3D Printed Chuff Magnet Cam - NICE!!

Looks good.  Do you run into any issue with the four magnets so close together?

I have yet to try it so it could be a total fail at this point. The idea is to adjust the reed switch position so as not to pick up a false chuff like you’d do with any other setup. Magnet spacing could be adjusted with tweaking the outer diameter of the cam. The other option is to use a Hall effect sensor. I’m always charmed by how well reed switches work.

Making the part itself was a great way to play with Tinkercad and to get the printer set up. Lots of stuff to play with and discover.

I know the ones on the tender wheel when I used two were frequently pretty tricky to get right, these look even closer.  You might get away with a less sensitive reed switch close to the cam to allow for the spacing of the magnets.

Smaller magnets, Hall effect sensors, 3D printed parts that take 10 minutes to produce, there’s nothing insurmountable here. I have been collecting reed switches in different sizes for a while now. I suppose one could print 4 lobe cams for microswitches too.

Do you have a 3D printer? I can post the .stl and you can give it a try as I’m not sure when I will get to. This part was just to do the initial printer setup and prove out the cad to real part pipeline.

Norm, I think it would be easier to just print cams. No magnets or reed switches needed. If the space for a cam is wide enough you can use two micro switches for chuff and smoke fan, though I know you don't care about smoke.

I machine mine but obviously you could print them as well.

Pete

Norm, before I decided that optical sensors were easier and was still using reed switches I discovered that the magnet did not need to pass by the glass envelope with the reeds but that the leads were steel and a magnet passing by a lead could close the reeds.  I am not sure if this is the case on all reed switches but it was on all I ever bought.  I did all sorts of shaping of the leads to adjust the timing of the closure of the reeds from bending them into a U to twisting them into a spiral or even an L shape . These configurations allow for a very sharp rise and fall of the magnetic field. One configuration I liked was the L where the magnets circular path was tangent to one leg of the L and you cut the length of the leg to adjust the duration of the closure.  The reed switches can even be anthwartship between two wheels on an axle with magnets passing by both leads.          j

Are those stock magnets that come with an upgrade kit? Or could you use smaller magnets if you needed to?

I think this is a great idea for a print though. No doubt about that.

@Norm Charbonneau posted:

Do you have a 3D printer? I can post the .stl and you can give it a try as I’m not sure when I will get to. This part was just to do the initial printer setup and prove out the cad to real part pipeline.

I don't have a 3D printer, I've been avoiding that as another giant time sink that I can't afford to get involved in!   Besides, I happen to have a product that I use for the task, the Chuff-Generator.

I have also had this idea. Similar to Norm I have printed mine, but instead of using magnets I am using them with a cherry switch. I had my buddy print them up in resin.

John, I like your board but quit using it because I kept getting inconsistent chuff rates. It just wasn’t worth the hassle and cost after awhile, sorry.

In any case I think you guys have sort of missed the point of this first exercise. I needed a first part to run through to completion to test the setup of the printer and to see what a simple design might look like once brought to fruition. I consider it a success even if the part serves as nothing more than a magnet holder. This will be one of many parts I plan on using for my DIY projects.

@BillYo414 posted:

Are those stock magnets that come with an upgrade kit? Or could you use smaller magnets if you needed to?

I think this is a great idea for a print though. No doubt about that.

There are quite a few different magnets out there nowadays. The ones I used here are pretty close to what you’d find in an ERR kit. The cams could be tweaked very quickly to host any size or shape available.

@Norm Charbonneau posted:

There are quite a few different magnets out there nowadays. The ones I used here are pretty close to what you’d find in an ERR kit. The cams could be tweaked very quickly to host any size or shape available.

I really like the idea of making a holder like this. It would almost be like the old magnets on the axles of older 3rd rail models like the Mercury and Santa Fe Texas.

@Sid's Trains posted:

I have also had this idea. Similar to Norm I have printed mine, but instead of using magnets I am using them with a cherry switch. I had my buddy print them up in resin.

I may try something like this for my older Lionels like my J1a that had the nylon two-lobe cam. The nice thing about these parts is that you could adjust them to synch the exhaust with crankpin angle.

