My "between projects" project.

Downeaster

Everything in XS
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I'm still adding little details here and there to the farm diorama. I decided some time back that a derelict thresher would look good behind the combine shed along with the dead tractor and the old hay loader. I asked around on a couple of ag boards for someone to give me some basic dimensions of a thresher as I've never seen one in person. A guy from Kansas runs one every year at the local tractor show and was kind enough to hook me up with some numbers and pictures of an Allis Chalmers thresher. As an extra bonus, that fits with the AC theme of the combine and tractor.

I used this picture and the 1:1 measurements he provided and used my scale rule to interpolate things down to "S" scale (1:64)

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I used those measurements to produce this scale drawing with several reference lines.

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That was transferred to some plastic sheet and cut out with an Xacto knife.

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Those parts were glued together with liquid Testors, using my 1-2-3 blocks and various magnets to hold things square and in position.

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I have to use VERY thin sheet to get the curve in the rear housing so I glued some forms on the inside. At this point the whole thing is a hair over 3" long and about an inch wide.

I bent up the straw blower pipe by inserting some #12 copper inside a suitably sized plastic tube, heating it up with a blow dryer and bending it to shape. I have tubing in various sizes to do the blower housings, and square tubing for the elevators.

The spoked wheels are going to be interesting. Not sure how I'm going to do that yet. The various pulleys I can turn on my mini lathe.
 
I've been noodling how to make the spoked wheels for the thresher for a while. To be in scale, or nearly so, they need to be made out of half inch tubing and have 8 spokes equally spaced around the circumference - i.e. every 45°. The spokes themselves would be .063 diameter.

I have a 3" rotary table for my Grizzly benchtop mill, but no way to hold the tubing. I took that as an excuse to buy a 3" 3 jaw chuck that fits my rotary table. Got it on Amazon, and with various discounts it was just a hair over $45. High precision it's not, but plenty accurate enough for model work.

Next problem? How to hold the tubing in the chuck without crushing it and still be tight enough to work with. Solution? Turn down a piece of wooden dowel to a snug fit and chuck that and slip the tubing over it:

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Then just crank the rotary table around in 45° increments and drill through the tubing and the dowel. Drilling all the way through both sides makes alignment pretty accurate and means I only need to drill 4 holes. Worked pretty darn well after a couple of adjustments to get things lined up.

Next problem? How to cut 1/8" wide rings off the tubing after the spoke holes are drilled and have them come out reasonably square and centered. Solution:

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Another piece of dowel chucked up in my mini-lathe and an Xacto knife in a boring bar holder to part them off. Wicked cool.

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And the finished products. Now all I gotta do is figure out how to glue them up. I have an idea, if it works, I'll post back with the results.
 
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Wheel jig works pretty well. Used the same dowel, bored a hole in the center to insert the tubing for the hub. Slipped a small disc of plastic over the hub for a glue point. Work the rim onto the edge of the jig so the spoke holes just clear the end. Insert the spoke from the outside, cut to length and apply a dab of liquid glue to the outside of the rim and another at the hub.

Do a couple at a time, wait for the glue to cure, rotate the chuck, do a couple more.

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Here's where I am with the overall project. Lots more details to add.
 
Very cool! So many details, especially given the tiny scale of it. Have you ever considered a 3D printer for some of the smaller pieces? A printer would make quick work of those spoked wheels.
 
Very cool! So many details, especially given the tiny scale of it. Have you ever considered a 3D printer for some of the smaller pieces? A printer would make quick work of those spoked wheels.

Thanks!

I've thought about 3D. However, the startup costs for hardware, software and supplies, plus the learning curve has discouraged me so far. If the funds present themselves, perhaps down the road.
 
Just did a little surfing re: 3D printing.

I have one word: GAS-puh! At a minimum, kiss $500 goodbye, and it wouldn't be at ALL difficult to add a zero to that.

Not gonna happen any time soon.
 
Understandable. You could certainly spend as much as you wanted to on a printer. That being said, my printer (Ender 3) was $250. There are millions of community-designed models available for free of charge, here is an example of a spoked wheel. When I make my own designs I use free, simple software - Tinkercad. The plastic filament is $20 for 2.2lbs of plastic. That equates to about 50 hours of printing. As an example, I am a big R/C airplane enthusiast and I printed this airplane (36" wingspan) from pre-designed files for about $10.

Really not trying to be difficult or argumentative here, just wanted to share how I got into the hobby for relatively little money and have really enjoyed it. If you like to tinker and make things it is a fun tool to have in the toolbox.

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Interesting, Rhy. That's much more within my budget.

How complex did you find the setup on the printer? I read the reviews earlier and some folks complained the instructions were sketchy and customer support was unresponsive. Of course, some folks would b!tch if you hung 'em with a new rope, so there's that.

I'm sure I could find a lot of what I need on Thingiverse, but I'd also want to create my own files I'm sure. Does TinkerCAD include a slicer and produce printer-ready files, or is there another step involved?
 
The setup was not bad. I think with some basic technical know-how it would go together just fine. I didn't call customer support, but would not be surprised to learn it was poor. Like with most things, the good price does end up shorting you somewhere and I'm sure customer service is a part of it. More importantly to me, the printer is mechanically sound and functions well once you get it running. Another benefit of this printer is that it is very popular and there is lots of user-based support for it.

TinkerCAD does not slice the files, it only generates the object file (.stl). I use free software, Ultimaker Cura, as a slicer and interface with the printer. You can make slicing as easy or difficult as you want. The pre-configured slicer profiles generally work well. As I became more experienced I have been messing with more of the advanced settings. Some models, like the airplane, came with its own slicer profiles.

If you find a smallish model that you would like to try or end up designing something of your own I would be happy to provide you with a test print of it. Get a better idea of what the finished product would actually look like before investing in one. Just let me know!
 
Direct from their website it's $210. Throw in a 5 pack of the filament and it's $255 shipped. WOW!!
@Rhy650 , is there a depository somewhere where people share their files?

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One of my former students has a "fleet" of <I think> about 60 or 80 of these medium-sized 3-D printers and he does contract jobs for companies and individuals all over the world. He did a lot of work on COVID-19 - related medical gear (specialized masks and ventilator parts etc.) at the outset of the pandemic and is now doing very well with contracts all over the world.

His machines run 24/7/365 and they are busy all the time.

www.PEPCorp.ca
 
And I still think you need to put a septic system on the bottom side of the board. Make sure you keep the well point far enough away.:)
 
@Downeaster
I have to ask. Would watching a replicator spit out a part be as satisfying as creating the part with your own two hands and your imagination.
Maybe not, but I'm thinking designing and coding your own part and then actually watching it come to life would be a close second.
 
I'm sure I'd still make 99% of the things I model the old-fashioned way, but there are shapes/constructs I can imagine but can't reproduce.

In the past, I've messed with various Freeware 3D CAD programs. At the moment, I'm messing with TinkerCAD, but it's kicking my ass. For a first project, I'm trying to make a hollow tube. Simple, right? Big cylinder for the outside, smaller cylinder for the inside, make the small cylinder a hole and Bob's yer Uncle. I suspect it'll get easier when I figure out how to specify coordinates so things are centered. Baby steps. Going through the tutorials now.
 
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