On Michael's Workbench - Air Loco

simond

Western Thunderer
I’m intrigued that the prototype designer thought wire handles were required. Normally used where the valve is going to be too hot to handle..?

much impressed with the model variant, happily I don’t need to worry about it in 7mm…
 

michael mott

Western Thunderer
I’m intrigued that the prototype designer thought wire handles were required. Normally used where the valve is going to be too hot to handle..?

much impressed with the model variant, happily I don’t need to worry about it in 7mm…
Simon thanks, I am guessing that they are not original or were the only ones left on the shelf when this loco was assembled.
 

michael mott

Western Thunderer
Almost there! Took a different approach, folded up an 8 legged spider from some .009x .030 copper wire in a new pin jig.
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Shaped a bit of 5/16 to the cross section profile for the top half then sandwiched it with a bit of rod in the tailstock, then folded down the legs.

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Step one completed on the proof of concept, tomorrow my silversmith friend is going to let me roll some more copper wire so I shall have some approx .010" x .005" rectangular wire which will get the sections closer to what I need.

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The tricky bit was folding the returns I had to file away a chunk of the dome form but it will still function well for forming the top curve.

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Its been a long day.

Michael
 

michael mott

Western Thunderer
So I now have an assortment of rectangular wire, well flattened round wire.

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I decided that the .017"x .006" would work the best. made a new jig and folded up the new spider.

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Then used a bit of maple in the tool post to fold the returns.

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Next the inner section was folded up on a new jig for the cross at the base.

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Then I made a heat sink cup to hold the base piece and the top the base piece was held by the taper pin and the top was a slide fit.

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They were then soldered with a very fine tip in the iron at 395 degreesF

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A jump ring was rolled from some 28G brass wire and soldered to the bottom. Iput the piece upside down back in the heat sink to fit the ring .

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So I now know how to make these little devils

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They are not an exact match but close enough for this loco, so on with the next one tomorrow.

Michael
 

michael mott

Western Thunderer
Te more I study these old photos that I took back in 2006 the more I see. Turns out that I missed a different valve handle on the little valve behind the big air valve. so set up the spin indexer horizontally to slice a small 1/4 inch domed disc. then recessed the underside to create the right look. but before that I was consistently getting a stiff neck from bending over the work on my little sit down workspace. So added a small tablature to the end of my stand up bench.IMG_3422x1024.jpg
so I can swivel round and work at a different height.

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Getting a little better at soldering up the little spider for the wire valve handles, you folk who solder up the brass etch kits set a pretty high bar to follow.
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The two bottom valves are now complete as far as fabrication goes, they need a bit of assembly and colour. I ended up fabricating the second one slightly differently than the first one also used a bit of ACC in the assembly. I used a small turned disc then filled out the cross and rounded the cross members a little and filed up the hex nut on the end. the nut is .046" across the flats.

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ready for the next steps.
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A couple of shots of the new pipe with the abandoned valve, the loops are a bit tighter and the new disc handle on the bottom of the valve where I missed the handle, I had to pop it off the dome first because I had not drilled the hole in the end for the missing handle.

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Will work on the pressure gauge today.

Michael
 

michael mott

Western Thunderer
Worked out how many 1/16th copper pipe T's and Elbows I needed and got those done today. They are slightly larger curve elbow than the really tight right angle type, and my story is that when this loco was assembled they had run out of stock of the tight elbows and grabbed the larger curve ones.

A bit of .093" brass rod annealed then bent to as tight a curve as I could without distorting the brass. then cutting and filing the ends
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Next the ends were cleaned up fron the filing then drilled for the 1/16 copper wire, I used a small centre drill then use 1/16th end mill.

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I turned up some end flanges from some 1/8th brass rod, I don't like using tube because it is gummy to machine and was too thin anyway. I used a #8 cut file to round the edges before parting off the rings for the elbows.

The T's were turned down from some 1/8th rod. I discovered a good way to hold the parts was to machine down some 9H mechanical pencil leads this got around the heat sink problem.

