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Scott Evil
18th October 2010, 05:09 PM
A pile o' parts I've been collecting, compiling, building, routing out etc since I kinda crashed and burned with my whole "~Diary of a Crapien~" 100% scratch build attempt.

A little less "R&D" this time...(It did serve its purpose though:blush:).

The airframe, couplers and motor mount tubing are ARR Blue Tube 2.0 vulcanized fiber. The nose cone is a 5:1 oJive from Performance Rocketry. All the other goodies are scratch fabricated 1/2" baltic birch, T6061 aluminum, 1/8" G10, galvanized steel and whatever else I end up throwing in the mix.

Built for a big "N" but should fly straight enough on an "L".

Pictured are a couple shots of said "pile o' parts" and an attachment of the RS9 dot RKT file.

Note Crapien I and Crapien II on the right.

FIRST EDIT: As this build evolves, it will be necessary to for me modify the .RKT file attached below. When I do modify and attach a modified design file in future posts, I'll come back here and edit inside the latest greatest in big fancy blue font.

--> [B]LQC V1dot1 TAC 9 C G10 Fins.rkt @ post 30

sodmeister
18th October 2010, 06:49 PM
Wow man ,I wondered what ever happen to that project :confused2:

Good luck with the new project.

Paul

Scott Evil
20th October 2010, 03:37 PM
OK, let's start from the top.

The PR nose cone and ARR tubing are both "LOC Compatible" but don't seem to be compatible with each other. The OD of the shoulder is too large or the ID of the tubing is too small, doesn't matter.

I sanded the shoulder until it was waaay too thin and sanded the BT until it was as thin as I could tolerate. I could stomp them together at this point but getting them back apart was a two person op. Not good enough.

My only recourse was to make the ID of the NC shoulder thicker so I could get the OD thinner.

Once I figured out that a double wrap of whetted glass is too much to keep my two hands on and that 5 pumps of Proline in a kegger cup will pretty catch fire before you're done with it:roll:, I mixed a 3 pump batch and decided a single ID layer would be appropriate to start with.

Well believe it or no, it turned out perfect with just one wrap.

I used little cheapie clips with the sharp ends taped off to hold the wrap from falling into the abyss before I inflated a party balloon to keep the glass compressed for curing.

Scott Evil
20th October 2010, 03:54 PM
I gotta real kick out of getting to pop the same balloon twice and was pleased with the lay-up. It's a little resin rich but will be just fine.

It's a good thing the double layer thing failed, one layer was plenty. The heavy glass I have looks like the same stuff used to mold the cone, little cotton runners through it and all.

Scott Evil
20th October 2010, 04:28 PM
The balloon didn't inflate the Y axis long enough to compress the the very end of the glass to the shoulder so I marked and cut off about an inch and a quarter with a dremel + diamond blade. Still about six inches left, should be fine.

I tried some 80 grit on a power sander for quite a while but this gel-coat is some hard stuff. I then hit it with the "Enforcer" ( a 4 1/2" flap disk grinder) and then hand sanded with some 40 grit to take down the high spots and once again smoothed it out with an 80 grit power sander.

I can get these parts assembled/dis-assembled by myself now on carpet without causing a hernia but some more fine tuning is needed before they get to the field. :gavel:

dixontj93060
20th October 2010, 04:40 PM
OK, I'll bite, why is your Blue Tube white? Did I miss something?

Scott Evil
20th October 2010, 05:35 PM
OK, I'll bite, why is your Blue Tube white? Did I miss something?

Awww man, you blew my grand finale Tim! :eek:

Just kidding, I guess it does look kinda weird. I've been collecting these parts for a few months now and some of them have had a little "Scotty Time" (white primer) previous to the start of this thread.

I'll try to keep the linearity in check.:blush:

blackjack2564
21st October 2010, 06:41 AM
Glad to see your back in business.

Will I see you at Midwest Power?

Scott Evil
21st October 2010, 01:56 PM
Glad to see your back in business.

Will I see you at Midwest Power?

Actually just layin' low as I gathered the parts.

MWP8? Been tentatively scheduling since last year to take vacation that week but the foundry gods have different plans for me. :gavel:

LDRS is lookin' good though.

