for your help.

Ian.

[Keith England]

Ian,

Quality in your photos looks good. By the way - i notice that there has been more than one edition of the Pro manual. You will notice that Bad Raven says page 11 and I said page 9, but I also notices some threads on the subject with different lengths specified for the servo to swash links. Differences may be quite small but you may want to check the manuals on both links?

I nearly bought a Pro recently. My 450SE V2 broke a tail belt just as I started an auto - how lucky can you get, I had plenty of energy in the main blades once they weren't driving the tail any more! When I first got the 450 it broke belts every 10 flights or so until I started using silicon spray and the orange Robbe belts. That belt had lasted more than 2 years. However the tail gearbox had been opened so many times the threads were stripping and I couldn't bring myself to pay £30 for a replacement when I could get a whole machine for not much more. In the end I got the GC metal tail unit which, other than cross head screws, looks exactly like the original and works well.