1lb Rockets Failing - I Need Help

[NeighborJ]

Lookin great, I'm jealous of your setup and I'd love to have some of Caleb's tools but having not worked in 6 weeks I can't afford it for now. I don't think you need to change your tooling if it works but if your like me, you'll still want the latest and greatest for optimal performance.

[joeyz]

thanks neighborJ, i have much more to learn and im happy for all these guys that have the latest and greatest but i too cant afford which is why i made that homade 1 ton press. its a expensive hobby. my wife already jumped on me for recently buying tooling, tubes and chems, lol

 

wish i could cut a deal with someone, trading power. one of my guys ordered too many 3-5 and even 8 meter ematches for our 1.4g and 1.3g shows and i had to eat that cost. rocket tooling and ematches are not cheap because of the metals. would be nice if someone were in need of ematches, i have cases of the stuff. I ematch everything for safety! i would even ematch my wife's dog if she'd let me, would love to see that dog take off into the sunset hahahaha j/k

 

Edited August 24, 2016 by joeyz

[NeighborJ]

That could be posted in the agora market here, it would sell.

[calebkessinger]

All stainless from here on out. Oversized ring on the bottom so the tubes have to be worked on.. No more squirting fuel or clay around the spindle and when you pick it all up on the first increment it doesn't fall out.

 

Yep Dave. I've said it before.. heck maybe here. the endburner specs credit the Duke, with just a freckle longer spindle so guys that use straight kitty litter can get enough in there to hold up well. And the nozzle rammers are stainless, or tipped with stainless so they will hold up to the abuse of an abrasive nozzle mix.

 

When you get your endburners pressed correctly you should be able to run 50/50 bp and sali whistle in them. Think baby increments. teaspoon at a time.

[calebkessinger]

I'll trade ya for some long ematch.

Just message me.

[joeyz]

caleb, okay, will do, will send you a message. too bad your not in texas, i got all kinds of stuff. i dont have anymore green 6 meter and yellow 8 meter ones left at the moment, 4th july and summer events ran me dry on those. we use those for 10" shells and special effects for wide stages, stadiums, etc. i have plenty of orange and white 3 meter and red 5 meter ones (see photo). i been using ematches for years on estes rocket motors and they work eggcellently everytime. we dont use anything cheapo, we use quality, reliable and safe equipment in our theme parks, water parks, stadiums, concerts and city displays.

 

 

BTW Caleb, i got your 5k gauge in today, wow that was fast, seemed like overnight. Dave (Dag referred me to woodys) and he was right about quality, shipment and customer service. i pleased with the universal core burner and I tested the new 5k gauge with just about 20 pounds hand pressure and it replied back with 500 psi, it works! (see photo). will ship the 10k tomorrow, first thing in morning. knowing what im pressing now should reduce that factor in my rocket failure and i thank you.

 

Edited August 25, 2016 by joeyz

[dagabu]

All stainless from here on out. Oversized ring on the bottom so the tubes have to be worked on.. No more squirting fuel or clay around the spindle and when you pick it all up on the first increment it doesn't fall out.

 

Yep Dave. I've said it before.. heck maybe here. the endburner specs credit the Duke, with just a freckle longer spindle so guys that use straight kitty litter can get enough in there to hold up well. And the nozzle rammers are stainless, or tipped with stainless so they will hold up to the abuse of an abrasive nozzle mix.

 

When you get your endburners pressed correctly you should be able to run 50/50 bp and sali whistle in them. Think baby increments. teaspoon at a time.

 

Aaron Hull used HOT sali in the very first end burner ever made with that set and it did just fine! Somehow, you got the ideal specs on that spindle.

[calebkessinger]

Glad it got there safe and sure sorry for the trouble.. Stuff not working right can be infuriating.

I'll pretty much bend over backwards for customers. Without them I'd be out o luck. This is my living not a hobby. If someone tells me of a problem I jump to fix it as fast as possible whether it was my fault or theirs.

[calebkessinger]

Ha.. their was no somehow.. Duke handed me one of his handout sheets from years past and I used those measurements + about .005 thou at the base of the spindle and about .125 on the length.

All credit goes to him.

Of course maserface scaled it up and down for me to fit all the sizes of tool kits.

 

I know what he would say.. That's some poor whistle... get ya some of that Swedish perc and make some hot stuff. :}

Edited August 25, 2016 by calebkessinger

[dagabu]

Geeze! I can actually hear him say that with his hamburger accent!

[calebkessinger]

I can hear him from my house also.

 

that was a good rocket.... now if you wanna make a real rocket let me show ya.