@Norm Charbonneau posted:

I may try something like this for my older Lionels like my J1a that had the nylon two-lobe cam. The nice thing about these parts is that you could adjust them to synch the exhaust with crankpin angle.

Oh yeah totally. I made these originally for a Weaver I5 Hudson, but plan to install them in some older tmcc models. 4 Chuffs makes an engine 100 times better.

@Norm Charbonneau posted:

John, I like your board but quit using it because I kept getting inconsistent chuff rates. It just wasn’t worth the hassle and cost after awhile, sorry.

WOW, I don't know how that happens.  As long as the tach sensor spacing is right, the chuff rates should be rock steady.  No need to be sorry, if it doesn't work for you, then it's clearly not worth the money.

Sid, I am on a side quest to get all my engines to a proper synched 4 chuffs whenever they come into the shop for maintenance. I’m hoping these 3D parts will help. I made the decision to get a printer after making my last scrap styrene Kadee drawbar on the 5011 Class project. I want better looking parts even if they won’t be seen. Lots of other stuff to make too - roller mounts, truck bolsters, board mounts, speaker adapters and maybe even housings. Watching the first print materialize got me pretty stoked!

@Norm Charbonneau posted:

There are quite a few different magnets out there nowadays. The ones I used here are pretty close to what you’d find in an ERR kit. The cams could be tweaked very quickly to host any size or shape available.

I have used McMaster Carr to get some pretty tiny magnets for holding doors closed. I was just curious if the ones you have are stock in case you needed to go smaller because of space restraints.

@Norm Charbonneau posted:

Sid, I am on a side quest to get all my engines to a proper synched 4 chuffs whenever they come into the shop for maintenance. I’m hoping these 3D parts will help. I made the decision to get a printer after making my last scrap styrene Kadee drawbar on the 5011 Class project. I want better looking parts even if they won’t be seen. Lots of other stuff to make too - roller mounts, truck bolsters, board mounts, speaker adapters and maybe even housings. Watching the first print materialize got me pretty stoked!

Yeah Bruk has been printing shields for the boards we use for a while and the smoke unit funnels as well. I look forward to using 3D printing more as well. I'm working on printing a full tank engine as well. Lots of things can be done with a printer.

Bill, eBay has some 1.5mm and 2mm magnets, 1mm thick. I just used some for sticking to my one of my Decapod’s drivers. Something I hope to quit doing!

@Norm Charbonneau I didn't think to check eBay. That's a good idea.

@Sid's Trains posted:

I have also had this idea. Similar to Norm I have printed mine, but instead of using magnets I am using them with a cherry switch. I had my buddy print them up in resin.

I’m curious on how you intend to attach these to the axle Sid,….Pete has sent me some of his aluminum 4 lobe cams, and I have successfully drilled and tapped holes alongside the flats, and then split the cam in two along the horizontal…..allowing a bolt together operation for a permanent solution,….I’ve done this twice now,….I’m guessing your gonna use cement?….if so, I’d like to know what cement you plan on using??…I hate glue and all it stands for, but if you have a bonding agent that does that trick, I’m all ears,….😉

Pat

@Norm Charbonneau posted:

I may try something like this for my older Lionels like my J1a that had the nylon two-lobe cam. The nice thing about these parts is that you could adjust them to synch the exhaust with crankpin angle.

The cam on the right was the first one I made. Its for a TMCC J3a Lionel which has the same axle diameter of the Pullmor J1s. The J3 and some of the J1s with solid wheels are screw on so easy to pull a wheel then the axle and install the cam without cutting it in half. I install all the cams one piece as quartering is not a big deal now.

Cam swaps are pretty easy on engines where the axles are held on with a bottom plate like most two rail engines.

Among those are the 2-6-0 Moguls and CC Niagara. Mogul wheelsets below.

Pete

I hope to try the magnetic chuff cam soon but in the meantime I just doodled these up in Tinkercad. Both are fairly experimental in a structural sense to see what I can get away with. I made a Deans plug hanger for some of my aux power plugs I use on some of my steamers and the uncoupler fork is based on the Rix one in HO:

I have 3d printed cams with magnets similar to what you have done. They do work just fine after some tweaking.

