Rocket tool sketcher

[rcmanic]

Can anyone provide a copy of the downloadable exe version of Pudidotdk's rocket tool sketcher? Seems the website posting for the program has expired. Was planning on making a few tools on my lathe. Thanks. Edited September 6, 2016 by rcmanic

[dagabu]

PM me with your address and I'll send you the file, MAKE sure you run your antivirus software on it first since I got it from the original source a few years back.

[CrossOut]

That tool designer is great for end burners but the core burning rockets should be taken with a grain of salt. Longer rockets simply scale the core longer resulting in a Cato 100% of the time. Great designer over all. I recommend using other tools dimensions as a starting point before altering core dimensions. Edited September 6, 2016 by CrossOut

[ExplosiveCoek]

Actually those core dimensions were too small for my liking (especially the whistle). The BP core burner is more suited for 6-3-1 IIRC, but make it a little bit smaller and straight bp will work too (even nozzled rockets).

[dagabu]

That tool designer is great for end burners but the core burning rockets should be taken with a grain of salt. Longer rockets simply scale the core longer resulting in a Cato 100% of the time. Great designer over all. I recommend using other tools dimensions as a starting point before altering core dimensions.

 

Have you actually tried the core burner design offered by RTS? The standard BP Coreburner tooling approximates traditional tooling specifications using a traditional 6:3:1 ratio, scratch mixed but with a shorter spindle, much closer to the tooling by SLD used for his Hybrid motors.

 

The nozzle is 50% of the tube ID which is about the same as a traditional black powder rockets nozzle ID. The spindle is about X7 the ID, much less than the X10 length of a traditional set.

 

What am I missing here?

[Maserface]

 

Have you actually tried the core burner design offered by RTS? The standard BP Coreburner tooling approximates traditional tooling specifications using a traditional 6:3:1 ratio, scratch mixed but with a shorter spindle, much closer to the tooling by SLD used for his Hybrid motors.

 

The nozzle is 50% of the tube ID which is about the same as a traditional black powder rockets nozzle ID. The spindle is about X7 the ID, much less than the X10 length of a traditional set.

 

What am I missing here?

 

The length of the tapered portion of a "Traditional Skyrocket" spindle is 7 times the bore of the rocket, not 10 times. The tube length is traditionally 10 times the ID (or nominal ID).

[dagabu]

Lol! Good catch, too brief of a glance, I'm afraid. None the less, the same holds that the tooling on RTS is close to the traditional specs and should work fine.

[CrossOut]

I don't recall reading suggestion for a specific bp ratio when using the design program. I am assuming that the preset designs assumed the user was experienced in knowing what ratios to use from the get go. My Initial rockets were standard bp (those cato as to be expected). From there I increased the charcoal until I stopped having having catos. My standard rp Mix at the time was about 70 20 10 and had occasional catos with this design. I eventually made powder slow enough. Which was close to the 6.3.1 ratio you guys mentioned.. I believe mine was 73.27.10 with paulonia charcoal

 

But what I ment was when customizing your tool dimensions, that if you stretched out the tube length to much the spindle length would also stretch out requiring slower fuels to prevent Cato. I guess long story short is don't make your rocket to long or stick with preset dimensions and you will be fine.

Edited September 7, 2016 by CrossOut

[rcmanic]

I figured that ANY tooling made, even replicates of the same design will need experimentation to dial in. There are just to many variables to make an absolute, consistent determination on best formula Vie quality of chemicals, where obtained etc.) The program at least gives a reasonable starting point and allows me to easily print out a set of plans.

[dagabu]

I don't recall reading suggestion for a specific bp ratio when using the design program. I am assuming that the preset designs assumed the user was experienced in knowing what ratios to use from the get go. My Initial rockets were standard bp (those cato as to be expected)....

 

Hmmm, standard BP for rockets IS 6:3:1 (the 75:15:10 ratio found on Wikipedia is for end burners, not core burners).

Black-Powder Rocket Fuel Formula

Potassium nitrate 60% 0.6 6 oz 180 g

Airfloat Charcoal 30% 0.3 3 oz 90 g

Sulfur 10% 0.1 1 oz 30 g

-SL

[wildcherryxoxo]

"I don't recall reading suggestion for a specific bp ratio when using the design program"

 

Details details details!

[CrossOut]

It's fine I got my ratios dialed in.. I actually never looked up bp specifically for rockets I just did my own experimentation to find a working ratio.

 

In Either case any amateur who wishes to use the rts will know after reading this topic.

Edited September 8, 2016 by CrossOut

[ExplosiveCoek]

Dagabu, it's possible to use 75:15:10 for core-burners instead of 6:3:1, just needs a shorter spindle .

