Printing airlock parts for my dust collector

[ddmckee54]

Good news, my real-live 24V power supply should be here Wednesday. That means I don't have to try temporarily cobbling in the other 24V power supply, Health & Safety will be SO pleased. My fused terminals were just delivered today, so maybe I can actually start wiring the panel tonight. I DO have to pick up some wire labels though. As a controls engineer, unmarked wires just make my skin crawl.

I got the motor bracket designed, printed, and installed over the weekend, but it's a different color than the rest of the airlock parts. I can live with that because I was running out of that color filament. I didn't think I had used that much of it, but then I remembered that particular color only comes in 0.75Kg spools.

It was probably a good thing I ran out. When I tried fitting the motor to the partially printed bracket, it DIDN'T fit. It was late Friday night when I designed the bracket, and SOMEBODY got the orientation of the shaft side of the 3D model 90° out of sync with the motor side. The gearmotor is not QUITE square, and the output shaft is not QUITE centered on the face, but it's close. And the mounting studs are on 60mm centers one way, and 65mm centers the other. I was using the motor side as my reference for all my measurements, and when I plopped it down on the model 90° from where it actually was and didn't catch it...

Anywho, I fixed that problem, measured the 3D model's dimensions, compared them to the real deal and when they matched - I said all is well with the world and printed the stupid thing. Several hours later as I was carrying the bracket down to the basement to install I remember thinking - I am REALLY gonna be pissed if this doesn't fit. Fortunately it did fit, it even looks like I'll have enough slack to be able to easily install the belt - Prior Planning and all that alliterative crap.

Over the weekend I also got the last of the grounding wires installed on the dust collector ducting. The entire cyclone system is now electrically connected to the house ground. That should prevent any static build-up in the system while it's in operation.

That light up ahead in this tunnel is DEFINITELY getting brighter.

Don

 

[awake]

It was probably a good thing I ran out. When I tried fitting the motor to the partially printed bracket, it DIDN'T fit. It was late Friday night when I designed the bracket, and SOMEBODY got the orientation of the shaft side of the 3D model 90° out of sync with the motor side. The gearmotor is not QUITE square, and the output shaft is not QUITE centered on the face, but it's close. And the mounting studs are on 60mm centers one way, and 65mm centers the other. I was using the motor side as my reference for all my measurements, and when I plopped it down on the model 90° from where it actually was and didn't catch it...

That sounds awfully familiar. Surely I haven't done something like that ... have I??

Don, remind me - are you running the grounding wire inside the piping or outside? (Does it matter?)

 

[ddmckee54]

Andy:

I'm running the grounding wire on the outside. I thought I had a picture of some of the wires installed, but I don't. I'll try to remember to get one tonight, along with a shot of the airlock motor bracket.

Actually the ground wires are more like jumpers around the plastic fittings. I know to have a proper bonded ground I SHOULD have run an individual wire from my grounding point to each fitting, but that would add up to a LOT of wire. I've got about 20 individual metal sections and if you figure an average of 20' of wire per section... You do the math, that's a bunch of wire. The way I did it all the connections are in series, so if I lose one connection then everything beyond that connection will be ungrounded. In my opinion this is sufficient, especially since there are people who say that grounding is not needed at all. And I used less than 30' of wire.

This is a static discharge to ground connection, not the ground connection on a device with enough volts and amps to kill you. I verified every connection as I made it to be sure I had a good connection between the metal sections. Checking the connections is something that I'll have to do periodically to ensure I've still got a good ground.

I read an article years ago about grounding a PVC duct for a dust collector, I think it was in Shop Notes or a similar magazine, but it could have been on-line. This article was about their un-official testing of various methods for grounding the PVC duct. They tried a bare copper conductor inside the duct, a bare copper conductor strapped to the outside of the duct, and an insulated conductor strapped to the outside of the duct. Their conclusion was that it didn't really matter how you did it all of the methods effectively reduced, if not eliminated, the static build-up.

