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jbvb
Fireman
Premium Member
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Posted - 01/05/2021 : 08:08:23 AM
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I continue to be impressed.
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Country: USA
| Posts: 6694 |
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Coaltrain
Fireman
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 Posted - 01/07/2021 : 06:37:00 AM
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the long awaited test run, not very impressive. it runs good but there is too much noise in the spur gears, which I figured was going to happen and I was just hoping that for some reason it would not be that bad. One options would be try and replace the center gears with plastic ones that I could steel out of either some old trucks I have or from a parted out Bachmann Shay.
A second option would be to replace the gear chain with a and actual chain (like Lee Snover did). I have had bad experiences with the chain drive but maybe I have to try it again. the biggest issue is that I do not know where Lee got his parts and he has passed away so there is no way to ask him. the main part needed would be the small brass sprocket, I have one left. the small brass sprocket would have to go on the crank shaft. I could 3D print a new crank shaft from Shapeways in brass with the sprocket teeth on it. I may 3D print a crank shaft for the test, it will not last long but maybe long enough to know if I want to use it or not. The chain is just narrow enough to hide in one of the journals, but the chain goes around such a tight turn, and from my experience that is bad at higher speeds.
the way out of all this is to just default to a Faulhaber in the tender driving the wheels through a Grandt Line gear set. The model would run great but it would defeat what I am trying to do, which is to use a can motor and not a coreless motor.
here is an assembled truck test, both with and without the line shaft. The line shaft would get stuck on the test rails because it is square so a little shake would free it up. the trucks run great and this is almost the final set. If I use 3D trucks I will need a way to pick up power, wipers would work but I am thinking of using half axle shafts and running small wires to the brass axle cups to eliminate the friction of the wipers
https://youtu.be/oM16HzpjPI4
here is the shay test run. the wobbling is from the wires dragging on the scenery, and then it did not help the the alligator clip picked up the Sergent coupler uncoupling tool. it is really hard to hold the throttle, an iphone, the test leads and run and film all at the same time.
https://youtu.be/xpqGIBNu7CY
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Coaltrain
Fireman
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Posted - 01/07/2021 : 07:13:58 AM
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here is the small brass sprocket I would have to use on a chain drive, I am not sure where to get these.
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jbvb
Fireman
Premium Member
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Posted - 01/07/2021 : 10:05:58 AM
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Usually where a particular kind of chain is sold, they also offer sprockets etc. to match.
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Country: USA
| Posts: 6694 |
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Coaltrain
Fireman
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Posted - 01/07/2021 : 10:44:57 AM
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quote:
Originally posted by jbvb
Usually where a particular kind of chain is sold, they also offer sprockets etc. to match.
they do, but not this small. Lee told me that this sprocket was not really for this chain but it works. At this point to test the drive I may just 3D print all the parts, if it works I will just have a new crankshaft printed from Shapeways with the sprocket cast into the crank shaft. inside the gear box I will just use the smallest side Micromark offers, which will change the gear ratio a little but that is fine.
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Chris333
Engine Wiper
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Posted - 01/07/2021 : 11:29:38 AM
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I thought the gear sounds were kind of cool. And there was no echo through the whole model like a brass model would do.
The way you want to do the pickups is how everything in N scale is done now.
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Coaltrain
Fireman
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Posted - 01/08/2021 : 11:48:05 PM
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Second test run video, it is working much better. I spent some time looking at all the spur gears, I polished them with a file and wire brush and they are way better now, I can now move forward with the grade test and see how it runs downhill
https://youtu.be/8vJ4q8bQUVg
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Coaltrain
Fireman
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Posted - 01/11/2021 : 09:37:19 AM
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another weekend of shay work in the books. I needed to address how I was going to pickup power from the rails now that everything is resin. I was going to take advantage of the brass bearings but I decided to use wipers instead. The main reason I changed my mind is that I wanted to make it maintainable without having to take anything apart.
Many years back when I was in HO I was an early convert to sound and I added the first version Soundtraxx decoders to some Atlas RS-3 locomotives. Those early Soundtraxx decoders did not have keep alive packs and they were very fussy about good contact, the smallest dust particle would make the sound cut out or the locomotive to stall, it was very frustrating. Atlas used brass plates with holes in them to pick up power from the axle ends and what I found would happen is that dirt would build up in the axle pockets and cause all kinds of running issues. The only way back then to fix it was to remove the wheels a few times a year and clean them. I did not want to have to remove the wheel sets on the Shay to clean electrical contacts so I decided to use wipers.
