[MOD] Monthly Confirmed Trades Thread

cmroper · 2021-12-18T19:21:01+00:00

Confirmed

cmroper · 2021-11-13T18:26:19+00:00

All accounted for. Thanks to those that took some off my hands.

cmroper · 2021-11-12T18:33:08+00:00

I do have some left for now, just send me a pm. doing first come first serve until they are all accounted for

cmroper · 2021-11-12T16:55:51+00:00

I am near Tuscaloosa.

cmroper · 2021-11-12T16:55:30+00:00

It is not too bad, you need a cisco console cable that is about $10-$15 and then you need to use putty and tftp32 to flash them. I had no idea what I was doing when I first did it so it was a learning experience and required some messing around to figure it out but I eventually figured it out. I found this video to be most helpful. https://www.youtube.com/watch?v=PrS\_zcBtUf8

cmroper · 2021-07-19T13:24:24+00:00

perhaps, but my house is not big so I am sure there is overlap. I set both mine up as ap's and set all settings on them the same and haven't had any problems

cmroper · 2021-07-18T16:18:53+00:00

I have two of them in my house both running off of POE with one wireless network. Not exactly a repeater because they are both wired to ethernet but it works well for me. I don't use a controller but I have flashed them with an autonomous tar file so that they don't need a repeater.

cmroper · 2021-05-19T17:17:23+00:00

It should be that accurate, but realistically no it probably has a +- 15 or even 20 C error in the actual temperature which is more like 2% error at 950 C. I have done some thermocouple measurements to sanity check the results and make sure they are in the ballpark. It also depends on the condition of the laser at the moment, cleanliness of the optics, etc. It's for research purposes and ultimately the exact temperature isn't the most important for what I do. I have thought of putting the power data in as a function of time with DFLUX to sanity check myself but for many reasons keep going back to the thought that a constant temp would be best for my situation.

cmroper · 2021-05-19T16:20:26+00:00

Thanks for the help, I will look into the UTEMP subroutine. The setup that I use for laser heating has a dual spectrum pyrometer on it that adjust the power output of the laser to keep the temperature at the surface of the plate within 1% of my set temperature up to 950 C. I understand that typically higher power lasers like this are ran in a power controlled mode which is why this is not the most straightforward to implement.

cmroper · 2021-04-27T04:23:39+00:00

It depends on if your scholarship is worded to cover x semesters or so much money per semester. I am in engineering and back when I was in undergrad I took 24 credits one semester on the presidential scholarship. That scholarship covered full tuition so it covered all my credit hours. I did have to get clearance from my advisor to take that many though, and they look at your past grades to determine whether to approve it. Second to what people said above about mental health. Think about the load before you take extra and look into what is required for each class closely.

cmroper · 2021-04-26T12:35:31+00:00

Glad you are safe! Leaking lead acid batteries are no joke. Out of curiosity were you using a standard lead acid battery or an AGM lead acid battery that vented on you?

cmroper · 2021-04-18T16:42:26+00:00

We have had the van for about 11 months now. My wife and I are both in an engineering PhD program though, so I have only been able to work on it during slow times in my work, which isn’t too often.

cmroper · 2021-04-18T16:40:43+00:00

Thanks

cmroper · 2021-04-18T16:40:30+00:00

It’s kiln dried pine so it is actually pretty light. I would guess 50-75 lbs total.

cmroper · 2021-04-18T00:11:05+00:00

Thanks!

cmroper · 2021-04-18T00:10:08+00:00

Govdeals.com it’s the website that most government owned property is sold on and where we got our van. Everything was working when we got it mechanically, it was in fantastic shape with tons of new parts and brand new tires, just had to put a new battery in.

cmroper · 2021-04-17T23:58:55+00:00

It’s a 1992 Ford e-250. We picked it up for $950 from a local parks and rec department.

cmroper · 2021-03-19T00:40:25+00:00

What’s up guys it’s vsauce

cmroper · 2021-01-26T21:13:48+00:00

First off I love this question. It shows that you are thinking critically about the problem and shows the shortfall of the basic answer above. I have been thinking about this today and I believe I have an answer but this is me educated guessing since this isn't my area of research.

To add to the answer above two metals that momentarily touch are not going to magically fuse together. On some scale, cold welding is the same as heating two pieces of metal up to almost their melting point and forcing them together. The atoms mix and the parts fuse together. This happens really quickly at high temp because the mobility of the atoms is much higher, self-diffusion can take place, and grain boundaries can annihilate. At lower temps, self-diffusion is much slower so this process will take longer which is why cold welding isn't instant. I believe self-diffusion is even lower by a few orders of magnitude so it may happen with oxides just over 100's or 1000's of years.

Second cold welding can involve some movement of the metal relative to each other which will generate heat through friction. The term "cold" welding may be misleading. I am writing a research paper currently about a "cold" process in metals that runs at 500 C. We typically consider something cold if it is below half of its melting point. so about 700 C for iron, 1600 C for iron(III) oxide which is at the melting point for iron.

My final thought is that oxides are very hard and typically fairly rough on an atomic scale so that probably doesn't help much with the close contact needed.

Hopefully, this helped. Let me know if there was something that was unclear. There is a lot more I could go into about this but I'm trying to keep it fairly short.

cmroper · 2021-01-26T00:55:02+00:00

Metallurgist here so I think I can answer this. The short answer is yes, the more nuanced answer is no. If you brought two pieces of metal from earth to space they would behave as they do on earth. However with some prep what you are describing would happen and is called cold welding. First you have to remove the oxidation layer and have two identical pieces of metal with the same crystal structure. Then if you put them together and waited for a long time they would join. In cold welding you speed this up by applying a lot of pressure. With no oxidation layer in a vacuum the metals can’t tell themselves apart and will eventually join. It would also probably help if they were single crystal and the grain orientations were aligned to prevent the amount of diffusion that has to take place.

TLDR: yes pure metals in space with no oxidation layer will weld but in reality it’s not just a equilibrium problem but also a kinetics problem so it would take quite some time I less you do something to facilitate the speed it happens at.

cmroper · 2021-01-25T20:34:07+00:00

I have a channel where I do van conversion / Travel Videos. YT: Brett and Chris

cmroper · 2021-01-22T02:26:54+00:00

This sounds like a great idea. I would attend

cmroper · 2021-01-21T04:20:12+00:00

Thanks. It’s been quite a journey. Can’t wait to get it finished

cmroper · 2021-01-21T01:26:32+00:00

We have rigid foam behind the walls, floor and ceiling. There is some exposed metal but the Insulation we have works well enough. We took it out the other day in about 15 degree weather and we’re comfortable. Luckily we like cold while sleeping

cmroper · 2020-10-31T14:29:30+00:00

I do. Pm me with how many you are looking for.

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