Author Topic: Zee Needs Popcorn  (Read 31771 times)

Offline zeeprogrammer

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Re: Zee Needs Popcorn
« Reply #45 on: June 04, 2018, 05:11:36 AM »
Zee, I really donít think you have anything to worry about. Anyone who is operating a lathe in a conscientious manner will disengage the power feed just before it touches the indicator stem and will hand feed to their set point. I really couldnít image even a half assed machinist power feeding alway to the stop or forgetting to disengage  :shrug:. Guess I just pay way too much attention to what Iím doing.

Thanks. That was certainly my thought regarding powered feed. But there was some good info.

But on that note...something I learned...

If I lock the dial indicator down too much...it squishes the tube the probe is in and it locks too.
That is...I locked the dial indicator...moved the carriage over to get a reading...and the probe wouldn't move.
Loosened a little and all was okay.

So yet another example of that gray area.

Or rather...the Goldilocks story...

Too tight and it don't move.
Too loose and it moves too much.
Just right...and all is well with the world.

P.S. I had to use the word 'squishes'. It's a neat word.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline AOG

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Re: Zee Needs Popcorn
« Reply #46 on: June 04, 2018, 12:06:59 PM »
I use a magnetic backed indicator that I put on the tailstock side of the carriage. That way you never have to worry about smashing it with the power feed. It also makes it easy to measure distances that are greater than the length of the indicators. When you get to the end of itís travel,  just push it forward to reset and continue forward.

Tony

Offline mklotz

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Re: Zee Needs Popcorn
« Reply #47 on: June 04, 2018, 03:22:49 PM »
Given that Murphy is alive and well, I would still fix it so that the stop rod could not be retracted far enough to allow the DI rod to be driven past the end of its travel.  A "reminder collar" on the stop rod might work.

Oh, and one other thing...don't ever put another tip on the DI; a longer tip increases the effective length of the DI rod and the problem is back.

I can't tell you how often I've been working away and suddenly couldn't move the carriage because it was up against the stop, set for a previous job and never released.  Fortunately, my left hand stop has no DI.  The DI is on the right hand stop.  Although it's a lot safer there, even that stop has a DI saver pin.

A DI on my left hand stop would be hard to see.  I have a swarf tray fitted to the carriage to keep crap off the ways and it overhangs the front way.


A DI on the right is always visible.

Having both a left and right hand stop is useful when machining features like the offset pin on a crankshaft. 
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Offline zeeprogrammer

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Re: Zee Needs Popcorn
« Reply #48 on: July 03, 2018, 10:19:50 PM »
Wow. I can't believe it's been a month. I suck.

There are two parts of the popcorn engine that I consider fairly complicated/difficult for me.
One is the crosshead guide and the other is the inlet manifold.

I started on the inlet manifold. It's composed of a body and 4 pipe nipples (3 of which are identical).

1st picture shows the body. Locations for the pipe nipples have been spot faced and drilled for a little locating pin machined on the nipple.
2nd picture shows the parts.
3rd picture shows everything (sort of) assembled).
I need to do a little filing/fettling to get the nipples to fully seat.
After silver soldering the part will be placed in the mill and the holes of each pipe nipple enlarged. The design is such that the locating pin will get machined out.

Now we come to (for me) the scary part. I have to silver solder the nipples to the body and could use some advice here.

I've done very little silver soldering.

The 4th picture shows the orientation I'm thinking to use to silver solder. At the bottom the body is threaded 3/8-32. I intend to make a holder for the body and put the holder in a vise or something to silver solder. Flux and drape some silver solder over the top of each nipple. Then have at it.
I'm also thinking of some white-out (correction fluid) to try and dam the flux/solder. But I may not.
I recall people having problems getting the white out off.

The nipples are a close fit in the body. If they weren't, or even so, I may wrap some wire around them to hold in place.

I'm also wondering if the solder will wick in well enough. I'm not sure I can dink the mating faces to ensure a small gap.

Thanks for any help.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline crueby

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Re: Zee Needs Popcorn
« Reply #49 on: July 03, 2018, 10:43:04 PM »
A few silver solder tips, sure there is more but thought of these:  play the torch on the back side away from the joint, let the metal heat the solder not the flame. If you melt the solder with the flame, the solder will jyst ball up and run off the joint.
Avoid holding in a vise, acts like a heat sink. I got some firebrick from home center, prtects the bench and reflects heat. Having part spanning two bricks lets you put flame underneath.
Make sure the flux is mixed well, it will turn to a solid first, then melt, gi cclear as the metal heats, then solder should fliw.
Have a long spike or pick to push solder wire back in place if it shifts, also can use it to help draw molten solder along a seam.
If flux goes black and dries up, it is soent, stop and try again after cleaning. Thats usually a sign of too small a torch, the more mass to heat, more torch you need. What kind do you have? Propane fed is good, acetylene is tough for a beginner, can overheat a small area too quick. Anything past a red hot part is way too hot, risks sagging. Heat evenly across both parts, if one part is smaller or thinner it will heat before a thick one and take all the solder.


Sure I forgot some tips, others will fill in!

Offline Ramon

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Re: Zee Needs Popcorn
« Reply #50 on: July 03, 2018, 10:52:32 PM »
Zee - you don't have a great volume of material here so it will not take a great deal of heat to bring that to temp.

Same advice as given to Gary recently. If you apply a solder ring around the nipples make sure they don't fall across the threads once you start. Personally I would apply the solder - just make sure the temp is up to 'flow' temp before before putting the solder stick to the joins. Clean it well (no finger grease) plenty of flux (as a paste) and get the heat up until the flux takes on a water like consistency ( a good indicator that the temp is about right).  If you do make a fixture or need to hold it in a vice make sure either does not act as a heat sink to prevent adequate heating of the part.