3d printing has brought modifying our trains to a whole new level. Example: is this Weaver H10 I converted to LEGACY. I ditched the old motor and installed a smaller Diesel motor but I need to reuse the old motor mount. So I designed an adapter plate to fit it.

That's awesome. Wonder if i could print a new encoder ring for my overchuffer Hudson. Give it maybe ~20% more peeping slots. Hmm. Can't believe how much fun I'm having this morning. About 6000 years ago I was taught orthographic projection in some godforsaken program I was in and even got some corporate CAD training in the early days of my career. They wouldn't get me a license though because 'I was just the electronics guy' haha.

Your motor mount demos the beauty of this stuff. Trying to cobble your own out of scrap and getting the hole pattern just right would be a total pain.

@Bruk posted:

3d printing has brought modifying our trains to a whole new level. Example: is this Weaver H10 I converted to LEGACY. I ditched the old motor and installed a smaller Diesel motor but I need to reuse the old motor mount. So I designed an adapter plate to fit it.

Bruk, did you see the discussion about replacing the Hogwart's locomotive motor with a larger motor?

Here's the post where the technique was discussed: https://ogrforum.com/...6#157406524304503216

Here's the plate that adapts the motor to the mounts.  I'd sure like to have a couple of these to do the Hogwart's locomotives.

Two and four hole mounting plates can be done with a center head and dividers. Three hole and any odd numbers are where CAD comes in. Total pain otherwise.

Pete

Super rough Kadee unbopper. I had some 8mm magnets laying around. On the next print I will make a socket on top of the frame to plug a dowel into instead of trying to print a handle as the first one fell off haha!

My Deans plug hanger for one of my Decs, just something simple to keep my aux tethers from dragging (I use these sometimes for aux power pickup where I don’t want to mess with the original tether, this one is actually for driver mounted magnets/reed switch). The first one I tried was a dud so I laid the doodle (I won’t dare to call these ‘designs’ yet) out along the Y axis for more vertical strength along the hanger. Pic below for comparison. I also played around with the box dimensions to hold the plug nice and snug. It’s easy to gusset objects in Tinkercad for stiffness. This was nice way to see what I could get away with structurally/dimensionally. Once painted it won’t look any worse than the old IR tether boxes imo.

Here is an improved Kadee fork that fits between the rails for more positive placement. Instead of trying to make a handle I made a socket so I could plug in a dowel. I need to make a slimmer version as this one won’t fit in between some cars. Maybe I’ll use some rectangular magnets. This also proved to me I need to pay more attention to my Kadee whiskers as some of the shorter ones don’t pull to the magnets.

I may do this again, with the part laid on its back so I can orient the print layers vertically in the finished part. I cracked one of the legs when I inserted the magnet but was able to CA it.

This thing makes cool music btw:

Turns out the radial magnet cam works like a charm! For some reason I made the first ones with a 4mm axle in mind and while it won't work in most of my engines, it works perfectly on a tender axle. I CAed one of the really rough initial prints onto one of my Q2 tender axles for the heck of it and then fully populated it with 4 magnets just to see if something with this small an OD would trigger a reed switch reliably. Normally it will just have two magnets on a tender axle but I wanted to see if the reed switch could keep up at different speeds. (Please note generic sound set with non-duplex/articulated chuff for clarity in detecting a potential dropped chuff, etc.)

Here it is installed. This will be real handy for situations where it might not be practical to mount magnets on a wheel. This is how I will run it, with just two magnets 180 out from each other as seen here. This gives me 3.8somethingsomething chuffs per driver rev, unsynched to crankpin angle/crosshead position.

