I was looking at this article today as well and had a few observations...
According to the Rocketdyne website the RL10C-1 is a pretty large ~25k lbf
engine. It has a length of 86" and a nozzle width of 57". It is an upper stage
engine but judging by the picture I'm guessing the version they tested more of
a sea level nozzle. Even if the engine doesn't have a full sized nozzle that is
pretty impressive that they printed such a large engine.
They mention using copper alloys and select laster melting (SLM). Note- this
is different then DMLS. I'm not as familiar with SLM but I did a quick google
and it lists a company called SLM Solutions. It sounds like SLM is similar to
the EBM process that Arcam uses. Also, I'm just guessing that the alloy they
are printing is in GrCop-84, which is sort of like a high strength / high
thermal conductivity copper alloy.
On Tuesday, April 4, 2017, 5:23:39 PM EDT, William Claybaugh
<wclaybaugh2@xxxxxxxxx> wrote:Do (AR) nose tips see the kind of heating that
would require inconel or the like?
I've wondered if USC/RPL's titanium nose tips are justified for a Mach 5
mission w/ a very short heat pulse....
To be clear, I have not done my own analysis, I'm asking two questions.
Bill
On Tue, Apr 4, 2017 at 7:01 PM Ben Brockert <wikkit@xxxxxxxxx> wrote:
I visited Atlantic Precision a couple years ago, one of the few shops in the US
with multiple EOS DMLS machines, and they were actively printing parts for the
RL-10 even back then. Printing the chamber is big and flashy, but there's a lot
of utility in cranking out highly detailed inco or haynes parts.
For any part with moderate complexity of the nickel alloys it's now cheaper to
print and lightly post-machine than to machine from solid material, even at
small production quantities.
That is of relevance to AR because a one-off printed and sanded nickel alloy
nose tip for a higher performance hobby rocket should quite affordable,
especially if you shop around and make it clear that you're not in a rush for
the part.
On Tuesday, April 4, 2017, Dave Klingler <davek@xxxxxxxxxxxxxxxx> wrote:
Ehhhh…one can always ask. Sometimes people like to talk about where they’re
headed. :)
Dave
On Apr 4, 2017, at 1:17 PM, William Claybaugh <wclaybaugh2@xxxxxxxxx> wrote:
Dave:
Anyone privy to such information is likely subject to a non-disclosure
agreement....
Bill
On Tue, Apr 4, 2017 at 12:24 PM Dave Klingler <davek@xxxxxxxxxxxxxxxx> wrote:
I just saw an article over at parabolicarc about AJR's first 3d-printed thrust
chamber firing. I’m trying to decide whether, from what I’ve read, they’re
substituting copper for stainless in a few spots.
I think design changes are probably unlikely this early, but at the very least
the new manufacturing process opens up the way for different materials and more
elaborate cooling passages that wouldn’t be possible using the old tube
benders. Is anyone on this list privy to what sort of plans AJR has for higher
chamber pressures or other improvements to the RL-10? What’s the schedule for
doing complete engine certification?
Dave Klingler