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The first samples.

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Took a bit of time but got them completed

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In order to complete the rest of the piping and related valves I needed to put the loco back together, I was concerned about getting the wheel back together after redoing those flanges, The plastic gear in the middle of the Axle has a set of stops so re-gauging was not a problem. I eyeballed the first set and then matched the second set. My guardian angel must have taken care of my eyeballing because it ran fine with the con rods on with no binding. It was my lucky day.

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Tomorrow I start on the new piping and valve for the front end. Mostly the section between the cylinders and flanges they are a bit over size.

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Michael
 

michael mott

Western Thunderer
Can you please describe that interesting looking
"holder, gripper, clamp" thingy?
Peter
hello Peter, I was tired of trying to hold things precisely with this device known as a third hand.
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I wanted something that could hold items accurately and firmly, and developed this unit.

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The base was pretty but not really practical, for soldering work so modified the base and the locking screws to this configuration. the new base is 1/2 inch thick aluminium. What I like aboud this design of third hand is its flexibility.
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I have made a number of different head for holding different materials for clamping and gluing.

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This first unit was made from some salvaged aluminium alloy and odd bits of brass. the wooden clamps are a simple design for holding thin sheet.
here is an assortment of holding fixtures the shaft is 3/16th.
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I did end up making a short run of thirteen with this configuration. The buyer had a choice of holding fixtures. with some spring holding fixtures and refined toolmakers clamps and boxwood sheet clamps.

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I won't be making any more but I am happy to share the drawings for the production model which functions the same way as my first crude prototype. I hope this explains the "holding gripping clamping thingy"

and today I managed to make all the square 1x72 nuts an bolts for the new flanges on the front of the locoIMG_3479x1024.jpg

Michael
 

michael mott

Western Thunderer
Thanks for the kind words Peter and "Renovator".
Because of the narrowing of the gauge on this model without scaling everything else down it is causing a few issues, The plumbing at the front end still need a bit of tweaking to make it look right. bolted on the "expansion" chamber yesterday as well.

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Michael
 

michael mott

Western Thunderer
A bit more plumbing and some priming after doing a bit of soda blasting with the new small blaster that was an early Christmas pressy!
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A split bracket to hold the line down to the valves that open the air to the sanders, The square headed bolts are 0 x 80.

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Michael
 

michael mott

Western Thunderer
It has been a busy week with first the big snowstorm and cleaning up, cold overnights -25C yesterday our female kitten was spade, and we had to set up a quite space for her till today. I used a large old printer box as a blasting cabinet/hood with the shop vac attached to the back, Also cobbled together a short section of parts to add in a drier into the line. I have some 80 mesh sand fines from a local sand pit along with the soda.
The results are encouraging with the sand , which is great because i have a gallon bucket of the stuff.
backing up a bit I have made all the parts for the plumbing from the sanding boxes which include unions T's and elbows. I also have decided to make some additional tiny elbows out of copper tube.

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Some time ago while working out how to make very tight bends in 1/16th copper pipe. I had one of the spring tube type benders but it has a limited range when it comes to the very small elbows.
step 1 anneal the copper tube then insert a bit of styrene rod to fill the inside.
step 2 using a couple of brass sleeves that have the ends radiused.
step 3 push the sleeves together then bend to right angle.

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Next job is to cut the elbow to length with the jewelers saw. (I read through the thread on the eclipse saw and grit blasting yesterday) I have a few saws and have to agree that the blade tension is key to not breaking blades. I like to use 5/0 and 8/0 Swiss blades.

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The styrene prevents pretty much all distortion , I haven't figured out yet how to eliminate the lines toward the centre.
The next step is to give it a blast with the propane torch which melts and pops out the styrene. the picture shows a different elbow that needs a bit of trimming at one end.

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The rings that will get soldered to the ends are turned from the 1/8th hard brass rod.
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after soldering the T's and gluing most of the rest of the assembly a quick shot in the blasting hood 50psi with the 80 mesh sand in the badger mini unit.

