Author Topic: Monitor Build  (Read 7791 times)

Offline flopearedmule

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Re: Monitor Build
« Reply #45 on: February 12, 2019, 02:17:01 AM »
I didn't get much time this weekend, but a little is better than none.
the bronze rod end is done, and I got the cylinders started.
The Stainless tube I bought from McMaster Carr is really good!  I think the only thing I will do is hone the inside with a brake hone and I think it will be good. :cartwheel:

Offline flopearedmule

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Re: Monitor Build
« Reply #46 on: February 12, 2019, 02:22:23 AM »
Any of you guys that have built this engine, what is the dimension of the center slot for the exhaust port?  I'm thinking maybe .188" ??

Offline flopearedmule

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Re: Monitor Build
« Reply #47 on: February 12, 2019, 02:35:30 AM »
I'm wondering if you guys would help me out with the D valve dimensions?  I would like to make sure the math is good before I start cutting. 

I have all the parts here to make the valve operate, any help would be much appreciated.

Online crueby

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Re: Monitor Build
« Reply #48 on: February 12, 2019, 02:42:20 AM »
The center port would be twice the width of the side ports, 0.188", which gibes with the slider opening of .375", so the opening would just span the center port and one side port.

Offline vcutajar

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Re: Monitor Build
« Reply #49 on: February 12, 2019, 11:07:54 AM »
That centre port dimension is also missing in the metric plans but according to a list of corrections it is showing as 4.5mm.

Vince

Offline flopearedmule

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Re: Monitor Build
« Reply #50 on: February 12, 2019, 06:24:22 PM »
The center port would be twice the width of the side ports, 0.188", which gibes with the slider opening of .375", so the opening would just span the center port and one side port.
Crueby,
Thanks for your response.
Here is what I get when I draw it on my CAD
I have a .313 stroke with the valve moving back and forth.  The green lines are the valve nut and the red is the ports.
With the .313 stroke, I have .0165 from edge of valve nut to edge of hole on the port.  I don't know about how they used to design these valves, and it seems like this would work.   
I have it drawn with .094 outer ports and middle exhaust port is .188............and space between the middle exhaust port to outer ports it is .094

Thanks again for your help.  Maybe there is a book that would help me to know more about these numbers and design??
« Last Edit: February 12, 2019, 09:43:25 PM by flopearedmule »

Online crueby

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Re: Monitor Build
« Reply #51 on: February 12, 2019, 07:35:10 PM »
That looks like it should work fine - there are a lot of old d-valve design books out there, most on full size engines but some on the model versions, where the subtle points of the design can be a little different (the full size ones were trying to squeeze all the efficiency out they could, we just want our models to run evenly). Attached is a pdf file I got a while back, dont recall exactly where, that gives a good basic design that can be adapted to most models, I've used it a number of times. There is also a word doc, not sure if that one will come through right, that has some additional info from another source.
Hope these help!
Chris



Offline flopearedmule

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Re: Monitor Build
« Reply #52 on: February 12, 2019, 11:19:51 PM »
Thanks Chris
I just didn't want to do the same thing as the overcrank engine.  the valve was drawn 90 degrees wrong on the prints, and had to make it over.  Time is too valuable LOL  my job gets in the way.
thanks for the reading on the valves.

Offline flopearedmule

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Re: Monitor Build
« Reply #53 on: February 26, 2019, 02:18:58 AM »
back to work on the Monitor this weekend.
glue in the sleeves and milled a flat

Offline flopearedmule

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Re: Monitor Build
« Reply #54 on: February 26, 2019, 02:26:35 AM »
made a brass bearing surface and used green lock-tite to glue it in.

Offline flopearedmule

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Re: Monitor Build
« Reply #55 on: February 26, 2019, 02:32:35 AM »
After my real job today, I went to the shop for a bit.  Milled down the brass plate and put the steam ports in.

The first one went great!  It turned out good.

The second one I put in,  forgot to dial in the X axis.  As you can see, I went down .020" before I realized it.... :cussing: :cussing: :cussing:
I will probably have to mill the pocket again, make another plate....start over, unless I can figure out how to save it.


Offline Kim

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Re: Monitor Build
« Reply #56 on: February 26, 2019, 05:35:03 AM »
Ouch... that hurts :(   Sorry about the extra divot there.  That's never fun.  But it looks super besides that!

So, what's the deal with the brass bearing surface?  I've not seen that before.  It's new to me.  Wouldn't it be similar to just use a brass D-valve sliding on the steel cylinder?  I'd like to understand the reasoning for doing it this way.  It looks like some extra work.  Though it does look really cool! :)

Kim

Offline vcutajar

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Re: Monitor Build
« Reply #57 on: February 26, 2019, 11:58:45 AM »
How about filling it in with JBWeld?

Vince

Offline flopearedmule

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Re: Monitor Build
« Reply #58 on: February 26, 2019, 12:23:08 PM »
Ouch... that hurts :(   Sorry about the extra divot there.  That's never fun.  But it looks super besides that!

So, what's the deal with the brass bearing surface?  I've not seen that before.  It's new to me.  Wouldn't it be similar to just use a brass D-valve sliding on the steel cylinder?  I'd like to understand the reasoning for doing it this way.  It looks like some extra work.  Though it does look really cool! :)

Kim


Kim,  The cylinder is Aluminum, not steel.
I had Aluminum on hand, and Aluminum is lighter and cheaper than brass.  I don't think Aluminum would have worked good for a bearing surface, so I inlay brass for the bearing surface. 

Mostly, I used aluminum because of weight.  I am building this scaled up 25%  and brass or steel is heavier. It did turn out looking pretty cool though. Thank You
« Last Edit: February 26, 2019, 12:32:01 PM by flopearedmule »

Offline flopearedmule

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Re: Monitor Build
« Reply #59 on: February 26, 2019, 12:28:16 PM »
How about filling it in with JBWeld?

Vince

I thought about that Vince, and I thought about heating the Loctite up to 500 degrees and releasing the brass, then braze in a filler and re-Loctite.  But I think that would be just as much work as milling this piece of brass out and start over.  I left it set up in the mill to think about it. 
I got in a hurry, it was getting late and the wife and kids were yelling at me to hurry in for supper.

« Last Edit: February 26, 2019, 12:34:55 PM by flopearedmule »