Recent Posts

Pages: [1] 2 3 ... 10
1
Vehicles & Models / Re: Chris's Marion 91 Steam Shovel
« Last post by J.L. on Today at 01:04:48 PM »
Hi Chris,

What a labour of love. You must be very pleased. I'll bet the end game in your head of seeing that boom operate under power must be driving you on constantly.
What a project!

Cheers...John
2
Vehicles & Models / Re: Chris's Marion 91 Steam Shovel
« Last post by kvom on Today at 12:50:27 PM »
It will be interesting to see how fast/slow the boom will move once these engines are hooked up.  The fact that you could slow the speed appreciably is encouraging.
3
Vehicles & Models / Re: Chris's Marion 91 Steam Shovel
« Last post by gbritnell on Today at 12:29:05 PM »
Outstanding job Chris!
gbritnell
4
From Kits/Castings / Re: The Alyn Foundry IF Allman engine.
« Last post by Chipmaster on Today at 10:39:42 AM »
That's a great result Jason, I have watched the video several times. Your skill has resulted in an attractive engine that
 inspires me to blow the dust off my own IF Allman castings and get started. I hope you will add further videos of the engine when it has been fine tuned and bedded in.

Andy
5
Your Own Design / Re: Sideshaft i.c. Horizontal engine
« Last post by Brian Rupnow on Today at 01:37:27 AM »
And a lovely thing it is, indeed!!  It fits into the space that was available, it doesn't foul the blades of the cooling fan, and that rather ridiculous long filler spout neck coming out of the tank at a 10 degree angle ends up in the correct spot. Far enough away from the sparkplug to prevent arcing to it, and convenient to fill.
6
Chatterbox / Re: Talking Thermodynamics
« Last post by steam guy willy on Today at 01:35:32 AM »
Hi MJM, thanks for the info ... very informative...
Willy
7
Dozerdroid, thanks and warm welcome to the forum :ThumbsUp:

Mike, I made a drawing for the 25, 50 and 140mm cylinders(printing area is max.140x140x140mm), height is 5mm. Well not actually cylinders, more like rings, as the biggest one would have taken over 6 hours to print at 'high' -setting, if it was a solid one:


And here are the settings, that I use to print the rings:


I printed them one at a time. Smaller one's outer diameter is spot on 25,0mm, also height is 5,0mm, but the inner diameter is 14,8mm. Bigger one's outer diameter is again spot on 50,0mm, and height is between 5,0 and 5,1mm. Inner diameter is 29,9mm:
 

Biggest one is still printing, and its inner diameter might be even closer. Generally the z-axis(horizontal) seems to be quite precise, also the roundness of the printed parts is quite good.

Due to the printed surfaces not being as smooth as machined ones, mating parts always seem to need some extra in them, which allows machining for closer fit.

And yes, error(s) seems to be proportional to part's size. That's why I chose quite bulky gear size(mod 1), when scaling down the transmission's parts. Even then, as mentioned earlier, there is some kind of an offset jazz going on with the smaller gear's(suns and planets) root diameter. Ring gears, as they are three times bigger in diameter, are somewhat more precise.

I haven't found an easy way to extract the actual tool paths from the gcode files for editing and measuring. I could do it manually, but after editing, the gcode file should still have a certain structure, as it also seems to contain plenty of commands other than coordinates, for the printer to accept it. Maybe I could do it for a single file, just to see the containing dimensions of the small gear.

But again, it might concern only Flashforge Finder, its bundled software, and probably also its firmware. 

What comes to how the software(Flashprint) compensates for the width of filament, I'm not sure, as the manual doesn't mention it.
8
Vehicles & Models / Re: Chris's Marion 91 Steam Shovel
« Last post by crueby on April 22, 2019, 11:29:35 PM »
Quote....'I have a DVD of Marion shovels in use .......they would rather waste a little steam than crack a cylinder' Chris.....do you mean over powered?, or being used  [at speed] beyond their design?................[or slamming :killcomputer: the engine into reverse prior to achieving a stationary rotation or moment?]

We see so many examples [in model engineering] of Stephensons reversing gear being thrust into reverse prior to engine the engine rotation is at rest

[I am uning a pair of servo slowdowns....the 1st to slow the speed of the throttle speed to zero, then the second slow down the reversing motion....as common RC servos rotate at 60 degrees in say 0.2 seconds which is totally unrealistic :Director: as we are looking more for near 10x fold of that rotational speed]

Derek
Hi Derek - I was talking about two different machines there, the comments about the drain cocks and wasting steam were referring to the Lombard Log Hauler up at the museum in Maine, not the Marion shovels. When they are showing the Lombard at thier events, they are not pulling any load at all, so the machine at that point is WAY overpowered. They keep the drain cocks on the cylinder cracked open to prevent condensation buildup, both at rest and during slow speed running when giving rides. They usually run at only about 2 or 3 mph, and with no load the throttle is barely cracked open - the stephenson linkage is only out to the first detent, so lots of cutoff too. If they gave it full power at start, it would do a major burnout! When they taught me to run the thhrottle/etc controls, I was surprised at how little the steam had to be opened up, but it makes sense, under real use they were hauling many tons of logs, so on level ground with just some passengers in the back, it is just barely ticking over.   :)
Chris
9
Vehicles & Models / Re: Chris's Marion 91 Steam Shovel
« Last post by derekwarner_decoy on April 22, 2019, 11:16:01 PM »
Quote....'I have a DVD of Marion shovels in use .......they would rather waste a little steam than crack a cylinder' ....Chris.....do you mean over powered?, or being used  [at speed] beyond their design?................[or slamming :killcomputer: the engine into reverse prior to achieving a stationary rotation or moment?]

We see so many examples [in model engineering] of Stephensons reversing gear being thrust into reverse prior to engine the engine rotation is at rest

[I am uning a pair of servo slowdowns....the 1st to slow the speed of the throttle speed to zero, then the second slow down the reversing motion....as common RC servos rotate at 60 degrees in say 0.2 seconds which is totally unrealistic :Director: as we are looking more for near 10x fold of that rotational speed]

Derek
10
Vehicles & Models / Re: Chris's Marion 91 Steam Shovel
« Last post by crueby on April 22, 2019, 10:22:38 PM »
I think you and the elves deserve a real gut busting slap up lunch.  :old: :DrinkPint:
Was going to, but got a call from one of my boating buddies and we took the canoes out to the local creek for a run this afternoon instead, all the clouds cleared out and it was a great day on the water. A big swan was building a nest at one spot, did not see any of the Herons or Egrets this time out. There was a bald eagle hanging out there last week, probably moved on to the bay at the lake by now. The turtles have migrated back in too...  :Lol:
Good evening to watch a movie with the elves (the popcorn fights get pretty intense)...
 :cheers:
Pages: [1] 2 3 ... 10