First HPR Build - Wildman Punisher 3

[thzero]

Wonder what the strength and temp ratings are on the 6 minute?

https://www.jbweld.com/product/j-b-kwik-professional-sizeKwikWeld™ cures to a dark grey color, is rated at a tensile strength of 3127 PSI and will withstand temperatures up to 300ºF.

https://www.jbweld.com/product/j-b-weld-twin-tube
J-B Weld™ has a tensile strength of 5020 PSI and sets to a hard bond overnight. It can withstand temperatures up to 550ºF when fully cured.

And for comparison, West System 105/204
https://www.westsystem.com/products/compare-epoxy-physical-properties/
System3
https://www.systemthree.com/products/general-purpose-epoxy-resin

 

[cautery]

Ah apologies...the pictures themselves make it look like the fins are misaligned/angled. A degree off is acceptable imo and I wouldn't expect a rocket kit to be more precise than that in this situation.

Zero apologies required! They are "off" but in the least "bad" way possible! They are all 3 close enough to parallel to the air-frame centerline to call them "parallel". Just the one slot is clocked a bit wrong..... Based on the arc angle chord and OD of the body tube, it is 1.9 degrees off of the 120 degree multiple (e.g. 118.1 or 121.9 degrees from the adjacent fin depending on the direction you travel around the tube).

With the jig slots being wider than twice the error, I am pretty sure that I can jig up using the accurate set of jigs and rotate the jig to split the error difference. THEN, I can index 2 fins off one side of the slot and the third fin off the OTHER side of the hole. With "back of the envelope math" I should be able to set two of them to be "straight" while resting (no daylight) against one side of the slot. The THIRD fin should require a small shim to keep the daylight "even" on both sides.... a little on one side and a lot on the other.

And no... I wouldn't expect closer tolerances on 100% of stock either.... unless I was the manufacturer.

Check the fin fixture.
Go to https://www.payloadbay.com/index.php?page=Tools&action=FINGUIDES
and print out a fin guide. Then lay the WM guide on top of the print out to compare.

As others stated. If fin slots are parallel to BT then all is good. Maybe just file out a side of the slot that is off so the fin fits in the guide. Internal & external fillets will fill in the small gap..

Excellent suggestion.... I did. The jig set is "better" than the tube, but ALSO suffers from the same malady.... TWO of the jig slots are near perfect. The third slot is clocked "out" a bit. Less than the tube, but still out.

I am guessing that a "perfect" jig is apparently quite difficult to make.
As described above, I AM able (just) to "distribute" the errors over the system and find a place where I can jig all three fins perfectly vertical while keeping them parallel to the air-frame center-line.

I tack my fins on with 6min JB weld all the time. I would not worry about the capabilities of 6 min vs original JB Weld. Both will outperform what you need them to do, most certainly.

Tack all (3) on in one shot, slide the alignment guides on, let it sit for 30min. Slide the guides off, let it sit an hour. Then do your permanent fillets. You should be able to do all of them in (1) sitting. JB Weld is zero sag so just do it all at once. You should be able to build the entire thing nearly in one shot.

Woo hoo! Pretty sure that is the direction I am going to head toward then. Especially after reviewing the material @thzero put together for me below!

https://www.jbweld.com/product/j-b-kwik-professional-sizeKwikWeld™ cures to a dark grey color, is rated at a tensile strength of 3127 PSI and will withstand temperatures up to 300ºF.

https://www.jbweld.com/product/j-b-weld-twin-tube
J-B Weld™ has a tensile strength of 5020 PSI and sets to a hard bond overnight. It can withstand temperatures up to 550ºF when fully cured.

And for comparison, West System 105/204
https://www.westsystem.com/products/compare-epoxy-physical-properties/
System3
https://www.systemthree.com/products/general-purpose-epoxy-resin

Thank you sir! You are a scholar and a gentleman! You didn't have to do that, but I sincerely appreciate the effort on my behalf!
Even the 6 minute is better temp-wise than the West Systems... cool!

 

[KenECoyote]

I am guessing that a "perfect" jig is apparently quite difficult to make.
As described above, I AM able (just) to "distribute" the errors over the system and find a place where I can jig all three fins perfectly vertical while keeping them parallel to the air-frame center-line.

Would a Guillotine-style jig or the fin jig I'm working on making in my build thread resolve the issue you saw?


(Work in progress and I'm going to add a rod to the end for verifying that the fin and guide are vertical.)

 

[thzero]

Thank you sir! You are a scholar and a gentleman! You didn't have to do that, but I sincerely appreciate the effort on my behalf!
Even the 6 minute is better temp-wise than the West Systems... cool!

