Pressing Rocket Fuel - Possibly lower pressures needed with waxed tubes ?

[mkn]

Holy Crap DD ! 3" ID motor..................whistle............. awesome.. I would love to see that launch someday !

 

 

Would you mid answering a few questions:

 

Who made the tooling

Spindle length trapper

tooling material

degree of polish on tooling

release tube support before or after spindle removal, or none

 

Fuel:

catalyst

mineral oil , Vaseline, or "dry"

 

 

 

With that much whistle on hand, is it possible for you to try a waxed 3/4 " ( 19 mm) motor - preferably a standard BP spindle or a universal spindle 7.5 " tube at that psi ?

 

 

Thanks for the info DD, this low pressure may not work for the larger motors as you have just shown. I am hopeful that we can find that we can roll our own tubes for low pressure use and be able to launch 4oz - to 3# motors with hot BP and or whistle.

 

if you need to dispose of the "chunks " of whistle.......my address is......

 

Matt

[ddewees]

Sali, iron oxide, Vaseline

 

I had the tooling made locally, all aluminum.

 

I have a cast tube support, but it's not needed at 3500 psi.

 

I'll likely reuse the chunks, but thanks for the offer.

 

http://i1149.photobucket.com/albums/o588/SaltLakeAreaPyros/Mobile%20Uploads/20141003_173340_zpsd4761f5e.jpg

[DavidF]

Could we see the spindle better please? A while back I had the idea that wax was good for everything. I wanted to press farfalle in 1# NEPT tubes, with no plug. So I stuck a piece of masking tape on the end, added an increment (the fuel had wax too) and pressed it. Poof, the increment came shooting out the bottom when I hit a certain pressure. I forget how much.

 

The fuel doesn't seem to grab the tube well in a waxed tube if there is nothing to keep the tube down. I would guess that tendency would be made a bit worse by the Vaseline in the fuel- I guess. I use wax in mine and I like it. Same thing though, squishy fuel in a squishy tube.

 

I've never made a rocket anywhere near that size, but what if you put a ring of PVC or similar with a clamp around it just around the base the tube mounts on? Maybe this would help consolidate the fuel in a better way for you?

[ddewees]

That's actually a good idea... I've been trying to figure out how to prevent it from happening twice. I also have almost no taper on the spindle, and was considering changing that too. Didn't have time to make another one today, but will probably use one or two increments of bp to start next time.

 

http://i1149.photobucket.com/albums/o588/SaltLakeAreaPyros/Mobile%20Uploads/20141003_173548_zpse242b835.jpg

[mkn]

I would also try a decent taper on the spindle and a very fine smooth polish, from what I read, that aids in the extraction. that spindle has a lot of surface area to create friction and not want to let go of the fuel.

 

also- how is the spindle removed, is it pulled straight out, or twisted and pulled, with a good taper and pull not twist, seems like it should pop out.

 

 

Must be easy to see if you rammer is getting clogged with fuel....

[ddewees]

It gets pulled straight out using a spacer/donut and long screw.

 

Yeah, I can clean out the rammer with my finger.

[Zmuro]

Can you also post a picture of your paper tube? Where did you manage to find them?

[ddewees]

We have two members in our local club who work with paper. One is for a publisher...

 

They have an unlimited supply of heavy walled 3" ID tubes.

[wildcherryxoxo]

gonna need a bigger hammer!

[ddewees]

That too... unless these lower pressures can truly work. I'm anxious to find out. Either way, they should make for interesting displays at the next rendezvous...

[wildcherryxoxo]

harbor freight 30t press only 100 bucks

I look forward to the video!

[mkn]

Hi All,

I built my first 1# Whistle with some tame Benzo whistle and BP mix at 50% 50%. The tube was home rolled and waxed, I also waxed the spindle for the first time, big difference ! IMO This is a must do if you have not tried, spindle removal was significantly easier.
The tooling is my own as well, very close to BP core burner specs. I pressed the fuel ( no nozzle) at 2,000psi on comp and delayed it with 1" of tame sali whistle.
The header is a modified version of a sandbag. I use a heavy wall tube with an open top, load the desired amount of sand and after apogee the sand falls out as rocket comes back down. The header weighed 800g and my two sticks totaled 62g. the header is great, I retrieve the rocket and can reuse it, the sticks, and even the tube for hand rammed BP.

I'd be interested in some feedback on performance of this rocket. It went to 300 / 400 feet, total flight time was 9 seconds +/- from lift to ground in a rainbow trajectory. The height attained was not enough for a header that would weigh 800g ( my heaviest is < 400g ) The gopro video is ok, but you cannot see the rocket as I continued to follow it after apogee.

- I think it is just too much weight , I wonder if Top lighting might work even with the Benzo / BP mix to get a more vertical flight
- the lack of aerodynamics with an open top cylinder forming a cup, how much would this affect flight performance

MOTOR STORAGE - I have not been storing these test motors with 2,000 psi on the comp. I am wondering at what time frame would a stored motor start to cato? Do any of the experienced motor builders have a reference, one month , three months or more. I believe this was the real reason for high pressures on the comp that were developed prior to waxing the tube. It seems that I am having good results pressing lower psi on the comp, It maybe time to store a few. What would be considered storage conditions, loose and exposed to environment or sealed in a ziplock with desiccant? Myself I would double bag with desiccant.

Overall it was fun, and I am good for a 600g header !!

Matt

[ddewees]

If you change your header to round or cone shape, you'll see increased performance on height.

 

I also think you should put away the sand bags, and use live headers now (with video).

[MrB]

If you change your header to round or cone shape, you'll see increased performance on height.

