Chris's New Steering Engine

[Kim]

The crankshaft is coming along nicely. Love the taper locks!   

So, I thought you were out to an RC Sub meet today (or yesterday?)  What happened to that?  Did it get rained out?  Inquiring minds need to know! 

Kim

[crueby]

The crankshaft is coming along nicely. Love the taper locks!   

So, I thought you were out to an RC Sub meet today (or yesterday?)  What happened to that?  Did it get rained out?  Inquiring minds need to know! 

Kim

The monthly sub run was today, but the weather was pretty bad - windy, cold, and rained most of the morning. We didn't do much actual sub running, mostly stood around and talked (which is fun too). The big event at the reflecting pool is in August, down near Indianapolis, this was just our monthly fun run at the local pond. Hoping the weather for the run next month is better!

[crueby]

[crueby]

This mornings playtime made up the eccentrics for the crankshaft out of some bearing bronze. Centered up the bar, and turned in the grooves for the straps to ride in. Then offset the bar, drilled a starter shaft hole which was used for the tailstock live center, and turned the bosses. All was done with the parting tool.

Then bored out the shaft hole to final size

And parted off the two eccentrics. That left a stub on the bar which was turned to the same dial setting at the same time as the two eccentric grooves. I'll use this as a go-no-go gauge when boring out the straps. In the picture you can see the turning tool - that was just used to trim back the parted-off extra material from the second eccentric.

Then the eccentric bosses were drilled/tapped for set screws, and the parts assembled onto the crankshaft. Positions are approximate at this point.

Then cut/drilled/turned the ends on a section of Acme threaded rod, 1/2"-8 pitch, which will go in the center of the crankshaft to drive the worm wheel above it, which will turn the control valve assembly when the engine is running.

I think the next parts will be the bearing blocks and bearings to hold the crankshaft. This is all progressing faster than I thought it would!   

[cnr6400]

 

[Kim]

Wonderful eccentrics!  And that Acme threaded rod of yours sure sees a lot of action!  That's a great way to make those worm gears. 

Kim

[crueby]

Thanks Kim/CNR!

Kim, I've accumulated several diameters and pitches of the Acme threaded rod, with matching Acme taps, from 1/4" to 5/8" OD. As you say, a great way to make custom worm gear sets by hobbing with the taps.

 

[crueby]

Today started in on the bearing support blocks. There are four of them, two surrounding the worm gear and two out by the crank disks. Cut down some 1-1/4" x 1/2" flat bar, and angled the ends:

Here they are all angled and to length, with the recess pattern sketched on. The final blocks will be 1.1" tall, so the top face will be milled down too.

Got a start on recessing the sides. One panel down, 15 to go! This will take a few sessions...

[cnr6400]

 

[ShopShoe]

This is going to be an amazing project. I am following.

It blows my mind to have YOU say that something is moving more quickly than expected.

I am glad that you are sharing the engineering side of this project, along with your top-quality modeling skills and your documenting of the same.

ShopShoe

UH-OH: In photo two of your last post it looks like the elves are trying to practice echoing  M.C. Escher.

[crueby]

This is going to be an amazing project. I am following.

It blows my mind to have YOU say that something is moving more quickly than expected.

I am glad that you are sharing the engineering side of this project, along with your top-quality modeling skills and your documenting of the same.

ShopShoe

UH-OH: In photo two of your last post it looks like the elves are trying to practice echoing  M.C. Escher.

Thanks!  And the elves have looked up Escher and started planning...

 

[crueby]

Another couple sessions and the bearing block bases have all the recesses done, and the top/bottom faces taken to dimension:

Next will start in on the caps...

[PaulR]

Fantastic!

[Kim]

Looking good, Chris! 

Kim

[bent]

Those taper locks are awesome, what a neat execution for the size as well. 

I'm watching this with anticipation - we briefly studied steam driven (later electric driven?) steering (and gun turret) motor servomechanisms as part of controls theory in engineering skool.  The origins of modern controls theory were actually employed by the British to improve the speed and pointing accuracy of turreted naval gun batteries, which were done by manual labor.   

I do need to look into the local RC clubs.  My neighbor does RC gliders, which sound neat, but I'd like to do some of the traction machines and maybe a sub too - a club up north of me a ways has room for all 3 pursuits, something I'll look into once I'm fully retired.