Author Topic: Monitor Steam Engine  (Read 157678 times)

Offline zeeprogrammer

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Re: Monitor Steam Engine
« Reply #30 on: December 25, 2015, 06:32:13 PM »
Thanks guys. Very helpful.

I did see that the metric plan cylinder had a brass liner. Slipped my mind when I posted my question.

Thanks Jason for the info on BMS.

I hadn't spent as much time on the metric plans but I should. There's more interesting detail.
As an example, the cylinder has a bushing for the piston rod in the metric plans but not in the imperial. (At least I don't see it.)

Today's plans have been delayed.  :cussing: People showed up way earlier than expected.  :cartwheel:
The party now begins.  :wine1:
Hopefully we'll all be good and not see too many  :pinkelephant:

In order for the full family to be together we are celebrating presents tomorrow.

Best wishes to all of you.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline zeeprogrammer

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Re: Monitor Steam Engine
« Reply #31 on: December 26, 2015, 12:57:19 PM »
Couple of questions...

1) When it comes to pressed bushings...do you finish the bushing and then press or do you press a blank bushing and then drill? Or, in the prior case, re-ream? My fear of course having the hole crushed.

2) I have a mini-lathe and mini-mill. Is this model too large? I think I'm okay (i.e. it's not obvious to me) but I may as well know now. As example, the cylinders are 2.25 diameter and 2.1875 long.

Uh-oh...grand-daughter is up. It's Hoppie time.

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

Offline Jasonb

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Re: Monitor Steam Engine
« Reply #32 on: December 26, 2015, 01:18:18 PM »
If you are buying in Oilite sintered bronze bushes then they are made slightly oversize so they squash down to size when fitted. If making your own its really down to how tight you get teh push fit and the wall thickness of teh bush as a thick bush won't compress as much as a thin one. You can re ream your own or make them a bit looser and loctite into place.

Should be doable on your lathe, if in doubt scale it down a bit say take the metric drawings and allow 1mm = 1/32" which will come out at about 75%.

Offline zeeprogrammer

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Re: Monitor Steam Engine
« Reply #33 on: December 26, 2015, 09:10:31 PM »
Thanks Jason.

Metal order placed.

Now for some tooling. Mainly taps and dies.
Probably a 1/2" reamer too. I have to believe I've nearly destroyed the one I have :)
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Tennessee Whiskey

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Re: Monitor Steam Engine
« Reply #34 on: December 26, 2015, 10:48:31 PM »
Ok, I'll cut it out. Yeah, that's how I wound up being Cletus, however, I'll admit to being the "Beav" type my whole life :lolb:  Now, if your ordering taps, get those thread forming thingees Stan uses or at least the spiral cutting ones. If you are replacing a trashed reamer that doesn't count as a new tool purchase , really, it's in the rule book :stir:  Replace the one and buy a +.0005 or +.001 reamer as your new tool purchase. If you use a good drill rod, silver steel, or even good 12L14, with a little polish, you've got a good running fit. I'm done playing now :cheers:

Cletus

Offline zeeprogrammer

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Re: Monitor Steam Engine
« Reply #35 on: December 26, 2015, 11:15:10 PM »
Thanks Cletus.

Why replace with an over or under? (I do have .001 over and .001 under besides the trashed .5)

As for taps...I'm looking now. Most of the tapping I need to do is blind hole or short through. I'm thinking of getting the full suite - taper, plug, bottom.
I know the taper is best for starting...but can a plug work in some cases? I ask because I suspect the starter may not get much bite if the hole is too short.

Couple of more questions...

1) The dies will be split rounds. My holder takes either 13/16 or 1". Any particular reason to choose one over the other?

2) Some of the tapping/threading on the drawings only show diameter...not thread count (or at least I don't see it). Most of the threading is fairly short (i.e. less than 1/2 inch). So I'm thinking a higher thread count might be better. What about these...

a) 1/2-20 instead of 13 or (or 28)
b) 3/8-24 instead of 16 (or 32)
c) 5/16-24 instead of 18 (or 32)
The 1/4 is more difficult for me. Seems the more common is 20 instead of 28. Just threading needed to hold a nut.

Keeping in mind my newbie-ness...higher thread count I believe gives a better joint but is harder to achieve? (Higher is probably more expensive but I'm not concerned about that...yet). Hm...that 1/2-20 is for a 1/4 distance. 5 turns if I'm lucky but more likely 3-4.