Your biggest issue is going to be preventing the solder wicking up the threads of the nipples so be minimal with the solder application - the thinner the solder (stick) the better.

I have not used the correction fluid so can't comment but a soft lead pencil has a similar effect - can be a bit messy so difficult to control on something like those threads

If you get a good fillet around each outlet then I wouldn't be too concerned about it wicking in enough - it'll find itself .

Hope that helps Zee - Tug

Ah, Chris is up first - same track  :ThumbsUp:
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(a very apt phrase - thanks to a well meaning MEM friend)

Offline zeeprogrammer

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Re: Zee Needs Popcorn
« Reply #51 on: July 03, 2018, 11:01:27 PM »
Thanks Chris!
Some tips I knew but others were helpful. I do need to get a spikey thingie.
I have a simple propane torch (often used to make creme brulee) but for silver soldering I have BernzOMatic Fat Boy (MAPP).
That should work for such a job...but probably not good when/if I get to boiler making.

Just to be clear...I mentioned the 'holder thing' as a way to avoid heat sink issues with a vise. I should probably make it out of brass.

Just saw your post Ramon...thank you very much. It sounds like you're suggesting I heat and apply the solder rather than place the solder and then heat.

I don't expect to be able to control the solder very well. More of an experiment. Later I can do some filing/sanding and even re-threading (I think).

That's one of the interesting things about this hobby...almost every project I've started has presented something I've never done before.
Or maybe I haven't done enough.  ;D
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline crueby

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Re: Zee Needs Popcorn
« Reply #52 on: July 03, 2018, 11:08:43 PM »
That torch will be fine for small parts. For a boiler, definitely need more, been there, done that!


As for applying solder first or later, depends on what you have. I use the fine wire style from jewelry supplier, it works better to wrap around the joint. For thicker stick type, applying it once the metal is hot is probably better as he said. You can also snip off short bits of the rod and lay along a joint. Both ways work well. Big thing is practise.

Offline Ramon

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Re: Zee Needs Popcorn
« Reply #53 on: July 04, 2018, 08:04:37 AM »
Zee - the reason behind 'heat then solder' is that you have several joints in different planes. Keeping the solder rings, or small pieces as Chris suggests, in place as you heat it will be difficult if you intend to do it all in one heat.

It can be difficult to neatly position solder to a joint but to help have more control over a thin bit of 'wire' solder waving around - drill a hole the size of the solder in the end of a length of mild steel rod (about 3/16 dia) and hold a short length of the solder in that - makes for much better control.  Just give the end of the solder a tap with a hammer to distort it enough to retain in the holder.

Your Mapp torch should be fine for the part Zee - something Chris mentioned though and I should have is that brass can be easily overheated and can distort under it's own weight so keeping an eye on overall heat and waiting for that flux to go fluid is important.

Another factor to be wary of is that the flux paste, as it dries with the initial heat, can move small pieces like your threaded nipples out of line so a means to keep them in place is a good idea - your fixture perhaps?

As I say to anyone with soldering questions - Cleanliness - flux - heat - in that order but just as Chris says practise is key.

Hope it all goes well for you

Tug
"I ain't here for the long time but I am here for a good time"
(a very apt phrase - thanks to a well meaning MEM friend)

Offline b.lindsey

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Re: Zee Needs Popcorn
« Reply #54 on: July 04, 2018, 01:08:51 PM »
Zee, does this part really need silver soldering. The soft solder (like that from PMR) will require much less heat and in my opinion would be plenty strong enough for the inlet manifold. Might be much more forgiving for this part though it would prevent silver soldering later.

https://www.pmmodelengines.com/shop/steam/boiler-accessories/solder-flux/

Bill

Offline zeeprogrammer

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Re: Zee Needs Popcorn
« Reply #55 on: July 04, 2018, 02:31:16 PM »
Thanks Chris.
Thanks Ramon.

Thanks Bill. That's an interesting link. 4% silver and that's what they use on their boilers. Melts at 430F.

I just looked in the box (not opened for years!) holding my supplies. I have 45 that melts at 1370F and 65 that melts at 1205F. (Harris Safety-Silv).
Interesting that the lower silver content requires more heat. But that stuff contains copper and zinc. PMR is tin.

Is the PMR stuff okay for locomotive boilers? Or does the ability to use different temperatures come into play?
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline b.lindsey

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Re: Zee Needs Popcorn
« Reply #56 on: July 04, 2018, 02:54:56 PM »
Zee, NO it's not good for boilers. PMR supplies it only as a filler material. The rivets take the pressure. But the 4% solder is great for things subject to less heat and pressure and if you will be running the popcorn engine mainly on air it will be fine for the manifold.

Bill

Offline crueby

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Re: Zee Needs Popcorn
« Reply #57 on: July 04, 2018, 02:59:28 PM »
If you have old silver solder, make sure it is cadmium free! Some of the older stuff had it, nasty for health.

Offline Jo

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Re: Zee Needs Popcorn
« Reply #58 on: July 04, 2018, 03:03:18 PM »
If you have old silver solder, make sure it is cadmium free! Some of the older stuff had it, nasty for health.

Only if you use it frequently in an enclosed area and breath the fumes in.

Best to always do silver soldering in a well ventilated area - much like running gas engines  ;)

Jo
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Offline zeeprogrammer

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Re: Zee Needs Popcorn
« Reply #59 on: July 04, 2018, 03:04:41 PM »
Thanks Bill. I did wonder because the boiler kit I have uses rivets but I didn't know if all PMR boilers did.

Thanks Chris. Yes, everything I have is cadmium free.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.