Author Topic: Chris's Marion 91 Steam Shovel  (Read 318092 times)

Online crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #720 on: February 18, 2018, 05:37:10 PM »
Hi Chris ,interesting stuff going on there...That was my job in the army as a control equipment technician !! no gyros though to stop it flipping over !!!
No warhead either!  Well, a turtle head, but it does not explode!
This one probably costs a few million less than the army ones too...  :o

Bet with your experience you could build a very nice RC submarine. Should have had you design the mechanism for my rowboat a couple years ago.

Online crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #721 on: February 19, 2018, 08:38:31 PM »
Good progress on the WTC for the sub, started with cutting some strips of the plastic to make the thickeners for where the bolts go, and milled the inside faces to match the curve of the tube:

Cut the strips into the individual parts, and solvent-welded them onto the tube. After that set up, drilled and installed some threaded inserts I made out of brass (with grooves horizontally and vertically cut into them to give the epoxy a mechanical grip on them), and drilled for the prop shaft thru hulls. Here is where it is now:

And a closer up view of the fittings and belt:

Next I need to make the mount for the motor, which will include an adjustable plate to allow for tensioning the belt when its all in place.
Hopefully a couple more days and I'll be back on the Marion build again!
« Last Edit: June 16, 2018, 09:01:12 PM by crueby »

Offline Farmboy

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Re: Chris's Marion 91 Steam Shovel
« Reply #722 on: February 19, 2018, 10:42:49 PM »
Just wondering what material you use for the glands on the prop shafts and servo rods . . . I expect you have mentioned it somewhere but I couldn't find it.

This stuff is just as fascinating as the machine builds. I love to see all your techniques and machining setups. All stored away for when I get some 'shop time  :cheers:

Mike.

Online crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #723 on: February 19, 2018, 11:13:49 PM »
Just wondering what material you use for the glands on the prop shafts and servo rods . . . I expect you have mentioned it somewhere but I couldn't find it.

This stuff is just as fascinating as the machine builds. I love to see all your techniques and machining setups. All stored away for when I get some 'shop time  :cheers:

Mike.
Thanks Mike, probably have not mentioned it here. The thru-hull fittings are all viton o-ring compression style, the outer nut holds the o-ring, and pushes it against the 'post' part of the main fitting, which has a slight concave on the end to push the o-rong against the shaft. With a little oil or grease, and an o-ring that is a snug fit on the shaft, it makes for a nice watertight seal while allowing the shaft to spin (in case of props) or slide (servos). I put a little blue loctite on the threads of the outer nut to hold it in place but still allow for wrench turning it to adjust the compression.
All of the WTC seals on the end caps and around the fittings are cut from rubber sheet, usually viton, sometimes silicone. This setup is how I've done all my subs, and usually get no more than a teaspoon of water into the WTC (if any at all) for the hour or two of run time I get on the battery pack. We are only going a few feet down in most cases, maybe 6 or 8 in a good pool, so the pressures are not all that high.

One more shop session for the day, and I got the motor mount made. It is just a couple of standoffs, bolted to the end cap, with a plate that bolts to the end of the motor, and has a bolt hole and a slot to hold it to the standoffs and allow tensioning the belt. I have not used a toothed belt like this in a long time (last time was 35 years ago on the Sabino model), so I am not sure how tight it needs to be, so I am going to start a little loose and experiment from there.



Next up will be the servo tray from some sheet plastic, get that made, then finalize the positions of the thru-hulls for the servo rods and the on-off switch rod. Once that all is done, I can wire it up, then make the gaskets, and get it mounted in the hull. Usually use a simple cradle with some velcro straps to hold it in place. Getting close to a ballast session in the tub!
« Last Edit: June 16, 2018, 09:01:24 PM by crueby »

Offline steam guy willy

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Re: Chris's Marion 91 Steam Shovel
« Reply #724 on: February 20, 2018, 12:05:20 AM »
Hi Chris yup i could do it but,  as this was in the previous millennium it would be thermionic valves and stuff...i learnt all my electronics in the early sixties  !! now there are things called integrated circuits and transistors and stuff !!!stuff you cannot repair !! When i was on maneuverers some equipment failed and the gunnery sergeant said what was wrong, and i said one of the field effect transistors had blown ,but ,if i had a lathe i could turn one up !! next thing i knew the machinery wagon arrived !! :facepalm: :Doh: ::)
« Last Edit: February 20, 2018, 12:11:06 AM by steam guy willy »

Online crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #725 on: February 20, 2018, 12:16:25 AM »
Hi Chris yup i could do it but,  as this was in the previous millennium it would be thermionic valves and stuff...i learnt all my electronics in the early sixties  !! now there are things called integrated circuits and transistors and stuff !!!stuff you cannot repair !! When i was on maneuverers some equipment failed and the gunnery sergeant said what was wrong, and i said one of the field effect transistors had blown ,but ,if i had a lathe i could turn one up !! next thing i knew the machinery wagon arrived !! :facepalm: :Doh: ::)


 :lolb:

Offline Firebird

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Re: Chris's Marion 91 Steam Shovel
« Reply #726 on: February 20, 2018, 07:14:28 PM »
Hi

Where Oh where do you find the time to do all this :headscratch: :thinking:

Let me in on your secret and I'll buy you a  :DrinkPint:

Cheers

Rich

Online crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #727 on: February 20, 2018, 09:38:06 PM »
Hi

Where Oh where do you find the time to do all this :headscratch: :thinking:

Let me in on your secret and I'll buy you a  :DrinkPint:

Cheers

Rich
Hi Rich,

Oooh, tough question, but worth a  :DrinkPint: !

