Track fiddlerI'm convinced you've already thought of this but what measures are you planning to balance the blades on the custom hubs you made?
Hi TF,
I certainly understand the need to balance the blades. I'm going to approach the balancing in stages.
The first step will be to install the cross bracing between the blades. I'm going to use 0.015" phosphor bronze wire. I will solder it in place and then grind the stubs smooth. This should add some stiffness to the blades which will be crucial for rounding them (see below).
The next step will be to get the blade hubs centered on the drive shafts. Currently I have one of the blades mounted on a temporary shaft which I can chuck into my drill to get an idea of how excentric the rotation is. I'm hoping to be able to use a marker pen to identify the 'high' side. Once I have the high side identified I will remove the temporary shaft, then drill the center hole slightly oversize, and then solder a bushing into the hole. Hopefully the markings will give me an idea of which way and how far the bushing needs to be moved to get it on center.
The third step will be to eliminate any side to side wobble. Hopefully once the bushings are soldered into the center of the hubs there won't be too much wobble, but I am anticipating having to make adjustments.
Once that is done, the next step will be to get the outside edges of the blade perfectly round, or at least as close to round as I can. Currently they are not perfectly round because of the way I shaped them. I did not cut the blades in an elipse. They have a constant radii. That meant that when I attached them to the hubs the centers of the blades were slightly further away from the hub than the ends were. I will put the temporary shaft into my drill and then run the drill at a reasonably high speed. Then I will use a large diamond grinding disc in my Dremel to grind the high spots off of the outside edges of the blades while they are rotating. This process will require a very gentle touch and will probably take some time because I can't afford to heat the blades up to the point where the solder might melt.
After all of that we still haven't addressed the issue of having the blades balanced. That will simply be a process of trial and error. If the blades are not balanced (which I fully expect), I will put them in the drill and arbitrarily add a tiny amount of weight to one side. Either the balance will get better or it will get worse. If it gets better I will add a very tiny bit more weight to the same spot and see what happens. If the balance gets worse then I will relocate the original added weight and try again. The process sounds a bit tedious but I think I can get it to work.
By the way, the balancing process will start as soon as I get the replacement worm gear from NWSL. You will remember that I melted the first one because I screwed up the order of assembly for the gearbox. I have ordered two replacements just in case I mess up again!
Wish me luck!
Cheers!!
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Good morning
It's a good thing you're obviously quite meticulous Dave. I can imagine one has to be with a small electronic motor linked to a custom drive.
About the nearest I come to understanding this impressive project of yours is a classic mussle machine motor and transmission. A bit far apart in comparison but sharing the same concept.
Which brings me to a new point of interest I'm sure you already thought of. Centrifugal force and balance. Just like a camshaft in an engine or anything else given RPMs need to be balanced.
Just last week I balanced someone's wobbly ceiling fan using masking tape and various coins to counterweight the blades. Quite time consuming! As always, the coins have to be removed and reapplied as one never knows where to start until the trueness starts getting better.
I'm convinced you've already thought of this but what measures are you planning to balance the blades on the custom hubs you made?
Looking really good so far Dave
TF
NorthBritStill following with a sort of interest. Not into the 'fiddly bits'. (It is not scenery ) It all looks really good though.
Hi David,
I'm glad that you have some interest in my project. Yes, there are a lot of 'fiddly bits'. I'd say that I'm about 1/4 of the way through the plow project itself (maybe less - I haven't even started the tender), and then there will be the whole issue of building a consist to push the thing. If I decide to add sound, that will be a whole new challenge given that I will have to learn how to transfer the appropriate sounds into a Loksound decoder.
I don't have a schedule, but I would like to see the plow finished within the next two or three months. I will put a sound decoder into it even if I haven't figured out how to re-program the sounds. That can be done later. After the plow is done I have to finish my long running Grand Trunk 4-6-0 project and then I will have to find a second locomotive. I already have a suitable caboose, maintenance car and tank car. The tank car will have to be repainted.
Say Hi to Dawn,
Still following with a sort of interest. Not into the 'fiddly bits'. (It is not scenery ) It all looks really good though.
