Building one of Rudy's steamers

[Deanofid]

Hi Mike;

It's 1200 wet or dry sandpaper wrapped around the file. After filing, the paper is put around the file and then used in the same motions as the file would be. It's for finishing edges without rounding off the corners.

Is that what you needed to know, or am I making it worse?


Dean

 

[Twmaster]

Perfect. Again, thank you.

 

[drRobutik]

Wonderfull machining abilities Dean,
lots of learning from you.
cheers

 

[arnoldb]

Dean, some exquisite little parts & neat machining tips :bow: - Thank you for showing

Regards, Arnold

 

[NickG]

Lovely work and we are all picking up hints and tips here. :bow:

It's not a race but think you'll have a runner before me at this rate!

Nick

 

[Deanofid]

Mike, drRobutik, Arnold, & Nick, thanks again for the kind remarks!


This next piece will be the eccentric.

A short piece of CRS is done up in the three jaw. First, the end that will take the eccentric
strap is turned to diameter and lenght.

It's made to a nice, close running fit and checked with its mating piece.

Then it's flipped end for end, and faced to within about .010" of finished length.

At this point, the piece is removed from the chuck and the location of the bore for the
crankshaft is marked out and center punched.

Time for the four jaw now, and the piece is dialed in with a wiggler.

This setup for the DI looks kind of a mess. I made the holder for use on the headstock of
another lathe and just didn't take the time to switch the rods and clamping nuts around to
make it easy on myself. Lazy, or whatever.

The bore for the crankshaft is drilled and reamed.

And then the boss for the set screw is turned.

So far, so good. The set screw hole is yet to be done, next chance I get to work on it,
(whenever that is). Jury duty tomorrow, so might not get anything done.

Still a few other things to do before it is ready to run in public. Lagging, a pulley for the crank
shaft, base and spokes need some kind of paint, then something for it to set on. Wood stuff, I
suppose. It'll be done soon enough. Maybe..

Thanks again for having a look.

Dean

 

[zeeprogrammer]

Looks great Dean.

When you say 'close fit' of the strap to the eccentric...can you describe it in a little more detail? I thought mine was a 'close fit'...now it's so loose it wobbles.

Did it take some effort to put on? To take off?
Do you expect it to get looser when it's run in?
Did you do anything else to it prior to fitting?

Thanks. I appreciate the help.

 

[Deanofid]

Hi Zee;

"Close fit" leaves to much to the imagination, I admit. Also, I should have said "close running fit".
For this particular diameter, a close running fit is having the eccentric strap bore about half a thou larger than the eccentric part it runs on. The bore in the strap is .910" and the diameter of the eccentric is .9095". (That's a slight deviation from the print, for any who are checking up on me.)
There are books that tell this kind of stuff about fits, and I don't know if I'm doing it how those books say. Just based on things I've done in the past.

It goes right on, but must be very well lined up to do so. If the strap is cocked just the slightest amount, it will get stuck going on. Same for taking it off.

Nothing was done to the pieces after machining, but I worked for a fine finish on the lathe for both of them. If you look at the first picture in this last post, you can see what looks like dust on the tool bit. It was a very fine feed, slow carriage speed, and as fast as the lathe would go, plus, that tool is very sharp. In the same picture, you can see the surface directly behind the running surface on this piece. See the fine lines? That was just a clean up pass to get rid of the factory finish on the piece. Compare it to the running surface, which doesn't show any lines, just shine, and a little of that metal dust from the finish pass.

The pieces run free, but you can't feel any slop in then if you move one inside the other. That will change a little as the engine runs in, and I expect to see gray oil running out of all the bearings for a while during that process. I mean, yes, it will get a little looser. Not much, unless I run it out of oil!

Truly, I wouldn't worry about your eccentric wobbling a little. As long as it isn't enough to change the valve travel so much that it changes the way the engine runs, it should be fine. I have one engine here that I made about 10 years ago. It's run for hours and hours, and everything is getting loose on it. It actually runs better than when I first built it. It's become "happy with itself".

Hope this is what you wanted to know. If not, ask again. Just like with an 8 ball.

Dean

 

[mklotz]

Zee,

If you're interested in being a bit more precise about different types of fits, you might want to look at the appropriately-named FITS program on my site.

