Raptor 30/50 v2 assembly
manual
Page 13 [click here for index]
Note about balance: If you have high frequency (above 10,000
hertz) vibration problems that you are trying to locate, then
often times it is from the clutch or fan. If you have a high
point balancer then check them before installing. I suggest
checking it with the clutch and fan bolted together. This will
allow you to balance the assembly as it will be installed and it
is also need so the cone of the balancer will center correct.
When just balancing the fan, the cone will not center correctly
due to the threads in the top of the fan hub.
***Note2:
When removing the fan it really is nice to have one of the delrin
crank locks. I bought one from Ron Lund of Rick's R/C and it
works great.. <Here>
is a link to it. Another thing you can do is use a plastic
toothbrush to jam between the case and the connecting rod.
*Tip: With the fan installed there should be no in/out play in
the engine crankshaft. When you pull on the fan there should be
no movement. If you develop any play in this later on, for
instance when you try to crank a fuel-locked engine, then this
can cause engine tuning problems. Refer <here> for more info.
===
First remove any washers from the crankshaft of the engine. Next
put a little blue loctite on the threads of the crankshaft and
screw the fan (3) all the way down. The bottom of the fan hub
should be against the front bearing of the engine. There is no
need to crank it down extra tight, I just make sure it is fully
against the inside race of the bearing with no gap. There should
be no in/out play in the crankshaft*(see tip at top). Put a drop
of loctite on the threads of the crankshaft nut and tighten the
nut. If you don't get it tight then it might unscrew when you go
to start the engine. If this happens you will notice the start
system locks up, this is because when the fan unscrews it is
shoved up against the top of the clutch bell. The original manual
says to use a towel to hold the fan while you tighten the nut.
The best method is to make a <fan
hub tool> like I did. Basically you just drill one big
hole and two bolt holes in a plate of metal. Click on the link
for the details. Two other common methods* of getting the prop
nut tight are: use a crankshaft lock (delrin block that goes
where the backplate is) or you can also use the technique of
using a plastic toothbrush handle to do the same. Some people
have had sucess using the piston lock tool (screws in place of
the glow plug), but beware that this can dent the piston. *Although
many use these techniques, you risk pre-loading the engine
bearings, that is why if you have the time it is best to make a
fan hub tool. Also you are applying abnormal stress to the
connecting connecting pin and rod..
Next place the clutch shim on the bottom side of the clutch (2).
Note: the shim has a direction it needs to go. When you have it
on right, the straight sides will be parallel with the straight
edge of the clutch shoes. Next attach the clutch to the fan hub
using two M3x10 bolts (1), use blue loctite on these two bolts.
The bottom of the clutch is the side that will fit into the
center of the fan hub. Note: Don't try to imitate the incrediable
hulk, if you really crank down on the two clutch bolts then
eventually the head will snap off.
*Note: In some cases the threads in the hub may not be drilled
all the way and this will leave some up/down play in the clutch.
This will cause the bolts to break as well as possible clutch
failure. I have also heard of an instance were the two bolts in
with the clutch bag were too long. Make sure the bolts you use
are 10mm.
*Advanced installation: If you have a dial point indicator
then take a little time and get the clutch on right. <Here> is a page on how to
do this.
Go to Page 14
***Note2:
When removing the fan it really is nice to have one of the delrin
crank locks. I bought one from Ron Lund of Rick's R/C and it
works great.. <Here>
is a link to it. Another thing you can do is use a plastic
toothbrush to jam between the case and the connecting rod.