Some of you may be familiar with field-servicable sensor plugs with screw terminals which can be used to connect the igniter leads with the inside of the e-bay quite elegantly and absolutely gas-tight (but it's finicky to actually "field-service" them).
The igniter leads pass through the part on the left (which has a seal at the left end) and then attached using the screw terminals. The socket with the cables on the right is screwed into the bulkhead, and the plug assembly is then plugged and screwed into the socket.
That's nice, but since the plug sticks out quite a bit from the bulkhead, it can (and will!) get bent or break off on landing.
So I looked for another solution. Cable glands exist but are designed for cables to pass through, not to contain connectors. But Phoenix Contact has small enough connectors that don't need soldering ("field-servicable" again, but much nicer because no screws) and are small enough to fit inside a PG-7 cable gland. So all we need is a way to hold the female connector on the e-bay side. That can be printed:
And this is what it looks like printed and with the connector:
On the other side, the igniter leads run through the acorn nut and a seal into the plug
The seal is printed from TPU, but it's impossible to drill properly sized holes for the wires. Maybe there are good alternatives.
All parts look like this
The bulkhead is just for illustration, it would need a slightly bigger hole. It would sit somewhere between the middle part of the cable gland, the seal washer and the white custom nut.
And this is what it would look like assembled (minus bulkhead).
Now I just need a rocket that I'm willing to entrust to this thing.
Oliver
The igniter leads pass through the part on the left (which has a seal at the left end) and then attached using the screw terminals. The socket with the cables on the right is screwed into the bulkhead, and the plug assembly is then plugged and screwed into the socket.
That's nice, but since the plug sticks out quite a bit from the bulkhead, it can (and will!) get bent or break off on landing.
So I looked for another solution. Cable glands exist but are designed for cables to pass through, not to contain connectors. But Phoenix Contact has small enough connectors that don't need soldering ("field-servicable" again, but much nicer because no screws) and are small enough to fit inside a PG-7 cable gland. So all we need is a way to hold the female connector on the e-bay side. That can be printed:
And this is what it looks like printed and with the connector:
On the other side, the igniter leads run through the acorn nut and a seal into the plug
The seal is printed from TPU, but it's impossible to drill properly sized holes for the wires. Maybe there are good alternatives.
All parts look like this
The bulkhead is just for illustration, it would need a slightly bigger hole. It would sit somewhere between the middle part of the cable gland, the seal washer and the white custom nut.
And this is what it would look like assembled (minus bulkhead).
Now I just need a rocket that I'm willing to entrust to this thing.
Oliver