Well I was curious too about it, the others I had linked because they are some of the epoxies I tend to use.

 

[cautery]

Would a Guillotine-style jig or the fin jig I'm working on making in my build thread resolve the issue you saw?

View attachment 550958
(Work in progress and I'm going to add a rod to the end for verifying that the fin and guide are vertical.)

Well.... yes and no. YES - If I had a known-good jig that produced work meeting my tolerance level, I would have used it right away and discovered the minor mis-clocking of the one slot immediately (I'd say the jig set, too.... but I would not have bought them had I already possessed a superior solution... and more $$$ of course). And having discovered it last November, the problem would have been resolved before I started building THIS November.

But, NO - No jig, save one that has infinitely adjustable fin clocking (and why would it?) would "resolve" the problem. It would need to be filled and re-cut. And it's not serious enough for that. It's going to fly just fine.... I predict "awesome" in fact.

HOWEVER, I am quite intrigued with your design so far. I'd like to fully understand your concept if you are so inclined.... Shoot me a PM.

Well I was curious too about it, the others I had linked because they are some of the epoxies I tend to use.

Well, thank you just the same! And NOW, I have the System 3 website.... and added to my list of adhesive systems to audition.

 

[boatgeek]

Well.... yes and no. YES - If I had a known-good jig that produced work meeting my tolerance level, I would have used it right away and discovered the minor mis-clocking of the one slot immediately (I'd say the jig set, too.... but I would not have bought them had I already possessed a superior solution... and more $$$ of course). And having discovered it last November, the problem would have been resolved before I started building THIS November.

But, NO - No jig, save one that has infinitely adjustable fin clocking (and why would it?) would "resolve" the problem. It would need to be filled and re-cut. And it's not serious enough for that. It's going to fly just fine.... I predict "awesome" in fact.

HOWEVER, I am quite intrigued with your design so far. I'd like to fully understand your concept if you are so inclined.... Shoot me a PM.



Well, thank you just the same! And NOW, I have the System 3 website.... and added to my list of adhesive systems to audition.

I can’t say enough good things about System 3 products. Their Silvertip is a great laminating resin and T-88 works well for long-cure adhesives.

 

[cautery]

"Discovered" a (new to me) technique quite by accident and chance today. A technique that I will add to the list for future use.
I used o-rings to shield the vent holes in the Punisher's centering rings to vent the booster out the back....

The o-rings work great to keep the holes open if you are going to inject adhesive, pour dams, seal, et al.
The ones I used had an OD JUST barely wider than the centering ring....
When I inserted the motor tube assembly into the air-frame the o-rings did TWO things.

1) Acted like "centralizers" which would come in SUPER handy if you needed to make very loose tolerance (wrong size/brand of tube match et al) parts work as CRs, bulkheads, etc.

2) Acted as friction stops that positively locate the motor tube fore/aft in the air-frame. This would come in super handy in a number of instances, probably led by the need to centralize and fix in place a motor tube assembly that has loose centering rings.

Would not have discovered this had I let folks talk me out of trying vents through the CRs...



That assembly would not hang there without the o-rings....

I can’t say enough good things about System 3 products. Their Silvertip is a great laminating resin and T-88 works well for long-cure adhesives.

Cool! I only briefly scanned some of their adhesive offerings.... Looks promising. Appreciate you taking the time to add your endorsement.

 

[cautery]

Nomenclature: Hole, Nut, 0.25"
Status: UNSAT
Prognosis: EOL

I just couldn't do it. Especially not after buying a few drilling tools today.... like a round stock centering jig. (If I can figure out how to house a dial indicator in a 1/2" drill chuck, I'll have something.)

Hole patching in progress.... just too far out.


It is somewhat difficult to tell from this angle, but the faint pencil line running through that partially patched hole does NOT bisect said hole geometrically.

This is bad in OCD-world, because the OTHER rail button hole falls PRECISELY astride said line, and thus.... these TWO rail button holes are NOT STRAIGHT. Never mind that they are intended to guide this rocket on its first 6 feet or so of violent acceleration.... FIRST STEPS and all that!

We're gonna try this again while I mull over.. uhh, contemplate... no, errrr..... dream about magic rocket tube jigs, ripped fin roots, filled slots, surface-bonded fins, and motor adapter/retention designs.


BONUS:

As an aside, here is the "Tool Report". Interior Tube Sanding Tools.... hideous name. Tried both versions out.

The rigid core version just isn't going to work. Even with only a slight mismatch in diameters, you still only get a very small contact patch.

The Flex-Core Sanding Tool (better) worked much better. With about the pressure you'd be applying anyway, the closed cell poly foam compresses and conforms to the significantly larger diameter quite well, producing a consistent result in a fraction of the time without the tool.

