I think I have refined the gearbox design enough to make it actually work. The housing will be made of brass sheet and strip. I haven't decided how thick the brass will be. I want something that is stiff but still workable with my limited assortment of tools.
I'm not sure if you can make sense of my drawings but I will try to explain. Despite the fact that I studied drafting in high school, any recollection of proper symbols disappeared into the ether a long time ago.
The front views are of the parts before any forming (bending) is done. The side views are of the formed parts. The circles with the cross are screw installation points, and the ones with the oval in the center will have elongated holes to allow for the positions of the components to be adjusted so I can control the gear mesh. Parts #4 and #5 are 1/4" x 0.032" brass strip. Part #4 will also have the motor mounts attached to it.
I'm going to use brass screws and nuts because in some places I want to be able to solder the screws in place.
Here is my crude attempt at a mechanical drawing. Click on the drawing to enlarge:
I'm still waiting on some components so I can't promise when I will be able to attempt assembly.
Tell me what you think.
Cheers!!
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
OvermodYou can probably use straight pins for the struts between vanes, too, which should help keep the impellers stable after soldering...
Hi Overmod.
My plan is to use 0.015" phosphor bronze wire because it solders so nicely. I think it should be firm enough to do the job. I don't plan on testing the plough with real chunks of ice. I will still have to use my blender to make the margaretas.
I'll need to make the holes for the cross braces before I attach the blades to the hubs. The blades need to be supported on a solid surface when being drilled because they are a bit flimsy (0.010" brass). I don't think that will be a problem once things are assembled but I have to be careful not to bend them too much when working on them. If the blades prove to be too weak I will make another set using thicker material. I have an assortment of brass sheet in stock and on order.
Last night I worked on designing the gear box for the blade drive. I think I have a plan worked out which will make it easy to adjust the gear mesh. There will be a few fussy parts to make. My plan is to get the motor and the blade assembly mounted on the frame and working. Then I will build the plough body around it. That will hopefully eliminate the need for a lot of shimming etc. to get the blades lined up.
One thing that is becoming obvious is that my usual rather roughshod 'good enough' construction methods won't cut it when it comes to making the gearbox. I can see myself having to make several stabs at the gearbox before I get it right.
Thanks for your suggestion about the straight pins,
You can probably use straight pins for the struts between vanes, too, which should help keep the impellers stable after soldering...
BATMANDave, this might sound crazy but why not solder the blades to the hub? Take a torch to heat the hub and tin it, tin the blades with the soldering iron, mate the two a run your soldering iron along the blade to do it.
Hi Brent,
Your suggestion doesn't sound crazy at all. In fact I intend to solder the blades in place. I'm sorry if I didn't make that clear.
Using the pins does a couple of things for me. First, it eliminates the need to hold the blades in place while soldering. Unfortunately my hands shake a lot so holding something steady is almost impossible these days. Second, having the blades pinned in place will prevent any disasters from happening if I get the hub too hot. I really don't want to watch the whole assembly collapse into a pile of junk if I overheat it and melt the previous joints. I know that I could use heat sinks, but the pins are more reliable. They will get ground off once everything is assembled. I also have lots of metal clamps that I could use, but they can get knocked out of place whereas the pins won't move.
I'm ready to solder the blades in place but I have a couple of technical things to figure out before I do that. One is how to attach the hubs to the drive shaft so that they don't wobble. More importantly, I have to finish designing the mounting mechanism for the blades and the input drive shaft. I want to make the mounting supports adjustable so I can get the gears lined up properly.
Thanks for your input.
Dave, this might sound crazy but why not solder the blades to the hub? Take a torch to heat the hub and tin it, tin the blades with the soldering iron, mate the two a run your soldering iron along the blade to do it.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
Dawn is doing fine. Just some days are not so good for her. A case of carrying on.
The really good days are great.
Thanks for enquiring.
David
To the world you are someone. To someone you are the world
I cannot afford the luxury of a negative thought
NorthBritSounds like you are having fun, Dave. Modeling as it should be done.
