The Home Machinist!

Beautiful!
Next: The scale pencil to go with the tiny clip board...
RussN

Hello My Friends
Thanks Steamer Al, and NP317. The castellated nut is .125" across the flats and is for a #2-56 bolt. The slots for the cotter pin are .020". That cotter pin is copper, but now I have some .015" soft stainless wire that I make them from. Here is a tiny one. This is a #1-72 bolt and castellated nut. After fiddling with this little baloney your eyes eventually go crossed.
Jack

Hello My Friends
Here are a few snappies concerning the throttle linkage. The top photo shows the original smokebox throttle lever and the replacement. The bottom lever was too long and not the right shape. So the top one was made up. Then we have a throttle rod guide that was made. There are two of them. And then just a couple overall views. No shortage of things to do!
Jack

Wunderbar
Asteamhead

Help My Friends
Thank you Asteamhead. Sometimes I'm like a kid in a candy store trying to decide what to make next. I think I will be making things for the inside of the cab. Things like water glasses, brake valves, steam turret, power reverse wheel and indicator, cab lighting, and the fire door. The fire door sounds like fun so that will be next. I want the fire door to look prototypical, be air operated, and large enough to get a coal shovel through. The operating lever for the door will stick up through the left rear of the cab roof. Right next to the whistle control lever. When running the engine you can rest your left hand on the roof, press the levers with your thumb, and shovel coal with your right hand. That makes firing on the run easier. Firing these little engines on the run is a lot of fun. The fire door is not going to be a perfect scale model but a reasonable representation. The first thing to do was make a card stock mock up. So a photo was enlarged to the size needed. This was determined by the size of the actual fire door opening in the back head. This dictated that the fire door be a bit oversize. When the opening in the door was sized to fit, the outer perimeter of the fire door base casting was too large as can be seen in our second photo below. So the outer perimeter size was reduced as seen here with the photo reproduction under the actual pattern that will be used. The prototype fire door also had mountings for the stoker coal elevator at the bottom. This was not included here but will be a separate casting set that can be used or omitted as wanted. Masters will be made for making investment casting molds. This actually makes the job easier as both silver, and soft solder can be used. Also epoxy and bondo. A fun little puzzle. More to come.
Jack

Hello My Friends
The fire doors have a lip on the back side and these were built up with brass shapes and silver solder. This could be done with a CNC mill if I had one...and knew how to use it. I'm an old school Bozo and am comfortable with files and such. The main door piece is .100 brass and the added lip is .062. Parts were roughed out using the band saw, and mill, then finessed with the disc sander, a small sanding drum, and files. Then they were stuck together with screws and silver solder. Everything was fluxed and small bits of solder placed here and there. Things were heated up with the torch and the solder slurped into place. The doors will have rounded edges and some lettering. Now its time to put a lip around the opening in the main frame using the same process.

Now the doors will get a lip and recess where they come together. This was done with a 3/32" end mill.

Here we have the lip for the main frame casting. Same routine as the door lip. The outer edge was roughed with the band saw and disc sander. Then the center was blasted out with the mill. The part was held using the universal holding fixture and the mill was just hand jived, cutting to a line made with the ultra fine point Sharpie. I have gotten pretty good at this over the years and can just about split the line when needed. Here it isn't really needed as the part was finessed with a drum sander and files. Then the part was stuck to the main frame with #0-80 screws and the center hole was marked on the main frame with the Sharpie in preparation for cutting out.

Here is a little on silver soldering. First everything was cleaned and rinsed with lacquer thinner. There was cutting oil on the parts from tapping the holes. Then the parts were fluxed, making sure to get flux into the holes for the screws, and also the screws. You want solder to flow into the threads, that way when you sand off the screw heads there will be no trace of them. The screws are done up tight and then backed off about a quarter turn to help the solder flow between the parts. After fluxing and assembling, tiny pieces of solder are nipped off the roll with wire cutters. Then they are placed around the part. You can see them in the third photo from the top. In this case I wanted a filet so more were used then usual, they were set about 3/16" apart all the way around. I always try to place the solder on the work piece before heating. That way as soon as the parts come up to temperature the solder melts and flows. This has some advantages, it helps avoid over heating the part before the solder is applied, and if you heat the part and then go poking away with a length of solder you will probably use too much and not get it where you want. After soldering, the door frame went into the acid pot for a while, and then was bead blasted. Then the opening was cleaned up with the small drum sander and files. Next up the pivot point bosses for the doors and the pivot arms that will fit to the doors and include the door operating levers. Also the air cylinder. This is a Standard fire door and unlike the Franklin Butterfly door has no gear teeth linking the doors. It has a system of levers and links to open the doors. In a way it's simpler, but in a way it's not. No gear teeth, but more parts to make.
See You In The Funny Pages...
Jack

Jack:
Really fun to see your progressive construction using silver soldering. My favorite method for complex parts.
Good old hand cutting and filing. Usually faster than using a CNC mill for one-offs. And I've done both methods...
Thanks for sharing.
RussN

Hello My Friends
Thank you Russ. It really doesn't matter how you make things, what matters is that you make things. I've known cats with the absolute most rudimentary tools that cranked out amazing things. And then there is the guy with a shop full of machinery that couldn't find his backside with both hands.... I hate it when that happens! But here is what this Bozo has been making. The main door frame casting has had its lip added, and also the bosses for the door pivots. Then we have a photo of the door mechanism on this particular fire door. Lets see, there are some levers, some links, pins, pivots, and an air cylinder with a sort of cross head. Some levers and links go over or under, and others jump out of the way when the doors open. It's a pretty cool mechanism. Now, how to make all this little baloney. Here is one of the first parts. Interesting little fellow isn't it. There are two different sized circular cut outs, and then the sides are tapered...

Here is how you might go about making that little rascal. First a length of 1/8" x 1/2" brass was clamped in the mill vise. A 9/32" end mill was centered on the workpiece and run straight in for 9/64". Then the part was cut off, and the other end had the same treatment except a 7/32" end mill was run in 7/64". Then we end up with something like photo #3. The next photo shows some scribbles with the ultra fine Sharpie just as a guide. Then over to the small disc sander. Yikes, that little guy gets real hot, real quick.