Scott Evil
28th October 2010, 03:49 PM
I made some modifications to the plan before I started cutting the airframe tubing to size.

I extended the main airframe to 42" to make room for a TAC 9C chute plus associated goodies that go with it. I also scooted the threaded rods further forward on the Av-Bay so I can still reach far enough in to get the wing nuts started. (:confused2: ? , the main and drogue airframes will have bulkheads with holes cut through it to accommodate the threaded rods, U-Bolts and charge canisters. This way, I get the main and drogue airframes secured to the Av-Bay without using external screws or rivets.)

I also weighed EVERY component and punched it into the RockSim Mass Overide. The results are actually not too much different from what the program came up with.

Scott Evil
28th October 2010, 04:21 PM
After I got the nosecone glassed and sanded to fit the airframe, I noticed that it didn't quite fit square, close to flush on one side and a little more than an 1/8" inch on the other.

So, when I marked and cut the tubing, I cut both ends because of irregularities in the factory cuts. (sitting on a glass table and rotated next to each other, they don't always stay parallel).

I used some masking paper wrapped around the tubing to mark and a diamond wheel to cut (< 1mm kerf).

Still no joy with the NC to BT fit, exact same gap.

Need to see if the NC tip orbits around while attached to the BT and rolled on a very flat surface. That should tell me what's off. Anyone's input on that one would be appreciated.

Scott Evil
28th October 2010, 04:32 PM
Here's some of the parts hawged together outside just to make it real.

Unfortunately, the Jet Stream is headed back up where it's supposed to be so I'll be spending some quality time with a leaf rake instead of epoxy or MWP this weekend (gotta work anyway):(.

Scott Evil
19th November 2010, 04:10 PM
Been working much more than playing the last couple weeks but I did manage to get a couple things done.

The first pic is cheap mock-up of the taped together fin templates, the cordless saw I hawged the subsequent fin lines out of 1/2" birch ply with and a sacrificial red shirt fin that I turned into a centering ring.

After I took a pic of the hawged out fins (see Oct. 28 post) I drilled them out and screwed them together to hopefully cure some minor tweakage/warp.

Screwing them together made it real easy to get them absolutely PERFECT size and consistency wise on a 20" disc sander.

Scott Evil
19th November 2010, 04:35 PM
And a quick "BTW"...

I also managed to get my nosecone and main airframe combo rolled on a big hunk o' glass. The tip of the nosecone doesn't seem to do any swirly twirly stuff while rolling so I guess we're golden as Y axis alignment goes. Just some minor sanding tweaking needed for an attractive fit.

Scott Evil
23rd January 2011, 04:48 PM
Work, Holidays, Work, Weather, and a downright loss of patience for trying to straighten out and glass tweaked 1/2" birch fins in a cold environment ( see here)
http://www.rocketryforum.com/newreply.php?do=newreply&noquote=1&p=146613
...has led me to purchase a sheet of 0.1875" G-10 for the fins and whatever else I throw in the recipe.

Here's where I'm at today, I'd go outside now and cut them out but I'll wait until for a nice tropical day of 10~15 ABOVE zero F.:cry:

BTW...GO PACKERS

sodmeister
23rd January 2011, 05:49 PM
I`m with you !

Paul

blackjack2564
23rd January 2011, 06:13 PM
Nice picture of your feet...... and ....er.... the fins too!:D

sodmeister
23rd January 2011, 06:30 PM
Nice picture of your feet...... and ....er.... the fins too!:D

Could have been worse ,at least he wasn`t wearing Penny Loafers !

Paul

Scott Evil
24th January 2011, 01:26 AM
Nice picture of your feet...... and ....er.... the fins too!:D

11 1/2 EE Steel Toe + Internal Mets...for "Scale".

Scott Evil
26th January 2011, 04:28 PM
I took said "chalkboard colored G-10" and cut all six fins out with a 21 PI blade only breaking one in the process.

Scott Evil
26th January 2011, 04:54 PM
Got the cut out fins and tooling clamped down so I could cut the G-10 out over my birch using a flush cut router bit. In theory, I should be able to just trim out the G-10 over the birch fins to get a mirror image .....right?

All set up and feelin' pretty righteous about PPE.