Hi David,
I am having fun! Thanks for following my slow progress.
P.S. How is Dawn doing? Better I hope.
Sounds like you are having fun, Dave. Modeling as it should be done.
Here is a brief update:
I seem to have managed to get the holes in the blade hubs close to center. I won't know for sure until I can get them mounted on a proper axle system.
I have been working on figuring out how to attach the blades to the hubs. So far I have managed to get 0.020" holes drilled through the mounting flanges on each end of the eight blades, and I have also been able to drill corresponding holes in the hubs where the outside pins will go. My plan is to get one end of the blades anchored down and then drill the second alignment pin holes at the opposite end of the blades. My accuracy is crude at best so I am doing things in such a way as to allow for lots of adjustment when positioning the blades.
My next efforts will revolve around building the drive system for the blades. I have several parts on order so that process will be delayed until they arrive.
So far this has very much been a learning experience which I am thoroughly enjoying. I have only made one significant error so far and that was when I cut the blades too small so there was no material left to create the mounting flanges. That was easily corrected.
I'll post more pictures once I have made more progress on the blades. Right now all I could show you would be a bunch of tiny holes drilled into the hubs and the blades. Boring.
I used Rich's suggestion a second time but this time I glued the template to the closed side of the hub. To make a long story short, the holes now appear to be pretty close to center. I will find out how accurate they are once I can get them onto a drive shaft and give them a spin.
I got the new blades with the flanges cut out. The blades on the right have had the flanges bent and the ones on the left are awaiting the process. The blades are brass. They just haven't had the templates removed yet.
You can also see the hubs with Rich's jig for drilling the centers out accurately glued to them. I soldered some 0.032" brass sheet over the old holes which were not on center. I just realized that I will have to solder the hole patches to the inside of the hubs or the drill will wander back into the old hole.
Two steps forward, one step back!
I got one but waiting till some young buck would beat me to it.
Maybe tomorrow or some young buck, as i seem to be growing older than the archives-
TzF
Dave, check YouTube for videos on drilling the centre of a circle, I'll bet there are plenty.
richhotrainI trace the circular object on the white back of a scrap of art foam board, snap a photo and transfer it to PowerPoint. Then, I insert a square over the circle, using the PowerPoint images. Draw intersecting lines across the circle, using the four corners of the square. That is your center.
Hi Rich,
Thanks for your help! I think I can do that with 3rd PlanIt. I'll let you know how it works out.
I have done that before.
I trace the circular object on the white back of a scrap of art foam board, snap a photo and transfer it to PowerPoint. Then, I insert a square over the circle, using the PowerPoint images. Draw intersecting lines across the circle, using the four corners of the square. That is your center.
Rich
Edit Note: Oops, I didn't quite cross two of the four corners of the square, but you get the idea.
Alton Junction
I have a question for all of you engineering and machining specialists out there:
I need to drill my rotary blade hubs exactly on center in order to mount them on the drive axle. I gave them a rough (read: very rough) try and as you can see by the picture, I failed terribly. They are close, but if I try to use them with holes even slightly off center, I think they will shake the plow right off the tracks.
So, how can I drill these exactly on center?
Just so you know, I don't have any fancy tools, i.e. a lathe. I have tried spinning them in a drill but the results weren't very good.
Help!
Track fiddlerThose blades look Factory man Good thing you didn't use your wife's good pair of sewing scissors Hopefully your soldering works all right for you without the said flange. I hate that when I forget a feature I thought of, especially when it involves multiple pieces.
Hi TF,
If you were to see the blades up close you might not be so complimentary!
I have decided to re-do the blades with a small flange. My plan is to use brass pins to locate the blades and hold them in place while I apply the solder. If I'm lucky I will be able to use the pins like rivets, but even if I just bend them over and squeeze them tight they should do the job. They can be ground off afterwards.
Good morning Dave
Those blades look Factory man Good thing you didn't use your wife's good pair of sewing scissors
Hopefully your soldering works all right for you without the said flange. I hate that when I forget a feature I thought of, especially when it involves multiple pieces. You'll get-er!