David
To the world you are someone. To someone you are the world
I cannot afford the luxury of a negative thought
Here is the revised drive linkage as per Ed's suggestion:
The first attempt at building the steeple compound engines isn't working out all that well. Basically the engines are too small. I was planning on using some Precision Scale components for the top cylinders and then I would scratchbuild the rest, but the top cylinders are too tiny to be realistic.
These are the current cylinders beside the plow. Keep in mind that none of the crankshaft or the engine frame details have been added:
Here are the cylinders up close. The brass parts are from some sort of compressor system, I can't remember what, and the bottom cylinders still have to have the surrounding wood slats added. The finished diameter will be the same as the top and bottom discs:
I will probably end up using the styrene cylinders as the smaller top cylinders in the compound engine and I will make bigger ones for the bottom. The brass bits can be used as part of the control mechanism.
gmpullmanI wish I had a better photo to show but what I found inside this Alco brass model was a short length of steel "intermediate" shafting with two shorter flexible tube connectors on either side of it.
gmpullmanIf you have a short piece of the same diameter shafting why not try it?
Hi Ed,
That is a great idea! I have lots of the 2mm shafting.
The current set up has about 1 1/4" between the ends of the shafts. I put as much torque on the tube as possible and, although it did collapse a bit, it never went out of alignment. I can't imagine that the drive system would ever get that much load on it, but I think I'll add the additional piece of shaft just to be sure. The tube will be difficult to get at once the engines are installed around it.
Thanks,
hon30critterI'm going to give it a try. Right now the distance between the ends of the shafts is about 1 1/4". I was going to shorten the shafts so only the tube would be visible but now that doesn't seem like a good idea.
Dave,
I wish I had a better photo to show but what I found inside this Alco brass model was a short length of steel "intermediate" shafting with two shorter flexible tube connectors on either side of it.
NYC_DES-3c by Edmund, on Flickr
Of course, as built the couplings were gum or India rubber which, as shown, was as brittle as hard coal. But the whole idea of the intermediate shaft was to avoid the torquing of the soft rubber (silicone) and prevent it from twisting or bunching up.
If you have a short piece of the same diameter shafting why not try it?
Good Luck, Ed
I got the 1.5mm ID silicone tubing yesterday, and as Tom suggested, it works great!
Thanks Tom.
I have started building the steeple compound engines. The parts are tiny. Animating it is out of the question.
Here is a rough sketch of what the steeple compound engines will look like.
This will give you a better idea of how big it will be (or rather, how small it will be. I don't think making any of the parts rotate would be worth the effort.
I think I have the proportions fairly close. I may resize them when I get a better idea of what they will look like inside the plow. The plow body is about 12 1/2' high inside.
OvermodNow that we have gotten this far, and are about to take up the issue of modeling the steam engines, we have to return to the prototype discussion.
Hi Overmod,
I have done a few sketches of steeple compound engines based on pictures from the web, and I have an idea of what I want to do. Before I start building them I'm going to do a drawing using 3rdPlanIt so I can get a better idea of the size of each of the components.
There will be two engines, each with a smaller cylinder over a bigger cylinder. There is probably room to do three vertical cylinders if I choose. The crankshaft and connecting rods will be exposed. The engine frames should be easy to build with styrene strips, and I have different sizes of styrene tube to use for the cylinders and the various plumbing bits. I've also got a bunch of brass castings of things like shut off valves to add to the illusion.
I think that getting the engines to turn with the driveshaft from the electric motor might be more work than it is worth, and I'd have to do them all in brass so they wouldn't wear out. The only moving parts would be the crank shaft and connecting rods since the cylinders wouldn't be visible. The thought is still in the back of my wee mind so you never know what will come out.
Now that we have gotten this far, and are about to take up the issue of modeling the steam engines, we have to return to the prototype discussion.
In the original, there was no bevel-gear or worm-gear drive to the rotor shaft (and it would not be happy if there were and the rotor encountered severe shock in packed snow and ice, as reported). The engines would have been transverse, probably on some kind of countershaft, and the final drive was the early version of Morse silent chain (probably multiple row, perhaps a great many multiple rows) between a pinion on the countershaft and a larger sprocket. The 'wise' way to tension this in modern practice would be a Weller tensioner with roller follower(s), which would also help with chain whip during shock, but I don't think this had been invented in 1904.