BTW, when I win the Nobel prize for building this rocket, I'll release the 3rd pic to the media as that's the smartest look on my face to date.:kill:

Scott Evil
26th January 2011, 05:34 PM
WOW! My theoretical plans sucked a$$ bigtime. My $14 router bit woosed out inside of a few seconds.

I find it amazing how fast it trashed the bit. I'm glad I didn't hose it down with isopropanol to keep the cut cool, smooth and lubricated like I planned to. That woulda been fun.

dixontj93060
26th January 2011, 05:40 PM
I have tried a number of things to cut G10... For small fins I typically use a Dremel diamond wheel and "nibble" my way around the pattern. For larger fins I simply use a jigsaw--slow going, but accurate and, although the blades hold up reasonably well, they are cheap to replace.


WOW! My theoretical plans sucked a$$ bigtime. My $14 router bit woosed out inside of a few seconds.

I find it amazing how fast it trashed the bit. I'm glad I didn't hose it down with isopropanol to keep the cut cool, smooth and lubricated like I planned to. That woulda been fun.

Scott Evil
26th January 2011, 05:54 PM
I figured I'd be golden with a router but obviously not. How do the Pros cut this stuff out?

gdiscenza
26th January 2011, 07:04 PM
Scott,

From a woodworkers perspective, a $14 router bit is going to crap out on you really fast.

A top quality Freud top shear flush trim bit will cost you about $35, and last a long time, as long as your router has the power to keep it going.

Another suggestion is to go slow, I mean ridiculously slow. The router motor whine should not noticeably drop in pitch if you are gentle enough.

Good luck!

G.D.

Rocketjunkie
26th January 2011, 09:23 PM
I figured I'd be golden with a router but obviously not. How do the Pros cut this stuff out?If you can get a carbide bit, it will cut it like butter. I space the fins apart on the sheet and use either a jigsaw or circular saw. Small fins I use a carbide burr in a Dremel and make multiple passes.

blackjack2564
26th January 2011, 10:31 PM
I figured I'd be golden with a router but obviously not. How do the Pros cut this stuff out?

Table saw or chop saw, always with a carbide blade.

ClayD
26th January 2011, 10:58 PM
I figured I'd be golden with a router but obviously not. How do the Pros cut this stuff out?

Verry expensive - high speed bits. not somehting you'll find at sears or lowes.
I am sure if you ask any curcuit board company, they will tell you the type of bit thier cnc machine uses...

Mcmaster has some...
http://www.mcmaster.com/#carbon-fiber-cutting-router-bits/=argq63

the fiber glass ones look like you can get for 8.00(not expensive i guess, and can run through them pretty fast.)

Scott Evil
27th January 2011, 05:31 AM
Oh yah, carbide...duh!

I haven't trashed tooling this fast since I was a kid.:marshmallow:

Ordered some of these http://www.mcmaster.com/#orders/=arle8a

Scott Evil
28th January 2011, 10:56 AM
While I'm waiting for my carbide tooling, I made some changes to the Rocksim file to reflect recent G10 substitutions. I obviously haven't weighed the replacement components yet but my guess is Rocksim has the mass pretty close. We'll see once I get it all cut out and weighed and mass overrided-ed-ed.

I also added primary and redundant (aluminum not PVC) charge canisters to the "drawn" design and a 54" PML Pilot chute to pull the deployment bag apart.

You may have noticed that the threaded rod is way too long. more on that later.

Scott Evil
11th February 2011, 04:58 PM
The ambiance has been a little chilly lately (-16 today) for cutting fins out so being the little problem solving monkey that I am, I went after some other issues.

This rocket is designed for the ability to install a 50+ inch motor. The design also uses direct drogue harness attachment to the motor hardware instead of other methods. (see rocksim).

Just an eyebolt on the forward closure of my CTI 75mm 6 grain motor hardware (biggest I have, gotta make it work) makes harness attachment kind of a PITA when it's 12" down a 4" tube right?

Scott Evil
11th February 2011, 05:09 PM
After looking for quite a while, I finally found some knarly a$$ hardware a guy could do some damage with.

I bought two and then separated them with extreme prejudice (but didn't heat 'em up and turn 'em blue in the process).

One I'll use for the motor attachment, two I'll use for the av-bay and the forth for the nosecone.