TF
I got the blades cut out. I used 0.050" brass sheet and I cut them with a simple pair of decent scissors. The scissors worked quite well. Here is the brass sheet with the templates glued to it (some have already been cut):
Here are the blades ready to have the templates removed. The one on the right is face up showing the template attached. The others are all face down but the templates are still glued on. I used canopy cement which comes off the brass quite easily:
I messed up a bit with the blades. My plan was to put a small return on the inside of the blades so the solder joints would be more solid. When I fitted the cut blades to the hub, they fit nicely but that was without the return being bent into them. That means that I won't be able to form the return flange. The blades will have to be soldered to the hubs as is, i.e. without a 90 degree flange. I'm sure they will be solid enough, but I was hoping it use the flange to clamp the blades to the hub before soldering. We shall see how it goes. I may have to remake the blades.
By the way, I have made each blade with a 135 degree curve. There are four blades per hub. The blades will overlap each other by 45 degrees. I don't know if that is correct for the prototype, but I think it will look fine for the model.
I made a wee bit of progress on the blade hubs tonight, although it doesn't look like much:
What I did was I cut the caps down to about 3' 6" wide HO scale and then I added a ring to the inside of the hubs which will act to control the positioning of the spokes when they are soldered in. It took about an hour of cutting, grinding and sanding to get the hubs cut, the rings to fit properly and to solder them in at the right depth.
Now I have to decide in what order do I add the blades and the spokes to the hub. I'm thinking that I should install the spokes last so that they won't move out of place when I am soldering the blades on. I think it will be easier to use heat sinks (wet paper towels) on the blades than the spokes.
First, of course, I have to make up the blades. That will no doubt take some head scratching, and some trial and error, to get eight blades all the same. I'm going to use 0.050" brass so I can cut them easier. I'm off to 3rd PlanIt to draw up some blade templates.
OvermodI think I am inadvertently starting to pull your ears, and I see the likely error of my ways, repent in the appropriate fashion, and will stop it forthwith.
Hi overmod,
Your answers have been complex, but they have also given me lots of ideas and I very much appreciate that. Don't stop now!
I think I am inadvertently starting to pull your ears, and I see the likely error of my ways, repent in the appropriate fashion, and will stop it forthwith. I look forward to seeing the detail progress of this lovely thing and remain 'on tap' if there is anything you actually need my advice or encouragement for.
OvermodWhy are you making the spokes separate when the prototype uses the visual equivalent of a piece of dished plate for the whole hub? Just mark the cutouts and etch out, then dish the whole shebang to shape.
Perhaps I don't understand your comment. The spokes look to me like they are separated by open holes. Recreating those open spaces with shears is easy, at least so far. I am cutting the spoke assemblies from a single disc so the only difference that I can see between your method and mine is that I am using tin snips and you are suggesting etching.
I have never etched any parts, and quite frankly I'm not interested in learning how to do it for this project. I will use my simple tools and limited abilities to create what I think will be a reasonable semblence of the original.
OvermodI think this is a cast hub on the real thing, but if there are reinforcing webs on those openings, etching will be the answer too.
For me, it would be easier to simply add webs to the spokes using styrene strip and CA. I'm not sure that I will go to that level of detail.
Don't get me wrong. I appreciate all the help that you have given so far, even though some of the terms were initially a bit over my head.
gmpullmanHere's a photo along with a few of what I call sprue cutters:
Hi Ed,
I have a set of the tweezer style sprue cutters but not the scissors style. I'll look into buying a pair. If I don't like the price then I will resort to filing.
Thanks,
Why are you making the spokes separate when the prototype uses the visual equivalent of a piece of dished plate for the whole hub? Just mark the cutouts and etch out, then dish the whole shebang to shape.
I think this is a cast hub on the real thing, but if there are reinforcing webs on those openings, etching will be the answer too.
