Author Topic: Steam Tractor 3/4" (Rudy K)  (Read 242033 times)

Offline b.lindsey

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #720 on: July 02, 2017, 05:53:42 PM »
Those look good Kim as does the screw. About time for another big family shot isn't it?  ;)

Bill

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #721 on: July 02, 2017, 06:01:35 PM »
Thanks Don and Bill!

About time for another big family shot isn't it?  ;)

Yeah, its getting close.  I had to take things apart do the Smokestack, and I haven't gotten it back together yet.  I'll When I do, we'll do another family portrait :)
Kim

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #722 on: July 03, 2017, 05:06:37 PM »
Yesterday, I made the Crank.  This was a fun little piece.  A LOT of steps went into this one, but interestingly, this is one of the first parts I’ve made where it all came out of scrap bucket! (Fun little trivia to share with your friends :))

Here’s where I’m headed.  Rudy suggest making it as two pieces – the inner piece with the triangles cut out, and an outer ring. Then solder them together.  This felt bad to me – to chew a 1” hold in a big piece of brass, only to replace it with another 1” piece of brass.  That is, it felt bad until I found I had a nice piece of 1 1/2" round brass in my scrap bucket.  It was there becase it was less than 2” long and had a 1/2" hole bored in it already.  But that was great in this case, since it meant half my job was already done!  And I had a little nubbin of 1” brass in the bucket too.  I should have taken a picture of the starting pieces for show-n-tell!


Anyway, so I started on the inner piece.  Faced off both sides, then drilled & reamed a 1/4" hole.


Then I cut the 3/8” hub:


Now to make the triangle cuts.  I started this way – straight up in the vise.  I found center using the 1/4" rod I’d stuck through the center hole.


Then I cut away everything outside of the 1/4" center post, down to my predetermined depth that I made up (the drawings are very unclear about these tringle cut-outs.)


Now, the next part was even less straight forward for me.  I chose to mill them out this way.  First, I marked the line I wanted to remove, then I lined it up best I could to march that mark, and milled down to it (being really careful not to mill into the center post).


Then I did the same to the other side, and figured that would have to do.


Then I turned it sideways and drilled & tapped a 6-32 hole for the Crank Pin.


To make the ring, I put the 1 1/2" round piece of scrap brass into the 3 jaw chuck and finished boring it out to 1”.


As I approached the 1” mark, I went very carefully to get a good fit for the 1” center piece that would have to fit. Like so:


Finally, I turned the outside of the ring down to 13/8”, per the plan.


And then cut it off to about the correct width.


Following this I went through the burnt offering sacrifice phase.  I cleaned the parts, fluxed them up and fried the little puppies to within an inch of their lives while trying desperately to get them to solder together.  Fortunately for you, I completely forgot to take any pictures of this disgusting event.  But trust me when I say, it wasn’t pretty.  But in the end, it cleaned up OK.  I chucked it up again and shaved off a little bit on each side to get the final width, and then filed away for a long time to get rid of the solder blobs.

After that, I drilled & tapped for a 6-32 set screw.


All this resulted in the final product: the Crank.
And I think he will do.


Thus ends this installment.  Thank you for visiting!
Kim
« Last Edit: July 05, 2017, 02:30:57 AM by Kim »

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #723 on: July 10, 2017, 02:43:40 AM »
I turned out the crank pin fairly quickly – it was exactly the same process as the gudgeon pin from a post or two back, so I didn’t post a lot of action shots, but here it is completed:


Before I can move along too much further, I need to mount the cylinder. So, that’s what I did this weekend (and part of the 4th).  First, I laid out the up-right part of the bracket on 22 GA sheetmetal.  Then using the scroll saw, files, and other various means, I cut out the shape.  This shows the part with a filing button mounted as I get ready to round the top part of bracket to make it look nice.


After rounding the mounting tabs I folded the edges to help stiffen the bracket.  And that’s the part in the top of this picture.  Next, I cut out and shaped the bottom part of the bracket that will connect to the Boiler Casing.


To hold this little part in place while drilling the holes, I used some double sided sticky tape.


Bending the tabs and shaping the lower bracket took some ingenuity, but I worked it out.  Here I’m using the inside of an extra bit of the Boiler Casing pipe to help shape the tabs and the curve of the part.


Figuring out how to get the two pieces mounted in correct alignment was a real puzzle.  In the end, I put some double sticky tape on the bracket and held them all up like “so” on the boiler casing and pressed it onto the tape.  Then I took it all apart and drilled one hole (the center one).


Then I took the tape off, placed a rivet in that hole, then drilled the next hole, riveted it, then the final hole. I think it came out looking pretty good:


Now, to mount the Cross Head Guide Bracket.  I’ve been waiting to mount this till now so that I’d get it in the right place.  I decided to mount this one first, THEN I’d mount the Cylinder Bracket.  I did this in a similar way, using double sticky tape to hold the parts in place.


But then, after I get it all setup on the mill, I discover that I can’t get the mill head close enough to drill the holes.  It hits the boiler casing. :(


So I strip the horn plates off the boiler casing, trying desperately not to mess up my double sticky tape joints, and found a way to hold that assembly in place to drill the rivet holes.


And then I riveted it together.  Now the two horn plates are forever connected.


For the final step, I again employed the double sided sticky tape to hold the bracket in the right place on the Boiler Casing.


Then I spot the three holes through the bracket base:


After marking them, I removed the bracket and the tape, then drilled and tapped the three holes for 2-56 bolts.

And here is the Cylinder, mounted and able to smoothly turn the crank and the whole gear chain!


Though that doesn’t seem like a lot, it was a significant amount of work to put all of those pieces together and maintain alignment so that things would slide and rotate as appropriate.  And I’m pretty glad it’s done now!