Scott Evil
11th February 2011, 05:33 PM
For the motor mount attachment I welded a nut to a 12" hunk of 3/8" threaded rod and secured the clevis/framis with couple hard washers and a nylock keeper.

This spins like it's on bearings! Weeeeeeeeeeeee!

I fancied it up a little with some red 3/8" ID poly to cover the rod and used a wingnut as a locknut for demonstration purposes (I might use a nylock to help me sleep better).

These parts are kinda heavy and expensive but they negate the need for D-rings on sewn Kevlar endloops.

Pros? Cons?

dixontj93060
11th February 2011, 06:43 PM
Uh, what can I say... KNARLY.:headbang:

Scott Evil
11th February 2011, 06:59 PM
Uh, what can I say... KNARLY.:headbang:

Thanks Tim, :cheers:...:headbang:

blackjack2564
11th February 2011, 10:08 PM
Pros? Con?

Well ....

I see a snagging point for your recovery harness. If it drops around the the rod and shackle, when the apogee fires, it will pull out the shock cord with a vengeance. It is quite possible it could wrap around, get caught on or tangle on your extended fitting, preventing a nice even stretch of the cord. I have seen this cause loss of L-3 attempt.

Looking at your file it shows 2 tubes for the fincan. Looking at the picture I see one.
Are they already coupled together?
Or is another one go on top? If not seems awful close to av-bay.
Bulk plate on top of your rig to keep harness from dropping around it?

If you have this issue addressed . OK then. If not, what then?

A simple resolution is to just bolt on your shackle right to the top of the motor.
When prepping for flight, before the motor goes in, drop the recovery line through the motor mount out the rear of rocket.
Attach to bolt on top of motor outside of fincan & install motor with shock cord already attached. This is how I do it and several others I've seen.

Leaves all the space clean for shock cord & nothing to tangle on.

My 2 cents.

dixontj93060
11th February 2011, 10:36 PM
Yes, for sure. But knarly is not perfect. Knarly is, well KNARLY. Life's a beach. Surf's up dude!
http://i903.photobucket.com/albums/ac232/drdoolittle/Icons%20Animated/Smilies/AnimatedGIF-SurferSmiley.gif


Pros? Con?

Well ....

I see a snagging point for your recovery harness. If it drops around the the rod and shackle, when the apogee fires, it will pull out the shock cord with a vengeance. It is quite possible it could wrap around, get caught on or tangle on your extended fitting, preventing a nice even stretch of the cord. I have seen this cause loss of L-3 attempt.

Looking at your file it shows 2 tubes for the fincan. Looking at the picture I see one.
Are they already coupled together?
Or is another one go on top? If not seems awful close to av-bay.
Bulk plate on top of your rig to keep harness from dropping around it?

If you have this issue addressed . OK then. If not, what then?

A simple resolution is to just bolt on your shackle right to the top of the motor.
When prepping for flight, before the motor goes in, drop the recovery line through the motor mount out the rear of rocket.
Attach to bolt on top of motor outside of fincan & install motor with shock cord already attached. This is how I do it and several others I've seen.

Leaves all the space clean for shock cord & nothing to tangle on.

My 2 cents.

sodmeister
11th February 2011, 10:52 PM
Scott ,how are you cutting the fin slots in the BlueTube ,I`m nearing that point very soon on my AIM-9 Sidewinder.Tools ,I have plenty of tools,just wondering if you use jigs and a router.I`m cutting 1/4" wide slots 15" long x 4

Paul T

ClayD
11th February 2011, 11:17 PM
what keept the whole thing from un-threading from the motor?

blackjack2564
12th February 2011, 01:32 AM
what keept the whole thing from un-threading from the motor?

Lock washer or nylon lock nut or Loctite on threads.

Scott Evil
12th February 2011, 05:04 AM
Pros? Con?

Well ....

I see a snagging point for your recovery harness. If it drops around the the rod and shackle, when the apogee fires, it will pull out the shock cord with a vengeance. It is quite possible it could wrap around, get caught on or tangle on your extended fitting, preventing a nice even stretch of the cord. I have seen this cause loss of L-3 attempt.

Looking at your file it shows 2 tubes for the fincan. Looking at the picture I see one.
Are they already coupled together?
Or is another one go on top? If not seems awful close to av-bay.
Bulk plate on top of your rig to keep harness from dropping around it?

