Author Topic: governors  (Read 30820 times)

Online Dan Rowe

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Re: governors
« Reply #15 on: October 17, 2012, 11:50:44 PM »
Jo,
If you use the 32 DP cutters you could add 2 teeth to make 18 teeth then the OD is 5/8".

 :DrinkPint:
Dan
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Offline Captain Jerry

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Re: governors
« Reply #16 on: October 18, 2012, 01:29:53 AM »
Jerry, I fear you are much faster than me at this (or do you get more time?)

Jo

Jo, I am retired so I may get more time.  I am also older and getting older fast so I have to work fast while I am still able to.  I am also not ashamed of working quick and dirty if I can get away with it.  The pedestal is literally only a fifteen minute job.  If you start with aluminum hex bar, you don't even have to set up a dividing head or spindexer for the flutes.  You can then index the blank in the mill vise.  I made a second one a bit faster because I decided I wanted to flare the top.



I appreciate the attention to detail that you bring to your projects.  That is something that I really need to work on.

Jerry



There are thing that you can do and some things you can't do.
Don't worry about it. try it anyway.

Offline jonesie

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Re: governors
« Reply #17 on: October 18, 2012, 03:07:22 PM »
 i like the gear driven gov.just received my copy of gears and gear cutting by ivan law, and with a quick look thru this looks like a real good buy.will be watching .  jonesie

Online Jo

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Re: governors
« Reply #18 on: October 19, 2012, 08:41:37 AM »
I have produced a rough set of drawings :D:





The plan is to knock this up in between continuing work on my Double Tandem Compound over the next week.

Jo
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Online Jo

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Re: governors
« Reply #19 on: October 19, 2012, 03:45:43 PM »
I always start a governor with the spindle. It is one of the simplest parts and everything else hangs off it. At the bottom of the spindle this engine has a nice bronze bearing that I have chosen to make out of this recycled gunmetal sprue. (The smaller one is made from a 1/2" brass noggin from the come in handy box).



The machining of the base for the larger one was conducted on the Prazimat using initially a 3 jaw SC chuck to machine the top and the bore.



And then mounted in a 5C collet for the underside to be machined.



This still needs the three mounting holes drilled but it was getting cooler and hasn't stopped raining all day so I wimped indoors. Before we go we need to scale the drawing for the second engine:



As you can see not everything has been halved, the scale size just would not have the strength needed.


It took a little longer to making this base mounting than the first due to the power of the Cowells. Then came those all important acorns at the top of the spindle:



So I now have two spindles, with base:



And the acorn sticks through to the middle of the entablature, where in good time there will be the top bearing mounted in a strut:


The next job is the sleeves, these are one of those interesting bits I enjoy :LittleDevil:.

Jo
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Offline NickG

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Re: governors
« Reply #20 on: October 19, 2012, 04:20:31 PM »
Hi Jo, are these the Cotswold Heritage castings or is yours a larger scale than that?

Interesting thread this one, thanks.

Nick


Online Jo

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Re: governors
« Reply #21 on: October 19, 2012, 04:35:02 PM »
The smaller engine is based around a set of Cotswold Heritage castings. But I will only be using the bevel gears from the set for the smaller governor. Both are being built around my measurements of our (University of Bath's) original engine :Love:.

The build thread for these engines is here: http://www.modelenginemaker.com/index.php/topic,809.0.html

Jo
« Last Edit: October 19, 2012, 06:00:57 PM by Jo »
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Offline Don1966

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Re: governors
« Reply #22 on: October 19, 2012, 07:43:31 PM »
Jo, I am thoroughly enjoying this thread and learning as you progress. All of this is new to me as I am an electrician/technician by trade, so I am game to all you are presenting here. Thanks for taking the time to show us less skilled machinist.

Don

Offline NickG

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Re: governors
« Reply #23 on: October 19, 2012, 08:02:03 PM »
Thanks Jo, the quality of those castings looks pretty good. I was shocked when I realised the original size ..

Wonderful job on the large scale so far, can't wait until it's picked back up!

Online Jo

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Re: governors
« Reply #24 on: October 20, 2012, 04:52:58 PM »
Today we are making the fixed sleeves for both the 1/6th and 1/12th scale engines. The starting point it to create a constructional drawing, showing the parts from which they are going to be made. On the drawing the black are the measurements for the 1/6th scale engine :D, the red are for the 1/12th scale ;D, you will note that not all the measurements are halved:



Starting with the body, turn to profile:



Bore to suit the spindle diameter:



Now we slit the end to take the arm hanger. You can use a slot drill if you want but I prefer a slitting saw and to take multiple cuts:



Which gives us this:



That?s it for the body, now for the arm hanger. This took a while as I first had to hack some suitable material out of an off cut. Once to overall size these have been coordinate drilled. Note the holes in the top these are smaller than the spindle diameter (the arms are the width of the spindle diameter so this assembly hole must be smaller).



We now need to profile the arms, yes you can use a mill and a rotary table but these were hand filed using my collection of various buttons superglued to the blocks as shown:



Next we check the fit of the arms in the slots:


Now we need to make our assembly piece it is simply a brass sleeve part the diameter to suite the spindle diameter, part the reduced size in the arms:




Now we use the assembly tubes  to keep the two parts aligned whilst we silver solder them together.



You want as little silver solder as possible and flux only where you want silver solder. This is what they looked like after:



Remember if you put too much silver solder on you will only have to remove it later. These are now cleaned up whilst they are still on the parent metal. It gives you something to hold in the vice. Now its is off to the lathe, drill and ream for the spindle diameter.



You should find that the assembly piece will come out with the drill meaning there is little to ream. Once the bore is to size each can be parted off, leaving us with two sleeves.



The second sleeve tomorrow. (I should be working on the DTC :ShakeHead:).

I have been thinking about balls and sadly I have not got the right sized ones so cannot cheat for the larger engine, so it looks like I will have to make them.

Jo
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Offline zeeprogrammer

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Re: governors
« Reply #25 on: October 20, 2012, 05:20:48 PM »
Very nice and highly interesting.

I was glad to see your box of buttons. I haven't seen many buttons, and I'm just starting my collection, so it helped to see what others have.

How did you do the cleaning up of the silver solder. Just filing? A bit of turning? Will you be pickling it?

Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Online Jo

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Re: governors
« Reply #26 on: October 20, 2012, 05:26:18 PM »
I knock up buttons as and when I need them with the smaller diameter designed to fit half way through the target metal to be reduced. They are left unhardened and then thrown when they get too damaged.

They were pickled in sulphuric acid but that only takes off the flux residue. The cleaning up was done with needle files.

Jo
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Offline smfr

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Re: governors
« Reply #27 on: October 20, 2012, 07:09:43 PM »
 :pinkelephant: Very excited to see some build progress here. This small stuff is so neat to see being made.

Simon

Online Jo

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Re: governors
« Reply #28 on: October 21, 2012, 04:20:47 PM »
The sliding sleeve is very much like the fixed sleeve except that we need an additional collar to fit under the arm section:



This is the set of parts made:



You will notice I chose to part the larger one from the parent metal. I did this thinking I was going to mount it in the dividing head but as it was I mounted it in the vice to do the slitting. These are the parts silver soldered together:



I then used some soft solder to help hide some of the gaps. Having cleaned them up here is our second sleeves:



They might need a bit more cleaning up :disappointed:

Jo
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Offline Don1966

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Re: governors
« Reply #29 on: October 21, 2012, 04:34:43 PM »
Awesome Jo, I like the way all the small parts end up fitting together. This gives me more insite on how to go about things. I never really realized that making parts had so many options. This is a great thread keep up to great work.

Don