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From Kits/Castings / Re: Textile Mill Diorama
« Last post by J.L. on Today at 05:53:40 PM »

The clamping setup allowed me to see the piston face at each end of the cylinder. The cylinder was then moved back and forth until the free space at each end of the bore was equal.

There is not much free space there!  ::)  The crankshaft is almost throwing the piston furthur than the cylinder's length.  To prevent the piston face from hitting the cylinder covers, the registers were cut from 1/16" to 1/32" and the location of the inlet ports were opened up by milling the registers flat to the interior faces of the covers. 

You will see the black o-ring in the photos. I removed it for ease of operation while setting the cylinder. I must say, it is rather hard and offers perhaps more resistance than necessary. I did widen the groove to let it squish, but am considering replacing it with a silicone ring. They are not as durable and wear out faster, but we are only talking about 30 psi of air pressure and the machine is not going to be running constently.  There also is no risk of deterioration due to steam.

I may have trouble finding just one from a local supplier. We will see.
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Chatterbox / Re: Worn Lathe Spindle Bearing????
« Last post by cfellows on Today at 05:34:48 PM »
I've ordered both a deep groove ball bearing and a tapered roller bearing. 

The pre-load on my spindle is provided by 4 belleville washers with an unloaded thickness of 11mm.  Since the tapered roller assembly is 4 millimeters thicker than the ball race, I think I could just remove 2 of the belleville washers and still have enough pre-load with the 2 remaining belleville washers.

The alternative would be to keep the 4 washers and shorten the sleeve that separates the inner race and the rear spindle nut which holds it all together.  Actually, this might be a better option.  I'll just make a new, shorter sleeve and keep the original for backup.

I'm definitely going to try the tapered roller.  If it works, I'll just keep the new ball bearing as a backup.
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Vehicles & Models / Re: 3.5" Northumbrian Loco
« Last post by crueby on Today at 05:22:20 PM »
Great tips. I have always had trouble with them, one thing I had not done was ream the smaller hole, that could well be the issue I had.




Thanks!
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From Plans / Re: Zee Needs Popcorn
« Last post by Stuart on Today at 05:17:41 PM »
Zee

Just put a teaspoon of domestic house hold bleach in your mix that will stop the bug growth I have a small tub of
‘Dip” made up now for two years still smells sweet

Well that’s what it sez on the tin( plastic container)

One tip I have passed this before if you dip steel fully immerse it or the surface of the liquid will etch a line that won’t buff out
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From Plans / Re: Zee Needs Popcorn
« Last post by crueby on Today at 05:17:22 PM »
I have used a variety of things, Sparex 2 which is a jewelry product, great on brass and copper, vinegar, citric acid (dont know proper concentration, too much and it wont dissolve more), muriatic acid from home center. Even salt water. All work, speed of less acidic is slower but safer. Vinegar is cheap at grocery store and works, store in a plastic jar, cap to keep smell down, works quite well, and is safe if you get any on you. Soak in pickle then wire brush in running water. I use fine brass wire to suspend parts in pickle, easy to remove without tongs, can reuse many times. Color can be removed with sanding or just a scouring pad.
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Vehicles & Models / Re: 3.5" Northumbrian Loco
« Last post by Ye-Ole Steam Dude on Today at 05:16:38 PM »
Hello again Baner,

A light compression spring centered over the top (outlet side) of the ball also aides in getting a good seal and it prevent swirling of the fluid causing the ball to chatter.

Have a great day,
Thomas
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From Plans / Re: Zee Needs Popcorn
« Last post by Ye-Ole Steam Dude on Today at 05:09:24 PM »
Hello Zee,

I use a product called Volcano which is an acid wash used for cleaning and brightening aluminum. I only use it one time to keep contamination to a minimum. Dilute one part to ten parts of water. Rinse your part really good after cleaning. It also works on stainless steel, brass, copper and silver. You can find it at most truck stops.

muleheadbrand.com   T.W.Pelton & Co.   870-535-1871

Hope this helps.
Have a great day,
Thomas
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Vehicles & Models / Re: 3.5" Northumbrian Loco
« Last post by Baner on Today at 05:04:00 PM »
Thanks for looking in Thomas.