If you have this issue addressed . OK then. If not, what then?

A simple resolution is to just bolt on your shackle right to the top of the motor.
When prepping for flight, before the motor goes in, drop the recovery line through the motor mount out the rear of rocket.
Attach to bolt on top of motor outside of fincan & install motor with shock cord already attached. This is how I do it and several others I've seen.

Leaves all the space clean for shock cord & nothing to tangle on.

My 2 cents.

Thanks Jim, your :2: is always welcome.

The idea was to to keep from having to that but as you point out, the way I have it is snag city. An easy fix. I'll go with plan "A" and pop the shackle right on top of the forward closure.

Attached was just photos of the raw motor mount tube and hardware. Picture a 7.5" zipperless fin can but with a centering ring instead of a bulkhead on top.

Sorry, the 2D on the RockSim is a little busy. Scooting parts around with the components menu helps identify what is what.

blackjack2564
12th February 2011, 08:44 AM
Why not just cut the MM down to 3ft. & glue a 1in flat strap Kevlar Y-harness to both sides of the MM through a notched top CR and between the fins ala Wildman style.
3ft is plenty for any length motor, unless you need longer because of the dual fins.

Keep your idea and connect the top of the motor to the recovery harness with a 6ft tail. [ or whatever size you deem needed]

Now you got the best of both, redundancy and no way anything is getting lost.

This done in many extreme projects. Not necessarily just wildman style but also when eyebolts are used on the top CR too.

It's done a lot where folks want to be sure they don't lose a motor case due to retention failure.
Especially big heavy motors.

Or a ballistic main event that would otherwise cause the motor to come out due to the horrific shock load of a high speed chute opening.

I always tie my motor to the recovery harness on anything 75mm & up.

Why? Because 2x I have yanked the motor out the back, but was lucky enough to find it. [before someone turned me on to tying the front of motor to recovery]

Anyhow just a thought. Glad to see you making some progress!

Scott Evil
13th February 2011, 01:10 PM
Scott ,how are you cutting the fin slots in the BlueTube ,I`m nearing that point very soon on my AIM-9 Sidewinder.Tools ,I have plenty of tools,just wondering if you use jigs and a router.I`m cutting 1/4" wide slots 15" long x 4

Paul T

I'm not sure yet Paul.

A router + jig is probably the cleanest cut but I'm not good enough with it yet to try it on a $90 tube.

I'll probably use my jigsaw or dremmel. I used a dremmel with a nice thin diamond cutting wheel to cut the lengths and that turned out pretty much error free.

sodmeister
13th February 2011, 04:54 PM
I'm not sure yet Paul.

A router + jig is probably the cleanest cut but I'm not good enough with it yet to try it on a $90 tube.

I'll probably use my jigsaw or dremmel. I used a dremmel with a nice thin diamond cutting wheel to cut the lengths and that turned out pretty much error free.

Thanks for your input Scott.Perhaps I`ll have to do a little experimentation on spare B-tube.I was thinking 1/4" solid carbide down spiral cutter and a jig ,but as you said ,don`t want to waste too much tube $$$$
I`ll post results.

Cheers

Paul

gdiscenza
13th February 2011, 05:05 PM
Paul,

You might want to take a look at a compound spiral bit, designed for routing clean edges on both sides of a piece of plywood. The lower half of the cutting surface is an up-spiral, and the upper half is a down-spiral. the effect is that the center of the material is slightly compressed during cutting, reducing chip-out on both faces. For any thicker layered material, it is the bit I would reach for first. You can buy them online from Woodcraft (http://www.woodcraft.com/Product/2081669/32074/Freud-Double-Flute-Mortise-Compression-Router-Bit-12-Shank-12-D-78-CL-Freud-77508.aspx).

G.D.

sodmeister
13th February 2011, 05:56 PM
Paul,

You might want to take a look at a compound spiral bit, designed for routing clean edges on both sides of a piece of plywood. The lower half of the cutting surface is an up-spiral, and the upper half is a down-spiral. the effect is that the center of the material is slightly compressed during cutting, reducing chip-out on both faces. For any thicker layered material, it is the bit I would reach for first. You can buy them online from Woodcraft (http://www.woodcraft.com/Product/2081669/32074/Freud-Double-Flute-Mortise-Compression-Router-Bit-12-Shank-12-D-78-CL-Freud-77508.aspx).

