Brand New Damper Design - "The Micro Damper"

David Crawford

TVWBB Member
I finally had time to work on this some. I have figured out how I am going to mount this on my UDS and will post more info on that after I am done. I wired up the Micro Damper last night with a temporary connection, because I was not sure how I wanted to connect it. I played with the servo and settings and I ended up with settings of 960us and 1890us for my setup. I hope that I can run some tests this weekend and see how it performs.

The only thing I am struggling with is the wiring. I don't really want a pigtail hanging off the damper and ideally would like a connector for two reasons. First so the cable can be disconnected...obviously and secondly so that if the cable gets damaged or a wire breaks from bending and stressing I can just fix the cable and not have to mess with the wiring in the damper. I don't want a RJ45 hanging on there for just 4 pins, so here is what I am going to try:

http://www.taydaelectronics.com/wafer-connector-2-54mm-4-pins.html

http://www.taydaelectronics.com/housing-connector-2-54mm-4-pins.html

http://www.taydaelectronics.com/crimp-terminal-connector-2-54mm.html

Check this out! That is a decent price.

http://www.taydaelectronics.com/sg90-servo-motor.html

For those of you not familiar with Tayda Electronics they based are in Thailand but have a warehouse in Colorado and I have usually gotten my stuff pretty quickly. Their prices are really good but they don't have everything like Mouser or Digikey. They do have a $5.00 minimum order. Also on usually the 15th and 30th (or there abouts) they put a code for a 15% discount on their Facebook page.

https://www.facebook.com/TaydaElectronics

I will post pictures when I get this installed on my UDS...anyone want to share PID settings that have worked well with this on a UDS??
 
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SteveCK

TVWBB Pro
That place sells stuff for cheap! Don't get that servo though, it won't fit. You need a MG90 or MG90s servo. Currently I have no plans to add a RJ45 keystone to the MicroDamper because in comparison to the size of the damper they take up a large chunk of real estate. I'll be looking at different connectors when I get some free time. PID settings of 9, 0.01, 4 will get you in the ball park.
 

SteveCK

TVWBB Pro
Did some snooping around online trying to find a connector that'd do the job. I ordered up a male and female DIN connector (links below), looks like it will do the job. The good news is everyone who has a MicroDamper right now can order up these parts and install them. There is enough clearance between the servo body housing and the servo that it should fit, you will just have to drill out the ethernet cable hole to get it in there.

http://www.mouser.com/ProductDetail/CUI-Inc/MD-40/?qs=WyjlAZoYn52miOs1CuRKWw%3D%3D&gclid=CjwKEAjw-vewBRDH1-b52Lig1hkSJACTPfVFMVcpwQ1uBMejv32l8-BXrMPQGgAYS420aBFCcGKksRoCgSHw_wcB

http://www.mouser.com/ProductDetail/CUI/MD-40CV/?qs=sGAEpiMZZMtAYTMy7wxAr38XxmkflkdN8qsJ5H%252brC3VtoUdullnnjA%3d%3d
 

David Crawford

TVWBB Member
Did some snooping around online trying to find a connector that'd do the job. I ordered up a male and female DIN connector (links below), looks like it will do the job. The good news is everyone who has a MicroDamper right now can order up these parts and install them. There is enough clearance between the servo body housing and the servo that it should fit, you will just have to drill out the ethernet cable hole to get it in there.

http://www.mouser.com/ProductDetail/CUI-Inc/MD-40/?qs=WyjlAZoYn52miOs1CuRKWw%3D%3D&gclid=CjwKEAjw-vewBRDH1-b52Lig1hkSJACTPfVFMVcpwQ1uBMejv32l8-BXrMPQGgAYS420aBFCcGKksRoCgSHw_wcB

http://www.mouser.com/ProductDetail/CUI/MD-40CV/?qs=sGAEpiMZZMtAYTMy7wxAr38XxmkflkdN8qsJ5H%252brC3VtoUdullnnjA%3d%3d
Those are a lot sturdier and a better connection that what I was looking at. I will most likely go with those if it looks like they will fit. I could easily have these in my hand tomorrow.
 

SteveCK

TVWBB Pro
It must be nice living near Mouser. I can only hope I get my order by Saturday. Not to mention the shipping charges on <$3 of parts.
 

