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Messages - webby2
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271
« on: April 07, 2020, 12:18:36 pm »
with what I have, as far as parts go and a few that I printed out I have started running a few basic tests just to bring myself back up to speed with where I was. I purposely built this setup a little loose, that is it was supposed deflect a little bit to provide for a visual indicator of where the forces are heading and stuff,, well it does not flex so much,, so much for that idea 
272
« on: April 07, 2020, 12:15:57 pm »
I have used the blue tape for a few prints and it does stop the fusion issue and still has some flex to it so I can still bend the surface to facilitate removal.
273
« on: April 06, 2020, 07:34:35 am »
interesting problem I am using a magnetic build surface, one that lets me pick up the surface with print when I am done and then place it back onto the printer when I have removed the print. Often a printing issue is with the print NOT sticking to the build surface, well with the surface I am using and the temperature I am printing at the extrudite is sometimes fusing to the surface. I have made a huge mess of my surface at the moment with holes and whatnot,, not a good thing. I think I am going to try and use Blue tape on the surface and see if that stops the fusing issue and still allows me to bend the build surface for easy removal. I will try it with the current surface first, before I put on the new one I have already.
274
« on: April 04, 2020, 06:02:10 am »
It has been about a year since I had to stop playing with my stuff and I am finally getting back to playing with things. What I was trying to do is simple,, I have been trying to pass an input into a flywheel that is mounted on the end of an arm that is free to move. This input is from a source that is mounted on the very arm that the flywheel is mounted to and the goal is for me to spin up the flywheel without imparting a rotation into the arm as well. Some of my prior printed test-bed parts made the move but not all of them,, some tests I need to redo since it has been so long since I did them,, and all that kind of stuff that happens when time passes. I am not in any kind of hurry so I will take my time and post things when I feel like it
275
« on: April 03, 2020, 08:43:30 am »
Funny way to look at an acceleration,, It is when you do NOT have an equal force of opposition
276
« on: April 02, 2020, 06:32:27 am »
I tried to speed things up too far,, bummer. So I can run at 45mm\s prolonged print without running out of extrudite,, petg,, well it stops coming out nicely so it looks like I am underextruding but the problem is that even tho the hot end is showing 247C it is not keeping up so the flow goes down and the pressure on the filament goes up. Slowing it down means that it takes longer to print,, what is a little more time
277
« on: March 31, 2020, 10:23:56 am »
Some days,,
An interesting thing keeps happening to my bowden tube,, I am guessing it is due to running at 247C,, but at the hot end it is slowly melting (getting soft anyway) and allowing the tube to pull up and out of the retainer leaving a groove in the tube.
I had to clean off a glob of plastic from the nozzle and I guess I hit the very tip with something while doing that. I did not notice it at first but the feed kept "popping" due to too much pressure,, well in the middle of a print things were looking fairly bad so I stopped the print and pulled out the tube and then ran a drill bit down to make sure the hole size was 0.4mm,, it was not.
It is back to printing as it was.
278
« on: March 30, 2020, 09:08:41 am »
I am running the printer with the bed set to 70C and the hot end set to 247C,, I increased my print rates a little and things are working fairly well so far with tolerances within +- 0.5%
279
« on: March 26, 2020, 11:12:29 am »
It took a little bit but I think I have the printer setup close enough This one is slower using petg than the other one was,, but it does seem to be doing its thing for me. Now to print some parts and assemble a testbed!
280
« on: March 23, 2020, 10:06:57 am »
It has been a while but I am starting back up on some of my stuff,, well I am now only using my latest printer, I gave the other one away to a relative and have switched over to petg.
Problems, problems and more problems,,,, not so much with the petg but with the printer and getting it setup nicely and THEN,, one of the retainers for the bowden tube failed.
These are just small things but when you are trying to get motivated and making things it sure is a damper on the old motivation.
