Workbench 2.0, Two-Stage 100K+ Build Thread and More

rocket sok
Shop deals on ebay
Advertise with us
The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Kip_Daugirdas said:
I dunno the D7A is fine, hasn't died on me or had any issues. I'm not a radio guy. For what I use it for, basically a 15 minute flight once a year, I'm not willing to invest more. Next year I'll have someone doing backup tracking.
I got tracking back at 26k on the way down. Last packet was at 7k because of terrain. Then I was driving to the rocket and about 4 miles out got another packet.

I must have a good D7A
Click to expand...

Yup, sounds good to me. Lucky too. I have to admit my two were used units so I don't know how they were treated in the past. Kurt
 
Ground Video from Rockets Mag (mislabeled as Noah's project). They got a great shot of the boost and if you listen hard enough you can hear me lose my sh*t when the sustainer lights. Good times!

https://youtu.be/RI3BAEyJ1_s

I hope to have a detailed video edit put together in a few weeks. Also I'm slowly rebuilding parts of the sustainer - no improvements, just a direct copy.

If CTI is back up and running by summer the motors will be an N2501 -> M685. I'm confident with this motor combo the sustainer will top 150k. Updates are also being made to the launch pad so the rail doesn't receive a kick from the 45 deg blast deflector. This was the primary cause for 10 deg off-vertical sustainer flight at Balls 25.

If the flight is successful, then I'll start figuring out what to do next. Despite lots of failures and one semi-success, I'm enjoying the high altitude two-stage projects. Just for kicks, I ran a sim with a 6GXL O3400 booster (same sustainer). The new booster wouldn't be anything special just a stretched (1ft longer) version of what I have today. With the exception of slightly larger fins and a larger main chute but the same avionics and interstage. 200k appears to be within reach. Pretty cool but where does this journey end...Workbench 2.1?
 
Last edited:
Kip_Daugirdas said:
Ground Video from Rockets Mag (mislabeled as Noah's project). They got a great shot of the boost and if you listen hard enough you can hear me lose my sh*t when the sustainer lights. Good times!

https://youtu.be/RI3BAEyJ1_s

I hope to have a detailed video edit put together in a few weeks. Also I'm slowly rebuilding parts of the sustainer - no improvements, just a direct copy.

If CTI is back up and running by summer the motors will be an N2501 -> M685. I'm confident with this motor combo the sustainer will top 150k. Updates are also being made to the launch pad so the rail doesn't receive a kick from the 45 deg blast deflector. This was the primary cause for 10 deg off-vertical sustainer flight at Balls 25.

If the flight is successful, then I'll start figuring out what to do next. Despite lots of failures and one semi-success, I'm enjoying the high altitude two-stage projects. Just for kicks, I ran a sim with a 6GXL O3400 booster (same sustainer). The new booster wouldn't be anything special just a stretched (1ft longer) version of what I have today. With the exception of slightly larger fins and a larger main chute but the same avionics and interstage. 200k appears to be within reach. Pretty cool but where does this journey end...Workbench 2.1?
Click to expand...

In addition to re-configuring the blast deflector have you considered adding guy wires about 3/4 of the way up the rail? 4 equally spaced tensioned wires (or ratchet straps) would lend a lot of stability to the rail.
 
As far as guy wires go, I did have some. I used 150lb paracord, I think I might go with some cord that is a bit heavier duty. I did my best to tension the lines equally when setting up.
ImageUploadedByRocketry Forum1479305496.504136.jpg
 
Kip_Daugirdas said:
As far as guy wires go, I did have some. I used 150lb paracord, I think I might go with some cord that is a bit heavier duty. I did my best to tension the lines equally when setting up.
View attachment 305457
Click to expand...

The setup actually looks pretty good. I would suggest replacing the cords with ratchet straps. You can tension the lines tighter with the racket and you should have some lying around. The big 10,000lb straps would be an option.
 
NateLowrie said:
The setup actually looks pretty good. I would suggest replacing the cords with ratchet straps. You can tension the lines tighter with the racket and you should have some lying around. The big 10,000lb straps would be an option.
Click to expand...