To ground, or not to ground, that is the question. Me, I jumpered all the metal sections together and tied the whole kerfluffle to ground.

Don

 

[awake]

Ah, all the 3d printed components made me forget that you are doing most of the ductwork in metal. Sounds good ...

 

[ddmckee54]

Last night I remembered to take a couple of pictures. This is the new motor bracket with the new gearmotor. It's just a LITTLE bit bigger than the old gearmotor. Still waiting on the 20T motor pulley.

The next couple of pictures are just the jumpers that connect the metal sections of the duct.

It seems like a HELLUVA mess just to get one little bitty panel wired up, but I'm getting there.

The blue and white thing in the middle of the shot is my 24V power supply that just arrived. I thought I was getting a deal on a used power supply, turns out it was NOS so I really did get a deal.

Don

 

[ddmckee54]

It's wired, I need to get some fuses, when I checked my stash, I found I did have any of the proper flavor.

Professional panel builders please turn away. They gone? OK, this is what the panel looks like.

Yeah I know, it's too crowded. But when I bought the panel all that was supposed to be in it was a smaller power supply, and a couple of smaller timing relays. I got hit by the dreaded project scope creep.

I'll verify the wiring tonight, hopefully install the correct fuses, and get the CORRECT labels on the fused terminals. When you buy used AB terminals off Ebay, odds are that they will already have some type of label on them - at least the SHOULD have a label.

The 20T gearmotor pulley arrived yesterday, so if I can find the belt I'll probably get the belt drive installed too.

If all goes well, maybe I'll even be able to see if I can let the magic smoke out of anything - hopefully NOT. I will do a live bench test of the panel before I install it. Once I get the panel checked out, all I've got to do is bolt it in, and connect 8 wires: incoming 120V hot, neutral, and ground; the 3 fan motor leads; and the 2 DC airlock motor leads - then we should be good to go.

I'll let you know if I need to find some more magic smoke or not.

Don

 

[ajoeiam]

Last night I remembered to take a couple of pictures. This is the new motor bracket with the new gearmotor. It's just a LITTLE bit bigger than the old gearmotor. Still waiting on the 20T motor pulley.

The next couple of pictures are just the jumpers that connect the metal sections of the duct.



It seems like a HELLUVA mess just to get one little bitty panel wired up, but I'm getting there.

The blue and white thing in the middle of the shot is my 24V power supply that just arrived. I thought I was getting a deal on a used power supply, turns out it was NOS so I really did get a deal.

Don

Hmmmm - - - what is NOS?
You're fortunate to have your PVC - - - here a local supplier says no stock and none to be had.
Found some elsewhere but that's to 2" - - - - argh!!!!!

 

[ajoeiam]

It's wired, I need to get some fuses, when I checked my stash, I found I did have any of the proper flavor.

Professional panel builders please turn away. They gone? OK, this is what the panel looks like.

Yeah I know, it's too crowded. But when I bought the panel all that was supposed to be in it was a smaller power supply, and a couple of smaller timing relays. I got hit by the dreaded project scope creep.

I'll verify the wiring tonight, hopefully install the correct fuses, and get the CORRECT labels on the fused terminals. When you buy used AB terminals off Ebay, odds are that they will already have some type of label on them - at least the SHOULD have a label.

The 20T gearmotor pulley arrived yesterday, so if I can find the belt I'll probably get the belt drive installed too.

If all goes well, maybe I'll even be able to see if I can let the magic smoke out of anything - hopefully NOT. I will do a live bench test of the panel before I install it. Once I get the panel checked out, all I've got to do is bolt it in, and connect 8 wires: incoming 120V hot, neutral, and ground; the 3 fan motor leads; and the 2 DC airlock motor leads - then we should be good to go.

I'll let you know if I need to find some more magic smoke or not.

Don

waiting!!!!!!!

 

[ddmckee54]

ajoeiam:

NOS - New Old Stock. A surplus part that is brand new, unused, but still packed in the original box. That power supply brand new, and they still make it, is about $90. I got it for about 1/3 of that.