Now, the rigid tool has its pluses... It is a nice rigid platform over which other materials can be placed producing an even better combination.
My guess is any PVC coupler, et al. with a consistent diameter and a layer of closed cell foam on top of that at least 1/2" thick, then the wet/dry paper atop that... You can tune texture, cut speed, et al. with padding thickness, material density,... I'll keep playing with this.

I see a place for soft and firm backed wet/dry in 220 and perhaps other grits. The rolls would be disposable for the most part. But there would be a much more expensive reusable tool/core for use with standard sandpaper for less wastes.

 

[cautery]

Aft Rail Button Broaching Nut (aka: 8-32 PEM Nut) - Basically a repeat of the Forward Rail Button Broaching Nut...

LEFT: Patch was done in 2 instead of 3 fill/sand cycles. Sanded flush. Then, I literally spent hours trying to get a vertical line coincident with the center of the fwd rail button location and on the vertical line that is parallel to the centerline. I used a small plumb bob and 40 GA nichrome wire to hang it. This gave me a sharp sight line to compare to the pencil marks. FINALLY got something with which I think I can live.

RIGHT: I won't go into detail on this drill setup, as it is near-abouts THE most janky and redneck make-do setup I have ever used. I will have proper jigs and tools before I do this again. Geeeeezzzz!



LEFT: Just like before, using my screw & washer stack "tool" to set the PEM.... another negotiation with the fiberglass.

RIGHT: I believe that I am still going to have the screws pointing slightly different directions.... Less magnitude than originally & in the opposite direction, but they are not the SAME. It will work great though.


Here's a question:

When you install your rail buttons, do you tighten them down until the button is non-rotating "snug", or do you use thread-locker to lock the screw JUST before the button locks down so that it can rotate during launch (less wear and friction?)?

I'm leaning toward a just barely freely rotating rail button.... blue or green thread locker.

Hopefully, I can get this broaching op finished and epoxy applied/cured. I'd LIKE to put the motor tube the REST of the way in tonight.

 

[rocketman328]

Thanks for that!




Hmmmm..... I'll store that away for later use. I am of course using JB Weld OROGINAL for the motor retainer, and am contemplating using it for tacking the fin roots in due to its higher temp rating, ultimate bond strength, ability to "read" the bond line from inside the motor tube, and most importantly, the long open/working time to get the fins PRECISELY where I want them.

But that is essentially 3 DAYS to tack 3 fins (properly).
Wonder what the strength and temp ratings are on the 6 minute?

I just noticed last night that my two rail button holes are "off" (still). It is the tiniest amount, but it bugs me still. (I REALLY need to get a REAL round stock jig.... the wooden one I am using is not accurate enough.)

The forward one (the one I re-drilled and repaired) is dead nuts on.... The aft hole is clearly not bisected exactly by the line that bisects the fin slot. I don't think it is enough to be significant, but it bugs me. IF it causes issues, I can just remove the buttons, drop a set screw in the holes, and use my fly-away rail guides.


Thank you! I'm trying my best considering the limitations under which I am operating.

Misaligned rail buttons would drive me nuts, lol. Two schools of thought I guess. The good ole boy method or good engineering, entirely up to you

 

[cautery]

Rail Button broaching nuts installed fore and aft.... they aren't perfect, but close enough to use reliably. And I always have the fly-away rail if I want.

Motor Tube Assembly Installed... Learned a lot on this one. Have a long list of additional tasks to accomplish on the next bird.

To use a PEM on the aft location, it required that the motor tube assembly be HALF installed... Had to get front CR past the station where the nut gets installed, or it ain't going.

Then, once the PEM was encapsulated and bonded to the inside of the booster tube, I did a final scrub, brush/wash, rinse the aft CR station front and rear face. Cleaned up the inside of the body tube as well to have clean and dry mating surfaces. Wet out the edge of the CR, the inside ring of body tube the CR scrapes forward as it is inserted. Added thickened epoxy on the CR forward face in between the fins and vents. Enough and just thin enough to flow and self-fillet between CR and body tube (fixed vertically in place to cure).

See the images below...

Misaligned rail buttons would drive me nuts, lol. Two schools of thought I guess. The good ole boy method or good engineering, entirely up to you

Me too.... that's why I filled and sanded the aft hole and re-drilled it. Took most of a day to finally prove to myself that the line I was drilling on was straight and parallel to the rocket center-line.

They're close.... see below.


LEFT: Here you see the PEM inside the body tube, the Motor Tube Assembly pre-inserted in front of the nut.
RIGHT: Another shot with the vent rotated out of the way. Took about a dozen bind/unbind cycles to get the PEM fully seated in a relaxed state.


