Author Topic: Vince's version of the MEM Corliss  (Read 219311 times)

Offline vcutajar

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Re: Vince's version of the MEM Corliss
« Reply #30 on: February 24, 2013, 10:16:31 AM »
Started carving up the recess for the spokes.  Started with a V shaped tool



and with multiple passes went down a depth of about 5mm.  Changed to a left-hand tool



and removed the taper left by the previous tool on the rim side of the flywheel.  Changed to a right-hand tool



and did the same on the hub side.  I estimate that I need to do this operation another two times before finishing off to the correct depth with an HSS tool.

If anybody thinks I am going to run into problems later on with this method please advise.

OK question time.  The flywheel rim is going to be 0.188" thick and 1.5" wide.  Is there enough metal to get a proper "flywheel effect"?  What I mean, is there enough mass at the perimeter of the flywheel?

Vince
« Last Edit: April 14, 2013, 06:09:12 PM by vcutajar »

Offline Ramon

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Re: Vince's version of the MEM Corliss
« Reply #31 on: February 24, 2013, 11:12:52 AM »
Hi Vince, That's a good start. Lots of swarf eh?  ;)

3/16 does seem a bit thin across 1.5 inches - why not step it to create a central ridge somewhat thicker say 5/16 and 3/4 wide. If you introduced a slight taper and used a well radiused tool too it would help give the impression of a casting.

Regards - Ramon

"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Jasonb

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Re: Vince's version of the MEM Corliss
« Reply #32 on: February 24, 2013, 12:35:08 PM »
Yes a 3/16 rim on an 8" flywheel does seem too thin, I'd be looking to at least doubel that to 3/8", 1/2" would be better

Offline vcutajar

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Re: Vince's version of the MEM Corliss
« Reply #33 on: February 25, 2013, 11:27:33 AM »
Well, I do not know what to say.  As I already started the turning process I am basically committed.  I can maybe increase the thickness by maybe a couple of mm.  Today was spent looking on the internet for Corliss flywheel photos.  All the ones I found had relatively thin and wide rims.  I only found one photo which had a thicker rim but it was thinner than the rest.

I will sleep on it and tomorrow I will decide what to do.

Vince

Offline Jo

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Re: Vince's version of the MEM Corliss
« Reply #34 on: February 25, 2013, 11:35:08 AM »
Vince,

The MEM Corliss Engine is based on the  Fraser and Chalmers Horizontal Corliss Engine



As you can see it does have a remarkably thin flywheel for it's size  ;).

Jo
Usus est optimum magister

Offline Jasonb

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Re: Vince's version of the MEM Corliss
« Reply #35 on: February 25, 2013, 11:48:19 AM »
But if you compare the likely bore with the diameter of the flywheel the Frazer has a flywheel about 9-10 times the bore dia but the MEM one is only 6.5 times the dia so really wants more mass in the rim to compensate for the smaller dia.

a flywhel 9 times the MEM bore would have approx 2.5 times the energy as one 6.5 times the bore for the same rim thickness, 3/8 rim would be 1.3 times and 1/2" about the same energy.

J
« Last Edit: February 25, 2013, 12:18:18 PM by Jasonb »

Offline Jo

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Re: Vince's version of the MEM Corliss
« Reply #36 on: February 25, 2013, 12:25:51 PM »
I have just reviewed the original thinking behind the choice of diameter of the MEM Corliss. It was based on the fact that 7 1/4" flywheel castings are commercially available, more than the momentum provided by the wheel and most lathes can handle flywheels of this diameter.

It is not practical to reduce the cylinder size further to make the flywheel look relatively bigger due to the Corliss valve bits getting fiddly  :shrug:. So a thicker rim may be desirable.

Jo

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Offline Jasonb

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Re: Vince's version of the MEM Corliss
« Reply #37 on: February 25, 2013, 12:42:41 PM »
Vince, how far have you got with removing metal, if its not too late can you make the rim section something like this?


Offline Ramon

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Re: Vince's version of the MEM Corliss
« Reply #38 on: February 25, 2013, 01:12:23 PM »
Vince, Jason,
I was actually thinking that the thicker 'rib' left by stepping would be inside the rim not outside. It looks Jason as if your image is conveying it on the outside but that may be my interpretation.

Ramon
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Jasonb

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Re: Vince's version of the MEM Corliss
« Reply #39 on: February 25, 2013, 01:23:05 PM »
No rib on the inside, thats the flat 1.5" x 3/16" bit that is already done on the bottom of the picture.
« Last Edit: February 25, 2013, 01:29:13 PM by Jasonb »

Offline Jo

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Re: Vince's version of the MEM Corliss
« Reply #40 on: February 25, 2013, 01:33:47 PM »
Vince,

If you can do what Jason is suggesting I think you will be on to a winner. You can not only keep the apearance of the wheel being thin but you gain weight  :ThumbsUp:

Jo
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Offline Ramon

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Re: Vince's version of the MEM Corliss
« Reply #41 on: February 25, 2013, 01:59:35 PM »
Jason, what are you using to produce images like that ?
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline Jo

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Re: Vince's version of the MEM Corliss
« Reply #42 on: February 25, 2013, 02:10:39 PM »
Looks like his copy of Alibre  ;).

Jo
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Offline Jasonb

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Re: Vince's version of the MEM Corliss
« Reply #43 on: February 25, 2013, 02:18:15 PM »
Another option if you have gone too far on the first side would be to add a barring gear :) and turn the other side thicker.

Ramon those are just screen snips from pdfs produced by Alibre. I posted those as some people have a problem opening the pdf files as it needs the latest version of Adobe Reader (free to download anyway). I have atached the pdfs below, if you open them and then click on the image it will then allow you to move the image about, zoom, change from solid to outline etc.

I also used Alibre to work out the mass of the flywheel rim for the comparrisons above, just draw a basic rim, tell it what material and it will give you all sorts.

Offline Ramon

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Re: Vince's version of the MEM Corliss
« Reply #44 on: February 25, 2013, 08:56:15 PM »
Thanks Jason, I have been considering trying to update what meagre skills I have with AutoCad 2d -  though I'm not sure I want to layout a deal of cash on it at the moment. However, rather than go off topic on Vinces thread I'll post something about it a bit later.

Apologies for the delay but for some reason have been unable to access this this evening.
 I was able to open the PDFs BTW  ;)

Regards - Ramon
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)