For longitudinal shaft drive, as pictured, the engines will be longitudinal, flanking the shaft. If you can take the 'final drive' off the center of the engine crankshaft, as in the first Honda Formula I engines more than half a century ago now, it would be 'better' than at the end of the crankshaft, but that's up to you and your 'servicing' crew's capacities. Each engine will have a hefty herringbone gear, and the center shaft a larger matching gear, with the right diameters that the engines at their best operating rpm (and steam consumption) will turn the shaft at the correct ratio through the 'final drive' you built. If I were doing this, the gears would run entirely encased, in an oil bath, but the 'cheaper' source might be a ship drive, which might leave them exposed...
I am tempted to note that if you were to have, ahem, a 'backwards' extension of the rotor driveshaft to, ahem, a fan in the smokebox of roughly the arrangement the Southern Railway (England) A820 experimental used, you could draft the boiler in concert with the engine output and not have to waste steam up a blastpipe. That would increase the water rate and hence the range of the plow; it might facilitate some 'snow melting' to assist with condensing or clean-feedwater makeup; and you could have some fun with a snow-assisted condenser arrangement on your extended tender... operating in nice cold air, of course...
And if you put a nice large clutch up by the final drive to the rotor, you could disengage it and run the engines to 'blow up' boiler pressure before starting a run...
tstageJust make sure you are looking for thick-wall silicone tubing. It's stiff enough so it won't buckle while torquing but still flexible to make up for any axial discrepancies. Du-Bro small (0.063" ID) Super Blue silicone fuel tubing (#221) worked well for me for a couple of brass driveshaft projects:
Just make sure you are looking for thick-wall silicone tubing. It's stiff enough so it won't buckle while torquing but still flexible to make up for any axial discrepancies.
Du-Bro small (0.063" ID) Super Blue silicone fuel tubing (#221) worked well for me for a couple of brass driveshaft projects:
While the OD of the above is closer to 3.5mm, the 1.5mm/3.0mm tubing might do the trick for you.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I tried the 2mm ID silicone tube and it was too loose. I went back to Amazon and for reasons unknown this latest search produced all sorts of results for 1.5mm ID 3mm OD silicone tubing. I have ordered a small piece and we shall see how well that works.
Thanks John, I think?!?
That's more than I ever wanted to know about plastic tubing!
Seriously, thanks for your interest in my project.
Perhaps at the risk of too much kibbitzing:
https://www.globalspec.com/learnmore/flow_control_fluid_transfer/pipe_tubing_hose_fittings_accessories/plastic_tubing
John
Attuvian1Looks like it's a function of the properties of a particular material: sufficient stiffness in one axis to resist extensive twisting, sufficient flexibility in another to allow the necessary bend to funtion as a universal. And must we presume that there won't be any significant degradation of these under continuous use? I also suspect that there's a factor involved in the distance between to two shaft ends. The shorter that is, the more likely your silicone tubing might just work.
Hi John,
I think the silicone tubing will meet all of those requirements except possibly the stiffness issue, and that's where my concern is.
I'm going to give it a try. Right now the distance between the ends of the shafts is about 1 1/4". I was going to shorten the shafts so only the tube would be visible but now that doesn't seem like a good idea.
I have seen lots of examples where a flexible tube was used as a link in locomotive drive systems, some newer and many older. Those tubes appear to be stiffer that the silicone that I have. I'm trying to figure out exactly what those tubes were made of.
hon30critter I need a bit of advice. I want to replace the NWSL universal joints in my drive system with clear tubing. I bought some 2mm ID 4mm OD silicone tubing (shafts are 2mm). I haven't tried it yet, but it seems awfully soft and I am wary of it twisting under load. What type of tubing should I be using? Thanks, Dave
I need a bit of advice.
I want to replace the NWSL universal joints in my drive system with clear tubing. I bought some 2mm ID 4mm OD silicone tubing (shafts are 2mm). I haven't tried it yet, but it seems awfully soft and I am wary of it twisting under load. What type of tubing should I be using?
OvermodRegarding the spelling of 'plow' -- the prototype of the thing you're building says 'plow' right on the side of it.
Yes, that's one of the reasons that I decided to stop pushing my obstinate spelling of the word. The spelling is legitimate, but it was a distraction.
Regarding the spelling of 'plow' -- the prototype of the thing you're building says 'plow' right on the side of it.