Hopefully there will be no smoke on the horizon, but that IS what fuses are for. As long as I test the panel correctly, incoming power, 24V power supply, power to fuses, then one fuse circuit at a time I should be OK. I could even get some itty-bitty sacrificial fuses, small enough that they'll blow before anything else does, for bench testing the panel. There'll be no load on the panel when bench testing, I just want to be sure it functions the way I expect it to function.

Don

 

[ajoeiam]

ajoeiam:

NOS - New Old Stock. A surplus part that is brand new, unused, but still packed in the original box. That power supply brand new, and they still make it, is about $90. I got it for about 1/3 of that.

Hopefully there will be no smoke on the horizon, but that IS what fuses are for. As long as I test the panel correctly, incoming power, 24V power supply, power to fuses, then one fuse circuit at a time I should be OK. I could even get some itty-bitty sacrificial fuses, small enough that they'll blow before anything else does, for bench testing the panel. There'll be no load on the panel when bench testing, I just want to be sure it functions the way I expect it to function.

Don

Thanks for the info!!!

I have also begun a journey into that strange black hole called electronics as well as its sister entity programming.

So much to do and so little time to get it all done in!!!!!!!!

 

[ddmckee54]

WELL..... It worked - sort of - kinda. When I bench tested it everything went fine, no magic smoke was released. So I tried bolting the back panel into the enclosure, but it wouldn't fit. Remember that scope creep? Yup, SOMEBODY didn't allow for the stick-out of the fittings inside the panel. I got around that little issue, my power supply is now resting on the bottom of the enclosure instead of being attached to the back panel.

With the back panel wrestled into place and fuses pulled, I plugged the beast in and held my breath... Still no tell-tale wisps of magic smoke. Next step, pop the fuses in one by one and check the panel with it live. No smoke, no fires, with the E-stop pressed in the panel was as dead as it was supposed to be. When I pulled out the E-stop the control power light came on just like it was supposed to. (I know, that's NOT how a proper E-stop circuit is supposed to work, but it's what I could cobble together with the parts on hand, OK?) When I flipped the fan switch on the indicator in the SSR (Solid State Relay) came on. I hadn't plugged in the fan yet. So... It was time to see if I could make the airlock go roundy-roundy. I flipped the switch to the HAND position and.... NUTHIN!!!! WTF, I checked that on the bench and I had power at the switch. Got the meter out and I DID have power at the switch. The only thing between the switch and the motor is the wire.

AWW MANNNN!!! There are 2 wires coming off that switch, a #9, and a #10. I checked the continuity, and - nuthin. Did I do that? Yup, I doooed that. The wire that goes to the + side of the motor is labeled #9 at the motor connection, but it's #10 at the switch. Okee-Dokee, simple fix, take the wires off the switch, relabel them and connect them to the switch - like they were supposed to be the first time around. Now why didn't I catch that when I bench tested the panel? Simple, I checked things at the switch, not at the end of the wire. (It's just a wire, what can go wrong?? Those little boo-boos are ALWAYS hard to find.)

OK, with that little boo-boo corrected it was time to power things back up and see if this actually works. Summa-na-gunnn, it actually goes roundy-roundy in HAND, what about AUTO? Flipped the airlock switch to AUTO, and turned on the fan, still with the fan unplugged. The indicator on the SSR came on, and the airlock started turning, time to do a little HAPPY dance.

Time to bite the bullet and try the fan, for real. I turned off the switch, plugged in the fan and turned on the switch and NUFFIN. WTF???? Waitaminute, the fan's got it's own ON/OFF switch. OK turned off the fan switch on the panel, and turned on the switch on the fan. I then turned on the fan switch on the panel. I could hear the fan starting to turn over..... then the fuse audibly went POP.