One word: Retirement!
I took early retirement from Kodak about 5 years ago when they went through bankruptcy and shut down all the consumer businesses (there is still a little of the commercial business side of the company left, any consumer products you see now named Kodak are third party licensees of the name). So, still young enough to be in good health, there long enough to start drawing pension early, and it frees up 9 hours of the day for playing on things I like to do!
Much lower stress, more time for outdoors stuff, no !@#%!@#ing meetings, and lots of hobbies. Can you see my smile from there?
 ;D

Online crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #728 on: February 20, 2018, 09:47:32 PM »
Hey, an actual update on the Marion project!!!!

Okay, all I did was bring in the mail and open an envelope, but I'll take that. The chain I ordered off eBay showed up today (well, one of the two versions, niether gave exact dimensions so I got some of each). It looks much better than the clock chain I had, much thicker wire was used in it. Here is a pic of the new chain on the left, old on the right:

I like the shape of the old better, but it is too lightweight, so I am leaning to the new one for now, will see how the other batch looks when it arrives. My thanks again to Dan Rowe for finding it for me! He also mentioned a way to get rid of the shiny finish, quick shot with a torch to dull it down and blacken it more like a raw metal chain. This chain is stainless steel, with some sort of shiny chrome-ish finish on it. Here it is after a shot of flame on the last few links:

Makes it look much better for this model.

Dan, take a bag of cookies and a glass of Guiness out of petty cash!   :cheers:

This morning I got the servo tray for the sub cut out, am in the process of getting it bonded to the supports to attach it to the end cap. Would have been done by now, but a molar I have been having trouble with (it has a hairline crack in the base, under the metal crown) has flared up again  with an infection, so off to the dentist. The antibiotics should (I hope) knock this down so he can find out the root ( ! ) cause on the next visit. In the meantime, I think I can get the work on the sub finished in another couple days, and back to work on the Marion again! Got one more week before the pool run, so the timing is looking okay, assuming no setbacks (like spending time outside, it was over 70 today, not bad for mid February in upstate NY).
« Last Edit: June 16, 2018, 09:01:39 PM by crueby »

Online Dan Rowe

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Re: Chris's Marion 91 Steam Shovel
« Reply #729 on: February 20, 2018, 09:54:42 PM »
Chris that chain looks really good especially after a bit of heat, The smokebox on my Shay is SS muffler pipe. I have cycled it through the burn out oven a few times and it really looks like a real smokebox no paint needed.

Dan
ShaylocoDan

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Re: Chris's Marion 91 Steam Shovel
« Reply #730 on: February 20, 2018, 09:58:40 PM »
Chris that chain looks really good especially after a bit of heat, The smokebox on my Shay is SS muffler pipe. I have cycled it through the burn out oven a few times and it really looks like a real smokebox no paint needed.

Dan
How durable is the color it imparts, does it just rub off again, or is it into the surface itself? Looks much better than painting it would, and the chemical blackeners dont usually work well on a lot of the SS alloys.

Online Dan Rowe

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Re: Chris's Marion 91 Steam Shovel
« Reply #731 on: February 20, 2018, 10:36:12 PM »
Chris, I took a normal eraser to the finish and there was no change.



Dan
ShaylocoDan

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Re: Chris's Marion 91 Steam Shovel
« Reply #732 on: February 21, 2018, 09:05:45 PM »
The turtle guts are being made up one by one, got the mechanical parts of the WTC almost done now. The u-joints that will go from the output shafts to the props are on, as is the tube to hold the radio antenna (that still needs to be epoxied to the end cap, and the other end sealed up).

The servo linkages to the thru-hulls are also done, and the receiver in place.

The remaining tasks: wire up the speed control unit to the battery and motor, make the gaskets for the thru-hulls and end caps, get the WTC mounted to the hull, make the final linkages from the WTC to the props and fins, and get it all ballasted/balanced.  Getting close to going back to work on the steam shovel, thanks for your patience!
« Last Edit: June 16, 2018, 09:01:50 PM by crueby »

Offline steam guy willy

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Re: Chris's Marion 91 Steam Shovel
« Reply #733 on: February 22, 2018, 01:34:37 AM »
Hi Chris,   just a quick thought...should the props turn in different directions to stop the turtle turning turtle ? or do the tubes prevent this happening ? or is the weight distribution avoiding that ? just pondering...torque reaction and all that (that i have no knowledge of).......
willy

Online crueby

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Re: Chris's Marion 91 Steam Shovel
« Reply #734 on: February 22, 2018, 01:57:49 AM »
Hi Chris,   just a quick thought...should the props turn in different directions to stop the turtle turning turtle ? or do the tubes prevent this happening ? or is the weight distribution avoiding that ? just pondering...torque reaction and all that (that i have no knowledge of).......
willy
Hi Willy,
Normally I would set them up for counter rotation, especially on a fixed prop or a high speed surface penetrating prop, but for this model its not important enough to justify the extra mechanisms. The steerable nozzles help prevent prop walk and torque steer, plus this is a low speed model. That said, we'll see how it behaves! I'd have it ready to go by now, if I wasn't fighting this #@$-*\+ tooth! Keep having to take breaks, more aspirin... Actually looking forward to seeing the dentist again Friday.
Chris