LEFT: Shot from the rear... Trying to show the degree to which the rail buttons are not perfectly aligned. Hard shot to get.
MIDDLE/RIGHT: These show it if you know what to look for. Forward button mostly in focus, The bases of the two screws penetrate the air-frame on the same vertical line. BUT, somehow the aft rail button is now "leaning" to the "right" relative to the forward rail button. Zoom in on right most photo and the magnitude of the error, such as it is, is apparent.



ABOVE: Motor Tube Assembly is epoxied into the air-frame. Used one of the fin jigs to fix the airframe vertically until the epoxy fully cures.

Should be able to get the wings tacked in tomorrow...

 

[thzero]

LEFT: Shot from the rear... Trying to show the degree to which the rail buttons are not perfectly aligned. Hard shot to get.

Looks more than good enough!

 

[cautery]

Front Centering Ring (CR) Epoxy Dam - Not as straight forward as one might expect.


Left to Right: First: 1x; no flash image looking inside airframe from the top. Dual harnesses are pushed down through the MT and out the back. Note the three tiny bits of daylight about 120 degrees separated. This is the gap between the centering ring/fin slot, et al. Gonna need to block that BEFORE we pour the dam here.

Second, is 1x; w/ flash where you can see the pour better and just how far it is down there to that unsecured CR.

Then, 2x; no flash with forward rail button screw run in all the way to show you where it is.

Finally, 2x; w/ flash. You can see the SS, 8-32 screw. More importantly, you can see the existing fillets on the inner diameter of the CR. I estimate that the volume "protected" by the o-rings I installed is about half consumed. I can use this in calculating how many CCs to deposit outside the "NO GO" areas of the fins and vents.

Now since those gaps need to be closed up first to stop adhesive migration, and my math MIGHT be a little off on the volumes for the outside fillets on the CR, I am going to REHEARSE first with WATER using the tool I hacked together below. (New temporary tool since my EFD hasn't arrived and my pressure activated fluid rod design is not finished yet.)


LEFT: Overview of the "Remote Epoxy Placement Tool" Here are the materials:
1 each - 10 ml syringe with Luer lock
1 each - Large gauge needle to accomodate whatever fluid viscosity you are dispensing.
2 each - 3/8" x 36" hardwood dowel rod
1 roll (partial) - 3M Electrical Tape 33, 33+, Super 88 or whatever you use
1 0.3mm pencil
2 pieces of Scotch Tape (3M) to cover and protect the volume markings.
2 each steel nuts, long, with ID slightly larger than 0.375"

RIGHT: Close-up shot of the volume markings transferred from the syringe barrel. LOADING by vacuum takes it above 10 ml. Push back to 10 ml and you are loaded and ready to shoot.



ABOVE: Here you see the airframe fixed vertically, and the new injection tool in place as for use.

However, I can't (should not) inject the dam yet. Need to close off those 3 gaps at the forward centering ring first, AND I just figured out that IF I tack the FINS in FIRST, then those gaps will likely fill themselves when I butter the root edge AND the forward and aft edges that contact the centering rings (to seal against internal fillet material migration.
And I am not ready for that yet.... So off to the "blue" home store for JB Weld 6-minute, red oak for table saw runners, finger jig materials, et al. Hopefully I won't have to go to the "Orange" store today.

 

[cautery]

Odds & Ends - Decided to write up all the "rat killin'" I did today. Spent some time on "Order of Operations" for the build going forward:

• Can't pour the front CR epoxy dam before I tack the fins in and close off those little gaps to the dam and the internal fillets.
• Can't tack fins in until I sand the airframe exterior....
• Don't WANT to sand the exterior until I have finished all the machining on the airframe.
• Can't drill the rest of the holes until I fit the avbay to the airframe & the nosecone.
• Can't fit the avbay to the airframe and nosecone until I drill the avbay bulkheads for the all-thread...

You get the drift... So here are the images for what I did/am doing tonight:



LEFT: Avbay bulkheads taped back-to-back with double-sided tape to drill the center hole for the all-thread.

MIDDLE: I have limited resources and no room for any more. Some newer stuff might help. My 25+ year old Delta Drill Press has seen better days. This is what I have to go through these days to hold </= 0.01" tolerance on positioning. I bought that drill press vise to make things "easier". Easier in some ways; harder in others. Had to clamp down two bridges across the vise to hold the traveling jaw down on the bed.... It kicks up when you tighten the vise.... which kicks the work-piece UP and causing a NON-vertical hole. Grrrr...

RIGHT: Bulkhead #1, bulkhead #2, 1/2" plywood backer..... Looking for wood.