I've done a little research into ball valves so I thought I do a post on what I found.

For those who don't know ball type valves are found all over model locomotives. They're variously called 'check valves' or 'clack valves' and elsewhere 'one way valves' or 'non-return valves'. Here's a picture:

Ball and seat by DAVID BANER, on Flickr
 
Basically liquid comes in from the bottom,the ball lifts, liquid flows. If it tries to come back down the ball is pushed onto the seat and flow stops. This only works if the ball seats properly.

The traditional method for creating the ball seat is to drill the port, ream, drop the ball on top the hole and smack the ball with a hammer, the ball is thrown away and a new ball is used in service. The ball is typically made of Stainless Steel.

My own experience is fairly limited, but I vaguely knew that some people had problems with sealing. So looking about I found, (in typical internet fashion) that the traditional method works for about the same amount of people that it doesn't work for...Some problems are as follows:

-Not hitting the ball hard enough.
-Hitting the ball to hard.
-Not reaming the hole.
-Not hitting the ball square on.
-Not replacing the ball after hitting.
-Cheap, out of round balls.

And solutions:

-Press, rather than hit the balls.
-Ream the hole. The hole needs to be perfectly cylindrical to fully contact the ball. Also, the reamer helps debur the seat area.
-Use a close fitting drift. Machine something up that's a tight fit in the bore to make proper straight contact with the ball.
-There's a few options for balls to use. Good quality stainless will generally work but is a bit wasteful and there can be minor differences between hit ball and service ball. Some people use rubber balls,(O-ring material) but they can get stuck on the seat or sucked into the pipe. There is also ceramic balls, (silicon nitride being the most common) which have the advantage of being super hard. These can form the seat without having to be replaced. They are a little more expensive than stainless steel, however.

So what I took from all that, and what I plan to do myself, is use the vice to press in silicon nitride balls with a suitable drift.

Two other things to consider. One is ball/seat size. Fortunately this resource is available:

http://ibls.org/mediawiki/index.php?title=Design,_Care_and_Feeding_of_Check_Valves

Here is a table from the link:

Everett Clem Ball Seat Table1 by DAVID BANER, on Flickr

I'm unsure how the data was compiled but plenty of people claim it sound. So in the case of my axle pump, the seat is 4mm or 5/32 so I've got 7/32 balls on order.

The other consideration is the finishing of the seat area. A concave finish such as left by a drill is considered unsuitable. Flat is better, and some say convex is best, though I found nothing definitive other than don't drill finish. I made a D-bit style cutter for a convex finish.

That's about it for balls. There is also another type of 'T' valve sometimes used instead of balls, (think tap washers) but I think I've gone on enough. If you got this far well done. I'm not anywhere near an expert on this, I've just collected other peoples experiences into this post. If there is anything I've missed (or got wrong) please chime in.

Dave.
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From Plans / Re: Zee Needs Popcorn
« Last post by b.lindsey on Today at 04:55:03 PM »
Zee, Stan has a recipe for getting rid of the red color. Shoot him a PM or email as I don't recall exactly what was in it.

Bill
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From Plans / Re: Zee Needs Popcorn
« Last post by zeeprogrammer on Today at 04:26:49 PM »
It's been a long time since I've done any pickling (other than myself).
A bit of research has led me to the following and I'd appreciate any thoughts...

I know there are different pickles, citric acid, sulphuric acid, vinegar, etc.

I intend to use citric acid.

1) Can be stored in a plastic container. I'm not sure if the type of plastic matters. I'd have a lid.
2) Probably better to start with a weak solution. I'm thinking one teaspoon per 8 oz water. (Very high concentrations requires heating.)
3) I'm not sure how long a batch lasts. Seems I recall people tossing it when it got a pretty funky smell.
4) Seems I recall people talking about the redness of the part after pickling. I can't recall what they did to reduce that.
5) Some people suggest correction fluid as a solder dam but I seem to recall trouble getting it off.

Thanks.
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