Thanks for looking,
Kim

Offline crueby

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #724 on: July 10, 2017, 03:00:33 AM »
Nice job on holding and shaping those brackets, tricky stuff!


 :popcorn:

Offline Ye-Ole Steam Dude

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #725 on: July 10, 2017, 10:49:37 AM »
Lots of time consuming and tedious work but the end results are great.
Thomas

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #726 on: July 10, 2017, 02:34:06 PM »
Thanks Chris and Thomas!
Kim

Offline Don1966

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #727 on: July 10, 2017, 03:37:59 PM »
Nice job on holding and shaping those brackets, tricky stuff!


 :popcorn:
I agree very nice work Kim....


 :cheers:
Don

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #728 on: July 10, 2017, 04:22:36 PM »
Thank you Don!
Kim

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #729 on: July 16, 2017, 02:13:27 AM »
Steam Tractor (Rudy K)
Cylinder Bracket

As I’ve put the Tractor together, and taken it apart, I have found that I’m getting little dimples and bumps around where the set screws engage with the shafts.  This makes it hard to get the wheels and gears on and off.  I know this comes as no surprise to you guys, but now I understand why you mill flats onto you shafts.  Not only does it help the set screw hold better, it keeps the dimples out of harms way.

This most recent time when I was re-assembling, one of the things I did was to mill flats on all the shafts.

But another thing I’ve found – the set screw on the main rear wheels are IMPOSSIBLE to get to.  I made the hole for the set screws in the hubs before I’d assembled the wheels:


And now, after assembling the wheels,it’s impossible to get a alan wrench in there so you can tighten the set screw between all those spokes.


So, I decided it was time to make new holes for the set screws.   I wanted these to be at an angle, and closer to the outside edge – easier to get at with a allen wrench.  So this is what I did.

I used a large sine vise to hold the wheels, then drill a new hole for the set screw, like so:


And since I couldn’t get a tap wrench in that close, I ended up using the bare tap, with a little itty-bitty hex wrench to turn the tap.


This worked great, and now it is SO much easier to assemble the rear wheels onto the axel.

After this, I started to move forward in the build by making three of these Valve Motion Pins:


And here are all the completed Valve Motion Pins:


While I only made a little progress on my build today, I resolved the issue with the rear wheel set screws, AND I fixed the problem with the DROs I’d been having. That was time well spent!  (see this thread: http://www.modelenginemaker.com/index.php?topic=7289.new#new)

Thanks for looking in,
Kim

Offline John Hill

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #730 on: July 16, 2017, 03:43:09 AM »
You have already found a solution to your wheel fixing screw but I could mention that traction engines often had holes in the wheel tread for fixing grousers.

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #731 on: July 16, 2017, 05:19:53 AM »
You have already found a solution to your wheel fixing screw but I could mention that traction engines often had holes in the wheel tread for fixing grousers.
That would have been an interesting solution - add a hole in the wheel right over the existing set screw.  Hadn't thought of that.  But maybe I'd have to drill a few extra holes to make it seem intentional? :)

Ah well, as you said, I've got it sorted now.
Kim

Offline Kim

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #732 on: July 23, 2017, 02:46:15 AM »
It was hot here today (well, it was up in the 90’s and that is HOT for me!) but I still did some work out in the shop.

The first part (the Valve Spindle Eye)I actually did last weekend.  But the second part (Rocker Arm), I did today.

The Valve Spindle Eye started as some 1/4" square brass stock. I first turned the end down, then drilled and tapped 2-56 for the Valve Spindle.


Then cut it off the parent stock.


On the Mill, I drilled and reamed the 3/32” hole for one of the Valve Motion Pins (see last update).


Then made some 1/4” filing buttons to use in rounding off the ends:


To mill the 1/16” slot down the center of that, I had to line it up perpendicular to the mill spindle.  To help get this alignment, I slid a 0.093” gauge pin in the hole and used that.  It helped significantly!


Then using a 1/16” end mill, I cut the slot.


Here’s the finished product.


It turned out great!

Except that today I realized that I was supposed to ream 3/32” on one side of it, and tap the other side.  :facepalm:  So I’ll be doing this piece again!


Today I made the Valve Rocker Arm.  This is a short piece of 1/16” brass plate, with a few holes and minimal shaping.

Here are the holes.  The end one had to be elongated by 1/32”, so I used a 3/32” endmill to do that.


To round the ends of the rocker, I wanted to use filing buttons.  So I made a set of 3/16” buttons.  Here I’m cutting off the second filing button:


And this is my setup for heat treating them.  When they get hot enough that they are no longer magnetic, they fall off and land in the water where they are quenched. I learned this little maneuver with the magnet from Dave Otto.  It’s been a great help!


And to temper them, I learned a new trick from reading one of Kozo’s books (A3 Penssy Switcher).  I put them on a piece of metal and heated them up from the bottom, through the metal.  This is MUCH better than direct heating, especially for these small parts.  I had such a hard time keeping them from getting too hot too fast.  But Kozo's method worked brilliantly!  (though it still took me two tries :))


Filing buttons in hand, I rounded the ends of the Valve Rocker:


And it's all done.


Thanks for taking a look!
Kim

Offline Roger B

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #733 on: August 01, 2017, 08:50:12 PM »
Still following along and enjoying   :wine1: I like the heat treatment methods for the filling buttons  :ThumbsUp:  :ThumbsUp: They would have been a good solution to rounding off the little end of the connecting rod.
Best regards

Roger

Offline b.lindsey

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Re: Steam Tractor 3/4" (Rudy K)
« Reply #734 on: August 02, 2017, 12:27:24 AM »
Kim, just curious....why is it necessary to temper the filing buttons?

Bill

 

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