Stick to round. Should there be an accident, be it a lose rocket, or a roundtrip, cone shapes makes for more damage when it hits a person. The tip snags / digs in, rather then bouncing of. Just an opinion, of course, but it's based both on the damages incurred from rockets, as well as the laws and regulations they are pushing here. This year we have a new maximum "composition weight" of 75grams for commercial fireworks. The rules and regulations where they allow pyro as a hobby can only get worse if people start using cone shapes, for rockets that get of course.

(Ideally it's a none issue, since all rockets should end up in the sky, but the performance difference isn't that big. Just use round headers ;- )

B!

[mkn]

If you change your header to round or cone shape, you'll see increased performance on height.

 

I also think you should put away the sand bags, and use live headers now (with video).

Yes, the live stuff is coming! I have handmade 5" hemis that I filled with 3/4 " spider stars, I'll check the weight and see what should lift it. Although we have deer season in a few weeks, so I will be preoccupied. Nov and Dec seem to go so fast, rifle season to muzzleloader to Christmas and NYE.

 

The rockets are stabile, a nice change from this spring when my hot BP was cato all the time, a combo of bottom lite and wax was the trick, I should try a top light hot BP with a waxed tube, maybe one more sandbag

[mkn]

Stick to round. Should there be an accident, be it a lose rocket, or a roundtrip, cone shapes makes for more damage when it hits a person. The tip snags / digs in, rather then bouncing of. Just an opinion, of course, but it's based both on the damages incurred from rockets, as well as the laws and regulations they are pushing here. This year we have a new maximum "composition weight" of 75grams for commercial fireworks. The rules and regulations where they allow pyro as a hobby can only get worse if people start using cone shapes, for rockets that get of course.

(Ideally it's a none issue, since all rockets should end up in the sky, but the performance difference isn't that big. Just use round headers ;- )

B!

yes round for the ball shells or flat if its a canister !

[mkn]

Hi All,

 

For a motor storage test, I now have some mylar bags for static and moisture control, from McMaster Carr. I pressed two motors today, a 4oz and 1#, both pressed with 50/50 benzo / BP mix and a sali delay 1.5 x ID, both at the 2K on the comp. Tubes are home rolled, waxed and waxed full length spindle I will store these with desiccant in the bag out in the magazine which will see cold temperatures ( VT winter) over the next two months. Then test them. The fuel is fine as I launched a 4oz with it today, nice 200g test header, great height.

 

Seems the low pressure works for immediate use, now its time to store them, which seems be when problems crop up for others.

I still have yet to do a 3# whistle, that is out of my league for now. I have been using red iron oxide and black copper oxide for catalyst, today I just made two batches with sodi sali and sodi benzo with copper oxychloride, can't wait to see the difference ! boy do I wish I had one of those ACME testers......

Matt

[Col]

Benz / cu oxy is nice stuff to work with, you`ll find the sali`s a bit waxy/sticky. I also prefer the sound of cu oxy to red fe oxide.

Edited November 1, 2014 by Col

[ddewees]

I agree...

 

My best sounding whistle motor was this rocket using kbenz and cuoxy...

 

[Video]

[mkn]

Nice DD ! did you find that one ....hahaha, those big open spaces ( and usually clear blue skies) , love um, but I can't complain we have a hunting camp a mile in from the highway with a large semi open field and beaver pond in front of camp.

 

Col , DD - Do you guy's think the copper oxychloride has more power ? Dan's Whichibuggy tests show apx 2.5 times the initial thrust, less burn time. So a faster burn putting more stress on the tube.

If so this would play a part in my home rolled tubes with recycled Kraft, and possibly the low pressures on the comp.

I load a BP core burner spindle that I made just above the spindle and then delay, no nozzle.

 

Can't wait for it to dry out and be ready to try, these cold temps sure do slow the drying.....

Matt

[Col]

Never had one play a tune on the way up like DD`s lol. Hard to say if the cu oxy has more power without an acme tester but 1lb`ers using benz do get away quicker with oxy than fe oxide. If you use a 3/16" wall tube you should be ok. I only use salicylate for whistle booster, no catalyst. Do a burn test with a few grams of the oxy whistle and you should get an idea if its quicker than your fe oxide. Probably best to do that test after you press a motor or it might play on your mind

[Bobosan]

Way up and way down with a drum solo in the middle.

 

Nice rocket DD!

[mkn]

Happy New Year All !

 

I was able to launch the stored 1# 2,000 psi on the comp motor tonight. This motor was stored for 2 months at ambient temps. ranging from 60 - 12 below. The motor saw 40 - 60 degree temp swings twice.

 

Motor was 1# 2K on comp BP and Benzo with a sali delay. Tube was home rolled, waxed and spindle waxed. The header was a 3.5 inch ball shell with home made hemis, TT to blue core, I used a 3 Second delay time fuse , as I knew the motor would be quite high so it would make its way back down a bit. The whistle stops and the header goes about 2 seconds later.

 

Success with a 2K on the comp stored motor !!

 

Matt

 

[Maserface]

Nice work, MKN, this gives us a lot to think about- When my shop warms up I am going to try this as well!


remind me what bursting strength you get on your home rolled tubes?

[mkn]

Maserface- the tubes burst around 3.5- 5.5K, depending on tube ID. IIRC, . Recycled Kraft Paper. I haven't tested too many. But don't have an issue at 2K and no tube support for 1/2" and 3/4"

 

Fuels are tame whistle with mineral oil. and my BP has mineral oil as well. The hybrid was a mix of powders then press. I made my tooling, but the specs are fairly similar to the Rocket tool Sketcher - BP core burner ,

 

I know I sure don't miss the tube support ! and the lower pressures are easier on the tooling. Waxing the spindle make removal a breeze. I have not done a 3# motor yet with these pressures, as the hybrid 1# lifts all I need now.

 

It will be great to have more people trying these lower pressures with more types of fuel and hotter fuels than I use.

 

Matt