shear pins

[hitomshoe]

I want to use shear pins on my madcow 4 inch fiberglass black brant II.
I have not found any rocketry site that sells shear pins and am confused
about what size to use and where to order them from. Any help would
be appreciated.

 

[AHansom]

I use 3 equally space 2x56 nylon screw for shear pins on my 3" and 4" rockets. I get mine from a local store that specializes in screws or " fasteners" for machine shops

 

[daveyfire]

93135A079, 2-3 of those (or similar) per joint will work well.

 

[JimJarvis50]

Assuming both items to be joined are fiberglass, get some #2-56 nylon screws from McMaster Carr, drill 5/64" holes, and lightly tap the screws in with a hammer. 1/2" pan head screws are fine. Piece of cake.

Jim

 

[degreaser]

Here are a couple more suppliers - smallparts.com and mscdirect.com. I checked Enco but couldn't find any there.

https://www.smallparts.com/dp/B00137OQN6/ref=sp_dp_g2c_asin

https://www1.mscdirect.com/eCommerce/NavigationServlet/Machine-Screws/_/N-77e6n?cm_re=Category-_-BodyLink-_-Machine+Screws&Ntk=All_MSC&Ntt=2-56+nylon&Ntx=mode+matchallpartial&Nty=1&rawInput=2-56+nylon%C2%A22-56+nylon

 

[COrocket]

Missileworks also has shear pins:

https://www.missileworks.com/index.php?main_page=index&cPath=3

I usually get them here because I order the PEM nuts for airframe screws at the same time.

 

[hitomshoe]

Thanks and I understand, found some stuff on web about size and etc.
What I really needed was the sites that have the shear pins.

Thanks all
Tom

 

[ClayD]

Hi have heard polystyrene rod works well for shear pins. That it is more brittle when it shears, if your G10 to g10, probably doesnt matter. But if you have paper phenolic, may save you some "hole reaming" fromt he nylon screw

 

[Crazyrocket]

I use 1/16 polystyrene rod. In cardboard tubes, drill the hole and harden with CA. For fiberglass, just drill the hole. I use it for all of my DD flights and not had any issues. The rods are readily available in your LHS.

 

[ClayD]

I use 1/16 polystyrene rod. In cardboard tubes, drill the hole and harden with CA. For fiberglass, just drill the hole. I use it for all of my DD flights and not had any issues. The rods are readily available in your LHS.

i am guessing you buy it in a certain lenght and cut it down, do you treat it a particular way to keep them from falling out or in?

 

[cmcain]

yea i cut em off about 3/8" to 1/2" long and i heat up one end and them push it against a steel ruler to form a flathead, my endeavour is done this way with 2mm styrene rod and i havent had a problem with them yet

 

[Crazyrocket]

i am guessing you buy it in a certain lenght and cut it down, do you treat it a particular way to keep them from falling out or in?

The rods come in 12" lengths. I just push it in and then use a scissor to cut it off. I leave just a small nub sticking out. Very simple and very quick. A 1/16" drill bit is perfect for a nice tight fit.

 

[Highpowerrocketyahoo]

I also use the pins from mcmaster Carr as previously mentioned. FG to FG dosent matter but phenolic to FG or phenolic to phenolic I use a cheap brass switchplate via lowes and cut out small 1/2" square plates out o it and embed that into the tubes or shoulder of a NC drill it and it shears the pins beautifully without hurting your tubes! One switchplate about .99 cents will do 6 or 7 rockets. I have pics if you need a ref.

 

[n5wd]

The rods come in 12" lengths. I just push it in and then use a scissor to cut it off. I leave just a small nub sticking out. Very simple and very quick. A 1/16" drill bit is perfect for a nice tight fit.

+1 more for the .015" styrene rods. You'll find them at hobby shops that deal with railroading as well as model aircraft. With 10 or 12 12" rods in a bag, a dollar bag (or was it $1.50?) will last a long, long, long, time.

 

[qquake2k]

I also use the pins from mcmaster Carr as previously mentioned. FG to FG dosent matter but phenolic to FG or phenolic to phenolic I use a cheap brass switchplate via lowes and cut out small 1/2" square plates out o it and embed that into the tubes or shoulder of a NC drill it and it shears the pins beautifully without hurting your tubes! One switchplate about .99 cents will do 6 or 7 rockets. I have pics if you need a ref.

I'd like to see pics. Do you glue the brass squares to the inside of the body tube?