And it was designed and built in Canada..
BATMANIt's the environmentally right thing to do. Your saving ink.
hon30critter I have decided to stop bucking the trend and upsetting my American friends. From now on I will use the the more common spelling of the word 'plow'. I can just hear the sighs of relief! I hope David and Bear aren't offended. Dave
I have decided to stop bucking the trend and upsetting my American friends. From now on I will use the the more common spelling of the word 'plow'. I can just hear the sighs of relief!
I hope David and Bear aren't offended.
It's the environmentally right thing to do. Your saving ink.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Attuvian1What are you going to use for the plow's tender
I managed to find an early Mantua tender body on eBay for a reasonable price. It lacks the frame so I'll have to scratchbuild that. I will cover the tender with wooden doors as was common procedure to keep the coal from freezing into a solid block with all the snow that would land on it.
I would like to model as many details as I can including the connections between the tender and the plough, but I have to find some pictures so I can get an idea of what they might have looked like. I have several detail parts on hand for the tender, including both manual and air operated brakes, and Precision Scale part #190 - Flexible armoured hose that I hope will serve as the water and steam connections (I'm assuming that there must have been some heat supplied to the tender to keep the water from freezing).
While I'm at it, I need to find some detailed pictures showing how the various bits attached to the steam engine were positioned. I have the Precision Scale parts drawing but to the amature eye, it is hard to see exactly where things go. Some of it is clear but much of it isn't. Any suggestions in that regard would be much appreciated.
As far as the location of the back of the steam engine relative to the back of the plough body, I have allowed for a little more distance between the two than I suspect the prototype had, as you suggested. I never liked the look of an engine with the backhead right at the edge of the rear of the cab floor, so I'm going to give the crew some room to move around. Modeller's licence.
What are you going to use for the plow's tender (oops, "plough")? From the original photo, it looks like the firebox was hand-stoked from under the overhang at the back end. That would make the backhead pretty close to the rear end of shell and might have exposed the fireman to some of the swirling weather (perhaps appreciated!). On the other hand, do we know how long this particular plow was actually used before its inherent shortcomings assigned it to the nether world?
Additionally, are you going to model the water hose between the tender and plow and any other connections that might have been used back then? Good luck finding photos of the plumbing involved. I'm interested as some day I'll have to model the connections between an SP Leslie rotary and the AC tenders that Espee employed . Five decades later, but the essential connections must have been somewhat similar.
richhotrainIt sounds to me like Brent is a Puritan, Dave. I will be a stand-in. Just tell me what you want me to say. I am a professional cusser.
Hi Rich,
Thank you for that most generous offer!!
Actually, I could recruit my wife if she could get her voice low enough!
I just realized something that I hadn't thought about. I need a pair of steam locomotives to push the plough! Duh!!
I have one suitable candidate already. It is a 4-6-0 which I am in the process of backdating to resemble an early Grand Trunk unit. To be honest, I have been working on this thing for years. It is now at the point where it needs paint, and I will upgrade the decoder from an early Soundtrax LC100 to a Loksound V5.0.
I also have a 0-10-0 switcher which might be suitable, but I think I would rather have the second locomotive more similar to the 4-6-0.
Any suggestions? Does anyone know what the Cumbre and Toltec used to push their rotary plough?
Attuvian1Maybe add a wet bar? Or at least a snack/souvenir shop.
Adding a souvenir shop would be interesting. I'll be the one sitting in the wet bar!
I could get really carried away and convert the whole layout to a winter scene in the mountains!
Attuvian1This entire project is great!
Thank you for saying that! I'm having a lot of fun. Even the setbacks are entertaining in a way.
I just ordered some 2mm ID, 4mm OD silicone tubing to see if it will work to connect the motor and the gearbox. The shafts are 2mm. I was hoping to get 1.5mm ID tubing but Amazon didn't list any and I'm not going to go to a dedicated supplier because I figure that the minimum quantity would be too expensive. The Amazon listing had one complaint that said the ID was too small. I'm hoping that will work to my advantage.
I had ordered a flywheel for the motor but it won't fit inside the steam engine without tearing the thing apart again, and I don't want to do that. Hopefully it will run smoothly without it. The decoder should help to smooth things out.