Author Topic: building the Frisco Standard Model  (Read 13832 times)

Offline crueby

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Re: building the Frisco Standard Model
« Reply #120 on: February 15, 2019, 01:52:20 AM »
Dave.  Holding the casting wasn't a problem.  The casting was solid (before boring it for the crankshaft journal).  My problem was that the casting kept closing down on the slitting saw, seizing it, and jamming it in the cut slot.  I was using a very slow speed, around 150 RPM.  I guess heat was the culprit but I thought I was going slow enough and was using Plenty of cutting oil.

It was a block of brass around one half inch by one inch cross section.

Ahh   got to wonder if its under stress.   Perhaps a cycle to red heat under the torch before you start might get the stress out.
With brass bar stock, an hour at 500f in the oven will stress relieve it without taking away the hardness like taking it to red heat will. Don't know if the same is true of a brass casting, seems like it would be.

Online Jasonb

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Re: building the Frisco Standard Model
« Reply #121 on: February 15, 2019, 07:04:58 AM »
Good outcome, suppose he could just write the revision onto the printed drawing before sending them out or add it to any build notes, don't need access to the original for that.

Online Jo

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Re: building the Frisco Standard Model
« Reply #122 on: February 15, 2019, 08:37:11 AM »
And then there were two!!   :whoohoo:



If you remember with the last update, I had uncovered an error in the drawings and was trying to determine what to do about it.  I finally decided that another casting was the only solution so I contacted Bob Banke. 
.....
Bob wouldn’t really confirm that the drawings were in error, but stated that he wanted the people that bought his models to have a good experience and if I needed another casting, he would send me one; free of charge.


Good outcome it is always nice to buy castings from reputable suppliers  :ThumbsUp:

I think you need to buy that other set of desirable castings from him so that you have adequate casting fondling time  :mischief:

Jo
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Offline Craig DeShong

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Re: building the Frisco Standard Model
« Reply #123 on: February 19, 2019, 12:15:08 AM »
Dave, Dave, Brian, Chris, Jason, Jo; thanks for your advice and comments. 

Finished up the lathe work on one of the connecting rods


but held off with the other.  I really wanted to get back to where I was with this cylinder casing and after a few days work, here’s the result.


Everyone’s been so nice, but many of you MUST be thinking it: so I’ll say it.  “You’d think that when the guy started boring the cylinders, and the bores were SO FAR OFF CENTER IN THE CASTING AND WERE SO FAR OUT OF ALIGNMENT WITH THE CORES, he would have checked the dimension????”  Yep, you’d think wouldn’t ya; well live and learn; won’t make that mistake again.
So as you can see, using the correct dimension, the cylinder bores center nicely in the casting.  Now I can finish the cylinder liners, one of which has been waiting patiently in the lathe, partially finished, since the beginning of this cylinder dimension fiasco.
Craig

Offline Art K

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Re: building the Frisco Standard Model
« Reply #124 on: February 19, 2019, 12:28:45 AM »
Craig,
Good to see the new cylinder turn out so well. Enough beating up on your self, by the time I see the photo it's to late anyways
Art
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Online steamer

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Re: building the Frisco Standard Model
« Reply #125 on: February 19, 2019, 12:38:29 AM »
Dave, Dave, Brian, Chris, Jason, Jo; thanks for your advice and comments. 


Everyone’s been so nice, but many of you MUST be thinking it: so I’ll say it.  “You’d think that when the guy started boring the cylinders, and the bores were SO FAR OFF CENTER IN THE CASTING AND WERE SO FAR OUT OF ALIGNMENT WITH THE CORES, he would have checked the dimension????”  Yep, you’d think wouldn’t ya; well live and learn; won’t make that mistake again.
So as you can see, using the correct dimension, the cylinder bores center nicely in the casting.  Now I can finish the cylinder liners, one of which has been waiting patiently in the lathe, partially finished, since the beginning of this cylinder dimension fiasco.


 :lolb:   Hey Craig....don't think you're the only one who's ever done it!....WE'VE ALL DONE IT....if you never make a mistake...you probably haven't done anything!...

