Author Topic: Freelance mill engine from Stuart castings.  (Read 32767 times)

Online crueby

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Re: Freelance mill engine from Stuart castings.
« Reply #30 on: November 29, 2017, 03:48:42 PM »
The proportions are looking fine on the engine. Also, the Meccanno parts look well used, now we know where you got your engineering talent as a kid!

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #31 on: November 30, 2017, 02:38:48 PM »
Hi Chriss, actually because i was poor i had a set called  Trix and every time a rattle went up the hoover pipe i got a clip round the ear because that was another wasted nut !!
« Last Edit: November 30, 2017, 02:43:19 PM by steam guy willy »

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #32 on: December 01, 2017, 02:01:41 AM »
The slides have been milled and drilled and are in place with some "Spares" just in case...I am modelling these parts on full-size practice so they are quite intricate here and there.

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #33 on: December 02, 2017, 01:03:07 AM »
The cross head is started and after turning the piston rod hole from square stock it is filed to shape using hardened silver steel buttons. also the profile is made using the hardened vice jaws as a stop to saw away unwanted material and then filed to shape ,i will remove a bit more to finish it off.

Online crueby

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Re: Freelance mill engine from Stuart castings.
« Reply #34 on: December 02, 2017, 01:08:05 AM »
Great file work as always!

 :popcorn:

Offline MJM460

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Re: Freelance mill engine from Stuart castings.
« Reply #35 on: December 02, 2017, 06:51:29 AM »
Hi Willy, Developing into another wonderful engine.  I really like those brass wear components each side of the more highly stressed steel centre piece.  The maintenance engineer will thank you forever.

MJM460
The more I learn, the more I find that I still have to learn!

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #36 on: December 02, 2017, 11:54:53 PM »
Hi All more work with the file and tidying up the parts. I am using the hardened vice jaws as a guide that the files do not penetrate . I have drilled holes in the ends of the slides and this was done on the original to save weight to help with the reciprocation of the parts. Also i am making this engine with guidance from old books with the technical drawings of real steam engines.  ......

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #37 on: December 07, 2017, 10:44:32 PM »
I have made a drawing of the conrod  and will start on this soon, as i have been making the new parts for the Southbend lathe  I have made a new leadscrew nut that is longer and also has a movable part to take up any play. I was also going to make a new leadscrew and did start this but could not find a chaser to clean up the thread once screw cut. However when i put the new nut on the old leadscrew it seemed to fit really well and reduced the play really well so i have now reassembled the parts to see how it functions....

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #38 on: December 07, 2017, 10:58:08 PM »
so the lathe is back together and there is minimal play. so i don't need to continue with the new leadscrew part. I did think that i could make a chaser by cutting up a die and making a holder to use as a chaser...So i can now get back to the engine .........

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #39 on: December 08, 2017, 02:36:55 PM »
Ok ,now back to the engine .....I have found this intriguing reversing lever system that uses a strait slot linkage rather than a curved type on an engine from 1883. I may make this as i have not seen it on an engine before. I shall make a quick meccano set up first to make sure it will work !!

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #40 on: December 14, 2017, 03:16:34 AM »
more work on the engine Have found that the valve gear is actually called the Allen valve gear and i have started on the crankshaft components . also is there a spreadsheet available for calculating the eccentric offset and dimensions to produce a working drawing starting from the valve travel ? or does one use an enlarged drawing ?

Online crueby

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Re: Freelance mill engine from Stuart castings.
« Reply #41 on: December 14, 2017, 03:52:20 AM »
I came across a similar straight link in the Marion hoist engine, which has a very short throw on the link. They only used the reversing lever at full throw one way or the other, where on locomotives and ships they would use partial throw settings to modify the lead/cutoff for efficiency on long runs. For the shovel and in a crane, they are doing a lot of short hauls, stopping and starting frequently.


The valve travel needed is the direct factor in the eccentric offset, total travel distance divided by two is the offset. For the straight line link, not used in partial throw, the length of the link is usually determined by the available space and the throw of the controlling levers.


I love those old drawings, amazing artwork!


Offline Zephyrin

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Re: Freelance mill engine from Stuart castings.
« Reply #42 on: December 14, 2017, 07:58:49 AM »
You will find an Allan valve gear model in the Dockstadter software package (free!), this may help you to evaluate the best length for all these links and the positions of the pivots....
but AFIK, the programs are old, and does not run on win10.

http://www.billp.org/Dockstader/ValveGear.html

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #43 on: December 14, 2017, 01:47:41 PM »
Thanks Chris and Zephryn for the info ...i do have a mac computer so i cannot see all of those links but i have taken some measurements  directly off the etched drawings and will see how that pans out ....
Willy.........

Offline steam guy willy

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Re: Freelance mill engine from Stuart castings.
« Reply #44 on: December 15, 2017, 02:20:32 AM »
More on the crankshaft...... Two pieces of 5/16 plate were tack welded together and marked out and drilled and reamed. The shapes were first angle ground out then some filing buttons  turned up to file the profiles .....I have made these crank webs with balance weights as per some engines.