Mike's Build Log

Moderator: Mike Everman

Mike Everman
Posts: 4926
Joined: Fri Oct 31, 2003 7:25 am
Antipspambot question: 0
Location: santa barbara, CA
Contact:

Re: Mike's Build Log

Post by Mike Everman » Thu Aug 17, 2017 1:45 pm

Methanol. Hah, I didn't know desiccant is termed a molecular sieve. What I don't know about chemistry would fill a large chemistry book!
I am very keen on going to the bronze foundry. You know you can 3D print PLA and cast just like lost wax? Local art prof is doing that here in Santa Barbara. We should spend a day or two doing that! Do some suitably difficult to fabricate pulsers.

On another note, I've printed another pot in delightfully Halloween orange, with a flange high up so I can screw it submerged in a jam jar jacket. I'll try a spray sealer just to be sure water does not seep in.
Mike
__________________________
Follow my technical science blog at: http://mikeeverman.com/
Get alerts for the above on twitter at: http://twitter.com/mikeeverman

Mark
Posts: 10743
Joined: Sat Oct 11, 2003 10:14 pm

Re: Mike's Build Log

Post by Mark » Thu Aug 17, 2017 2:32 pm

One of these may help to monitor the conditions to see if it's you or the air. https://en.wikipedia.org/wiki/Hygrometer

Sometimes I wonder if there's another unknown mysterious quality about air that affects jam jars other than barometric pressure and humidity, as if the air could be electrically charged. One time on a old bridge that was relegated for fishing my car antenna started to buzz at the very top and you could run your fingers up and down the length of the antenna to modulate the sound. Everyone's antenna was doing that on the bridge and people were remarking about it taking with each other. My antenna had been broken so I pulled it out of the base and walked around with the buzzing St. Elmo's Fire effect. There was a steady breeze that day.
When bees fly they create static electricity and this helps them collect pollen, it then sticks to their hairs. There's a funny video where people are climbing stairs to the top of some old building and the girls hair especially is so electrically charged from the weather it stands straight out in all directions, the group laughing hysterically at the strange phenomenon.

I once thought about doing a Lord Kevin Water Dropper using methanol instead of water. The falling alcohol drops create static and spark into a fire which starts the collecting vessels jam jarring - "Will It Jam?" - yes! It's funny to think about falling drops starting a fire, starting a fire with methanol that way. Of course people blow themselves up all the time pumping fuels into containers using metal funnels and not grounding the equipment. This sort of thing ...
https://www.youtube.com/watch?v=GsQ9Pu5pXpg
https://www.youtube.com/watch?v=4YTuDu0kPHc
https://www.youtube.com/watch?v=2sSqzLPMb4s#t=5m15s
Presentation is Everything

Mark
Posts: 10743
Joined: Sat Oct 11, 2003 10:14 pm

Re: Mike's Build Log

Post by Mark » Thu Aug 17, 2017 3:41 pm

Mike Everman wrote:Methanol. Hah, I didn't know desiccant is termed a molecular sieve. What I don't know about chemistry would fill a large chemistry book!
I am very keen on going to the bronze foundry. You know you can 3D print PLA and cast just like lost wax? Local art prof is doing that here in Santa Barbara. We should spend a day or two doing that! Do some suitably difficult to fabricate pulsers.

On another note, I've printed another pot in delightfully Halloween orange, with a flange high up so I can screw it submerged in a jam jar jacket. I'll try a spray sealer just to be sure water does not seep in.
With all those vibrant hues I'm going to confer on you the "First On Your Block" award for flamboyancy of color in jam jar jetting. That might a good marketing point now that I think about it. Colors sell and you could make a ten pack of Mike's Disposable Corn Starch Jam Jar Jets for demonstration purposes. Planned daily obsolescence is good enough for contact lenses, it should be good enough for jam jar PLAJETS.