281
« on: March 19, 2020, 03:16:00 am »
I ran across this on another site https://www.youtube.com/watch?v=rxFXsoqbfrkIt is about buoyancy. The thing is you need to follow the water. If you started with the upper and lower tanks filled to some level and marked, then you push in the "float" it will raise the water level in the lower tank, it has displaced water. Then you move it into the tube and allow it to float up to the second valve, close the first valve and then open the second valve. In this condition the water level in the lower tank is still up at the higher mark and the water level is still at the original mark in the upper tank. The float goes up the tube and into the upper tank, now you remove the float and the tank is now at a lower level of water, the float has displaced some of the water. As the float has moved up the tube the water from the upper tank has flowed down below the float to fill the void that the float would leave as it moves up. Now when you close the second valve again and open the first valve the water in the lower tank is still at the higher level and you have replaced the displaced water from the float being pushed into the lower tank with water from the upper tank via the opening and closing of the valves.
282
« on: March 04, 2020, 05:31:47 am »
Just to show the depth of my ignorance  To me a changing flux density looks a lot like a moving magnetic field,, or maybe a circulating magnetic field,, it is still moving but in a closed path whereas normally the field is not in motion in the local area. This allows that it could still be propagating somewhere beyond the local area.
283
« on: March 04, 2020, 04:48:18 am »
Not that it matters,,
I wish to revisit the cap to cap dump loss in energy.
The setup is 2 identical caps, one charged up to some voltage and the other at 0V,, if then I connect the 2 caps together the final energy stored is 1\2 the initial energy stored in the single cap.
0.5CV^2
This is an often used relationship and it works as we use it, but where is the loss in energy?
Another formula we use often is F=ma.
This is a two part thing,, sort of.
If this was done with liquid, so I have a tank filled with liquid at some pressure and I have another identical tank that I connect it to that is at no pressure,, how much resistance to flow is there when I first open the connecting valve? There is zero resistance (except of course for all the line losses) to the liquid flowing.
This makes it easy to understand that some of that stored energy via pressure is being expended to accelerate the liquid, this does not transfer the stored energy into the other tank but only serves to expend energy against the liquid to make things happen faster.
When this energy has been used to accelerate the liquid it can no longer be used since it has been transformed into velocity,, then it hits the tank walls and is transformed into something else like heat.
With the cap to cap thing there is the same situation, there is no initial resistance to flow so the initial voltage is used to accelerate the charge carriers into the other capacitor, the loss is not due to the contacts, it is due to the forces involved being converted into accelerating some mass that then ends up "hitting" a wall and transforming its velocity into something else like heat.
The other part to this is in dealing with a fixed volume and quantity and pressure. If you change any of these 3 parts you change the energy of the system of all 3 parts.
If you double the volume with the same quantity the pressure will drop, if you increase the quantity within the volume the pressure will go up,, and of course if you decrease the pressure the energy stored goes down.
You then might start so see that the quantity and volume that is enclosing that quantity is related to the pressure, and this is something we also use and have an understanding of.
How then can you make this dump thing work out to provide for a conserved energy exchange?
Well doubling the volume means that the quantity needs to increase and to increase the quantity you could use an exchange system, one that might be able to take the moment of acceleration and convert it into a non acceleration but rather moves more quantity than that that is being discharged so that now the energy out equals the energy in.
There are ways of doing this, I have made a few for the more mechanical side of things and the same should also work for the cap to cap dump thing.
284
« on: February 29, 2020, 06:21:42 am »
If a coil passing current is producing an EM field of some value,, how much current must flow to have that field?
That is, does a certain amount of current need to flow for a certain amount of time before the field is there.
Does the field need to propagate some distance before it is at is density close to the coil?
If the distance of propagation is just far enough to cover a secondary coil, how long would it take?
285
« on: February 11, 2020, 08:18:51 am »
Take a closed chamber, place 2 balloons inside that chamber, the balloons do not see the chamber only the other balloon but they stay fixed in position relative to the chamber.
Blow the balloons up and seal them.
The balloons measure there distance apart by using there own dimensions, so many diameters apart if you will, or so many degrees from several points on the surface of the balloon.
Change the pressure within the chamber.
The balloons did not move but there is a change in the relative distance of separation.
Sure there are flaws in the setup but the general thought is easy enough that if I am measuring and comparing things to myself I might not be aware of changes within myself that would affect what I see outside myself.
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