dorkpunch engines #3: Boring the cylinder.

I had some time to kill at the shop while waiting for my wife. She said she would be over in half an hour, which of course means 2 hours. She even ran a little late so it was more like 2 and half so I was able to knock some holes in some aluminum.

1/8" pilot holes, 3" deep through the cylinder. The two for the valves are the finished diameter for the valve guides. The cylinder has a long ways to go... 7/8" more to be exact.



To drill them I had to use a big 'ole aircraft drill. Started with a normal drill bit, got as deep as it could go, then switched to this long one. Figured there was less chance of the holes going crooked on me.



Makin' chips.





Makin' BIG chips...



and big messes.



"Finished" cylinder. The drill bit is obviously a bit rough, so I plan to hone it with a brake master hone and then match the piston to the finished bore.



Because of the vice I was using, I couldn't drill all the way through. This is not a problem though, because I still need to machine off about 1/4" to get it down to the stroke I want.



Bottom.



Will hopefully start doing some figuring on where the valve ports need to go and the final diameter of the valve heads.

Thinking I should have left the bore a tad smaller- its pretty close to some of head bolt holes. Won't have a lot of gasket area in those two spots.

Live and learn...

dorkpunch engines #2- Cylinder and Head.

Back to our home built hit and miss engine model.  Here's what we're starting with:




Ordered all of these on ebay.  Need to check and see what the alloy is, but whatever it is its darn soft and machine very easily.

Makin' chips.



This is a shakedown run- testing how much I've forgotten since college and seeing how sucky this lathe really is. Turns out I don't remember much...   It also turns out that my lathe needed some tweaking but I didn't figure that out until later.  *sigh*

Machined it down, lazily marked a few spots and drilled some holes.



Countersunk.



Parting off the head. Took FOREVER. Need to align the tool- sits too low.



Head and cylinder.


Tapped the holes.



Teensy plug I'll be using:



Fits together quite nicely!





Plan is to use some soft copper sheet I have as a gasket. Now the hard part begins- figuring out how to get the piston and valves in there.

So far this is LOTSA fun- many things are starting to come back to me.  Really enjoying being able to make chips fly, but I've got a loonnngggg ways to go before its up to par.

dorkpunch Engines #1. (re) Learning how to machine.

So I stumbled across this video a while ago.



I've been wanting to try my hand at making some type of miniature model engine for a long time now. I have seen dozens of these cool videos- in fact, here are two more.






I've built a couple of really simple air engines, and even use the one as a project for my Grade 8 students to build.  Here was my first attempt ever at building an engine. This was my test bed for the above engine- basically copied but simplified from one I found on Instructables.





I adapted that one to this one- VERY simple to make and pretty easy to get running decently. ZERO machining- all done on a drill press or with hand tools. Little bit of welding but it could be done without it if you had different chunks of metal.

From this:



To this:







Back to the topic at hand.  I've got my own idea I've been kicking around for a while- flathead with an atmospheric intake valve, 1" bore and I'm thinking either 1.25 or 1.5" stroke. Not sure how I'm going to do the governor but I've got a few ideas. No idea how well it will work, if it ever even DOES. I don't have a real great track record at finishing projects...

Been working on dumping the ideas swirling around in my head out onto paper and the computer.

Here's the general idea.









Currently thinking flathead, with atmospheric intake valve. Main design constraints are the limiting factors of the tools I have, so the goal is to make it as simple as possible and entirely built on the tools I have access to- a Smith 1250xl (?) lathe / mill combo. Been playing around a bit and have made some shavings, will get more pics posted. 

Dan's Chariot #7 - Modifications.

Started on some of the modifications. Took it all apart, took some measurements, and hacked the tongue off:



Took a big chunk out of the middle and tightened up the bend.



I will have to straighten the back end of it just a bit, but the theory is the tongue will plug into the trailer "stinger" style, but 90 degrees to the direction of travel, sorta like this:



Although it will be much shorter and have several gussets. Couldn't find a really tight fit for the square, so the tongue will have a gusset / spacer plate on the top and front where it plugs into the trailer to get a good fit. Holes drilled / pins installed so the tongue can be unplugged and eventually a castor wheel of some sort plugged in so they can use it as a stroller. We'll see where it goes from here!

FINALLY got my wife to stay home from school long enough that I could dedicate some time on this project. Crazy first year teachers... She gets home after 8:00 on average.

Cut the receiver down, drilled some holes, and cut some gussets out.



Start welding!



Tongue installed.



Made it a BUNCH shorter. Hope the curve is big enough to clear the tire!



Set it across two tables, and bounced my wussy 175 lbs up and down pretty good at the joint- it flexes a teensy through the tongue, but the receiver and back half of the trailer is RIGID.



While I was doing some welding, I cut the plastic sheet out and got it warming up to do some bending.







In between all of that, I made a few more brackets.







Whew. Makin progress. 

Boxed in the back of the tongue for some extra strength(?).



Stuck it back together...



The frame as it sits so far.



And with the seat and leg pan kinda sitting in place.



Plan on making some aluminum sides for the leg pan to match the fenders.

Left to do... Hmm. Finish the fenders, make some extensions out the back for them, sides for the leg pan, bolt it on, thread the new axle, get all the misc nuts and bolts I need for the seat belts, TEST IT OUT! and then paint. I think. Probably missing 3 or 4 steps still.

Well, now you're all caught up.  RREEALLLY need to get this thing done.  Lego League is going already, so that eats into a big chunk of my time and it seems like all the "extras" I get to participate in this year just because I'm a teacher are adding up quick.  It WILL be done.  Shall I make a goal? 

End of October.  Or else.

Dans's Chariot #4- Axle.

Took me long enough, but I finally got a belt for the lathe so I could run it in the higher RPM range and got the axle turned down. I'm using a Smithy CB1220-XL.  It's pretty beat- lotsa chatter but it works okay.  It's got a weird belt setup for changing the spindle speed- 2 short belts with an idler in the middle for the lower RPM's, or one long belt and remove the idler for higher RPM.  Long belt has been looong gone since before I started teaching here but I managed to find one that fits.  Took forever to get the idler loose enough that it came off the shaft too.  Got it all figured out and we're in business.

The axle started out as "sucker rod"... Not exactly sure what that is but I'm guessing it has something to do with well drilling.



After I hacked off the end and the goofy plastic piece, time to start spinning.




Haven't quite figured out how to change the crossfeed speed... It looks like there are a few gears that interchange but the other gears are missing.  With the spindle spinning about the correct RPM, the cross feed would fly down the metal.  Got a little warm, as you may be able to tell by the chips.



Finally got both sides turned down enough!





Looking good, although I think I may have to unbend a few of the curves to make the tongue higher of the ground. Right now, by my estimates the lowest point is 3-4 inches off the ground.



Picked up some castleated nuts, bushings, and washers so next week it should be a little more permanent.  Need to brush up on my welding and get the joints finished off too, then I can cut out the hitch end, make the seat brackets and mount the seat, and do some testing.  Long ways to go still and not enough time to do it!