Ratchet straps could work if I go a bit lower - like you suggested 3/4 of the way up. Another option is to use 1/8" dia wire rope similar to what you see being used on sailboat stays to stabilize the mast. The only thing is I don't want is to over tension and introduce a bend/twist in the tower - they are just for stabilization.

pyrobob said:
Fantastic flight!
Click to expand...

Thank you! I want to do it again! Is it summer yet?
 
Last edited:
It's hard to really get guy lines tight. Something always wants to bend, pull other things to far etc. Best bet is to use nonstretch materials..and just snug them up good. We use 3/16 ss cable on the upper portion snd 1/8 kevlar on the lower part. And just use a simple to adjust "taught line device".....Tony
 
tfish said:
It's hard to really get guy lines tight. Something always wants to bend, pull other things to far etc. Best bet is to use nonstretch materials..and just snug them up good. We use 3/16 ss cable on the upper portion snd 1/8 kevlar on the lower part. And just use a simple to adjust "taught line device".....Tony
Click to expand...

Thanks Tony, I like the idea of a cable for the upper portion then some low stretch line for the adjustment length. I used these carabiners for the tension adjustment.
ImageUploadedByRocketry Forum1479320483.631229.jpg
 
Kip, I ended up not attaching my blast deflector to the truss, but rather simply placed it on the ground. This would likely solve your kick problem. I'll have to have my buddy email me the pictures of the pad out in the desert to see if the blast deflector is in it. It is simply a twice bent piece of steel, about 30 inches square.
 
Rebuilding times two! Still a lot of work despite this being the second time around. The difference this year is I'm starting early!!

What you see there is a pile of boards, brackets, bulkplates for two sustainer avionics bays and two camera payloads. It's a lot of crap - I seem to forget that :)
ImageUploadedByRocketry Forum1486169428.421121.jpg

I'm building two sustainers because they don't seem last more than a couple flights but I hope my recovery/reuse rate starts to improve. The goal is to get all the airframe work done in the winter and just have composites (fins) left to do once it warms up outside.

The only update to the design is a new payload bulk plate for the sustainer. The old design had one high-alt 1/4" NPT cannon charge which required me to use 1/8" T-charge as a backup. I found the T charges to be finicky (sometimes only fired out one end) and made packing my already small recovery bay more awkward. So the update is two 1/8" NPT cannon charges which I was able to squeeze in behind the GoPro. (New guy is on the left.)
ImageUploadedByRocketry Forum1486169549.265692.jpgImageUploadedByRocketry Forum1486169608.216359.jpg

In addition, I'm designing a new first-stage booster for a 6GXL case. This really just consists of some new fins to account for the added booster length. It will have 4 fins instead of 3 with a .250" longer span than what was on the original. This change is to push the CP back given the added 10" of airframe for the longer case. The avionics and interstage will come from the original booster.

Improvements to the launch pad are also being made but I'll document that in my pad thread.

As eluded to in a previous post the flight goals for 2017 are:
Flight 1: CTI N2501 -> AT M685
Flight 2: CTI O3400 -> AT M685

Flight 2 on the new booster is a stretch goal but I would really like to squeeze it in.

I often get asked: "Why are you using commercial motors?"
I know commercial motors can be lacking in performance and are expensive - particularly the 98mm boosters. But I'm choosing to fly commercial because I know what I'm getting performance wise and that really helps me dial in my staging delay and predict my ascent time/apogee. Overall I think it increases the likelihood of success.

So will I start flying EX in these projects? You bet...just not this time around.

More to come...
 
Last edited:
Hahaha - I love those "pile of parts" photos :)

Kip_Daugirdas said:
What you see there is a pile of boards, brackets, bulkplates for two sustainer avionics bays and two camera payloads. It's a lot of crap - I seem to forget that :)
.
Click to expand...

rings.jpg
 
Hi Kip,

I'm machining some bulkheads for a 3" project. I like how you used the 1/8" NPT pipe as a charge well. That's a lot easier than machining them from solid stock. BTW: McMaster has them in aluminum if you want to shave a few more grams.