[dagabu]

Im watchin! Hey, you and Nate coming to MMF? Thinking of coming down...

[calebkessinger]

It'll be just me. Nate's got school and football.

 

What size tubes is that tooling for J?

[joeyz]

joe's semester semi final on rocket failure lol

 

as a new guy, learned so much from you guys in such a short time and made so many fixes.

here is what im working with now and thank you dag for your lecture on the nozzle washer line and convergent science, phils tubes and caleb's tools. im definately in better shape then i was weeks ago.

 

i pressed some new rockets with calebs tools and phils tubes, both fun, nice and easy to work with.

here is a couple of pictures for a sanity check with corections to the nozzle thickness. i would like to know if my practices are correct. dag or anyone else, if you can examine the nozzle washer line, looks like i passed it with clay, is this amount okay? also take note at the hair line fracturse on surface of phils tubes. before clamping and pressing, all you saw was spiral lines, now i see these little crunch wrinkled lines? am i pressing too hard? i am pressing 1lb core and end burners at 2,000 psi on the gauge. the fine cracks are just outside surface cracks, i assume its okay.

feedback good or bad always appreciated.

 

 

 

PS: havent waxed tubes yet, trying to resolve one issue at a time on rocket fails. waxing tubes is definately on my to do list to minimize catos. definately waxing tubes before i go final on bp and whistle fuels. im just trying to eat this big elephant of rocketry one bite at a time.

Edited August 26, 2016 by joeyz

[NeighborJ]

Those wrinkles are called tube pull down, the comp is grabbing the inside wall of the tube before it is completely compressed. This causes the tube to pull down, which is not good because it will try to relax by pulling the grain apart afterwards like a spring.

The part where you say "Haven't waxed tubes yet" is very telling. IMO this is the primary purpose for waxing. The wax will act as a lubricant and help prevent tube pull-down. Waxing in itself can create several issues but all are able to be overcome by cleaning the wax from areas where the nozzle and bulkhead are located.

Edited August 26, 2016 by NeighborJ

[joeyz]

Oh my, nicely explained and now my immediate priorioty. Going to get started on waxing right away. Thanks brother!

 

Gee, thats a pain everytime you cut a tube when no time, wont vaseline work? LoL

Edited August 26, 2016 by joeyz

[calebkessinger]

That motor should fly just fine. I like what i can see for the thickness of the nozzle.

you need to grab the tube tighter with a support. If you pressed it without a support good luck..

I don't like waxing the tubes cause of the things Neighbor J just brought up. It makes a mess of the rammers.. and brings on more problems than I want to deal with. I've made stacks of rockets with phils tubes without waxing and they all work fine.

 

So.. you need. Tube support. Crank down the pvc support a little more, you should have the clamps touching all the way up it. You'll know if you go to far cause it will collapse the tube and your rammers won't fit.

 

If you don't have a pvc sleeve I can send ya one with the next box i'm sending you.

[joeyz]

thanks caleb! you also make great points. i did use a pvc clamp (see picture) of what im using. i will make a another rocket today and clamp the metal hose clamps tighter. thanks for your tip on the clay nozzle, you can see the washer line where i exceeded it. i will label this rocket with cracks and test fly.

 

new update...i just found out, looking closer with a 3" diameter magnifying lens, they are definately very thin light tears open cracks of outter tube surface (expansion) rather then the tube being pushed down too much causing ripples/wrinkles (compacting). no feel of swelling, outter tube is smooth along entire length and no wabbling when rolling across the table, rolls on the table like a wheel or ball and passes light test with flashlight between two surfaces (table & rocket tube). i feel/see no tube swelling/bulging at all as you would sometimes feel during initial start of pressing the clay nozzle of most tubes. nice even pressed rocket, uniformity.

 

examining inside of tube, no signs of same condition as outside (its good) but still, your logic of proper tight clamping to me does both, keeps tube from shrinking downwards and prevents expansion swelling of the sides.

 

in my own analysis, i have ruled out humidity (damp tube) variable because its dry here in texas. also ruled out wet composition thats expanding after pressing, mix is fine, the surface cracks are immediately visible after removing pvc clamp. also ruled out faulty o-rings, not space shuttle rocket hahaha

 

agreed, phils tubes its great stuff, no concerns from me on tube integrity in contrast to other pyro site tubes. after this batch of use, if all works fine, looking forward in getting more when these runs out. confidence from you and dag, i bought half a case to save cost of reorder and shipping, it should last me a couple months.

