kennethw Senior Heliman Location: Singapore
My Posts This: Topic Forum | Installing Mechanics into FuselageMade about 15 successful simple flights of the mechanics and getting impatient, so started to fit the whole thing together. So far, everything is going quite smooth, but hit a few snags.
Since I'm rotating the main blades CCW, the tail pulley mechanism need to be reversed to allow the tail to continue to spin upwards. First thing I noticed was that the bearing in the tail mechanism are not 'centred'.

Interestingly the instructions do not mention which plate to use on which side. Since they are flanged bearings, I assumed that the flange was on the inside so the bearing can't be pushed out and fall out of the mechanism.
To make it work on a CCW head, I needed to reverse the bearings so that the pulleys will mesh correctly. Luckily, the bearings came out with some light tapping.

The tail mechanism all in one piece.

Since everthing was reversed for the tail, including the tail being on the left, all the internal tail braces had to be reversed too.
After fitting everything into the fuselage, I know that I shall need to do further adjustments to the SK360. The original place that I put it did not allow me to access the switch or the connector. More importantly, I would not be able to see the light to see if the SK360 had initialized properly. As such, I added a small platform to the wooden frame and placed the SK360 there. I also cut away the front portion of the Raptor mechanics to make space for some Cockpit work. Now, I am able to easily see the SK360 light from the side window.

Made a rather large blunder while fitting the tail sections all together. I 'furtigued' the Tail push rod at the servo end a little without noticing it. When the entire tail was put together (everything including the covers and all), I noticed that the servo was able to pull but not push because it would bend right at the link joint. I also noticed that there is a lot of 'flex' in the wooden frame that holds the tail servo.
As someone else had mentioned in their build, once you put it together, it is nearly impossible to take it apart.
I managed to slide my hand in and pull the link off the servo and pulled the entire push rod out. Reversed it and put it back in and it seems to work because the bent part is now at the tail end and still inside the guide, so it doesn't bend. However, I'm going to get another push rod, better safe than sorry. I am also going to find a threaded metal rod that is about 10cm to link the servo link to the push rod connecting just inside the guide; this should give it more strength as this is the weak point due to lack of bracing.
Another blunder that I have made is that the last tail belt is a little tight, but can't do anything about that now, all epoxied together. On spool up (without blades), the rear belt housing gets warm, and typical of over tensed belts, the whole mechanism slows down very quickly on power down.
Hopefully this will not affect the Heli other than reduced flight time due to more power needed to drive the entire thing.
There was additional butchering of the mechanism because the Aileron Levers were a little wide and rubbed against the fuselage. The top Elevator push-pull ball and linkage was removed because that also rubbed; so, now there is only one control arm pushing the Elevator Lever. Hope this works.
I've fitted the 4-blade head back on and it sits really low. I have about 6mm to the top of the marker beacon, and 10mm to the top of the fuselage. On spin up, nothing seems to contact, so I'm taking the risk. I'll post some pictures this evening. |