ABOVE: A little video of this drilling operation...



LEFT: Avbay bulkheads taped back-to-back, drilled, all-thread in, verified straight with squares.

RIGHT: I ordered special drill bits sized to CLOSELY fit the diameter of the 4-40, aluminum all-thread. All-thread is 0.1072". Through-holes were drilled with a 0.1085" (or so) bit.



LEFT: Avbay roughly assembled with 4-40 aluminum all-thread, aluminum washers, and aluminum nuts. The all-thread will provide the ground plane for the pyro circuits.

RIGHT: A little demonstration of my ongoing work to make the seams disappear. I have the pieces indexed for best "unmodified" fit. Drew an index line across both seams. Then with a little bit of inward pressure, I twist the pieces together approximately 1/8" either side of the index mark. This very slowly, and rather accurately, grinds down the high spots and results in a VERY close fit. The smaller the swing distance on either side of the index mark the better for the fit..... but the time to finish goes up rapidly as the twist arc decreases.



LEFT: My 20+ year old Craftsman Table Saw..... It is a compromised tool in virtually every respect, but I surely have built a lot of stuff using it. I'm going to spray it down with that "green" stripper.

RIGHT: Fully covered; tick tock...

Gotta go draw up the cross-cut sled and finger-joint jig... To be continued.

Y'all be well!

 

[cautery]

LEFT: Doing a test of the 3M High Strength Small Hole Repair, Heavy Duty Interior/Exterior White Patching Compound. Masked off a section around the PEM test I did on the 1/16" G10 Fiberglass sheet.

RIGHT: I purposely dug grooves in the test section with the back of the tip of my knife. Then I sanded the section with 220-grit wet/dry paper to simulate a piece prepped for primer/paint but has some filling needs.



LEFT: Waiting on it to dry.... It DOES dry fast. And it'll take a little time to get comfortable applying it.

NOTE: HIGHLY recommend that you take a portion, sufficient for the task at hand, out of the tub and close it back immediately. Make SURE it is snapped on all 4 sides. THEN, use your spatula to stir/mix the material before application. It is well-mixed already, but it gets smoother and easier to spread with just a little mixing.

Planning on doing "test" fillets with varying diameter tools and then use those test fillets to further test the 3M stuff as a glazing putty.

RIGHT: 15 minutes and I was able to scrape the high areas clean with a plastic scraper and the grooves were hit with a plastic bristle brush. Sprayed on a second coat in selected areas, and will let it sit until tomorrow. Need to wipe it down, flush it clean with water, and blow it dry with air. THEN, check to see if I can tune up the saw linkages, et al. Zero odor.... was able to use it indoors (garage) with the door OPEN to keep me from freezing to death.

I think I may be done tonight.... we'll see...

 

[cautery]

3M High Strength Small Hole Repair Patching Compound - Preliminary Test Results

Bottom Line Up Front: This stuff has performed better than I could have possibly expected!! It deserves greater attention and "real" testing. Barring some unforeseen discovery, I will be using this on this project as a glazing putty for the entire airframe prior to some paint system.

Shout out to my man @jqavins for turning me on to this 3M stuff HERE!!! And to @hobie1dog for mentioning the use of "spackling compound" and restoring all those rockets which appears to have prompted @jqavins. And to @lakeroadster and everyone else who was part of the discussion leading up to "planting the seed".

Preliminary Test Description - Bugger up a section of fiberglass similar in composition to the airframe. Use the 3M product to try and "repair" the issues and prepare the surface for primer/paint system. Looking for 1) full fill in one pass (not often achievable), 2) durable enough to stay where it belongs under wet sanding (400 & up), 3) is at minimum "heat neutral", meaning the use of the product doesn't make heat MORE of an issue.

Results below...


ABOVE: After allowing the compound to dry thoroughly, I block-sanded with 3M 600-grit, wet/dry. Sanded dry first to "see", then when it was "close", I switched to wet sanding. I was pleasantly surprised that it reacted so well to wet sanding. The primer, polymer, and "trade secret" ingredients apparently make it somewhat waterproof after curing.

The "repaired patch" and surrounding area are much, MUCH smoother than the rest of the plate. As new, of course, the plate still has the peel ply pattern on it, which gives it some texture. But in the repaired area, you cannot tell the difference between bare vs. covered in 3M compound.... at all.

Gotta mention that there BBQ torch right? So yeah, I was contemplating a rocket with this stuff on it then traveling at MACH+ (a LOT past MACH 1). Likely to get a mite toasty at those speeds in certain areas.

