INTRODUCING: the "Roto Damper"

[Bryan Mayland]

The cat5 distance limitations only apply because of the fast signaling rate being transmitted across the wires.

Quoting this because it is cool and I finally actually get to use a fact from my college education (which never happens). It isn't a CAT5 limitation it is a 100Mbit ethernet limitation. Before any ethernet frame is transmitted the physical layer transmits 56 ones and zeros, on off on off on off on off. At 100 mbit at the speed of light, a client on the far side of a 100m connection is guaranteed to see the first on off transition before the transmitter finishes the 56 bit preamble. This prevents anyone else from transmitting at the same time. CDMA - Carrier Detect Multiple Access

Anyway, the distance of the CAT5 cable isn't a big deal when added in series to the thermistor because even at 500F the resistance is still in the kiloohm range and 100ft of cat5 wire is like 2 ohms.

[RalphTrimble]

Good to know, I wasn't sure how low the resistance of the probes went, sounds like a couple ohms shouldn't be an issue.
I'm doing a test print of the housing with the probe jacks now, if all goes well I will be scrounging around for filament to print a new top half, it might have to be multi-color.... I'm really looking forward to testing the HM with everything running over 1 CAT5 cable... one small step for BBQ kind... lol

[JuanGarcia]

Ralph,

I was thinking round for the grill adapter.... any color would work (the blue seems cool though) i am now interested in the "remote probe" option also....

[T Hayes]

It would be nice to have a small PCB with 3 probe jacks on one side, and a cat5 jack on the other side, and a couple of through hole spots for soldering the blower/fan wires to. And then find a spot in the plastic housing to locate this.

[RalphTrimble]

I've worked out the design to hold the CAT5 jack and 3 probe jacks, the test print of housing went well last night, everything fits just right. I am printing a top end of the valve now that will have all these features integrated.

T Hayes, I see no real need for a circuit board, the CAT5 jack I am using is a punch down style made to work with wires so a circuit board would be inconvenient. Perhaps if I was using a board mount CAT5 jack a circuit board would be more appropriate, but then I would have to worry about fitting the board into the small space and having it in position where the CAT5 jack can mount and the probe jacks can mount while all of them meet their respective holes in the enclosure, which would be difficult cause the CAT5 jack has to snap into the side and the probe jacks have to screw into the back. It's just easier to do with wires IMHO and I can't see any drawbacks from using wires instead of a circuit board.

[RalphTrimble]

OK, it took every scrap of filament I had laying around but I got a print of what I hope to be the final prototype of the "Roto-Damper" printed up and assembled last night. It's a funny multi-color unit but I think it looks kinda cool that way, at least I won't have trouble remembering which one is the prototype! Since I printed the parts onto Kapton tape the mating surface(s) are much more flat and smooth than the first valve, and I didn't need to print the parts with the rectangular base pad to keep them flat. This valve closes even tighter than the first valve, there is very little leakage even when quite a lot of air pressure is applied.

I have the three probe jacks integrated and working through the CAT5 cable now, it's really tight in the wiring cavity but everything fits, barely... I have tweaked the opening for the CAT5 jack a little bit to make the fit just right and reinforce that corner a bit as well. Finally, I added a mount for the blower that I think worked out really nice. I had thought of using a screw to hold the blower in place, but to do that I would need to either extend an arm out beyond the radius of the cirlce or all the way up to the screw hole on the top of the fan, which would just about double the size of the print. I ended up settling on a press-n-fit design that holds the fan really well, beauty is you just press the fan in there and you are good to go! I've put the fan in and out of the prototype a dozen times and it still holds firm like the first time, and I have plugged/unplugged the CAT5 jack dozens of times to test for durability, everything remains solid after putting it through those paces...

Here's a pic of the latest prototype valve:

Just to give you an idea of the scale, the valve measures 3 inches from top to bottom, not including the blower.

Here's a pic of the back of the valve showing the CAT5 and 3 probe jacks:


Here's a pic of the bottom without the fan installed, and you can see the inside of the wiring cavity:



I've got a wide roll of Kapton tape on order (along with more filament) so early next week I will print it out again in a solid color and will be updating the initial post in this thread at that time to reflect these developments, hopefully including a better video to showcase the "Roto-Damper" in action...

...looking back over this post I get to thinking I should have ordered some red and white filament along with the blue, cause I can see a "US Patriot" model of Red, White & Blue looking really slick. Although I made this one muti-color only because I didn't have enough of one filament to print a complete part, as it turns out a multi-color unit looks pretty slick....

[Steve_M]

Looks great!

[JuanGarcia]

Looks nice Ralph... I need one of those!

[RalphTrimble]

My Orange and "glow in the dark" Blue filament was delivered today, still waiting on the roll of wide Kapton tape for the printing bed. Once I get he Kapton tape I can start printing up the parts. So far with the last prototype I haven't run into any issues so I think the design is good to go....

[Troy Gamm]

Looks great Ralph!