Author Topic: building the Frisco Standard Model  (Read 31105 times)

Offline steamer

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Re: building the Frisco Standard Model
« Reply #15 on: January 03, 2019, 01:33:56 AM »
Oh I like this!!! 

Dave
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Offline Art K

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Re: building the Frisco Standard Model
« Reply #16 on: January 03, 2019, 03:13:55 AM »
Craig,
You are coming right along. The first shop I ever worked in had a right angle attachment, I think I saw it in use once. They also had the key way cutting gizmo that went on the back.
Art
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Offline Craig DeShong

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Re: building the Frisco Standard Model
« Reply #17 on: January 03, 2019, 06:52:12 PM »
Dave, Dave, Tim, and Art; thanks for your comments and encouragement.  Again, thanks for those of you silently stopping by.

Got a little done today.  I thought I’d get the main bearings out of the way.  In this photo I’m sizing one of the bearings.



After cutting it off the stock, I’ve turned it around in the lathe and am facing the outside face.



I then drilled a starting hole in all four bearings.  This isn’t the final size; I thought I’d leave that till I have the crankshaft finished.

Even though the drawings don’t call for it; I thought I’d stake the bearings to the block.  Were one of these bearings to “catch” and start spinning in the aluminum casting, I don’t believe the casting would last long. :o

« Last Edit: October 17, 2022, 05:43:52 PM by Craig DeShong »
Craig
The destination motivates us toward excellence, the journey entertains us, and along the way we meet so many interesting people.

Offline Tennessee Whiskey

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Re: building the Frisco Standard Model
« Reply #18 on: January 03, 2019, 07:26:56 PM »
From one of those that is silently watching: really nice work  :ThumbsUp: :ThumbsUp:

Cletus

Offline 10KPete

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Re: building the Frisco Standard Model
« Reply #19 on: January 03, 2019, 07:47:31 PM »
This is an engine design I've admired for a long time. Watching you  build one is going to be great fun!

 :ThumbsUp: :popcorn: :popcorn:

Pete
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Offline Ye-Ole Steam Dude

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Re: building the Frisco Standard Model
« Reply #20 on: January 03, 2019, 08:56:42 PM »
Hello Craig,

Beautiful so far and going along quite well, also good idea on the bearings.

Have a great day,
Thomas
Thomas

Offline maury

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Re: building the Frisco Standard Model
« Reply #21 on: January 03, 2019, 10:55:07 PM »
Craig, Just tuned in. I noticed you have a very nice collection of engines. You are a very accomplished builder. My Hat's off to you.

I have one of these kits under my bench, and have had a false start on it. It's a very early one of the production, and the drawings had a LOT of problems, so I set it aside. Since then, I understand the drawings have been redone with the problems fixed, and I have received some of the updates. I'm in a bit of a backlog now, so the kit will have to wait it's turn, but I'm still very interested in your build. This is a very hansom engine. I saw an original at Portland Indiana several years ago.

I'm not being critical of your work, but I have a few questions. I have noticed from your pictures that some of the mounting holes and bearing cap holes have missed the center of the bosses. It's just I'd like to understand what happened. Is it the drawings, is it a build up of tolerances, or are the castings actually off? If it's just a mistake, I understand, I've made more than my share if these.

I see you are doing a splendid job on the machining, keep posting your progress.

Also, just as a note. I have seen at least one of these engines built using spark plugs instead of the authentic igniters. I urge you not to take that short cut. I have built numerous igniter engines, and find them to be more reliable starters and runners.

Good luck
maury
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Offline Craig DeShong

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Re: building the Frisco Standard Model
« Reply #22 on: January 04, 2019, 07:29:02 PM »
Maury.  Good catch.  I was going to discuss this later, when I addressed the gears but now that you’ve observed the problem, I’ll address it now.  Hopefully this discussion will help someone who follows and who builds this engine.

As I stated earlier, Bob Banke specifically states in his building notes that there are close tolerances that must be observed.  I didn’t fully understand this till I ran afoul of a problem.
As we all know; castings are irregular blobs upon which we impose a specific order.  No two castings are the same so someone else, building this engine, may or may not see difficulties similar to those I encountered.

As I interpreted the drawings, I established the centerline for the crankshaft by halving the distance between the two sides of the casting (x in the following diagram).  I then located the locations for the pedestals (Y).  Lastly, the locations for the base mounting holes (Z) were located.  All this seemed good.

I proceeded to drill the holes as per the drawing specifications.



When I went to position the journal caps on the base, the bottom casting lined up well with the base; the casting on the top did not line up well at all.  Rather than hold to the dimensions on the drawings, I chose to position the upper bearing cap as shown below.



Normally, this might have been ok, but with the tight tolerances required by this model, the location of the two left most threaded stanchions interfered with the position of the helical gears that drive the vertical side shaft.  You can see in this photo below.



The best remedy for this I could discern was to fill the original tapped holes in the base casting with aluminum threaded rods and re-drill the holes, holding to the dimensions given in the drawing.  The result of this is that, though the gears now have the necessary clearance, journal cap is no longer centered on the engine base casting.



As a result of my error, I needed to bore the base and bearing caps for the crankshaft bearings around .040 in. over size to get the bore “true”.  I’ve compensated for this by making the bearing OD oversize also and I believe this isn’t going to cause any residual problems.   Hopefully, I can move forward without any additional error.