I expect there is another spoked disc on the inside of each drum, but there may be cantilever mounts to put bearings near the centerline of the drum to take the shock loading better.
You'll balance the rotor the same way we do balance wheels on watches: set up two level knife edges for the rotor shaft, then use small weights on the inside of the drums until the rotor can be poised at any position without tending to roll. You can use threaded screws and weights (again as in watch practice) for fine adjustment.
hon30critterHi Ed and Tom, Thanks for the sprue cutter suggestion.
I completely missed what you were looking for, Dave. I posted a link to a precision shear. Here's a photo along with a few of what I call sprue cutters:
Xuron-9180 by Edmund, on Flickr
I tried my 9180NS on some .010 brass and they cut beautifully.
Micro-Mark and I'm sure others offer sprue cutters.
Regards, Ed
Track fiddlerI never doubted you for a minute Dave
Thanks TF!
This project is turning out to be as much fun as I hoped it would. My biggest fear is that I won't be able to get the rotary blades balanced well enough to run smoothly, but I'm working on solutions for that too.
I never doubted you for a minute Dave
I've had times the right tool for the right job was left at home or at another job and I still needed to get the job done with what I had to work with.
A guy named Primitive Pete took over and I got done with what needed to get done.
A guy named Dave who can build a rotisserie layout can have no problem building a side discharge rotary snow plough. I have all the confidence in the world in you.
Looking good Kid, .....Carry on!
As promised, here are a few pictures of the meager progress that I have made:
The first step was to remove the roof from the Accurail 36' double sheathed boxcar. Accurail molds their roofs and sides as one piece so getting the roof off requires a bit of cutting. I used a new #11 blade to initiate the cuts. Then I took a used #11 blade with the tip slightly broken off and used it backwards (sharp side away from the cut) to scrape out the cuts. The backward broken blade removes a lot of material very quickly and also has the benefit of leaving the edges of the cut square. When you use the sharp side of a #11 blade to do the whole cut, not only is the cut harder to make, but the blade produces a raised rolled edge on the cuts which has to be removed.
The next step was to extend the frame about 6' at the back in order to give the plough a more balanced look (thank you Bear for the suggestion). I cut the coupler mount off of the bolster assembly and inserted a piece of 0.040" V groove styrene in between the two parts of the frame. The spacing on the V groove styrene was almost identical to the width of the floor boards, and the 0.040" thickness matched the thickness of the original floor almost perfectly. Serendipity! I then added in the center spine, and Accurail was kind enough to supply an extra cross brace to finish the appearance:
Next I decided to tackle the rotary blade hubs. I had printed several copies of my side view sketch that were close to HO scale, so I cut the picture of the center hubs out of one and glued them onto some 0.010" brass discs. If you look at the edges of the discs you can see why I had to replace my tin snips! Sorry, I forgot to clean off the plastic scrapings from the roof removal, but you can see how much material is removed with each pass of the backwards blade:
The next task was to cut out the hub spokes and file them down. There is a bit more filing to do and they have to be trimmed to length. I had to flatten the spokes out because the cutting process bent them out of shape a bit. Then I put the spokes in the center of a 3/4" copper plumbing cap and pushed down. They formed a curve quite easily. (I believe that I owe either Brent or Ed thanks for that suggestion). The caps will form the outside of the hub where the blades will be attached.
That's as far as the work has progressed. The next step will be to figure out how deep (wide) the rotary blade center hubs will be. I suspect the the caps are too wide as they are now so I will have to do some sketches to figure out the blade dimensions, both rotary and stationary. Once I have the hubs trimmed down I will be able to solder the trimmed spokes into them. I'm going to take a ring of 3/4" brass pipe and slip it inside the hubs. That will give me a stop for the spoke ends so it should make it fairly easy to get the spokes square to the hub. They have to be square if I am going to power the blades. Otherwise everything will be wobbly and probably unbalanced too.
I also have to figure out how to build the front of the plough so that the blade drive mechanism is accessible. I have some ideas. I'll know better once I have them on paper.