# Source for Carbon Rods?

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#### Victor Bravo

##### Well-Known Member
HBA Supporter
When will my hi-aspect Cessna 172 motorglider wings be ready?

#### bmcj

##### Well-Known Member
HBA Supporter
I'm checking out some Chinese suppliers right now for 2mm x 5mm strip.
Are those converted from spent nuclear reactor rods???

#### Hot Wings

HBA Supporter
Log Member
It comes in 410-foot spools, and initial pricing will be $350 each That just put the last nail in the coffin of the idea of building with Spruce.$340 to AS+S for spar caps + packaging and freight - vs - $350 for carbon and have enough left over for aileron, elevator and rudder spars. The cost of the resin and hardener is well offset by not having to glue 18 laminations of Spruce together. Now I just need space and time. #### Lendo ##### Well-Known Member BoKu. remember also your Carbon Flat Strips are already under strain with Dihedral, that should also be considered, if testing straight pieces. Davidjgall, I appreciate your input and High Modulus may well be OK, however the quality US produced Carbon Rods were made by Toray (Japanese) Standard Modulus Tow. Jim Marske's Manual, uses tested strengths and deflection values from those strengths. I believe from a well known designer that even those values should be derated. From my research the High Modulus strips are made for flat application to reinforce other composite like Concrete- externally affixed. Naturally these are just indicators to me, I'm not an engineer. Don't get we wrong I'm not being negative - just the Devils advocate, to assure proper and safe assessment. George #### davidjgall ##### Well-Known Member That just put the last nail in the coffin of the idea of building with Spruce.$340 to AS+S for spar caps + packaging and freight - vs - \$350 for carbon and have enough left over for aileron, elevator and rudder spars.
The cost of the resin and hardener is well offset by not having to glue 18 laminations of Spruce together.

Now I just need space and time.
Hmm. Seems to me an "I told you so" gets inserted here about now....

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
But we tested both our China-sourced and Graphlite pultrusions, and the numbers are comparable.
So does this mean that I'm safe to start with final calculations for my project using numbers based on Graphlite specifications...............presuming appropriate FOS are also used?

#### flyndude

##### Member
I just went to his website and I could find no pricing or way to order monarch F plans. It really isn't what I am interested in for me personally but I would like to see some general wing construction details if I could. I could not find layouts/rib spacing on the website.
Jim's gliders are now being built and sold by Matt Kollman
https://kollmanwings.com/home_Page.php

#### Lendo

##### Well-Known Member
I spoke to Jim the other day, he finally replied to my e-mail about the situation with Carbon Rods, he nearly died recently (Covid I think) and is well over 80 now and says he's retired but still very helpful with information. He thanked me for spreading the word about his Manual.
BTW he says he can't even get an answer from the new European Company to supply quality Carbon Rods, he feels he's probably not a big enough player - probably volume dependent.
George

#### Dewey Vicknair

##### Active Member
I have a plan worked out to replace the wood caps in the Sky Pup spar with carbon tow placed in a dovetailed slot routed into Dow billet foam which will increase its MTOW. Easy Peasy.
How are you getting the wing attach fitting loads into the spar caps? What about the uprights that the wing attaches to? Will that handle the higher gross? In a gust? What about the fuselage structure under your butt, which is literally hanging from the uprights to which the wing is attached? Numbers please.

#### proppastie

##### Well-Known Member
Log Member
the devil is in the details as they say.....that is what we call "design" and how it is done will be on the drawings (if there are drawings) and in the detailed stress analysis. the simple answer will be "as strong or stronger" and most likely if it is just a "plan" "he has not worked that out yet".

#### TLAR

##### Banned
Mr. Vicknair
Would you like to have a conversation about the concept first?

#### BoKu

##### Pundit
HBA Supporter
So does this mean that I'm safe to start with final calculations for my project using numbers based on Graphlite specifications...............presuming appropriate FOS are also used?
According to our first round of tests on the most critical metrics, you'd be safe enough. But in aeronautical enterprises, "safe" can be a pretty fuzzy concept.

#### Hot Wings

##### Grumpy Cynic
HBA Supporter
Log Member
But in aeronautical enterprises, "safe" can be a pretty fuzzy concept.
Understood! I will still exercise my own due diligence once I get to the point of actually ordering some.