Chris's Build of Steering Engine

[crueby]

You guys and your puns!   

Great work on the gears though, in spite of the puns! 

Chris, why didn't you just drill a hole for the outer corners on the large gear?  I was wondering that yesterday but forgot to ask.  Then saw that you did that very thing on the worm wheel and it made me wonder all over again!

Thanks,
Kim

On the larger gear the diameter of the outer ends of the spokes is much larger, too big for a drill, other option would have been to use the boring head. The inner diameter on both gears is large too.

[Kim]

You guys and your puns!   

Great work on the gears though, in spite of the puns! 

Chris, why didn't you just drill a hole for the outer corners on the large gear?  I was wondering that yesterday but forgot to ask.  Then saw that you did that very thing on the worm wheel and it made me wonder all over again!

Thanks,
Kim

On the larger gear the diameter of the outer ends of the spokes is much larger, too big for a drill, other option would have been to use the boring head. The inner diameter on both gears is large too.

Ah... makes sense.  I'm picturing them the size of other gears you've made but these are bigger I guess.  What's the radius of the holes you've used in the gears around the spokes?  I guess I'm just having a hard time getting my mind around what size they really are!

Kim

[crueby]

You guys and your puns!   

Great work on the gears though, in spite of the puns! 

Chris, why didn't you just drill a hole for the outer corners on the large gear?  I was wondering that yesterday but forgot to ask.  Then saw that you did that very thing on the worm wheel and it made me wonder all over again!

Thanks,
Kim

On the larger gear the diameter of the outer ends of the spokes is much larger, too big for a drill, other option would have been to use the boring head. The inner diameter on both gears is large too.

Ah... makes sense.  I'm picturing them the size of other gears you've made but these are bigger I guess.  What's the radius of the holes you've used in the gears around the spokes?  I guess I'm just having a hard time getting my mind around what size they really are!

Kim

Yeah most I have made were in the 1 to 3 inch range, this one is over 4 inches. I posted the pdf of the gear drawings back in post 141, that shows the spoke details on pages 6 and 7.

[Kim]

Yeah most I have made were in the 1 to 3 inch range, this one is over 4 inches. I posted the pdf of the gear drawings back in post 141, that shows the spoke details on pages 6 and 7.

Wow, I didn't even notice that attachment!  I had to go back and look at it.

Lots of good info there!  But I didn't see where you gave the diameter of the large gear.  Just the inside radius, not the tip diameter or reference diameter or whatever it's called for a gear.  I'm sure it's there, but I didn't see it.  It did say something about tooth details TBD though. Maybe that was part of the TBD?

Kim

[crueby]

Yes, I hadn't yet worked out which module cutters and how many teeth on each gear when I drew up the CAD model. I'll add that in to the final plans later, think I have mentioned those numbers in the posts along the way. Same sizes overall, just had to add a few teeth to the counts, got within a few thou of the design.

[crueby]

Continuing on again with the gear spokes, ran down the sides of the spokes on the larger gear to remove the pie shaped pieces between them

The pile of pie pieces will be fed to the shop elve's goat...

Then took finish cuts down each side - the first cuts were made back a little from the final dimensions, this way gives a better finish on the surface

Then the final sequences, cuts down both sides of each spoke, on both sides of the gear, to give the finished spokes a '+' shape

Kim - you wanted a better feel for how big this gear is - here it is with all the spokes cut and the extension for the sprocket and clutch bolted on:

So, now on to do the same spoke shaping on the smaller worm wheel:

So far I have the waste pieces in the center of each spoke space removed

As with the previous cuts on this gear, everything has to be done twice, once from each side, since the gear is so thick. Still remaining is to make the cuts to form the '+' shape on each spoke... Good place to break for lunch!

[Kim]

Wow! That's a good sized gear, Chris! 

Lot's of work into crossing out those gears, eh?  You're doing a fabulous job, as always, Chris!   

Kim

[Michael S.]

Hello Chris,
The big gear looks very nice. You did an excellent job with the spokes in the + cross section. Of course, that costs extra time.
I'm just wondering if there are such small >bicycle chains< for the connection to the rudder? Do you already have an idea?
I look forward to further progress.

