Author Topic: Chris's Build of Steering Engine  (Read 52194 times)

Online crueby

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Re: Chris's Build of Steering Engine
« Reply #105 on: September 26, 2022, 09:14:01 PM »
Difficult to take the pictures - oh Yes - but still - the Pre-Cut Gear looks nothing short of Amazing  :praise2:
It is harder to get a good idea about the finished item, with all it's facets - but you are Happy and that is what matters most (I most likely would be too)  :cartwheel: :cheers:

Per
Its a subtle difference, same general shape but the hobbing adds the trapezoid outline of the acme teeth to the curves of the involute precut, especially widening the bottom of the valleys. The precut one wouldn't mesh more than about halfway, after hobbing its full depth, so function is a big change.


 :cheers:

Offline Kim

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Re: Chris's Build of Steering Engine
« Reply #106 on: September 26, 2022, 09:55:13 PM »
That's some mighty fine hobbing there, Chris!  :ThumbsUp: :popcorn:

Kim

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Re: Chris's Build of Steering Engine
« Reply #107 on: September 26, 2022, 10:13:07 PM »
That's some mighty fine hobbing there, Chris!  :ThumbsUp: :popcorn:

Kim
Thanks Kim,  I'd seen it done by others for years, this is the first time I've dared try it. Really works well, not hard to do. If I'd been able to find a tap to match the rod it would have been even easier.

Offline Elam Works

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Re: Chris's Build of Steering Engine
« Reply #108 on: September 26, 2022, 10:23:20 PM »
With the worm diameter about the same as the worm wheel width, you tend to have a high helix angle on the worm. This hobs away a lot of the tooth shape at the edges of the worm wheel and they take on a triangular shape. Hence in full scale they tend to use a worm diameter 1.5x of the worm wheel width or more. Then the edges of the worm teeth look more like involute teeth.

-Doug

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Re: Chris's Build of Steering Engine
« Reply #109 on: September 26, 2022, 10:40:16 PM »
With the worm diameter about the same as the worm wheel width, you tend to have a high helix angle on the worm. This hobs away a lot of the tooth shape at the edges of the worm wheel and they take on a triangular shape. Hence in full scale they tend to use a worm diameter 1.5x of the worm wheel width or more. Then the edges of the worm teeth look more like involute teeth.

-Doug
Hi Doug,
The next steps are to put the wheel on the lathe and turn a taper on the outside corners, effectively narrowing the wheel but leaving it wide for the spokes and the hub. This picture shows what it will look like (just a lot smaller than the picture!)  I've seen ones like you describe, with the teeth being almost a full semicircle. I know that the Acme thread I am using does not accurately match the original, but its pretty close.
 :cheers:



Online crueby

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Re: Chris's Build of Steering Engine
« Reply #110 on: September 27, 2022, 03:49:39 PM »
As mentioned yesterday, the sides of the gear were turned on a taper in to the teeth

Then taken up to the arbor press to broach the key slot for the hub

Cut through nice and clean

Here is the worm gear/wheel ready to start cutting spokes. But, since the other large spur gear gets a similar set of spokes, and things are set up for gear cutting, I'm going to cut the other two spur gears and then start in on the spokes.



Online Vixen

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Re: Chris's Build of Steering Engine
« Reply #111 on: September 27, 2022, 04:03:31 PM »
Hello Chris,

Have you measured  the between centers distance; Worm to Wheel?

Mike
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Online crueby

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Re: Chris's Build of Steering Engine
« Reply #112 on: September 27, 2022, 04:17:57 PM »
Hello Chris,

Have you measured  the between centers distance; Worm to Wheel?

Mike
Definitely, thats the distance I used to lay out the wheel, and measured it as I was cutting it. If I couldn't hit that number, the height of the bearing blocks could have been adjusted.

Online Vixen

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Re: Chris's Build of Steering Engine
« Reply #113 on: September 27, 2022, 04:48:10 PM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp:
It is the journey that matters, not the destination

Sometimes, it can be a long and winding road

Offline Kim

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Re: Chris's Build of Steering Engine
« Reply #114 on: September 27, 2022, 05:02:01 PM »
Boy, tapering the sides of the worm gear changes the look and tooth profile dramatically, doesn't it?  :popcorn:

Kim

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Re: Chris's Build of Steering Engine
« Reply #115 on: September 27, 2022, 05:56:28 PM »
Boy, tapering the sides of the worm gear changes the look and tooth profile dramatically, doesn't it?  :popcorn:

Kim
Sure does, got rid of the chunky look. Getting the spoke cut will change it a lot too.


I've been getting the blank for the other bigger gear ready, this one is a normal straight tooth gear, just larger diameter.

Offline Don1966

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Re: Chris's Build of Steering Engine
« Reply #116 on: September 27, 2022, 06:03:48 PM »
You make cutting gears look easy Chris. Good inspiration for those who buy their own instead of making them. For those who want to cut their own I have the spread sheet for making cutters and the different gears just PM me. I can’t post spreafsheets in plans a drawings the file is too big. By the way Chris can you take a photo of that arbor press I see a hand wheel on it.  Just interested in seeing it.

 :cheers:
Don

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Re: Chris's Build of Steering Engine
« Reply #117 on: September 27, 2022, 06:23:27 PM »
You make cutting gears look easy Chris. Good inspiration for those who buy their own instead of making them. For those who want to cut their own I have the spread sheet for making cutters and the different gears just PM me. I can’t post spreafsheets in plans a drawings the file is too big. By the way Chris can you take a photo of that arbor press I see a hand wheel on it.  Just interested in seeing it.

 :cheers:
Don
Sure thing Don. Here are a few pics of it. I got it a year or two ago, works well, not a huge one but enough for the broaching work.

closeup of the label

and the other side, it has the handwheel on the left and a lever on the right - I use the lever mostly for the heavy pressure.



Online crueby

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Re: Chris's Build of Steering Engine
« Reply #118 on: September 27, 2022, 06:28:34 PM »
Here is the start of the second gear blank. Its over 4" across, so it is being cut from a piece of stress relieved flat bar stock left over from the Ward pump engine model. Started by drilling/reaming the center hole with it clamped to the mill table on top of a piece of wood.

To save as much usable metal from the piece, I milled it out to a circle rather than using a saw - those outer areas will get used for something I'm sure.

After several rounds with the small end mill, the center was freed. I'll set that up on the lathe with the riser blocks to turn it to final OD. With the larger diameter, I am using the 4-jaw chuck to hold the blank - it both holds the arbor more securely, plus it has the slot around the edge to clamp it to the rotary table since the larger part gets more turning force on it, and the chuck could unscrew itself otherwise.



Offline Michael S.

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Re: Chris's Build of Steering Engine
« Reply #119 on: September 27, 2022, 06:45:35 PM »
I think you did the worm gear perfectly. It was a nice demonstration of how to make it. For a one-off production, it's totally okay. I like it very much.

Michael

 

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