G.D.

Indeed ,great bits ,but pretty "mucho dinero".Seems most come in 3/8 & 1/2 diam. ,but even 1/4" are not cheap.

I have an Onsrud 1/2" dbl.comp. bit I bought years ago online ,cost me almost a hundred bucks !

Think I`ll have to try the down spiral on this one ,or at least try it out.I have used it for slotting Phenolic before with good results ,but I may have to re-learn the process I used.

Paul

Scott Evil
18th February 2011, 05:49 PM
Why not just cut the MM down to 3ft. & glue a 1in flat strap Kevlar Y-harness to both sides of the MM through a notched top CR and between the fins ala Wildman style.
3ft is plenty for any length motor, unless you need longer because of the dual fins.

Keep your idea and connect the top of the motor to the recovery harness with a 6ft tail. [ or whatever size you deem needed]

Now you got the best of both, redundancy and no way anything is getting lost.

This done in many extreme projects. Not necessarily just wildman style but also when eyebolts are used on the top CR too.

It's done a lot where folks want to be sure they don't lose a motor case due to retention failure.
Especially big heavy motors.

Or a ballistic main event that would otherwise cause the motor to come out due to the horrific shock load of a high speed chute opening.

I always tie my motor to the recovery harness on anything 75mm & up.

Why? Because 2x I have yanked the motor out the back, but was lucky enough to find it. [before someone turned me on to tying the front of motor to recovery]

Anyhow just a thought. Glad to see you making some progress!

Sorry, it took a bit to run this through my head.

I'd say my av-bay bulkheads may be more likely to fail structurally under a mondo shock load but they don't have several pounds of APCP packed inside to break them before they get to do their job.

The primary shock load[s] are intended to focus on the forward closure of the motor hardware to keep the fin can attached to rest of the rocket. If this fails via cato or other event, there could be a fairly heavy fin can doing the free fall thing.

So tentatively, I'll go with what I have but add some redundancy like you suggested. I'll pop some split foam pipe insulation around my long swivel invention to keep the Kevlar from looping inside the unused MMT and also add a Wildman style loop through the centering rings and epoxied up the distance of the MMT through the top (CR1).

With the threaded yolk style swivel still right out in the open at the top of the motor mount, I can secure both the sewn Kevlar loop and the MMT loop at a much closer tension point if that matters much more than just convenience of assembly.

Thoughts?

sodmeister
18th February 2011, 08:17 PM
Just a note on the slotting of BlueTube.I made a 3 sided box ,24" long and 3" wide and 2 1/2 tall to hold the tube in.I routed a 1/4" slot down the center ,starting 1" from the bottom and running 16" long (for my purposes)I double stick tape some 120 grit sandpaper on the sides to help grip the tube ,and ran it dwon my router table/table saw using a 1/4" down cut spiral carbide bit.It worked out quite well ,just a single edge razor blade to clean up the slot ridges and a few swipes of 180 SP and Bob`s your uncle !!

I used 1/4" Baltic Birch for the bottom and 3/4 BB for the sides.Just had to make sure all was square and 90.I ran the jig against my Biesemeyer table saw fence.

Paul T

Scott Evil
19th February 2011, 05:50 PM
After months of R &($) D...

FINALLY...


Some viable fins!

sodmeister
19th February 2011, 06:51 PM
Scott ,I presume the router bit you now used made things go smooth.Could you tell me what bit you ended up purchasing ,as I will be in the market for one soon.

Fins look great BTW ,and yes R&D can indeed be quite costly (probably less than my mortgage ;) )

Cheers

Paul

Scott Evil
20th February 2011, 02:42 PM
Paul, I picked up one these http://www.mcmaster.com/#31615a22/=b44zbi
for cutting the CR's with a Jasper Jig

and two of these http://www.mcmaster.com/#35505a61/=b45188 for trimming the fins out.

Basically what I did was rough cut the G-10 so it was about an 1/8" larger on all sides. clamped it to the original birch fins and just went after it with the router.