[NeighborJ]

ExplosiveCoek, from what I understand Caleb has a line of "skinny spindle" motors which you can load with the hottest bp you can make, also works on whistle. The 1# version can use stinger tubes.

[dagabu]

Dagabu, it's possible to use 75:15:10 for core-burners instead of 6:3:1, just needs a shorter spindle .

 

I was really making that comment about the spindles in the RTS program and was alluding to the choked version of the bp rocket. I really need to clarify my intentions more and use more emojis!!! One can do a scratch mix of 75:15:10 that is slower than 6:3:1 as well so the numbers by themselves are mostly irrelevant unless the process is presented along with the ratio.

ExplosiveCoek, from what I understand Caleb has a line of "skinny spindle" motors which you can load with the hottest bp you can make, also works on whistle. The 1# version can use stinger tubes.

 

...but not with a nozzle.

[DavidF]

http://www.pyrobin.com/files/run%2031%2C%204%2B4hr%20crack%20willow%20BP%20on%20BP%20tool%2C%20nozzled.jpg

The thrust curve above is for crack willow-based hot ballmilled black powder.

http://www.pyrobin.com/files/run%2032%2C%204%2B4%20hr%20balsa%20BP%20dry%2C%20BP%20tool%20with%20nozzle.jpg

The thrust curve above is for balsa-based hot ballmilled black powder.

http://www.pyrobin.com/files/run%2033%2C4%2B4%20hr%20sumac%20BP%20with%20nozzle%2C%20BP%20tooling.jpg

 

The thrust curve above is for staghorn sumac-based hot ballmilled black powder.

 

The charcoals were milled by themselves for 4 hours in a 6" ID Sponenjar jar with mixed-size brass media. The 750 gram batches of 75-15-10 were also milled for 4 hours with the same setup. The propellant was granulated with straight alcohol. The tooling was standard BP tooling.

 

I'm not suggesting that everybody wax their tubes. I'm suggesting that if they do, they might change their opinions about what can and can't be done with pyrotechnic rockets.

Edited September 8, 2016 by DavidF

[dagabu]

HOT DAMN! Dave, you really got this down! Nearly 74 pounds of thrust!!!!!!!!!!!

[DavidF]

Thanks Dave. My highest peak thrust was 107 or some such. Wonder if I could beat it....Other stuff on the go right now though.

 

P.S. The descriptions on Pyrobin (where I posted these) state that these were 3 nozzled 1lb rockets, and I see that I failed to mention that on this forum. Sorry, but that little detail makes a difference

[NeighborJ]

Dave am I reading that right? You used over an oz more of bp on the balsa to get the almost identical curve as the sumac? That chart certainly is revealing about the fuel density and potential energy content of the fuels used.

I said it before and I'll say it again, I want an acme test stand.

[wildcherryxoxo]

 

...but not with a nozzle.

 

 

still drinkin the duke-aid?

[DavidF]

NeighborJ, you are reading it right, but it isn't right. The Acme has a 100kg load cell in it. The accuracy at very low weights is not so good. I found this out early on- not a complaint- and just weighed my motors before and after firing after that.

 

I'll honestly say though, I wasn't looking to have the hottest black powder- necessarily, per unit of weight. My goal was to see what power I could get from the rocket motors, made as we (or I) would usually make them. I customarily press my rockets to 9000psi, which is more than most folks do. However many scoops it takes, it takes. I don't didn't weigh the motors. I will say, the different propellants weren't so different in texture and density. In the end I achieved my goal satisfactorily enough to call it a job 'done' and move on to other tests.

 

It's a continuous learning process for me. The Acme is a guide, for sure. These runs were early in my rocket experiments. I would never make my rockets this way for general use. To try to find out the reason(s) for CATO, I am trying to find out the reasons for no CATO. This could take a while

 

EDIT: here's the most powerful BP motor I've tested so far- NEPT tube (old):

 

http://www.pyrobin.com/files/run%2052%2C%20mostly%204%2B4hr%20sumac%20fuel%20super%20duper%20BP%20spindle%2C%201lb%2C%20nozzled2.jpg

Edited September 9, 2016 by DavidF

[pudidotdk]

New link to online Rocket Tool Sketcher:

www.ma.dk/rts

 

Downloadable .exe (8 MB):

www.ma.dk/rts/rockettoolsketcher.exe

 

 

Sorry for the temporary downtime.

I know this complicates things since the old link is still floating around, but I couldn't justify the cost of maintaining the old website just for the URL.

Besides, you will save 6 button pushes when typing in the new URL (yay).

 

- Nic

[dagabu]

AWESOME! Thanks Nic!

[SKC]

Thanks a lot pudidotdk.