Poly(lactic acid) or polylactic acid or polylactide (PLA) is a biodegradable and bioactive thermoplastic aliphatic polyester derived from renewable resources, such as corn starch (in the United States and Canada), cassava roots, chips or starch (mostly in Asia), or sugarcane (in the rest of the world). In 2010, PLA had the second highest consumption volume of any bioplastic of the world.
https://en.wikipedia.org/wiki/Polylactic_acid
Presentation is Everything

Nick
Posts: 365
Joined: Fri Oct 17, 2003 10:36 am
Antipspambot question: 0
Location: Somerset, UK
Contact:

Re: Mike's Build Log

Post by Nick » Thu Aug 17, 2017 5:16 pm

OK here is the dewatering data from Dave the alchemist :D
To get the water out of the ethanol, you need potassium carbonate. Add enough so that there is solid powder remaining at the bottom after a day or so. If it is liquid, you need to add more. Carefully pour off the dry ethanol, wash out the wet pot. carb. with clean water (preferably thunderstorm rain collected in the Spring under a waxing moon! :lol: ) and recover by crystallisation for reuse. The pot. carb. can be made from Oak ashes and rainwater, but it’s a lot easier just to buy a kilo off the internet.

Enjoy!

Nick

Nick
Posts: 365
Joined: Fri Oct 17, 2003 10:36 am
Antipspambot question: 0
Location: Somerset, UK
Contact:

Re: Mike's Build Log

Post by Nick » Thu Aug 17, 2017 5:19 pm

I am very keen on going to the bronze foundry. You know you can 3D print PLA and cast just like lost wax? Local art prof is doing that here in Santa Barbara. We should spend a day or two doing that! Do some suitably difficult to fabricate pulsers.
Great stuff! - I hope to see Dave in Sept so hopefully can arrange a Pulsejet Bronze-Out Fest! :D

Cheers

Nick

Mike Everman
Posts: 4926
Joined: Fri Oct 31, 2003 7:25 am
Antipspambot question: 0
Location: santa barbara, CA
Contact:

Re: Mike's Build Log

Post by Mike Everman » Mon Aug 21, 2017 2:12 am

Last PLAJET experiment before I have to take a couple of weeks off of this fun project!
http://www.youtube.com/watch?v=eVyjyci_NG8
Mike
__________________________
Follow my technical science blog at: http://mikeeverman.com/
Get alerts for the above on twitter at: http://twitter.com/mikeeverman

Nick
Posts: 365
Joined: Fri Oct 17, 2003 10:36 am
Antipspambot question: 0
Location: Somerset, UK
Contact:

Re: Mike's Build Log

Post by Nick » Mon Aug 21, 2017 6:43 am

Nice work Mike - the design looks pretty proven dimensionally I guess we need to build it from something more heat resistant. If you want to send me the stl file I'll get it printed in resin when I get from Europe late sept/oct?

:D

Nick

Mike Everman
Posts: 4926
Joined: Fri Oct 31, 2003 7:25 am
Antipspambot question: 0
Location: santa barbara, CA
Contact:

Re: Mike's Build Log

Post by Mike Everman » Mon Aug 21, 2017 2:18 pm

Great! I'll redesign on my trip for a full jacket, including water cooling of the "vortexifier".
Mike
__________________________
Follow my technical science blog at: http://mikeeverman.com/
Get alerts for the above on twitter at: http://twitter.com/mikeeverman

Mark
Posts: 10743
Joined: Sat Oct 11, 2003 10:14 pm

Re: Mike's Build Log

Post by Mark » Mon Aug 21, 2017 8:45 pm

That's a good way to assist the PLAJET with a jam jar water jacket. Maybe if you're casting metal, the flow rectifier could be a drop-in piece as some moldings don't turn out so well unless everything is just right. Another thought is that maybe if you had some common/universally available aluminum parts, all that would be needed is the joiners to connect it all together. For example, this cap on my small Coke can is a snap-fit and the lid diameter on the small and regular sized Coke cans are the same oddly enough. Design in a top that also holds an augmenter or snorkel as well as the body together. Then the joints would be the only areas that would give out under prototype testing and you'd save materials, if indeed a snap fit would perform as hoped. And if water cooling could keep the plastic from fatiguing, then that would be nice too.
https://s-media-cache-ak0.pinimg.com/or ... 0bb6e5.jpg
Attachments
DSC_0008 (6).JPG
DSC_0013 (2).JPG
Presentation is Everything

