optikaman
Veteran
Location: EnglishTown N.J.
| I got the gear upgrade and a new belt today and installed it.
These are the steps I took to install the new gear.
1- remove the tail boom, makes it easier to work on the heli.
2- remove the fuel tanks
3- disconnect the EGT sensor, glow plug wire and electronics box. (the box with the HP5 label), Be carefull when you remove the electronics box as the hall effect sensor is located on the back.
4- remove the turbine, disconnect all gas and fuel lines
5- remove the lower gear and bearing block assembly
6- loosen the starter assembly
7- remove gear from shaft, there is a 4mm bolt holding the gear to the shaft. you will need to heat the gear for removal and there is an insert that has to be removed from the gear. the insert is milled with a lip and limits the gear from sliding off the shaft.
The original gear is a 23/76 tooth gear and the new gear is 25/76 tooth. You will need to apply some locktite to the shaft and insert because the gear is not keyed to the shaft., you will also need to heat the new gear to install it on the shaft as it is a tight fit.
Now reverse these steps and your finished. You will need to adjust the belt tension and alignment of the lower gear assemble, I used a dial caliper and measured the distance between the top and bottom of the gear and the side frame as a reference.
I adjusted the top and lower belts to what I think is the same tension, I used a metric ruler and measured the amount of flex between both belts.
' HP5s came with both 267 and 270mm lower belts. If you had one with a 270mm lower belt already you might need to slot the holes for the engine to raise it up. This will misalign the starter. All you need to do is loosen the starter and re-center it to the compressor nut and your good to go.' Thanks for this info BOB
I took my time and had the upgrade done in just over an hour.
Alan.... |