The wipers are mounted to the bottom of the lower bolster with 0-80 screws and they sit in a shallow recess. the wipers are made from Phosphor bronze and the design is that each wheel has two points of contact, that makes 16 points of power pickup. I will solder a micro plug on the wiper so I can remove the screw and the wiper for cleaning without taking anything else apart. I could also replace a wiper if one wears out or gets damaged. This design follows my desire to make an easy to maintain locomotive.
I photo etched a sheet of wipers, which was a huge adventure in itself. I am still working in a temporary space so the only place to set up my photo etch stuff was on the floor by the furnace. Everything went well with getting the photo resist on the bronze sheet, where it all went wrong is with the etching . I had just a small amount of ferric Chloride left in one of my bottles so I decided to use it up and not open my new bottle. after a while etching it did not seem like the acid was working, my thought was that the old acid was weak, so I poured it back in the old bottle and opened the big full bottle of new acid (I am sure you see what's coming). I poured in the new stuff, almost all of it so it mixed with the little bit of old stuff that could not be poured back out, I wanted to make sure it was as powerful as possible. Just then my 3D printer finished a print, so I thought while I wait for the acid I will clean the print, I just have to step over the acid tank to reach the 3D printer. Yep, kicked over the acid tank and all that ferric chloride. In a frantic pace I used my hands to block it from going under the brand new furnace, I did have gloves on. I yelled for paper towels and was able to contain the spill from actually going under anything. I piled on the baking soda and some water to neutralize it while I set the tank back up and filled it with the little bit of new acid I had left, that way I could keep the etch going while I clean. It took me an hour to clean up that mess good enough to hopefully keep my furnace from becoming a rusty piece of junk. The fumes from the acid will rust metal, proof is that the metal clamps from the etch kit are all rusty from the little bit of fumes in the box when I store it away.
meanwhile, I forgot about the wipers etching away in the tank. I took them out and there was just a small amount of over etching, but still plenty good enough for testing them out. The Bronze must be a little harder to etch than brass. If I left brass in the tank an hour it would be gone.
here is the spill site all cleaned, but stained forever. Maybe I can paint over this spot, maybe nothing will ever stick to it. what a mess.
anyways, back to the shay. here is the Cad design of the wiper. I was thinking of using my riveter and add one rivet to the end of each wiper but the bronze does not rivet well. again, I can always work on the final design later, and if someday I decide a small little rivet will work better I can just swap it out.
here is a wiper, unbent and then bent into final shape. I have the final truck set prints done and they have provisions for the wipers. I will get them assembled this week and then put the trucks to bed and move one.
next I will move on to the final gearbox print, which will included a detailed firebox (all the details) and the cylinders and crankcase all detailed. it is going to take some time, there is a lot of work there and CAD design can take as long as scratch building.
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jbvb
Fireman
Premium Member
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Posted - 01/11/2021 : 10:55:59 AM
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I was scared as I started to read about your accident. Are you aware of "acid into water, never water into acid"? FeCl3 isn't really an acid, but it's certainly reactive/corrosive. Internet suggests baking soda/water to ensure co ensure neutralization. A person I know tripped carrying a jar of FeCl3 up the stairs of a subway station in Cambridge. He told the fare collector, but I guess the MBTA didn't do anything special. Both the steel treads and the concrete under them were pretty decayed a few years later.
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Country: USA
| Posts: 6694 |
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Coaltrain
Fireman
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Posted - 01/11/2021 : 1:38:16 PM
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I poured the box a baking soda in the ferric chloride dry, smeared it around, then added a little bit of water to make it paste like, then smeared that around, then more water. I just hope I don’t have a big hole there in a few years and a rusty furnace.
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Chris333
Engine Wiper
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Posted - 01/12/2021 : 2:56:17 PM
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Try muriatic acid to clean the spot on the floor. Sometimes when my ferric chloride seems to lose it's power I pour muriatic acid in with it. Long ago I bought a big bag of powdered ferric chloride that needs to be mixed with water. I never etched bronze though.
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