View Full Version : blade grip spacers?
Scured
03-13-2012, 05:35 PM
i have rail blades on my 7hv...and i sold my old edge se blades to another guy, and gave him the spacers that my rail blades came with before id even finished building the heli. i kept the 4 1mm spacers that i used on my chaos 700 and thought that was all i needed for this heli too....but...i was wrong...so i went to lowes and tried to find some 2mm spacers or 1 mm spacers. and couldn't find any... i found some that were in the middle. and these i could only fit 3 of them between the blades...so i put 1 on the top and 2 on the bottom of the blade. and the blades are a little above the feathering shaft. im trying to figure out this bad wobble shaking vibration that i get when i have my blades attached i im guessing thats what it is...
sooo basically....where can i get some spacers? im in Orlando Fl at the moment...i tried graves hobbies..but they dont have any...no one seems to have em. wanted to fly while im here
Rob43
03-13-2012, 05:52 PM
I found styrene sheet stock at my hobby shop. They stocked it for model trains. It's .080" thick - but it also says 2mm. I traced a circle, and drilled out the center to 5mm. One grip was tight, and the other was not. Material is like this:
LINK (http://www.amazon.com/Evergreen-Scale-Models-White-Sheet/dp/B0006O5I84/ref=sr_1_2?s=toys-and-games&ie=UTF8&qid=1331678889&sr=1-2)
Best wishes,
OverTemp
03-14-2012, 05:16 AM
Besides the fact that the manual specifically cautions against using uneven spacing on each side of the blade (page 21, CAUTION, 1/2 way down the page), this is a very bad idea. It's been known to cause failures in other helis.
You are rotating a large mass with (hundreds of pounds with centripetal acceleration) cyclicly back and forth above the plane of the blade grip's rotation at thousands of RPM, causing extreme stresses. I know logos have broken blade grips because of it, and they are known for their very strong grips.
OverTemp
03-14-2012, 05:17 AM
Duplicate
chucky21022002
03-14-2012, 08:21 AM
I used blade spacers from radix blades. I comes with different thickness.
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GimpyGolden
03-14-2012, 08:45 AM
I'd love to find some nice plastic spacers to fit these grips well, they seem to lead/lag smoother.
I will likely follow your idea Rob.
My Edge blades came with 2mm alloy spacers.
Looking at ReadyHeli I don't see them being sold separately.
alexmit
03-14-2012, 10:29 AM
You can also buy the plastic spacers from Nankin. They are sold separately as a compass part. If you use 2 of them, you will most likely need to sand them down so they will fit either side of the blade.
Right now I'm using 2 spacers that came with my Rail Blades and the Compass plastic spacer underneath.This gets me within .5mm of dead center. I do plan to work on 2 sets of the plastic washers to get them exactly the same so the blades center perfectly. I just looked and saw that there are 2 thicker metal washers in my pack of new rails that I may try as well. Sanding on plastic washers is tedious and not very accurate.
Rob43
03-14-2012, 11:09 AM
Besides the fact that the manual specifically cautions against using uneven spacing on each side of the blade (page 21, CAUTION, 1/2 way down the page), this is a very bad idea. It's been known to cause failures in other helis.
You are rotating a large mass with (hundreds of pounds with centripetal acceleration) cyclicly back and forth above the plane of the blade grip's rotation at thousands of RPM, causing extreme stresses. I know logos have broken blade grips because of it, and they are known for their very strong grips.
Not sure what you're saying is a bad idea. The grips are 16mm open, the blades are 14mm. Need 2mm spacing both sides. Simple as that. Fact of the matter is, the grips as-supplied have residual stress from machining, leaving them to have about .005 variation in gap. One side will be tighter than the other.
OverTemp
03-14-2012, 04:21 PM
The bad idea is something like 2.5 mm spavin on one side and 1.5 mm on the other. The blades need to be centered in the grips. Anything else is hard on the entire system.
Scured
03-15-2012, 12:45 AM
i got some 0.5mm spacers. would that be too many in each grip? even if it puts the blades directly center in the grips. didnt see why itd be a big deal
OverTemp
03-15-2012, 08:50 AM
That would be fine! Just a pain to put in.
alexmit
03-15-2012, 11:14 AM
I just tried and found out the thickest spacers that ship with the Rails center the blades perfectly in the 7HV grips.
Scured
03-15-2012, 11:54 AM
yeah i know but like i said. like a dummy trying to be nice. i gave away the spacers it came with when i sold my edge se blades
Cullen Colapietro
03-15-2012, 07:09 PM
I somehow have a handful of different sizes from different blade purchases. I just hang on to them as some blades differ in size. The Mavrikks needed less spacing than the Edge for example.