Steam powered tonka truck

[scalebowler]

Almost finished machining the frame tonight in class. Still have to take .110" off of the frame to get it to the height of the valve block and then buy a longer end mill and machine everything else to the final thickness (everything else will be .250" thick) Then just drill and tap or ream some holes and then clean out the other piece for the frame, make the front axle and it will be ready to go

[scalebowler]

Made a tremendous amount of progress today and have the frame just about all machined. Still have to drill, tap and ream a few holes for the axles and the bolts that hold the two pieces together and trim down the top (plan to do that after both pieces are made so I can make sure both are exactly the same height) Pretty much the square looking piece on the upper left is the valve block. The piston and cylinder will bolt to that and steam ports will be drilled in that. The part below it will have a small section cut out and the front axle will bolt onto that and will allow you to set the angle and have it drive in a circle. The areas on the right are (top) the area that holds the firebox and (bottom) the area that will later become the transmission where all the belts and pulleys will go.

(machined aluminum is a very hard surface to photograph so some pictures have some bright flash reflections on them but I think you can still see what they are. If not let me know and I can explain what any of them are)



View of the back where the firebox will go (top area) and where the belt drives for the transmission will go (bottom area)



Top view of the part



Really good overview of the part showing the firebox in its location

[Creighton]

Hope all that goes well!! You must be double jointed cause my thumb will never make that angle.
Thanks for the updates!!
Creighton

[scalebowler]

Made some great progress on the steam truck last thursday. This picture shows the final height of the frame with the piston (on the left) and the firebox (on the right) The firebox will sit under the boiler in the bed of the truck and be held in place by two high strength magnets. I got the main frame section milled down to the correct height. Only thing left on this piece is to tap the holes, machine the front axle slot and put a spot for a magnet to hold the firebox in.



And a really bad picture of the truck body sitting on top of the chassis to kind of show how it goes together

[scalebowler]

Frame is almost complete for the steam tonka truck. Just have to mill that one side down to the correct height, get some shorter machine screws, mill out the section for the front axle, and put the decorative pattern on the sides that will both look nice and hide scratches. After doing all this the only thing I will have left to do is make a crankshaft, pulleys, a steam inlet tube, and a rear axle. I would hope to get this thing done within the next 2-4 weeks or at least running. So expect a video of this little thing driving around the floor in a few weeks.

[scalebowler]

Made some good progress since the last time I posted anything. I got the chassis almost 100% machined out. I think it's about 99.99% complete with just a steam inlet, the body mounting bolt holes, and a spot for the magnet that holds the burner in the firebox left to machine. I've spent the last few days designing the last few parts. So far I've designed an adjustable front axle and a rear axle and am now working on the crankshaft/flywheel assembly. After that the only parts I will still need are some drive pulleys and I'm thinking about just buying some premade ones for that then drilling and reaming them to convert them from what ever metric size they are to the 1/4" and 3/16" diameter holes that I need. Hope to get that stuff done tomorrow in class or at least get the steering axle made and the rear axle machined and ready for grinding. I will also have to drill out and possibly ream 3 of the tires and tap the other one. Not to worried about that since it should only take a few minutes on the lathe for that.

Chassis almost finished



Body sitting on top of chassis to roughly show where it all goes



Rear of truck showing boiler, firebox and bed of the truck



Steering axle parts





Rear axle

[scalebowler]

Got that steering block mostly made today. Turned out pretty good I think. Just need to drill and tap a few holes and this half of the steering axle will be done. Next part is just a piece of keystock so it's no big deal. Just clean the ends up, drill and tap some stuff and then it's off to the rear axle and crankshaft.

[scalebowler]

Have not had much free time and have been working on other projects at school so I had this project on hold for quite a while until now. I finally ordered the final parts that I need to finish it and if the arrive before my class I will modify them on thursday and then all I'll have is just some final assembly, some paint and some fine tuning of the engine. Hoping it all runs

[scalebowler]

Well the engine is not running BUT I did have it going a few weeks ago. Only problem is while I was testing it I did not have the screw holding the cylinder to the truck tight enough so it worked its self out which caused the cylinder to shoot off while the piston dropped and then struck a bolt and bent the rod. I now have to order a new piston and cylinder assembly since I really don't want to make a new one and it would be about the same price in materials to make it as it would just to buy it. I did how ever get the pulleys modified and the chassis worked on so that the axles all spin very smoothy and I also decided to play with some  of the things on the EZ-Trak on the milling machine (2 axis CNC system on a few of the mills at school and at my work) and I put a decorative pattern on the outside of the chassis. I told the machine to drill a row of evenly spaced holes and to repeat that row a set number of times. I then took an end mill that was slightly larger than the spacing between the holes (so the circles would overlap) and then just touched the surface of the part in each one of the "holes" I really like how it looks now. I think it looks more professional than it did before.

[scalebowler]

Nearing the final stages of the truck. In this picture I'm doing a test fit of the wheels and pulleys to see how everything looked. Wheels are not attached right now but I do like how it looks. I do need to get a 3 or 4 inch long 1/4 inch diameter dowel pin for the rear axle though since right now the front wheels are sticking out much more than the rear ones and as they won't look right when I put the rest of the truck on. I really like how the pattern I put on the frame distorts the reflection of the wheels and it seems to have made it a little more shiny looking