Johnny Depp in The Lone Ranger said that Kemosabe, in his language, meant WRONG brother. I wonder how they would have said WRONG fuse? The ONLY fuses I could find last night were AGC type fuses. This is a non-time-delay, fast acting fuse - mostly for protecting electronics. I found 2A fuses and 10A fuses, I also found 20A fuses but I DIDN'T want to go that high. I doubted that the AGC fuse would handle the high inrush current of the fan motor, but I thought it was worth a shot. I was right, it didn't work.

I called around to my local friendly electrical suppliers, and fuses is HARD to find right now. You usually don't get what you want, but you take what you can get. I wanted MDL-10 fuses, couldn't find any - anywhere, but I did find two MDL-12's. They're set aside with my name on them, and I'll pick them up at lunchtime.

While I was running the airlock, I noticed that the gearmotor was awfully noisy, gear-wise. It was a used unit off Ebay so I'll probably have pull it apart and re-grease the gears. This thing is a Dayton and should be almost silent while it's running.

What's left, the final filters. After that, the system is usable as is, and will probably stay this way until I build the Mk.II control panel. That'll have a PROPER E-stop circuit, and will automatically start the system when I open a blast-gate. And EVERYTHING will be connected to terminals. Not connected willy-nilly like it is now. (Didn't have room for terminals in this panel, bit in the butt by that damned scope creep again.)

I am NOT gonna show you any pictures of the inside of this panel, I've got my professional pride you know. Let's just say it works and won't burn down the house. (And leave it at that.)

Don

 

[ajoeiam]

WELL..... It worked - sort of - kinda. When I bench tested it everything went fine, no magic smoke was released. So I tried bolting the back panel into the enclosure, but it wouldn't fit. Remember that scope creep? Yup, SOMEBODY didn't allow for the stick-out of the fittings inside the panel. I got around that little issue, my power supply is now resting on the bottom of the enclosure instead of being attached to the back panel.

With the back panel wrestled into place and fuses pulled, I plugged the beast in and held my breath... Still no tell-tale wisps of magic smoke. Next step, pop the fuses in one by one and check the panel with it live. No smoke, no fires, with the E-stop pressed in the panel was as dead as it was supposed to be. When I pulled out the E-stop the control power light came on just like it was supposed to. (I know, that's NOT how a proper E-stop circuit is supposed to work, but it's what I could cobble together with the parts on hand, OK?) When I flipped the fan switch on the indicator in the SSR (Solid State Relay) came on. I hadn't plugged in the fan yet. So... It was time to see if I could make the airlock go roundy-roundy. I flipped the switch to the HAND position and.... NUTHIN!!!! WTF, I checked that on the bench and I had power at the switch. Got the meter out and I DID have power at the switch. The only thing between the switch and the motor is the wire.

AWW MANNNN!!! There are 2 wires coming off that switch, a #9, and a #10. I checked the continuity, and - nuthin. Did I do that? Yup, I doooed that. The wire that goes to the + side of the motor is labeled #9 at the motor connection, but it's #10 at the switch. Okee-Dokee, simple fix, take the wires off the switch, relabel them and connect them to the switch - like they were supposed to be the first time around. Now why didn't I catch that when I bench tested the panel? Simple, I checked things at the switch, not at the end of the wire. (It's just a wire, what can go wrong?? Those little boo-boos are ALWAYS hard to find.)

OK, with that little boo-boo corrected it was time to power things back up and see if this actually works. Summa-na-gunnn, it actually goes roundy-roundy in HAND, what about AUTO? Flipped the airlock switch to AUTO, and turned on the fan, still with the fan unplugged. The indicator on the SSR came on, and the airlock started turning, time to do a little HAPPY dance.

Time to bite the bullet and try the fan, for real. I turned off the switch, plugged in the fan and turned on the switch and NUFFIN. WTF???? Waitaminute, the fan's got it's own ON/OFF switch. OK turned off the fan switch on the panel, and turned on the switch on the fan. I then turned on the fan switch on the panel. I could hear the fan starting to turn over..... then the fuse audibly went POP.