I did find that the little end knob on the bit liked to burn into the wood and cause little divots if your not careful. No flaws you can see at arms length but not 100% perfect either. ( < 0.5mm deep, some type of filler should get it nice and pretty)

Turning the router speed down to about 60% or so seemed to help that quite a bit.

The flush cut bit got pretty tired and slow on the last fin but probably still has some life left for thinner material.

sodmeister
20th February 2011, 04:27 PM
Sounds good Scott ,thanks for the info.I also do the same for ply fins ,rough cut then place on a master fin template and run it on the router table using a bit with a bearing.

Great project BTW !

regards

Paul

dlb
22nd February 2011, 06:35 PM
Lock washer or nylon lock nut or Loctite on threads.

Exactly, less weight, more room and no tangles, KISS!

Scott Evil
27th February 2011, 04:30 PM
Exactly, less weight, more room and no tangles, KISS!

I've put quite a bit of thought in this set-up and am still thinking through all the fault modes. The more opinions the better.

Scott Evil
27th February 2011, 04:46 PM
I wanted to re-do some of the bulkheads and centering rings in G-10 but was not satisfied with my current tooling. So I picked up a for reals Jasper Jig. Well, it didn't fit my cheapie router so I made my own using the Jasper as a template. (this "Watering Hole" post got me kicking myself in gear http://www.rocketryforum.com/showthread.php?t=19497 )

Some re-posted photos if you don't feel like double linking into TRF.

Scott Evil
23rd May 2011, 07:13 PM
My apologies for the dis-continuity and gaps in time on this thread. It is what it is.

Rocket is designed to fly up to six grain + 98mm but only having 75mm 6 grain hardware on hand, here's what I came up with to keep the recovery materials from getting stuffed and snagged down the motor mount.

I hawged a disc out of aluminum instead using foam or something to barricade the recovery materials from getting looped around the threaded rod extension I put on the forward closure.

The third pic represents some redundant harnessing. If the motor blows the forward closure, there's still some Kevlar to keep the rocket more or less as ONE object falling from the sky.

patelldp
23rd May 2011, 07:39 PM
My apologies for the dis-continuity and gaps in time on this thread. It is what it is.

Rocket is designed to fly up to six grain + 98mm but only having 75mm 6 grain hardware on hand, here's what I came up with to keep the recovery materials from getting stuffed and snagged down the motor mount.

I hawged a disc out of aluminum instead using foam or something to barricade the recovery materials from getting looped around the threaded rod extension I put on the forward closure.

The third pic represents some redundant harnessing. If the motor blows the forward closure, there's still some Kevlar to keep the rocket more or less as ONE object falling from the sky.


I understand your concern...but holy cow man! That is overkill, not to mention a lot of weight in the rear of the rocket. I've never seen someone prepare for the motor to blow a forward closure before.

I have a Competitor 5 kit that I recently flew on a 76-6000 load, and all I do is quick-link the shock cord to the top of the motor. The eyebolt in the case is locked in by a nut and lock washer so it doesn't rotate. On the flight previously mentioned, the rocket had spun so many times that the cord went from 30' long to just under 10'. The eyebolt didn't budge.

In the grand scheme of things, it appears that you have prepared for the worst. If I were you, I would rely on the Aeropack retainer to hold the motor, and then attach your kevlar to the motor mount via a pair of forged eyebolts, or the way that PML and Wildman kits glue the cord to the motor tube.

Scott Evil
23rd May 2011, 07:46 PM
I've been stewing on getting the ends of 7 1/2" Blue Tube nice and flush so all the body sections fit nice and cool style.

No joy with guaranteeing perpendicular on some knarly bandsaws in my neighborhood.

What I did was cut a length of banding steel (like the stuff you use to secure boxes down to a pallet) and then hawg an 8" hose clamp around it.

This theoretically makes for a nice surface to sand down to.....Theoretically...I have yet to stack up the tubing after all the the power sanding, we'll see if they all fit later...

S.E.

Scott Evil
23rd May 2011, 08:51 PM
I've never seen someone prepare for the motor to blow a forward closure before.

You Have Now... :roll:

Scott Evil
24th May 2011, 12:42 AM
I understand your concern...but holy cow man! That is overkill, not to mention a lot of weight in the rear of the rocket. I've never seen someone prepare for the motor to blow a forward closure before.