So I torched the patch... and the surrounding uncovered, but sanded areas. I mean... I really torched it.... Flame front contact, back and forth as evenly as I could across the entire square.... I stopped at just short of "smoke" starting to come from the surface (non repaired surface) but definitely after smelling some off-gassing in a "waft".

Then, I quickly took temp readings from several areas on the "repaired" portion vs. the non-repaired, but sanded areas.

THE REPAIRED AREA WAS SIGNIFICANTLY COOLER!!! Not just a little bit cooler.... Potentially game-changing cooler!

Unpatched, but Sanded = Approx. 240° F
Patched and Sanded = 140°-160° F

80-100 degree reduction! That's a 33%+ reduction. Does not seem possible, so I repeated it, and then tracked it out longer. Same massive temp delta, and the delta held fairly consistently as it cooled with the expected delta decay over time as the temp approached ambient.

After "torching the crap out of it" and letting it cool, I then felt the area with my fingertips and fingernails. (Should have inspected with magnification, too.) It was SLIGHTLY rougher... very slightly. And I found a place in one of the large gouges where I could JUST barely catch my fingernail. Was this due to ablation? Or did I miss this spot during inspection? I don't know.

All I can say is I am pretty happy with the results. Someone with more time than me should design a real test regime. I am going to find out in real time how this works UNDER a paint system. Frankly, I'll sacrifice a paint system if I have a super smooth intervening layer protecting the rocket from the heat.

 

[cautery]

More Tools... sort of.

Love my "Ball on a Stick" Filleting Tool! Thanks for the name, @jqavins I am, after all, a minimalist at heart.

I assembled two more sizes and replaced the aluminum all-thread with stainless steel....


Bottom: 9/16" diameter ball, 9/32" radius. Very conservative. Worked well on the centering ring fillets. Not sure if it is "enough" for external fin fillets.

Middle: 5/8" diameter ball, 5/16" radius. Might work for external fillets (structural consideration only).

Top: 3/4" diameter ball, 3/8" radius. Clearly would be "enough" and "prettier" for the aestheticians among us... likely a tiny bit more aero. at lower velocities.

Will likely add to both ends at some point.... Going up in size by 16ths gets expensive fast from here. Going down is going to require smaller diameter handles and another tap set soon.

 

[cautery]

Working through some stuff...

I dunno... don't ask me to explain.

 

[Hobie1dog]

Working through some stuff...
View attachment 551673
I dunno... don't ask me to explain.

impressive, I'm a notebook junkie now late in life.

 

[KenECoyote]

Working through some stuff...
View attachment 551673
I dunno... don't ask me to explain.

 

[cautery]

REQUIRED TOOLS - Really TRIED to get a "bunch" done today, but the world conspired against me.

The good news is that the stripping of the table saw top went well. And the machining of the 6 tabs off each miter slot only took like a thousand Dremel cutoff wheels to finish.

Also good news is that I successfully set the saw blade path parallel to the miter slots....
And luck of all luck.... BOTH miter slots are parallel.... AND when the rip fence is clamped in place square IT TOO is ALSO parallel to the saw blade path. I can't tell you how frustrating it is to manually index (using a metal ruler and magnifiers) the rip fence fore and aft to the side of a blade tooth EVERY time you set a cut.

I've needed to do this for a very, VERY lone time.

So, I focused on getting the table saw runners made...


Used a 1.5" x 1.5" stick of Red Oak.... (My goodness but this hardwood stuff has gone insane at the Blue AND Orange home stores. I should have paid a little more and gotten the UHMW plastic (aka: butcher block white PE) from McMaster. Then, I'd also have my 19/64" drill bit I need too.

Thin strips? No zero clearance insert and no time to make one?
Use video #1

Need assistance figuring out how to cut the miter strips?
Use Video #2

Note: cutting thin wood strips.... even hard wood without a splitter on your saw is a PITA. Get a splitter or be prepared to use a supplemental stick to hold the "good" piece against the fence and a push stick to finish it off... You need pressure down on the table and behind the board to push it through. But you also need a firm pressure against the fence. I'll be adding a splitter to the sled...

And then you will still get the "off cut" side bowing back into the heal of the blade and getting the edge buggered up.
I did manage to get two longer than needed blanks that will work "good enough". Now , I need to cut a sled base, shim the strips up in the grooves a bit (and shim the bows out), and then glue the base down to the strips. I'd like to make them replaceable, but that's just more fiddling than I am prepared to do.

When these runners wear out, I'll toss and make a new sled/jig. Haven't decided if I'll integrate the jig and a smaller sled for just this job or make a bigger sled with the ability to clamp a jig to it.

Video #1


Video #2



Let's see what other trouble I can get into, now. The night is young!

 

[cautery]

WARNING: Brainstorming ahead...

