View Full Version : Razor belt jumping
busted blade
02-19-2007, 06:41 PM
my tail rotor drive belt jumps out of the flanged bearing on the tensioner and rides on the flange of the bearing. the belt is installed properly and the tail rotor is square. i have tried the belt adjustment in all the holes. anyone experienced this or have any suggestions
mudbogger2
02-19-2007, 07:42 PM
Are your brass spacers under the belt tensioner bearings or on top of them?
If the maingear is not in the proper location(spacers in the wrong position) it could cause this.
Aussieheliguy
02-19-2007, 08:02 PM
WOW and I thought I was the only one. I moved the bearing mount above the brass spacers, fliped the c/f mount and added some nyloc nuts below the plate to support the pem thread inserts and no probs with the belt now after a 7 flights....I submit a pic shortly
Aussieheliguy
02-19-2007, 08:10 PM
Can someone tell me how to attach pics please
mudbogger2
02-19-2007, 09:01 PM
Click the reply button instead of using the quick reply box.
then use the browse button to find the pic you want to upload. Then press the add attachment button. Then press the submit button.
Aussieheliguy
02-20-2007, 02:40 AM
Here is a pic of what I did
wattybotts
02-20-2007, 07:28 AM
I had this same problem for awhile and I eventually traced it to a bent boom going right into the helicopter. I had a few hard landings, and I guess it got tweaked just a hair. Since the boom was higher than the helicopter going into the front clamps, the belt wanted to ride lower, therefore causing it to jump. Take a look at your boom right where it goes into the front clamps, and you might have the same problem.
Aussieheliguy
02-20-2007, 07:40 AM
ok I'll chk but this was happening on the bench with brand new kit not flown yet..
Bernie
busted blade
02-20-2007, 11:09 AM
mine also has not seen a hard landing therefore boom is not the issue. even with the belt tensioner adjusted all the way up it still seems like it could be tighter. i know from experience that belts of the same part number vary slightly in length and im wondering if possibley mine is a little longer. my pulley and tensioner are on boom centerline
wattybotts
02-20-2007, 12:32 PM
In that case just pull the boom out of the clamps just a bit. The belt is holding the boom from sliding out, so just adjust it like you would to adjust Rappy belts.
Aussieheliguy
02-21-2007, 04:55 AM
Hey Busted , I couldn't stop mine running off the bearings no matter were I had the tensioner set, so thats why I did the mod....
busted blade
02-21-2007, 12:52 PM
thanks for the input guys. Bobby, i bent the boom up slightly (it is very soft with the boom support loose) and that solved the problem. now the belt rides a touch above center on the drive pulley and is staying on the idlers
wattybotts
02-21-2007, 12:56 PM
Cool glad to hear you got it resolved.
lawrenmd
04-11-2007, 11:18 PM
I now have about 60 flights on the Razor and this past weekend the tail belt started riding off the tensioner bearings on the drive side. i tightened the belt but that only made it worse. Pulled it apart tonight and checked everything including the boom. I could not find any problems, anyone else have this issue? I may try a new belt, from my experience once a belt has been tweaked they won't run true anymore.
Thanks
misskimo
04-11-2007, 11:35 PM
hey , yeh! mine has been running on and off , sometimes its dead nuts , then like the last 2 flights I did , it run on the flange ,
Dave , I know what you talking about , but small as these belts are, I dont think the flange will tweek it , but it might , its running on the back side , kinda hard to tweek it from that side, plus its running with the gran , but I hope they come up with somethiing soon , I dont like it either , since I cant bend my carbon boom to fix it , :smokin:
t-rexn8
04-12-2007, 01:57 AM
Didnt you cut down an Ion boom Misskimo?
Its a shame the boom is not carbon fiber, everything else is.
misskimo
04-12-2007, 02:54 AM
yep! well it was an old Fury boom
Aussieheliguy
04-12-2007, 03:11 AM
Do the mod I did guys it will stay in the bearing flanges.......Mine does
misskimo
04-12-2007, 10:38 AM
hey , Ill try it when I make it home from work
lawrenmd
04-12-2007, 11:09 PM
I called MA today and spoke with Tim about the belt issue. He has a fix for this and was even considering adding the parts into the next kits. Basically what they did was to add an additional non-flanged bearing to the drive side of the tensioner between the two flanged bearings thus eliminating the spacer on that side. By doing this it allows the belt to ride where it wants to on the bearing surface without riding off the flange. I installed the additional bearing and asscociated washers today after I picked them up, no charge by the way! I will post the results of the mod as soon as I can get some flying time!
misskimo
04-12-2007, 11:40 PM
hey , cool ,
Ultraviolet
04-13-2007, 08:54 PM
The Miniature Aircraft test pilots claim that this belt issue never came up during
hundreds of hours of test flights.
So I ask you............what are the odds ?
Always some differences in prototype testing and final released kits imop.
Cheers,
Tom C
lawrenmd
04-14-2007, 02:03 PM
Ok finallysome flights, 6 today with the mod. No more problems with the belt.
Ultraviolet
04-14-2007, 02:40 PM
Question, Why is the main gear on the Razor considerably wider than the tail drive belt ? If the main gear/ pully was the same width as the drive belt it would hold the belt captive between the flanges thereby eliminating any up down motion.
Maybe it was a standard size off the shelf item that was available in quantity at a low price.
Not sure. Hopefully MA will shed some light on the issue.