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and with one of the new elbows that will get glued once the piping has been shaped for fitting to the loco/

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The union is turned out of some 3/16th steel hex. (lovely free machining steel)

Michael
 

Ian@StEnochs

Western Thunderer
Thank you Michael.

Your use of pencil leads to align components is inspiring and a technique I will now adopt.

I like your method of preventing tube collapse with styrene rod. I have used solder wire in a similar way in fine tube and Cerrobend low melting point alloy when piping up my large scale steam traction engine but never thought about styrene.

A most inspiring build of an unusual prototype. Excellent modelling.

Ian.
 
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Rob Pulham

Western Thunderer
Hi Michael,

I can only echo what Ian said, I can see a whole new rabbit hole of small parts opening up following your description of micro tube bending and small pipe fittings manufacture.:bowdown::bowdown:
 

michael mott

Western Thunderer
Ian and Rob, thanks for your kind words. I have learned a great deal reading through many of the threads on this forum. Ours is a great hobby that touches many fields, and likewise many of the members bring their broad knowledge base to share with others. It feels good to be able to contribute to this wealth of shared knowledge and skills.

Michael
 

michael mott

Western Thunderer
Making something to look like it has been smashed and fixed a few times is challenging to say the least, The left hand side sand box has probably clouted a mine prop or two during its life.

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I folded it up out of some .010" brass after using my trusty old commercial jewelers saw with a 8/0 blade.

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worn the finish off of the handle over the years.
Used the third hand to solder up the brackets to bolt it up to the tank.

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The sand box still needs some welding beads I will sort that with some putty later.

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Every time I take a picture I realize how much stuff there is to make!

Michael
 

Dog Star

Western Thunderer
Good day Michael,

The light bulb came on this morning and I realised that I had a question about the prototype... so I went back to the start of the topic and started reading through. I still have the first question and that has been joined by a second.

This title of this topic is "air loco" and I equated that to the term "fireless" which is applied to engines, in this country, where the boiler is a pressure vessel for steam from an external source. So... after studying the prototype photos is "if the air loco is run on compressed air then how does the storage vessel get filled with air?".

After re-visiting the photos at the start of this topic I think that the prototype has cylinders of different diameters so is the prototype a compound loco?

regards, Graham
 

michael mott

Western Thunderer
Hello Graham, the short answer is basically yes. When I first started this model way back it was because I had come across this loco sitting outside the museum in Canmore Alberta in 2004 the frame and tank were separated as they were doing a restoration of sorts for display.

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The photograph clearly shows the difference in Cylinder sizes.
At the time I had no idea about these locos or how they worked, I am getting a better basic knowledge as I continue working on this model

At that time I had this older Aristo craft o-4-0 loco and embarked on a rather circuitous journey to the present day. I am cutting my teeth so to speak with this model regarding these air locos and I will be going back to Bankhead where the loco that I am basically representing now.

Now that I have come this far I owe it to myself to finish this model, and will be able to hold it up to an accurate model of the Loco that will be made with the proper gauge and a more accurate set of dimensions and details. This "prototype" model is teaching me a lot of things about how to make various parts and sequencing of construction. Although it has crossed my mind to just start all over again, the next one will built to represent one that is recently delivered to the mine as a new loco. also with the proper gauge.

The Porter Locomotive company made a variety of these little air locos, They were very limited in their capacity of distance and needed to be filled a lot the two large valves one on each side were used to fill them up even inside the mine. I do have a number of different builders drawings of some smaller Porter locos but none however of the one that is on display at Bankhead. The really unfortunate situation is that the loco at Bankhead ids unprotected and is suffering the ravages of the Canadian winter and the destructive ravages of vandals stealing souvenirs. I hope to get back to Bankhead this coming summer and to take the needed time to measure and take all the pictures that working from the ones I have, that I wish I had taken the first time or second time for that matter. My friend Martin Johnston in Minneapolis did a presentation about these air locomotives at the Narrow Gauge Convention in 2018. Martin has been a great help.

Michael
 
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