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

Offline 10KPete

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Re: Monitor Steam Engine
« Reply #36 on: December 27, 2015, 02:06:36 AM »
The answer to your questions about thread pitch is right there in the last part of your last sentence...

Divide 13 by 4.....

Pete
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Offline cfellows

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Re: Monitor Steam Engine
« Reply #37 on: December 27, 2015, 04:30:10 AM »
Zee, I use nothing but plug taps and bottoming taps.  Don't think I even own a taper tap.  However, I do use a tapping guide to get the tap straight.

Chuck
So many projects, so little time...

Offline Jasonb

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Re: Monitor Steam Engine
« Reply #38 on: December 27, 2015, 08:16:49 AM »
1. upto about 1/4" I would go with the 13/16, 1" over that as you don't need the leverage on the smaller sizes and a big die stock and small thread can be harder to keep straight.

2. aim for 1.5 x diameter if not shown

1/4 x 28 would be my choice and is in proportion to the other threads you list and easier to cut than 1/4 x 20

The tapping drill size you use will have a big effect on what taps you can use, for a large thread depth then you will need the taper, if you are only going for 60-65% then you can get away without the taper. Material and thread pitch also comes into it - you can happily use a 1/4 x 40 plug into brass but try that in stainless with a 1/4 x 20 and it won't be very easy :-\ I use taper taps 80% of the time

Offline Jasonb

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Re: Monitor Steam Engine
« Reply #39 on: December 27, 2015, 08:23:49 AM »
Just had another look at the drawings, these larger 1/2" and 3/8" threads are for steam fittings and glands, you want fine threads on those, if it were me making the engine I would be using 3/8 x 40 and 1/2 x 32 or 40, 1/2 x 20 is far to coarse a thread for these type of uses. I'd also suggest using these fine threads on a lot of the rods as it will give you finer adjustment of their length.

So my list would be

1/2 x 40 or 32
3/8 x 40
5/16 x 40
1/4 x 40 (1/4x28 for fixings)

Over here these are all termed ME threads you would have to either get these or find the nearest UNS or UNEF

This is what you should be looking for on teh glands, this one is 3/8 x 40
« Last Edit: December 27, 2015, 08:41:08 AM by Jasonb »

Offline Don1966

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Re: Monitor Steam Engine
« Reply #40 on: December 27, 2015, 02:47:54 PM »
Zee you can get your tap and dies here and look under Model engineer tap and dies. They are located in the states. This is where I got mine........http://britishfasteners.com/taps/model-engineer-taps.html

Don

Offline zeeprogrammer

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Re: Monitor Steam Engine
« Reply #41 on: December 27, 2015, 03:00:30 PM »

Thanks guys. I can't express how much I appreciate the help and time you're giving me.

Jason, your comment about ME threads seems to explain why I didn't see any specification for thread pitch. I came across this at https://britishfasteners.com/threads/ME.html

quote:
ME = Model Engineer Threads
These come in 32 and 40 tpi sizes
No official across flats dimensions are given for ME ( Model Engineer ) threads as nuts and bolts are not commercially available
:unquote

The included chart shows for a given diameter there is one thread pitch.

 :lolb: Don...your post came in while I was typing this. Scary, no?
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline Jasonb

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Re: Monitor Steam Engine
« Reply #42 on: December 27, 2015, 03:51:35 PM »
The included chart shows for a given diameter there is one thread pitch.


Look again Zee, 1/4" and above you can get two pitches 40 and 32 tpi. We also sometimes use 26tpi just to confuse things more this is Brass or cycle thread but can be used on larger fittings.

Offline Jo

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Re: Monitor Steam Engine
« Reply #43 on: December 27, 2015, 04:06:57 PM »
There is also 60 tpi  :Love:

But don't confuse 26 tpi brass with 26 tpi cycle  :hellno:

Jo
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Offline zeeprogrammer

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Re: Monitor Steam Engine
« Reply #44 on: December 27, 2015, 05:16:25 PM »
Look again Zee, 1/4" and above you can get two pitches 40 and 32 tpi.

 :Doh:

We also sometimes use 26tpi just to confuse things more this is Brass or cycle thread but can be used on larger fittings.
But don't confuse 26 tpi brass with 26 tpi cycle

All of which sent me off googling. Oh thanks for that.

My head hurts.  :insane:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.