 

miner surface cracks, outter tube closer examination. probably something not to worry about, its not a space shuttle

 

my homemade pvc clamp (left). if you think clamp tightness is a concern, maybe i can lay a peice of sandpaper on table and take the half moon pvc pipe and take off 1mm to allow more diameter pressure when clamping.

 

-joe

Rocket Wizard Student, amatuerpyro university

better than monster university lol

Edited August 26, 2016 by joeyz

[NeighborJ]

Hey Joe what species charcoal are you using? I've noticed that certain types and meshes will act spongey and once the support is removed the tube swells up a little, or if I remove the spindle before I take the support of it will cave in.

The other thing I'd like you to check is measure the exact length of the tube before and after you press it. When a tube swells it will grow shorter.

[joeyz]

i'm using commercial mix charcoal of hard woods for rocket fuel. i keep my best charcoal for better firework items.

I remove the pvc clamp clamps first, then put spindle base in vise and slowly twist out spindle.

okay chief, will do some measurements before and after on next rocket.

 

i think whats causing the hairline thin cracks is i need to shave down a frog hair on pvc pipe to put more pressure around tube diameter. this may be the cause and cure.

Edited August 26, 2016 by joeyz

[Mumbles]

If your tube isn't quite the right size for the support there are a few things you can do. Lightly shaving down the support is one option. Another is to wrap your tube in a turn or two of light paper to slightly increase the OD. I don't know how tight is exactly right, but you shouldn't be able to push or slide the tube around in the support once fully clamped in.

[joeyz]

nice one mumbles, thats a pretty slick quick fix. i think i will use that option because if i start shaving down by hand, it will never be precise again. the cuts along the pvc is exact wide of jig saw blade. last thing i want is an oval (egg) tube risk of pass fire somewhere along the walls and cato.

 

yes, its current configuration is tight enough so you cant remove the tube after clamping, one of the things i immediately checked after creating the pvc clamp on tube. going try clamping down a bit tighter like caleb mentioned and see if problem goes away, if not, going to try your paper towel option and test again.

 

phils tubes and 1" pvc cut with a jig saw is a perfect fit without having to really cranking down to warp the pvc to bend wrap the tube.

 

stationary loosely resting before clamp and tested one hand fist squeeze test, tube hard to move but will move.

 

after clamping, tube doesnt move at all.

 

im thinking like you guys, i need just a frog hair more gap so it clamps a frog hair tighter because maybe the clamps reached its limit, pvc to pvc end contact, therfore paper towel trick or shaving down pvc a frog hair is answer. this could be one of those cases simular to the dental office when you get a filling or crown. after they are done, they check the contact gap between the upper and lower teeth for proper bite pressure, hahaha

Edited August 26, 2016 by joeyz

[Mumbles]

To clarify, I was talking about 30lb kraft or something. I'm not sure how well paper towels would work. I don't know how something sort of compressible would work.

[NeighborJ]

Hey Joey I'd like to make one suggestion with your support. The adjuster screws are laying on the split, it's probably just ocd but I turn them so it is off of the split. My reasoning is due to the fact that the bottom of the clamp is raised and can push on one side or the other creating a lip after it is pressed. I've never had any problems with the slight lip but I don't want any either.

You've jinxed me, my 1# 1-5 ratio endburner has started to make a slight crackle. It is definitely increment related because I need to press it a lot more than the1-4 ratio and it burns fine. I think I will need to start wetting my comp so it compresses more evenly at a lower pressure. I get nervous doing that with this motor because the moisture tends to swell the nozzle and at 1-5 it is running that ragged edge.

Here's the vid, I used home made fuse and shoved some dragons eggs in the top as an indicator but it's hard to hear at over a thousand feet.

[joeyz]

mumbles, roger, sorry, thought you meant paper towel. i made adjustments, sanded down the sides of pvc for larger gap. I think i went too far of a gap and have to make another pvc tomorrow but im going to try this one and see what happens of out curiosity and building up my experience.

 

neighborJ, thanks for the tips on the clamps, made adjustments as you mentioned and now they are offest from pvc crack line. i also now use a 8mm rachet instead of the slippery run away screwdriver tip, no more ouchy on the fingers and i get more torque on screws lol

 

team, see new photos of corrections i made. going to press another rocket tonight if you guys think im ready to do so with what i have now or should i make another pvc with smaller gap.

 

 

 

debating to get a small torgue wrench to ensure each clamp screw has proper lb/psi.

 

neighborJ, sorry about your rockets, dampening the compo worked so much better for me. also, now that i have caleb's pressure gauge i, i can be certain that each press is exactly the same. no more guess work for me.

Edited August 26, 2016 by joeyz