Found 4-40 LumaDyne Tube Fasteners

[Antares JS]

Apogee has been sold out of the LumaDyne tube fasteners in the 4-40 size for a long time, and I need one set to finish my current project, and two sets to finish my next project, so I'm looking for three sets total. I've even tried contacting LumaDyne to see if these can be found anywhere else but got no reply. Thank you in advance for any help.

This is the exact item for reference: https://www.apogeerockets.com/Building-Supplies/Misc-Hardware/Aluminum-4-40-Tube-Fasteners-3-pk

 

[FMarvinS]

You may want to consider flat weld nuts https://www.mcmaster.com/weld-nuts) epoxied inside the fiber glass coupler or body tube and countersink drilled hole through the outside body tube. I have used these regularly with either 6-32 or 8-32 flat headed undercut (82 degrees) 1/4 to 1/2 inch length machine screws (https://www.mcmaster.com/flat-head-machine-screws). One hundred screws are less than $5.26 and 25 weld nuts are less than $6. Obviously these are cheaper than the LumaDyne fasteners and the screw heads are flat in alignment with body tube yielding less drag than the LumaDyne fasteners. The only additional item needed is a counter sink drill bit of appropriate size (home depot).

Good luck!
Fred, L2
ICBM, Camden, SC
KG4YGP

 

[rfjustin]

PEM Nuts friend, PEM nuts...

 

[crossfire]

PEM Nuts friend, PEM nuts...

Justin
The prem nuts I understand a under size hole is drilled in the tube and nut is pressed in. Do you use any epoxy to help hold nut in place?
Thanks

 

[rfjustin]

Justin
The prem nuts I understand a under size hole is drilled in the tube and nut is pressed in. Do you use any epoxy to help hold nut in place?
Thanks

Not typically. I have only needed epoxy for Carbon fiber tubing or very thin tubing.

 

[Antares JS]

PEM Nuts friend, PEM nuts...

PEM nuts look interesting and I especially like that they are available in #2 and #4 size, but my question is how do you install them on the inside of a tube? Can you press them in by hand or do you need to use a tool? Do the regular sheet metal ones work or should I use the soft metal/plastic ones with blue tube? I'm looking at the McMaster page on them here.

https://www.mcmaster.com/pem-style-nuts

Thanks for the help. I am really liking these alternatives.

 

[FMarvinS]

Pem nut installation-see frame #9 in : https://www.rocketryforum.com/threads/proper-pem-nut-usage.132253/

Fred

 

[Antares JS]

Thanks a lot! That's super helpful. I'm going to mark this thread as "found" since I'll be switching these projects to PEM nuts rather than using those inserts.

 

[Siya]

They are back in stock with Apogee