Michael

[crueby]

Hello Chris,
The big gear looks very nice. You did an excellent job with the spokes in the + cross section. Of course, that costs extra time.
I'm just wondering if there are such small >bicycle chains< for the connection to the rudder? Do you already have an idea?
I look forward to further progress.

Michael

Hi Michael,


I do have some 1/4" pitch bicycle type chain and sprockets that I used on the Mann truck, it is available from a number of sources here, especially the robotics suppliers all carry it. It would be nice to go smaller than that though, plus if I am going to hook up a rudder section the chain needs to turn on two planes, port/starboard around the steering engine, then fore/aft to head back to the rudder. Either that means a 90 degree turned link, or using a normal link chain which can bend in any direction. The 90 degree link would need to be far enough from the steering engine to let the sprocket on the engine make several full turns, which means that there would have to be a lot more height to the model. Using a standard link chain is possible, it just takes a different shape sprocket, which I have made for clocks in the past. Standard link chain is readily available in many sizes too.


Another option is to use cable - on the steering engine that I saw at the show at Mystic Seaport, there was a drum with a spiral slot for the cable to run in. That would work, but the drum takes up a lot more room on the shaft - that engine did not have a clutch to disengage the engine so it had more room for the drum.

So, no hard decision yet, but I need to decide soon.


Chris

[crueby]

Wow! That's a good sized gear, Chris! 

Lot's of work into crossing out those gears, eh?  You're doing a fabulous job, as always, Chris!   

Kim

Thanks Kim!  Quite a few steps, and making sure the alignment from one side to the other means a lot of checking measurements.   

[cnr6400]

 

[Michael S.]

The bicycle chain does not have to change direction. There is a transition to normal link chain.
It is deflected backwards via rollers.

Michael

[Michael S.]

I have a picture of it:

[crueby]

The bicycle chain does not have to change direction. There is a transition to normal link chain.
It is deflected backwards via rollers.

Michael

Good to know!  The roller chain would still have to be long enough for the several rotations of the shaft and sprocket either direction, which means the model would have to be larger. At first I was thinking taller, but if it was wider, the roller chain could go out to the side, transition to the link chain, then around a roller back to the rudder. That could work! Could even make a scale model of the engine room telegraph to put next to the steering engine...

[crueby]

The spokes of the worm wheel were milled to form the '+' shape like the larger one was. Same process, just different dimensions...

Here are the gears so far:

Before I start laying out the vertical walls, I wanted to do one more check of the shaft-to-shaft distances on the large gear and the smaller spur gear. To do that, I dug out one of the gear meshing tools made years ago when making clocks. This tool has two pivots, one fixed, one moveable, so it can be adjusted for different size gears. To handle different hub hole sizes, it is neccessary to make a little bushing to fit over the pivot and inside the hub. Then the gears are set in place and the handwheel turned to bring the gears into mesh. You want an easy movement, but without too much backlash slop. Once that is achieved, the gears are pulled off, and the distance between the pivots can be measured to find the optimum shaft spacing. For clocks, it is common to drill the first pivot hole in the side plate, and use the sharp tips of the pivots on the tool to scribe from there to the location for the other pivot - one of the points is placed in the plate hole, and the other point umoved like a compass scribe.

Here is the tool with the gears pulled off to show the mechanism. The two blocks on the right are fixed and threaded for the threaded rod. The block at the end of the rod to the left moves with the rod - it has a pair of e-clips to hold it on the end of the rod. That block and the second from the right have the black pointed pivots in them. The block farthest to the left is also fixed, handy to do small gears without having to wind the rod all the way back.  I measured the distance between the points, and it is only a few thou under the designed distance, so I'll note that on the plan sheet for when I make the vertical walls.


There are several types of meshing tools that clockmakers use - all do the same job, just different ways to make them. Very simple to make, and great for testing gears before drilling the shaft holes BEFORE finding out the distance is wrong! Just a little off and the gears will either bind up or run too sloppy or miss teeth if too far apart.