Want to see my collection of con rods for the Wallaby?    I'm looking for a fixture I can turn them into..... 8)

Carry on son Carry on!!!!   :popcorn:
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Offline Craig DeShong

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Re: building the Frisco Standard Model
« Reply #126 on: February 20, 2019, 09:49:30 PM »
Dave: not beating myself up over this, just very disappointed I didn’t catch an error that I probably should have.

Moving on.

Yesterday I finished up the first cylinder liner and installed it.  Here I'm about to part it of the base sock.


Today I did likewise with the second.  I used a .001 inch interference fit and the liners pressed into place a bit harder than I thought they would; still they fit the cylinder bores nicely.  When I blow into the water inlet and close of the two water outlets I don’t feel any leaks.

Craig

Online steamer

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Re: building the Frisco Standard Model
« Reply #127 on: February 20, 2019, 11:27:24 PM »
Dave: not beating myself up over this, just very disappointed I didn’t catch an error that I probably should have.

Moving on.



Welcome to the club!

Looking good man!
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Damned ijjit!

Offline b.lindsey

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Re: building the Frisco Standard Model
« Reply #128 on: February 21, 2019, 12:18:12 AM »
Looking great now Craig.  Just a little hitch, but good to hear the casting issue was resolved with such good service. Onward and upward now.

Bill

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Re: building the Frisco Standard Model
« Reply #129 on: February 21, 2019, 12:27:46 AM »
Looking great now Craig.  Just a little hitch, but good to hear the casting issue was resolved with such good service. Onward and upward now.

Bill

That is a sweet looking engine!

Dave
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Damned ijjit!

Offline 10KPete

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Re: building the Frisco Standard Model
« Reply #130 on: February 21, 2019, 02:17:48 AM »
Oh, that's lookin' sweet! I like the liners and I'm curious how thick the walls are? The look thin....

 :ThumbsUp: :ThumbsUp:

 :popcorn: :popcorn:

Pete 
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Offline Craig DeShong

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Re: building the Frisco Standard Model
« Reply #131 on: February 21, 2019, 02:36:35 AM »
Pete
You can see the liner has a shoulder at the top to prevent the liner from working down the cylinder bore.  The shoulder is 7/8th inch long.  With the casting overbored in the center to form the water jacket, the liner is in contact with the casting for only around one inch on top and around another inch at the bottom.

The liner is 4.155 inch in length and the wall thickness at the bottom is 1/16th inch, at the top, a bit more.
« Last Edit: February 21, 2019, 02:46:08 AM by Craig DeShong »
Craig

Offline 10KPete

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Re: building the Frisco Standard Model
« Reply #132 on: February 21, 2019, 04:07:00 AM »
Thanks, Craig! I would never have thought a cast iron liner could be that thin. Especially direct cooled.
Learn somethin' every day!

Cheers!

Pete
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Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline Roger B

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Re: building the Frisco Standard Model
« Reply #133 on: February 21, 2019, 11:14:51 AM »
Good progress Craig  :ThumbsUp:  :ThumbsUp:  :wine1:

Pete, the liners on my 20mm bore twin are 1.5mm thick and will have direct cooling.
Best regards

Roger

Offline Craig DeShong

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Re: building the Frisco Standard Model
« Reply #134 on: February 21, 2019, 02:20:56 PM »
I’m looking at the drawings for the pistons and, really, I need your opinion.  Here is a segment of the drawing:



The supplied material is a cast iron round.  The drawing specifies that you bore out the top of the piston (I assume to reduce the weight), then silver solder in a round disk to seal the top surface.  The builders’ notes specify that after this is done, you are to turn the piston to size and form the ring groves.

To me, this seems a bit convoluted when you could just make the piston directly out of aluminum (with a solid top) and still end up with a lighter piston.  Since the crankshaft has no counter weights, I would think a lighter, aluminum piston might be preferred.  I’ve made lots of aluminum pistons for IC engines and had no trouble with them.

Your thoughts ?  :help:
Craig