Johnny Depp in The Lone Ranger said that Kemosabe, in his language, meant WRONG brother. I wonder how they would have said WRONG fuse? The ONLY fuses I could find last night were AGC type fuses. This is a non-time-delay, fast acting fuse - mostly for protecting electronics. I found 2A fuses and 10A fuses, I also found 20A fuses but I DIDN'T want to go that high. I doubted that the AGC fuse would handle the high inrush current of the fan motor, but I thought it was worth a shot. I was right, it didn't work.

I called around to my local friendly electrical suppliers, and fuses is HARD to find right now. You usually don't get what you want, but you take what you can get. I wanted MDL-10 fuses, couldn't find any - anywhere, but I did find two MDL-12's. They're set aside with my name on them, and I'll pick them up at lunchtime.

While I was running the airlock, I noticed that the gearmotor was awfully noisy, gear-wise. It was a used unit off Ebay so I'll probably have pull it apart and re-grease the gears. This thing is a Dayton and should be almost silent while it's running.

What's left, the final filters. After that, the system is usable as is, and will probably stay this way until I build the Mk.II control panel. That'll have a PROPER E-stop circuit, and will automatically start the system when I open a blast-gate. And EVERYTHING will be connected to terminals. Not connected willy-nilly like it is now. (Didn't have room for terminals in this panel, bit in the butt by that damned scope creep again.)

I am NOT gonna show you any pictures of the inside of this panel, I've got my professional pride you know. Let's just say it works and won't burn down the house. (And leave it at that.)

Don

Hmmmmmmm - - - - - and how do you suppose that I am going to be able to learn how to make a great panel if I don't get to see what it looks like right now.

I get the 'I want it done well' thing - - - but I've been watching over your shoulder for a while for the learning experience for a while.
Would like to 'get' that part of it too.

Please?

 

[ddmckee54]

You WANT to see a picture of a rat's nest?

This is what my first 3D printer looked like after I got done putting it together - ALMOST according to the instructions. The instructions didn't say anything about about coiling up the extra wire.

This is what it looked like after I got done rat-killing.

While my panel doesn't look QUITE that bad, it's definitely a rat's nest. I can give you some ideas of what I look for in a good panel design.

1 - Will it be easy to service? This panel has got 1 strike against it already, there's fuses, relays, switches and other serviceable stuff inside - behind a non-hinged, non-captive, screw on cover.

2 - Are there adequate terminals? There's strike 2, there are no regular terminals inside the panel. Why not? No room, but I'm coming to that. You should wire the panel to terminals, and the field devices to terminals. Field devices that are wired directly to the panel make it harder to trouble shoot the system, and also make for a messier panel.

3 - Is there room for expansion? We're up to strike 3. Initially this panel was only going to contain a couple of small Omron timing relays and an ON/OFF toggle switch. Then Operations started in on their wish list. Scope creep, remember those words because they'll bite you right in the butt every time. A good panel should have all the required parts to do the job, PLUS about 15-20% of the panel area available for future expansion. Why didn't I use a different panel? Because I already HAD this one, I had gotten this panel before the scope creep struck. It was adequately sized for what I was initially going to put in there, just not for all the stuff I eventually DID put in there.

4 - Is there adequate room in the panel? Strike 4. When designing a panel, you got to start thinking about the volume you have available in the panel, not just the area of the panel. My power supply for instance is 3.5"H x 1.5"W x 4"D, I've got an 8"H x 6"W x 4"D panel - should fit right? Not so much, the panel dimensions are outside dimensions, when you add in the back panel, the usable volume inside of the panel is reduced to more like 7" x 5" x 3.5". Trust me on this one, when you've got EVERYTHING assembled, and you're wondering why the cover won't fit... That is NOT the time to discover this problem. And it's not just the hardware that needs to fit in the panel, you've got to be able to get your grubby little pinkies in there to to work on anything. And you WILL have to work in the panel at sometime.

I'm not happy with this panel that I built, and it will get changed in the future. BUT, it will work for now. Just do as I say, and not as I do, when designing a panel.