SteveCK

TVWBB Pro
Great price, nice find! It's somewhere around 5dB louder (roughly 50% perceived louder if my recollection is correct) than the other fan, let me know if the noise is too much. The fan that I currently spec out is, I think, a little more powerful than what is needed to run a UDS in the winter. I'll find out once it gets cold up here in the NE though.
 

David Crawford

TVWBB Member
For anyone that is going to add the connector that Steve called out in the post above read this before you do any drilling!

I will be picking up the connectors at Mouser tomorrow so I decided to enlarge the hole tonight to be prepared for installing it. The data sheet shows the O.D. of the connector to be .551" so I was going to use my step drill to open it up to 9/16" (.5625"). I ran my drill at a fairly slow rpm and did well up to 7/16" where I started noticing hollow spots to appear in the part. I thought if I was very careful I could keep going but I started getting some "splittering". I quickly saw this method was not going to work. After thinking for a few minutes I decided that since the part was made by heating the plastic I could repair it with heat. I used my high wattage soldering gun and was able to repair the splittering and enlarge the hole by melting and smoothing the plastic. By enlarging the hole this way it also filled in and reinforced the hollow areas I was seeing because the molten plastic flowed into these areas. I let the part cool and then used my step drill turned by hand to clean up the hole. It is now ready for the connector install tomorrow.
 
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Benjamin Thibault

TVWBB Member
Spin it fast, and then slowly put it into the hole and it will cut better. I drilled that hole as soon as I got my Microdamper, and have also drilled the hole for the grill side connection (to 1 3/8) both with a step drill.

What ends up happening is it pulls up a layer and then it wants to keep splintering. If you spin it fast it will shave off really nicely.
 

SteveCK

TVWBB Pro

David Crawford

TVWBB Member
I purchased and picked up the connectors. When I got back to my vehicle I decided I would look at them and I am glad I did. They did not supply me with the mounting nuts that go with the panel mount side (I bought two panel mount and two cable ends), so I had to go back in and get them to pull them out of stock for me. It was challenging to get the connector mounted in the damper body but I got it done. I will supply more info and pictures later.
 

SteveCK

TVWBB Pro
Sorry Dave, I jumped the gun a little bit saying it would fit. Once I get mine in I'll see if its worth designing around or if the other connector I posted would be better. I'm anxious to see how you made it work though.
 

David Crawford

TVWBB Member
Sorry Dave, I jumped the gun a little bit saying it would fit. Once I get mine in I'll see if its worth designing around or if the other connector I posted would be better. I'm anxious to see how you made it work though.
Not a problem Steve it does fit! It wasn't that bad and I enjoy stuff like this.

I am glad that I bought two connectors because I ended up using both of the mounting nuts to secure the connector. The shoulder on the connector was just a little over 5/8" so I used my lathe to reduce it to just under 5/8" (this could easily be done with a Dremel or a file). I enlarged the hole in the Micro Damper body to 5/8" which was getting really close to the edge. To secure it I installed one nut inside the damper body and one outside. I think there is enough thickness there that you could modify the print so that you end up with a counterbore type hole with a shoulder nearest the inside of the body that the connector could be tightened against, then this could be installed with just one nut. I started out trying that but it just was not working with the step drill...an end mill maybe. I figured this was just prototyping so I did it the fastest way I could think of.

Soldering the wires was a little tedious partly because I believe this is a PCB mount connector. The connections are just a pin and not a solder cup like a lot of connectors have. The pins are pretty close together so I would strongly suggest using some shrink tube to insulate them. As you can see in the photos, I left the fan and servo wires long. I did this so there was enough length to pull the wires thru the hole and do the soldering outside of the damper body. If your nut is going to be inside the damper body be sure that you place the nut inside the body and run your wires thru it before soldering to the connector!