Here is a circumferential version for setting magnets reliably on the back of a wheel. This is for my other Q2. With the 3D printer, I can change the axle diameter or magnet size at will by doodling it out in TinkerCad:

So, the TL;DR version of this thread - I finally broke down and got a relatively inexpensive 3D printer and used it for some fairly successful experimentation (except for that Kadee uncoupler thing haha). I was able to come up with some creative solutions for applications I long dreamed about improving. If you look at this one project, just on the tender alone I have a custom drawbar, a nice elevated RS4 m/b mount, two types of magnet retainers, and a nice bolt-on Kadee adapter integrated into a drawbeam. The best part is that each piece can be edited very quickly to fit any project. Here's my Q2 project vid showing some other 3D assisted applications like a speaker hole drill pattern tool:

@Norm Charbonneau posted:

Turns out the radial magnet cam works like a charm! For some reason I made the first ones with a 4mm axle in mind and while it work in most of my engines, it works perfectly on a tender axle. I CAed one of the rough prints for grins onto one of my Q2 tenders and fully populated it with 4 magnets just to see if something with this small an OD would trigger a reed switch reliably. Normally it will just have two magnets on a tender but this proves that my idea wasn’t too shabby I gotta say.

Looks great Norm. I like the 8 chuff setup. Sounds like you have a J1a or M1a soundset in that Q2. Interesting choice, but whatever works haha. I'm still fine tuning my design. Will have a video of mine soon.

Hold up Sid, still trying to edit this mess!

Reed switches have a pretty fast response time, so I suspect as long as you have enough space to have them deactivate that it should work fine.

I seem to have perfected my setup. As I showed before I have a two piece resin printed cam. I filed the piece down so it is nice and smooth on all edges. I attached it to the axle using an industrial grade addhesive and made sure it was centered on the driver. This setup uses a basic cherry switch mounted to the chassis as stock on this Weaver I5. No issues with an double chuffs or miss chuffs. Works great. Video coming soon.

Here is the I5 in action. Cam works well and the customer is getting a nice engine back with a consistent 4 chuff setup in it.

Note: The LED flicker in the video is caused by the camera.

That’s awesome Sid! I like the color. Can your pal make me a batch or two of some Hemingray Provo #2s?

I printed some extended Kadee boxes for my Weaver N5c the other day. This allowed me to custom fit the length to secure the box to the frame and not the platforms. I did not want to drill the platforms. The brass screw only holds the cover down. I printed the pivot into the cover, sort of opposite of a standard setup. This allowed me to install the assembly as one unit. I even printed and extended center beam, something I would have made out of styrene in the past.

@Sid's Trains posted:

Here is the I5 in action. Cam works well and the customer is getting a nice engine back with a consistent 4 chuff setup in it.

Note: The LED flicker in the video is caused by the camera.

Sid how are you getting 4 puffs out of the smoke unit? Know if the opening for the cam is wide enough for two micro switches you can drive the fan without additional interface electronics. Just make the cam the full width of the opening minus a bit for clearance. Makes for a very clean and inexpensive install.

Pete

@Norton posted:

Sid how are you getting 4 puffs out of the smoke unit? Know if the opening for the cam is wide enough for two micro switches you can drive the fan without additional interface electronics. Just make the cam the full width of the opening minus a bit for clearance. Makes for a very clean and inexpensive install.

Pete

This engine is what I call a budget friendly upgrade. It has an ERR cruise Commander in it, ERR Railsounds, LEDs, and a Sunset smoke unit in it. This unit is similar to the old Train America studios turbo smoke units where at idle it lets out a stream of smoke and when the chuff wire is grounded it puffs. There is a diode in line between both the smoke unit chuff signal wire and the cruise commander chuff signal wire to prevent back feeding.

@Norm Charbonneau posted:

That’s awesome Sid! I like the color. Can your pal make me a batch or two of some Hemingray Provo #2s?

I printed some extended Kadee boxes for my Weaver N5c the other day. This allowed me to custom fit the length to secure the box to the frame and not the platforms. I did not want to drill the platforms. The brass screw only holds the cover down. I printed the pivot into the cover, sort of opposite of a standard setup. This allowed me to install the assembly as one unit. I even printed and extended center beam, something I would have made out of styrene in the past.

I assume you are talking about this kind of insulator Norm. I could ask my buddy if he could print something of that size.