chevell's blog archive for April, 2011 - RC Groups
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Archive for April, 2011
Posted by chevell | Apr 21, 2011 @ 10:40 AM | 902,646 Views
I just completed this set screw mod on the heliworx head.

First picture is Heliworx head being drilled with #50 size drill for 2/56 stainless set screws.

Second picture shows the tapping process. The hole needs to be drilled perfectly straight and you have to be sure and tap the hole straight as well.

Third picture shows me spinning the head up to speed after I spent some time getting this mainshaft straight again. I have a procedure for this using a block of hardwood in my vise. This one is using the shorter 48mm mainshaft. I straightend the mainshaft for free in this case.

Forth picture shows a side by side comparison of my head next to the Heliworx head, not much difference between the two. They perform the same task but I made mine for 2.50$ in parts.

This mod makes it much easier to remove the head. It also eliminates the use of the pin which can be a real pain to remove. That is why this head was sent to me in the first place. I had to get the pin out first which was not easy, seemed to be stuck in there a bit.

I can do this mod for 12 dollars plus shipping. You couldn't do this mod yourself for less because the drill and taps plus the 2/56 set screws plus shipping would cost you more than that. Not to mention the machine work plus the precision and expertise required. I am in fact the one who originally came up with this idea of using set screws in place of the pin.

This is a very worth while mod because everytime you bend the mainshaft you will most likely need to remove the mainshaft to replace it or get it straight again. Dealing with that pin everytime is a royal PITA and tends to slowly beat up your nice expensive Heliworx head.

If you have a Heliworx head this is the mod you want.
Posted by chevell | Apr 05, 2011 @ 04:55 PM | 906,576 Views
Today were going to talk about the proper use of thrust bearings for the Xtreme framed V120's.

In case nobody was aware nearly all larger heli's use a combination of radial bearings and thrust bearings in the head support. There are plenty of good reasons for this besides the fact that it's the mechanically correct method for reducing friction on a helicopter head.

I decided that the el cheapo chinese radial bearings that my Xtreme frame came with weren't doing the best possible job of reducing friction. This was evidenced with the fact that if I over tightend the collar just a hair it would bind the radial bearings up big time. It made no difference if the tail gear was on or not so this wasn't caused by a gear mesh problem.

This apparent binding due to side axial loading a radial bearing is what happens everytime you use pitch in either direction. Placing high axial loads on radial bearings is mechanically incorrect, IMO this can lead to premature bearing ware and lots extra friction.

This isn't something you want on a micro heli that has very limited battery and motor power. As a result of using incorrect bearings you can expect to see wasted power with reduced run times, premature motor and bearing ware, unsmooth operation, increased bogging during pitch manuvers, and higher temps of both the battery and the motor will occur.

Luckily the Xtreme frame was designed to use both radial bearings and a thrust bearing at each end of the head support. It was...Continue Reading