Mike Everman
Posts: 4926
Joined: Fri Oct 31, 2003 7:25 am
Antipspambot question: 0
Location: santa barbara, CA
Contact:

Re: Mike's Build Log

Post by Mike Everman » Mon Aug 21, 2017 9:47 pm

Huh, I've not seen those can tops before.
I've been thinking a lot about just the top end, that is held with the jam jar ring. Seals really well, like water tight as you can see in the video.
I can iterate a lot of variations on jam jar top ends that way, without making the whole vessel.
I just wanted to quickly try flare inside vs. out vs. both vs.?
Certainly not for longevity, but quick to answer "will it jam?" Ha
Mike
__________________________
Follow my technical science blog at: http://mikeeverman.com/
Get alerts for the above on twitter at: http://twitter.com/mikeeverman

Mark
Posts: 10743
Joined: Sat Oct 11, 2003 10:14 pm

Re: Mike's Build Log

Post by Mark » Mon Aug 21, 2017 11:01 pm

Those can tops fit tightly as seen here. Maybe of some use for other projects too. I wouldn't use it for its original purpose though, it's just something to tinker with.
https://www.youtube.com/watch?v=nElkCNbwHls#t=3m21s
https://www.youtube.com/watch?v=DfTYxbCD1lI

"I can iterate a lot of variations on jam jar top ends that way, without making the whole vessel."
That's a good idea.

Be nice to have one of these. Imagine the future where all this stuff will be commonplace and boring. ha
https://www.youtube.com/watch?v=zApmGFDA6ow#t=5s
Presentation is Everything

Nick
Posts: 365
Joined: Fri Oct 17, 2003 10:36 am
Antipspambot question: 0
Location: Somerset, UK
Contact:

Re: Mike's Build Log

Post by Nick » Tue Aug 22, 2017 9:02 am

Mike Everman wrote:Great! I'll redesign on my trip for a full jacket, including water cooling of the "vortexifier".

Good stuff, I don't know if the "vortexifier" will need water cooling because of the high temp tolerance of the resin - maybe one with water cooling, one without?

What I did discover with water cooling is that my big pots would be reluctant to start/run if the water in the jacket is initially too cold - this is probably due to the evaporation of the alcohol being supressed by the cold water. Tepid water works best in my experience :D

Cheers

Nick

Mark
Posts: 10743
Joined: Sat Oct 11, 2003 10:14 pm

Re: Mike's Build Log

Post by Mark » Tue Aug 22, 2017 3:00 pm

Anything below the flash point of methanol won't light, that being 11 to 12 °C (52 to 54 °F). I've experienced that when trying to buy longer running times with my thick aluminum paintball tanks by putting them in my outdoor freezer for just a bit too long. Kerosene >38–72 °C (100–162 °F) Gasoline (petrol) -43 °C (−45 °F) Propane −104 °C (−155 °F; 169 K).
Presentation is Everything

Mike Everman
Posts: 4926
Joined: Fri Oct 31, 2003 7:25 am
Antipspambot question: 0
Location: santa barbara, CA
Contact:

Re: Mike's Build Log

Post by Mike Everman » Tue Aug 22, 2017 4:26 pm

Nick, refresh my memory; your long duration experiments were propane fired, no?
Mike
__________________________
Follow my technical science blog at: http://mikeeverman.com/
Get alerts for the above on twitter at: http://twitter.com/mikeeverman

Nick
Posts: 365
Joined: Fri Oct 17, 2003 10:36 am
Antipspambot question: 0
Location: Somerset, UK
Contact:

Re: Mike's Build Log

Post by Nick » Wed Aug 23, 2017 6:24 am

Mike Everman wrote:Nick, refresh my memory; your long duration experiments were propane fired, no?
Hi Mike, yes propane - very tiny amounts - start on alcohol then switch over to gas :D

Are you going to have a crack at a long run?

Cheers

Nick

Post Reply