Originally Posted by jimbomilligan

The manual I have says 130 for carbon.

I believe my DA-170 manual does too. Seems too tight to me? The hub uses 6mm allens. I also use washers for the allen heads

Doesn't the EVO have a Wood hub? within the Carbon. Maybe over compressing the hub?

I dont believe there is wood in the hub, I believe it is resin. Prince props used to use a carbonated laminated wood in the hub/bade structure.

Straight from the DA170 manual. 75in-lbs. The 85 manual says 90in-lbs for carbon. But I personally torque mine to 120in-lbs. I think DA told us 120 at some point.

Just be careful not to over tighten which im a good example of doing .... stretching my bolts which made them jokers come loose and sheer the rest , I learned the hard way twice..

Originally Posted by jimbomilligan

The manual I have says 130 for carbon.

Jimbo - what is the date on your manual. Mine is "09/08". If yours is dated newer than that I'd like to get a PDF of it (just for general reference).

I can't find this manual on the DA website

There was another lengthy thread on prop bolts a while back. What finally came out of it was the manual calls for too much torque, and most guys tighten them even more than that. Look up the tightening torque for the bolt you are using, and consider that an absolute maximum. Most likely less torque than that is is necessary to keep from crushing the prop hub.

I just found my manual and its dated 4/09 and he is right it says 110in lbs for wood and 130 in lbs for carbon ,but that cant be right. anyone tried, i been 85in lbs and its been working ,On my manual were it says reccommended prop sizes right underneath that it says the torque rec.. but the manual online does not say that it is not there so i assume they changed it http://www.troybuiltmodels.com/ns/manuals/DA-170.pdf

The manual on the troy built web site is the same date as my manual "09/08". So it seems to me that the newer manual (4/09) shows 130 in-lb for carbon fiber. I've been running 75 with no problems, so I think I'll stick with this. I do check them every dozen flights or so. Sometimes they do move a little.

Same as mine

Originally Posted by AJTACZ628

I just found my manual and its dated 4/09 and he is right it says 110in lbs for wood and 130 in lbs for carbon ,but that cant be right. anyone tried, i been 85in lbs and its been working ,On my manual were it says reccommended prop sizes right underneath that it says the torque rec.. but the manual online does not say that it is not there so i assume they changed it http://www.troybuiltmodels.com/ns/manuals/DA-170.pdf

I have had issues with Mejzlick props because the heat from the engine softened the hub contact area. So the bolts had to be tightened continuosly. They should use a better resin and let it cure with a proper thermal cycle.

Originally Posted by modelcompositi

I have had issues with Mejzlick props because the heat from the engine softened the hub contact area. So the bolts had to be tightened continuosly. They should use a better resin and let it cure with a proper thermal cycle.

If th e engine gets hot enough at the drive washer to soften the resin - you have serious overheating problems -
Personally I have neve seen a Mejzlic or a ZM or any prop which was not slipping - show a heat problem

Neither have I.
Mejzlik uses a special powder filled polyester ring as pressure resistant hub inlay, which is better resistant to heat than epoxy.
If the engine hub gets too hot to touch and hold, there is a cooling problem or excess friction in the crankshaft assembly.

The only time my prop hub ever got that hot was when the front bearing was failing.

Originally Posted by dmcquinn

The only time my prop hub ever got that hot was when the front bearing was failing.

Thanks to everyone I will check the temperature from the hub after each fly, maybe I had the same trouble.