Hindsight being 20-20, I’m thinking that my initial measurement layout was flawed.  Were I to do this again, I might proceed as follows:
I would locate the crankshaft centerline by placing the journal caps on the base and drawing a line down through the center of the two as shown by C/L.
I would the spot drill the eight frame mounts by center of boss, regardless of the dimensions on the drawing.  I would use these frame mounts to mount the base to a builders plate and then mill the side plate edges parallel to the C/L at a known distance, and then mill the top and bottom of the builders plate perpendicular to the C/L.
Using the C/L I would locate and drill the four pedestal mount holes (Y) and then the eight Journal cap mounts.  The location for the crankshaft main bearings could then be located and bored as I did above.



This would result (at least for my casting) in the casting for the engine base being a degree (probably no more) askew from the centerline of the crankshaft.  I doubt this would result in a problem.
« Last Edit: October 17, 2022, 05:49:09 PM by Craig DeShong »
Craig
The destination motivates us toward excellence, the journey entertains us, and along the way we meet so many interesting people.

Offline maury

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Re: building the Frisco Standard Model
« Reply #23 on: January 04, 2019, 08:09:28 PM »
Craig, thanks for the analysis. I'd be interested in seeing the corrected build. Might even be worth trying to get another bearing cap casting. I know when I was selling kits, a number of builders wanted an extra part now and then. Was always happy to help them get a successful build.

It may be that a little pattern work is needed to properly address the problem. Are you sure you have the crank bore centered on the features of the base casting?

maury
"The trouble with socialism is that you eventually run out of other people's money."... Margaret Thatcher

Offline Craig DeShong

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Re: building the Frisco Standard Model
« Reply #24 on: January 04, 2019, 10:36:21 PM »
Well, that's the problem Maury, at least with these castings.  I have the crank bore centered on the base casting features and with that, the one bearing cap won't align.  As I describe above, with the crankshaft aligned with the bearing covers, then the other measurements, as given in the drawings, won't come in align without a little fudging.
Craig
The destination motivates us toward excellence, the journey entertains us, and along the way we meet so many interesting people.

Offline b.lindsey

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Re: building the Frisco Standard Model
« Reply #25 on: January 04, 2019, 10:45:58 PM »
That is a shame Craig. Hope your work around will turn out ok. It's a very nice engine. One would hope that castings would be prover better before release, but not always the case I guess.

Bill

Offline Dave Otto

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Re: building the Frisco Standard Model
« Reply #26 on: January 05, 2019, 12:20:51 AM »
Hi Craig

I have some pictures that I took at the GEARS shows of a few of these completed engines, one being the original that Ed Banke (Bob's dad) had built. At least two of them have the same bearing cap that you are having troubles with shifted off the gear boss a little bit. same as what you have done with yours. Curiously on the engine that Ed had made everything lines up really nice.

If you would like to have a copy of these pictures PM me your email address and I will send them to you.

Dave

Offline Craig DeShong

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Re: building the Frisco Standard Model
« Reply #27 on: January 05, 2019, 02:22:05 AM »
I was visiting a friend earlier today; a very competent tool and die maker who spent thirty years in the tool room before he retired.  Now he too, builds engines as a hobby.

His current project is a twin cylinder steam engine.  He was showing me a casting that came with his “kit”.  Looking at it, it was obvious to see that when the part was cast, the cope and drag became somewhat misaligned.  He was discussing the care he was taking to make sure that when he machined the part from this misaligned casting, that all the required surfaces would be met.  Though the top and bottom of the casting were out of alignment he was convinced that the necessary part was still contained within the casting; his job was to bring it out.  At no time did he fault the foundry for giving him an “out of alignment” casting.

Likewise, In my discussion of the base and journal caps on this Frisco Standard I’ve tried very hard not to blame my failure on the drawings or the castings that were delivered.  It is obvious to me that an appropriately machined base and journal caps were contained within the materials provided and that a competent machinist could have successfully executed them. 

I was unable to do so to my satisfaction due to: inexperience? (I’m a computer programmer, not a professional machinist), or just plain not thinking things through enough.  I’m quite sure that were I provided with fresh casting I could execute the task much better.  I was also told that the mark of a “good machinist” is being able to get oneself out of the occasional jamb they find themselves in.   

So, we’ll proceed forward with this build.  When the engine is complete it will be hard to see the error and only you and I will know too look for it.  I won’t spread the news if you won’t. :embarassed:
Craig
The destination motivates us toward excellence, the journey entertains us, and along the way we meet so many interesting people.

Online Jo

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Re: building the Frisco Standard Model
« Reply #28 on: January 05, 2019, 08:25:25 AM »
Though the top and bottom of the casting were out of alignment he was convinced that the necessary part was still contained within the casting; his job was to bring it out.  At no time did he fault the foundry for giving him an “out of alignment” casting.

Likewise, In my discussion of the base and journal caps on this Frisco Standard I’ve tried very hard not to blame my failure on the drawings or the castings that were delivered.  It is obvious to me that an appropriately machined base and journal caps were contained within the materials provided and that a competent machinist could have successfully executed them. 

I totally agree if the part can be taken out of an out of line casting it is worth a punt. Its all part of the additional fun of working with castings - proving to yourself you can  :)

Sometimes other flaws can make a casting unusable  :( I have seen castings delivered from foundries that had holes and deep marks on the bores of cylinders that really shouldn't have been allowed out of the foundry  :ShakeHead:


If you want to see horrors that have been repaired you want to look at the base of my third Triple Orphan 'Lucky'. A bit of a fettle around your casting on the base plate and no one will ever know  ;)

Jo
Enjoyment is more important than achievement.

Offline Roger B

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Re: building the Frisco Standard Model
« Reply #29 on: January 05, 2019, 10:36:34 AM »
Excellent progress  :praise2: I like the right angle attachment and a good save on the bearing cap  :ThumbsUp:  :ThumbsUp:
Best regards

Roger

 

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