So I am literally watching glue dry and thinking about the top end of the rocket vs the bottom end vis-avis recovery.
I put a dual harness in the booster partly for redundancy in case one of them fails, on a flight yeah, but trying to repair the only one? No.

So what about the nosecone?

If I stick with a central welded eye bolt then the single harness is "easily" replaceable.

But, what if I don't want to glue in an eyebolt at the inside tip....

What it, sayyyy I want it to be just an all-thread rod for adjustable weight via custom lead washers, orrrrrr... to put some other compartment up there with something in it... I don't know...

The eyebolt just seems... limited.

And why do I have to choose?

Surely we can use the eyebolt or all-thread to clamp the tip on while it is glued up, and then have employed some manner of preventing its bonding in such that AFTER cure, we can REMOVE it... If this can be done, then I can have my cake and eat it to.... I choose if there is to be something up there and what it is!

But what about the harness(es)... I submit that you could still hook them on the central all-thread rod, et al. Just use several nuts on the aft side of the harness connection. But what if I don't want anything in there...

Or what if I want the central piece to be part of an antenna with the nosecone tip as a capacitance hat!

Guess we could bond the recovery harnesses on the inside of the nosecone just forward of the avbay ledge for a few inches parallel to centerline....

Harness really only needs to hold the nosecone weight (and whatever is in it). Use two for backup and it can be tiny... like 1/8" or 3/16".
Say, an inflatable bladder with the harness loops affixed.

Use the Syringe Tool to apply the thickened epoxy in a stripe on each side.... Then, insert the bladder partially inflated to align harnesses and inflate slowly until satisfied that it has well compressed the harness loops into the adhesive and flat against the nosecone wall. Need a non-bonding plastic layer in there...

Hmmmm...

 

[cautery]

More Math... and stuff.


Above: The math... a little geometry sprinkled with some trig for a little extra "kick".



LEFT: Two fresh slices of some 40-year old 3/4" hardwood plywood. Straightest, most stable stuff I have for fences on a crosscut sled, and.... it was free.

RIGHT: Glued up face to face (after block sanding with 60-grit to remove the finishes) to counter any warping/cupping in the cabinet door in the last 4 decades. Titebond III, painted on with a brush. You see the clamps... Cleaned up the squeeze out already. Made two of these out of 1 door.... front and back fence.


ABOVE: It's too cold and too dark to run the saw outside, but I just hate the dust. And I don't have room for a shop vac...
I give you .... "The Saw Skirt"

About 95% effective on first try. I am going to use that rag as a gasket around the blade height wheel.... that is where it is leaking.

I bet I could make a reusable one from microfiber shower curtains from Walmart, some lead rope cut into 2" pieces, and a few vertical seams to close individual weight pockets. Draw string around the top (or bungie), and there ya go.

"Necessity is the mother of invention..." (paraphrased from "The Republic", Plato.

 

[KenECoyote]

Surely we can use the eyebolt or all-thread to clamp the tip on while it is glued up, and then have employed some manner of preventing its bonding in such that AFTER cure, we can REMOVE it... If this can be done, then I can have my cake and eat it to.... I choose if there is to be something up there and what it is!

Sure, I have been doing that for years as well as others. I use an all thread coupler and nuts to lock everything.

 

[KenECoyote]

More Math... and stuff.

View attachment 551845
Above: The math... a little geometry sprinkled with some trig for a little extra "kick".


View attachment 551846View attachment 551847
LEFT: Two fresh slices of some 40-year old 2/4" hardwood plywood. Straightest, most stable stuff I have for fences on a crosscut sled, and.... it was free.

RIGHT: Glued up face to face (after block sanding with 60-grit to remove the finishes) to counter any warping/cupping in the cabinet door in the last 4 decades. Titebond III, painted on with a brush. You see the clamps... Cleaned up the squeeze out already. Made two of these out of 1 door.... front and back fence.

View attachment 551848
ABOVE: It's too cold and too dark to run the saw outside, but I just hate the dust. And I don't have room for a shop vac...
I give you .... "The Saw Skirt"

About 95% effective on first try. I am going to use that rag as a gasket around the blade height wheel.... that is where it is leaking.

I bet I could make a reusable one from microfiber shower curtains from Walmart, some lead rope cut into 2" pieces, and a few vertical seams to close individual weight pockets. Draw string around the top (or bungie), and there ya go.

"Necessity is the mother of invention..." (paraphrased from "The Republic", Plato.

Great thinking, but be careful in case the saw dust build up is sparked by the motor. Years ago I got a vacuum panel kit for my table saw that worked pretty well, and it was somewhat simple and can be home made with a few panels and a hose attachment point.