I tried running the dust collector over the weekend, and I wasn't getting anything out, stuff went in, but didn't come out. I tore the airlock off and found that the material had bridged over the airlock opening. After I got that cleaned and put back together I tried just picking up the sawdust in the bin and running it round and round, I wasn't getting as much out as what went in, and the belt was skipping. The belt tension was flexing the bracket and when a slug of material hit the airlock, the vane coming around would add enough extra flex to the bracket to allow the belt to slip. I redesigned the motor bracket and added a brace to keep it from flexing. The belt doesn't slip anymore, but I'm STILL not getting as much out of the airlock as I put in.

I've got too much leakage through the airlock. I'm thinking I may have to re-design the guts of the airlock. It currently only has 4 vanes, which means that most of the time I've only got 2 vanes sealing the opening between the low pressure inside the cyclone, and the higher pressure outside the airlock. I'll take it up to 8 vanes, and tighten up some of the fits. That should keep the material from being pulled back into the cyclone. Start ups are always baby steps at first.

Don

 

[ajoeiam]

You WANT to see a picture of a rat's nest?
View attachment 135290
This is what my first 3D printer looked like after I got done putting it together - ALMOST according to the instructions. The instructions didn't say anything about about coiling up the extra wire.

This is what it looked like after I got done rat-killing.
View attachment 135291


While my panel doesn't look QUITE that bad, it's definitely a rat's nest. I can give you some ideas of what I look for in a good panel design.

1 - Will it be easy to service? This panel has got 1 strike against it already, there's fuses, relays, switches and other serviceable stuff inside - behind a non-hinged, non-captive, screw on cover.

2 - Are there adequate terminals? There's strike 2, there are no regular terminals inside the panel. Why not? No room, but I'm coming to that. You should wire the panel to terminals, and the field devices to terminals. Field devices that are wired directly to the panel make it harder to trouble shoot the system, and also make for a messier panel.

3 - Is there room for expansion? We're up to strike 3. Initially this panel was only going to contain a couple of small Omron timing relays and an ON/OFF toggle switch. Then Operations started in on their wish list. Scope creep, remember those words because they'll bite you right in the butt every time. A good panel should have all the required parts to do the job, PLUS about 15-20% of the panel area available for future expansion. Why didn't I use a different panel? Because I already HAD this one, I had gotten this panel before the scope creep struck. It was adequately sized for what I was initially going to put in there, just not for all the stuff I eventually DID put in there.

4 - Is there adequate room in the panel? Strike 4. When designing a panel, you got to start thinking about the volume you have available in the panel, not just the area of the panel. My power supply for instance is 3.5"H x 1.5"W x 4"D, I've got an 8"H x 6"W x 4"D panel - should fit right? Not so much, the panel dimensions are outside dimensions, when you add in the back panel, the usable volume inside of the panel is reduced to more like 7" x 5" x 3.5". Trust me on this one, when you've got EVERYTHING assembled, and you're wondering why the cover won't fit... That is NOT the time to discover this problem. And it's not just the hardware that needs to fit in the panel, you've got to be able to get your grubby little pinkies in there to to work on anything. And you WILL have to work in the panel at sometime.

I'm not happy with this panel that I built, and it will get changed in the future. BUT, it will work for now. Just do as I say, and not as I do, when designing a panel.

I tried running the dust collector over the weekend, and I wasn't getting anything out, stuff went in, but didn't come out. I tore the airlock off and found that the material had bridged over the airlock opening. After I got that cleaned and put back together I tried just picking up the sawdust in the bin and running it round and round, I wasn't getting as much out as what went in, and the belt was skipping. The belt tension was flexing the bracket and when a slug of material hit the airlock, the vane coming around would add enough extra flex to the bracket to allow the belt to slip. I redesigned the motor bracket and added a brace to keep it from flexing. The belt doesn't slip anymore, but I'm STILL not getting as much out of the airlock as I put in.