I have a Competitor 5 kit that I recently flew on a 76-6000 load, and all I do is quick-link the shock cord to the top of the motor. The eyebolt in the case is locked in by a nut and lock washer so it doesn't rotate. On the flight previously mentioned, the rocket had spun so many times that the cord went from 30' long to just under 10'. The eyebolt didn't budge.

In the grand scheme of things, it appears that you have prepared for the worst. If I were you, I would rely on the Aeropack retainer to hold the motor, and then attach your kevlar to the motor mount via a pair of forged eyebolts, or the way that PML and Wildman kits glue the cord to the motor tube.

Actually Dan, I think I'm doing exactly what I think you're recommending in the last paragraph.

1) I have an Aeropack retainer to capture the motor hardware on the back end..

2) The recovery harness attaches directly to the forward closure of the motor hardware. My version looks exotic but is essentially just an imitation of bigger motor hardware.

3) There's an extra "WildMan" loop of Kevlar as a back-up to keep the fin section attached regardless of a motor failure.

I know that trashing the forward closure on motor hardware hardly ever happens, ...but...

Scott Evil
24th May 2012, 04:16 PM
...Whoosh!...(blowing the dust off of this thread)

A handful of traumatic events on the home front have sidelined the project quite a bit. My apologies for such a flaky build thread.

However, a year and a day is a lot of time to re-think things and make a few changes.

More to come...

grouch
24th May 2012, 04:56 PM
Glad you dusted it off, first time I have seen it. Looking forward to the finish.

Scott Evil
8th June 2012, 03:40 PM
Made some drastic adjustments to the build after stewing on it for a year (Thnx Eric, CJ and The WildDude).

The 60" upper section allows me to do something kinda neat. Rocksim to follow when I get the new stuff weighed.

Thinkin' about a Von Karman...maybe.

Photo of new part set after a good scrubbin' with dish soap and green scotchbright.



QUESTION: For those who have been able to stay awake through my past yammerings ( Sono-Tube to Blue Tube and now G12), should I start a new/3rd thread so interested people don't have to suffer through...?



86218

dixontj93060
8th June 2012, 03:45 PM
Wow, bet that G12 was a "pretty penny". Have to ask though, why did you abandon the Blue Tube?


Made some drastic adjustments to the build after stewing on it for a year (Thnx Eric, CJ and The WildDude).

The 60" upper section allows me to do something kinda neat. Rocksim to follow when I get the new stuff weighed.

Thinkin' about a Von Karman...maybe.

Photo of new part set after a good scrubbin' with dish soap and green scotchbright.



QUESTION: For those who have been able to stay awake through my past yammerings ( Sono-Tube to Blue Tube and now G12), should I start a new/3rd thread so interested people don't have to suffer through...?



86218

Scott Evil
8th June 2012, 05:02 PM
Wow, bet that G12 was a "pretty penny". Have to ask though, why did you abandon the Blue Tube?

OK, ya busted me on the G12 thing Tim...:blush:

The sixty inch tubing length is integral to the new plan.

Blue Tube is righteous but G12 is a whole different critter, I can see why it costs so much.

dixontj93060
8th June 2012, 05:07 PM
So are you selling your Blue Tube "scraps"?


OK, ya busted me on the G12 thing Tim...:blush:

The sixty inch tubing length is integral to the new plan.

Blue Tube is righteous but G12 is a whole different critter, I can see why it costs so much.

Scott Evil
9th June 2012, 03:22 PM
So are you selling your Blue Tube "scraps"?

Odds are fairly good they'll hit the Yard Sale eventually. If you're interested let me know (PM).

Scott Evil
17th June 2012, 01:12 PM
Been playing with Open Rocket a little and finding that I really like a lot of the features. Here's a translation from RockSim that I've been putting together, there's a few pounds of mass objects not included yet but it's good start.

One reason all the expensive air frame appealed to me is that you can get it in 5 foot sections. The plan is to set it up so the av bay just slides up and secures into the Main/Drogue tubing, no switchband or separate tubes for apogee and main chutes. 5 feet of G12 is just what the doctor ordered for that.





87160

Yoehahn
17th June 2012, 07:40 PM
FYI: you can buy blue tube in 6' sections direct from Always Ready Rocketry- I personally prefer Fiberglass tho...