Making the cable was not bad at all but again these are just pins and not a solder cup. I did make a bonehead move while making the cable. I had already crimped the connector on the other end and after I finished soldering I saw the strain relief sitting there that needed to go on first! I have plenty of the crimp on connectors (I used a 6 pin, not an 8 pin) so I just cut it off, installed the strain relief and crimped a new one on. I double checked my wiring, put the damper body together, hooked it up and everything works fine! I am ready to fire up the UDS this weekend.

https://goo.gl/photos/5TTgyLNZShz5mRAq7
https://goo.gl/photos/TmLtz55jbDDExjBc6
https://goo.gl/photos/R3mnng99cEUipRHz6
https://goo.gl/photos/ZjqQ9Uz7G38itoDe7
https://goo.gl/photos/qjhXJ17WtoKpP6M76
https://goo.gl/photos/E275sCQVbL7jThDfA
 
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SteveCK

TVWBB Pro
Looks good Dave! I certainly have a little design work to do to make that fit easier. Hopefully I can get that done this weekend when the parts come in. How bad was the soldering? Do you think maybe a crimp like in the photo below would be better? I'm sure those could be sourced for a couple pennies each somewhere.

 

David Crawford

TVWBB Member
Looks good Dave! I certainly have a little design work to do to make that fit easier. Hopefully I can get that done this weekend when the parts come in. How bad was the soldering? Do you think maybe a crimp like in the photo below would be better? I'm sure those could be sourced for a couple pennies each somewhere.

I'm not sure there is enough clearance between the pins and they are fairly small diameter.

The soldering is not that bad, but I would not want to build 100 of them! As you can see in the photos, I soldered the wires parallel to the pins. The problem is you need three hands so you can hold the iron in one hand, the wire in one and then add solder. I tinned the wires and pins then put a small amount of solder on the very tip of the iron then touched it to the joint of wire and contact. Another possible way would be to bend the tinned wire in a hook around the connector pin but it would come off at a right angle and you would not be able to use the shrink tube.
 

SteveCK

TVWBB Pro
So Christmas came early and my shipment from Mouser showed up today. I really like the connection feel the DIN makes, it's good and solid but there are things I don't like about it. The male and female key into each other in only one orientation, so you have to look at the male and and line it up each time you plug it in. Secondly wiring the male part does look pretty tedious since it's such a small piece. Thirdly, the male end just seems too chunky for me. Overall I think this will be a good addition for those people out there who already have a MicroDamper and want to add a plug. That said, looking at it a little more the easiest way to install it would be to drill a hole just slightly smaller than the metal nut that is provided, then place the nut over the hole, get out your soldering iron and with very little pressure heat the nut up until it melts it's way into the body. The nut should stay put once melted in there (if it ends up falling out at some point in the future you can epoxy it in). Once the nut is in place you can screw the female end right in from the inside of the servo body housing.

I think I will take the design to a 3.5mm 4-pole phono jack. Currently the MicroDamper won't fit the female side (it's only a few mm off), but I can go redesign to make a counter set hole for it to fit in. The female adapter is a little more expensive at $2.73, but the male ends can be had for <$1, or if someone wanted to they could spend a few bucks more and get various anodized colors, gold finishes, silver finishes, etc. Overall I think the phono jack will make for a much more aesthetically pleasing look, and it will also give better "trip protection" in case someone has too many beers next to the pit and stumbled over the cord.

Here is the female end I'm looking at (currently out of stock at mouser): http://www.digikey.com/product-detail/en/SJ5-43502PM/CP5-43502PM-ND/1956558
 

Steve_M

TVWBB Guru
Is a phono jack a good idea? You'll be dragging various power and data signals over the contacts as its inserted and removed.
 

SteveCK

TVWBB Pro
Hmm, good points. Obviously it wouldn't matter as long as you plugged in the microdamper side first, but I'm not willing to compromise functionality over aesthetic design. Perhaps Ben is right? If the tip was assigned servo position, then second was servo power, third fan power, fourth ground, then I think it would work.
 

David Crawford

TVWBB Member
I used my Micro Damper today while cooking a couple of chickens. I did not get the results that I wanted, but it was not the dampers fault. I got a later start than I wanted so I decided to cook the chickens at 300 degrees. The UDS came up to temp pretty quickly for me and I put the meat on. I was doing some other things and noticed that the temp had dropped all the way to about 250. I went and looked and the damper was 100% open but I could not hear the fan and thought it had died. When I brought up the GUI I saw that I had Max fan set at 30% and that clearly was not cutting it, so I changed it to 80%. That solved that problem, but I obviously have PID tuning issues as I was getting some pretty high overshoot. The damper seems to work well, I just need to do some more testing.

I meant to take pictures of how I mounted it and forgot. I will do that sometime soon.

The chickens didn't care, they turned out to be very good. I had brined them overnight which always works well for me.
 

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