Would you mind telling me where to find that U bolt you're using as an anchor point?

Thanks,


Chris
 
ChrisAttebery said:
Hi Kip,

I'm machining some bulkheads for a 3" project. I like how you used the 1/8" NPT pipe as a charge well. That's a lot easier than machining them from solid stock. BTW: McMaster has them in aluminum if you want to shave a few more grams.

Would you mind telling me where to find that U bolt you're using as an anchor point?

Thanks,


Chris
Click to expand...

I think the aluminum 1/8" NPT tubing has a smaller ID than brass so it can withstand the same pressure rating? I'm not positive b/c I don't have any in front of me. But I'm sure either will work.

Search for 'rope guides' in McMaster, I used P/N 8860T83, w/ 10-32 flatheads. The flatheads screw directly into tapped holes in the 6061 bulkhead - no nut on the backside. With .20" of thread engagement the 10-32 will break before stripping the aluminum threads.

They aren't load rated but for small rockets they can take very harsh deployments without any issues.
 
Last edited:
Thanks guys. I knew I had seen them somewhere but I couldn't remember the name of them.
 
I will forgo the end of the season closing parties at ski resorts this weekend and dork out on this project. When you look at it, I don't have much time until summer Black Rock launches start. There's still the variable that it's a lake but I'm going to build like we had another drought this year.

On tap for this weekend:
I want to airfoil, tack and fillet the fins on sustainer 1 and 2. This time around I am using Hexel IM7 6oz fabric - thanks for the introduction Steve Heller. The fin blanks you see in the pic are .060" nominal G10 FR4 with two layers of carbon laminated to each side. 0, 45, G10, 45, 0 layup pattern. These came out a bit thicker than the fins .100" versus .085" on the original Workbench sustainer. This is because the G10 I used on the rocket was .050" thick - I couldn't find more of this stuff. Must have been a sheet on the low end of the manufacturing tolerance.

I will be using my manual jig to sand in 5 deg on each side of the fin. 6 fins = 6 hours heh. But I like the manual jig because I can really control the bevel. I shoot for .010" of the original edge of the fin to remain after the bevel - so pretty damn sharp.

After the bevels, I'll tack them to the airframe with JB Weld Quick. Then fillet with HTR212 and milled fiberglass. So here's to being productive and getting work done this weekend.
ImageUploadedByRocketry Forum1492275342.257402.jpgImageUploadedByRocketry Forum1492275409.061901.jpg

Workbench 2.1 booster blanks are the naked G10 ones. They haven't been laminated yet like the sustainer sets.

Hopefully your weekend is productive too!
 
With reference to the EasyMega and the issues with baro based apogee detection over 100k ft MSL, would it be possible to leverage the 3 axis magnetic sensor for the apogee event? I could be grasping at straws here but I routinely fly at our smaller field with a simple magnetic apogee detector (specifically Wooshtronic's uMAD). It's a fairly flawless system. I say fairly as on Sunday I had my first failure with it; specifically I was arming it via the twist and tuck method and when I went to tuck the wire "switch" into the airframe the apogee charge blew. Strange.

Regardless, great flight and thanks for documenting everything Kip. You've convinced me to pick up an EasyMega for staging despite the issues with documentation.
 

Similar threads

Rocketman_dan
Agena I High Performance Two Stage Pathfinder
Replies
1
Views
353
waltr
W
J
Balls 31 two-stage to 50K attempt
Replies
4
Views
1K
kjhambrick
K
Kane
Design and Build Thread: ARO-B Two-Stage
Replies
22
Views
2K
Kane
Kane
morgandemarigny
building LOC Terrier/IRIS as a two stage dual deploy
Replies
1
Views
401
Titan II
Titan II
Superza
Road to Three-Stage
Replies
10
Views
1K
Superza
Superza

Latest posts

Back
Top