Hop-ups - Motor Replacement Mods::

$8 DYI upgrade!
Author: Pouncer
Author Email: Pouncer at RCGroups
Specs: Prop Replacement for the Minium
Material Required: CF Prop/prop saver
Downloads available:
Notes: Rumaging through my spare parts box I found this inexpensive 100x4.7mm carbon prop that hasn't seen much use, until now that is. After (taking off) the prop I put the carbon one on using one of Bob Selman's prop savers.
It flies very nicely!

Climbs on even lower throttle now, and more silent, particularly at lower rpm's, a consequence of slightly more efficient prop and a small weight savings.Flight duration is noticeably longer.

Nothing revolutionary mind you, it just feels smoother and more gentlemanly (for lack of better word), and at $7 for the prop and $1 for the saver a worthwhile upgrade.
Needed a little down-trim and loops are wider for some reason.

Prop info:

100mm x 4.7mm Carbon Fiber Mirco Prop

Propsaver link:

1mm Prop Saver

Motor Fix
Author: Tim Wolff
Author Email: Tim Wolff at RCGroups
Specs: Gearbox Repair Method
Material Required: None
Downloads available:
Notes: Tim came up with this great method of fixing the gear box. Please read below:

Remove the whole gearbox assy. from the plane. You need to seperate the bushing from the spur gear AND the shaft.

Try to determine if it was actually glued or if the splines on the shaft have been pushed back into the bushing.

Clean eveything up in some warm soapy water. You can use electric motor or automotive brake cleaner on the metal parts.

Put it back together and make sure it spins freely. Then take it apart again. I'd use Tamyia Threadlocker or other plastic safe adhesive to lock the bushings in place in the gearbox housing. Then install the propshaft and spur gear making sure there is a little endplay (the shaft can slide fore and aft a bit, just enough to be noticable. Install the motor and set the gear mesh by rotating the motor in the mount. You also want just enough free play in the gear mesh to be noticable.

You should be able to see the spur gear move a tiny bit without the pinon moving. Turn the spur 1/4 turn or so and check it again. Turn about another 1/4 turn and repeat 2 more times. Set the mesh where the gears fit together the most tightly. The mesh will be looser on other portions of the spur, but that is ok. It is important that there is no binding between the gears.

Now put the prop on and measure the distance between the rear of the prop and the front of the spur gear. Find a length of hard stiff tubing (brass or alu.) that slips over the propshaft and cut it a mm or so longer than the measured distance. Slide the tubing on before installing the prop. There should be no endplay in the tube, it should be locked in place with the prop.

Check that there is still endplay in the shaft where the shaft rides in the bushings. Shorten the tube if needed. The tube will keep the shaft from being pushed back into the spur and bushings when the propshaft strikes an immovable object by transfering the force to the spur gear and untimaltey the gearbox frame. Use a single SMALL drop of lubricant on each bushing. I use automatic transmission fluid because it dosen't evaporate nearly as quickly as other std. petroleum based lubricants.

I think the spur gear is nylon and dosent require lubrication. I think it is better to leave it dry. Lubing it makes a mess and attracts dirt. Check that the prop spins freely and install it back in the plane. Four dots of hot melt, one in each corner should do it and it will be a heck of a lot easier to remove again should the need arise. Hope some of this is helpful.

Motor Protection
Author: galaxiex
Author Email: galaxiex at RCGroups
Specs: Protects Gear Box from Crash Damage
Material Required: Metal Tubing
Downloads available:
Notes: I was having (a problem) w/ the gear sliding on the prop shaft on accidental/ very gentle nose in, (so) here is how I fixed it... small piece of aluminum tubing,
I held the prop shaft w/small, good quality (snap on tools, electronic) needle nose pliers and unscrewed the prop, yes mine is threaded, I seem to recall some people saying theirs were not threaded...

The length of the tubing is slightly critical, too long and it binds the shaft, altho slightly short should not be a problem...

I deliberately dropped it on it's nose a dozen times from 3 feet up onto a hard floor and no more problem w/ the gear moving out of place... still flys great!