I've got too much leakage through the airlock. I'm thinking I may have to re-design the guts of the airlock. It currently only has 4 vanes, which means that most of the time I've only got 2 vanes sealing the opening between the low pressure inside the cyclone, and the higher pressure outside the airlock. I'll take it up to 8 vanes, and tighten up some of the fits. That should keep the material from being pulled back into the cyclone. Start ups are always baby steps at first.

Don

Wasn't trying to tick you off!!!
Your design summary (1 to 4 above) is great.
I was/am trying to learn from what isn't working for you. Don't think I have enough years left to make mistakes on most of my 'projects'.
So the question wasn't meant to be insulting or demeaning just viewing the opportunity for learning (and you seem to at least have some idea of what you're doing - - - - NOT like me!!!).

Suggestion - - - try adding some wipers to the blades on the airlock.
Would think that might be the fastest and easiest upgrade.

 

[ddmckee54]

Not ticked off, got thicker skin than that, just surprised that you would want to see a wiring nightmare. I was just showing you a picture of what the inside of the panel resembles - since I don't have any pictures of the actual panel. A messy panel is something you really don't want to have. To quote part of the 10th Electrical/Electronic Commandment, "lest thy successor teareth his hair asunder and go slowly mad in his attempts to determineth what manner of creature hath wrought such a nest within said equipment."

Regarding the wipers on the vanes, I had actually thought about something similar to that. (Great minds work alike and all that.)

Many-many moons ago in the early 90's, my boss at that time came up with the idea of building a tabletop PLC controlled batching system to use at our company customer Christmas party. That way other people could get a better idea of what we actually DID for a living. We made individual cups of hot chocolate with several options, one of those was adding Peppermint Schnapps to make Peppermint Patties. I designed that beast to include a hot water tank- actually a new coffee urn, a mixer, 3 pumps, 2 airlocks/rotary valves, and a dispenser for marshmallows that we never could get to work right. I later found out from the guys that make Lucky Charms, that they always had trouble with the marshmallow bits too. Marshmallows are sticky little suckers.

One of the people that worked in the office had a good recipe for instant hot chocolate mix. One airlock was for the chocolate mix, and other for the creamer mix. The airlocks had vanes made out of a sheet of flexible silicone. It took a LOT of testing at the office to make sure we had the mixing JUST right. Fortunately there were plenty of volunteer test subjects.

That hot chocolate machine is long gone now, but it was the hit of the customer Christmas parties for several years. When we would talk to our customers about the when the Christmas party would be for the next few years, one of the first questions asked was if the hot chocolate machine would be there?

I might see if I can source something similar to that silicone sheet and make the vanes out of it. I was kind of loose with the fit of the current vanes. For one thing I wasn't sure how much torque my original gearmotor was capable of. This Dayton gearmotor uses a larger motor and a lower gear ratio, so I'm not as worried about it being able to overcome the extra drag.

Don

 

[awake]

That hot chocolate machine is long gone now, but it was the hit of the customer Christmas parties for several years. When we would talk to our customers about the when the Christmas party would be for the next few years, one of the first questions asked was if the hot chocolate machine would be there?

Was it the hot chocolate, or was it the Schnapps?

I can hear the marketing slogan now: with our PLCs, it's a "shnapp" to make!

 

[ddmckee54]

Actually there weren't that many that went for the Peppermint Pattie option, the vast majority went for the hot chocolate. And many of them went for the "Extra Chocolate" option.

 

[ddmckee54]

Back to the airlock leaking dilemma.

I found some 1mm sheet silicon rubber and I've got it on order. I figure it'll be faster, to try modifying the existing airlock rotor design like ajoeiam suggested, before throwing it out for a new design. The 1mm sheet will let me replace the existing vanes with the rubber sheet sandwiched between a pair of reinforcing plates, and still get that assembly in the existing slot. I've got a 10" x 20" sheet coming so I should be able to make quite a few vanes.

Don

 

[awake]

Here's hoping your efforts will not be in vane! ... err, in vain!

 

[ajoeiam]

Here's hoping your efforts will not be in vane! ... err, in vain!

Ouch - - - - that is just too punny! (sic)