 

[thzero]

WARNING: Brainstorming ahead...

So I am literally watching glue dry and thinking about the top end of the rocket vs the bottom end vis-avis recovery.
I put a dual harness in the booster partly for redundancy in case one of them fails, on a flight yeah, but trying to repair the only one? No.

Probably over thinking it.

On a 3" build (MacPerformance tubes for this rocket not LOC or Wildman for once, something different) with a 54mm motor mount, I'm pinched for space. This one will weigh about the same as my 3" LOC/Madcow that I built and used for my Level 2, so would have used a single forged eyebolt for lower except I ran out of space because of the nature of the build (there is a coupler in the way and it reduces the gap between coupler wall and motor tube obviously) so ended up going with the MacPerformance Kevlar strap which I like how he put it together - its in mechanically and with epoxy. Would I do two? Not really - its beefier Kevlar than the shock chords are. If it ever gets to point that it looks damaged, I'll just cut it out and create a different recovery point for a new harness or build a new fin can. The rest of the it will be single forged eyebolts (payload bay bulkhead, then the ebay bulkheads).

For the nose cone, with head-in deployment not sure where you'd find the room to get that fancy - I've seen my buddy's Punisher that he runs with head-in.. oof. As ideas... for a 5.5" scaled down Warlock with 3d printed fins, and head-in deployment, it was tight with the parachute even in that big of rocket (rocket clocks in about 9.5lbs). I had 3D printed in PETG a ring to go in the rocket that has two eyebolts attached to it (it also allows me to bolt in a GPS tracker). The ring was fiberglassed, and then epoxied in and then bolted in with grub screws that were epoxied in to.

 

[cautery]

Sure, I have been doing that for years as well as others. I use an all thread coupler and nuts to lock everything.

How do you keep the initial glue up from trapping the eye bolt or rod?

Super lube? Vaseline? Gotta fill or eliminate threads in the glue pour...

Great thinking, but be careful in case the saw dust build up is sparked by the motor. Years ago I got a vacuum panel kit for my table saw that worked pretty well, and it was somewhat simple and can be home made with a few panels and a hose attachment point.

Sure, this is merely a field expedient deal for now... maybe a vac system in the attic above the ceiling. Frankly, I just need to pull the ceiling rock down...

Also have both a bottle and chemical fire extinguisher handy...

Probably over thinking it.

Always....

Just thinking through all the options.... not even just for this project. A lot of stuff I am doing is of course not necessary for a cert rocket....

A lot of it is skills building and learning stuff BEFORE I need it.

 

[Handeman]

Just thinking through all the options.... not even just for this project. A lot of stuff I am doing is of course not necessary for a cert rocket....

A lot of it is skills building and learning stuff BEFORE I need it.

You sound like you are doing your cert the way I did. The whole goal was to learn as much as I could about HPR. I ended up learning more from that DD L1 cert rocket than any other I ever built. With all that I learned, most of it was learned flying it, not building it.

Good luck on your journey.

 

[cautery]

You sound like you are doing your cert the way I did. The whole goal was to learn as much as I could about HPR. I ended up learning more from that DD L1 cert rocket than any other I ever built. With all that I learned, most of it was learned flying it, not building it.

Good luck on your journey.

EDIT: I apologize. I am "under the weather" today and I did not give a proper response.

Yes sir. Largely, that is my approach. I am looking forward to flying what my hands make. If it survives, I have quite the flight program for it.
Thank you for the good wishes.

Be well!

AND yet, still true...

I'm getting a late start in HPR. I don't have time to dork around for a decade.

 

[cautery]

Picture dump...


Left: Completed fences post glue up and fresh cut each side to parallel.

Middle: 10" x 100T triple/flat blade... 0.094". This sled belongs to THIS blade.

Right: Red Oak runners this narrow and thin is a NO GO in my opinion. Shimmed the rail true edges for near 100% contact on INSIDE miter groove faces. This is until I can replace them with UHMWPE.



Left: Thin nuts used as spacers to raise the miter bars out of the slots to affix them to the base.

Middle: More shimming...

Right: And even more shimming... 600-grit worked well.



Left: I measured this out a number of ways and confirmed it with a number more. I finally just made myself do it.

Right: Double-sided tape so far. 105 lbs on feet just outboard of the rails.



Left: Pretended this front bridge was the back bridge for a "rehearsal" in squaring up a bridge.
However, I am thusfar quite disappointed in my shimmed/taped wood rails. I will mitigate.

Right: Looking down a "throwaway" centerline on the base. Where the line disappears is the 90 degree seam with the bridge. For scale... the "in focus" pencil mark is the back edge of a sharpened 0.3 mm mechanical pencil.