You don't really need the program since all it does is an idiotically simple calculation, the details of which you can glean from the data file reproduced below.


Data for FITS program (Shaft/Hole fit computation)

Entries are: fit name,constant,allowance
constant is measured in thousandths of an inch
allowance is measured in thousandths of an inch per inch of shaft diameter
Example: For a push fit on a nominal 1" shaft, machine the hole to exactly
1.0000", and machine the shaft to -0.35*(1.0)-0.15 = -0.5 thou less than the
nominal size (0.9995").

STARTOFDATA

Shrink,0.5,1.5
Force,0.5,0.75
Drive,0.3,0.45
Push,-0.15,-0.35
Slide,-0.3,-0.45
Precision Running,-0.5,-0.65
Close Running,-0.6,-0.8
Normal Running,-1.0,-1.5
Easy Running,-1.5,-2.25
Small Clearance,-2.0,-3.0
Large Clearance,-3.0,-5.0

ENDOFDATA

 

[zeeprogrammer]

Thanks very much Dean. That was very helpful.
I like the 'happy with itself'...goes for all of us ;D

Thanks Marv. I'm going to add that to my 'reference book' I started a few weeks ago.

 

[NickG]

Marv,

what do I need to put into the program to select the type of fit?

Thanks,

Nick

 

[mklotz]

The program gives you a numbered menu of the available types of fits. You input the number corresponding to the desired fit. It will all be obvious when you run the program.

 

[shred]

The program gives you a numbered menu of the available types of fits. You input the number corresponding to the desired fit. It will all be obvious when you run the program.

Since I like tables in the shop (I have them hanging all over the place), I threw Marv's raw data into Excel. Really the last chart is the only one needed, but all 3 fit on one page. (I suspect 'delta' is technically the wrong term, but it makes sense to me)

Cleverer would be a graph or similar infinitely-variable chart, but this will cover most of the fits I might want to do. Calculating exceptions isn't that big a chore anyway.




View attachment fits.xls

 

[NickG]

Just figured out why I can't get it to work ... when I load it up it says "Failed to open Data File FITS.dat" the file is there but won't open it for some reason. ???

Nick

 

[mklotz]

When one of my programs requires a data file (many of them do), it expects to find it in the default directory - the one from which the program is being run. Similarly, if a program produces an output file (many of them do), it will create that file in the default directory.

 

[Deanofid]

Hi all;
Got some more done today. It's bits and pieces time. The engine parts are done, but
it needs some plumbing, and all the finishing things, like paint, a lubricator, etc.

This first bit is for friend Zee. Not to make any kind of point to any one, but only to share
that everyone makes mistakes, even if we are actually paying attention and minding our biz!

This piece is the sub base, and I thought it was finished long ago as it was one of the first
pieces made. Today, while fitting it up just for one last check before painting it, I came across
these two holes marked in blue. They're in the wrong place, and would end up under the main
base instead of out in the open, where they will be used to mount the engine to a piece of a tree.

The holes need to be filled so the proper mounting holes can be drilled. The correct position
for the holes puts them right through the edge of the bad holes, so when they are filled, the
plug has to be good 'n tight so it won't spin when the new holes are drilled.

I turned up the end of a decent sized piece of aluminum, with the end that will be the plug
about .002" over the size of the bad holes, and beveled the end just a touch with a file. This
will be a pretty tight press for such a small hole, and that's the reason for making the plug on
the end of a larger piece. It would be a heck of a time getting it in if I cut the plug to the
proper length and tried smacking it in with a hammer.

Now, the larger part of the round stock can be used as a driver for the plug. I have a small
press, and used it to push the plug in. The larger diameter of the driving end gives plenty of
material to hold on to while getting the plug started in the hole. The extra length helps in lining
it up for a straight press.

After the plug end of the piece is pressed in, the bigger piece is cut off near the base plate.

File off the stub from the plug, and the dirty little secret is safe. Except for the part where
I blab it over the internet...

So, that piece got painted today, and I masked off the rims of the flywheels and painted the
spokes and hubs too.

Time for some plumbing work.
I got these elbows from PM Research. They come in a casting tree, as can be seen in the
picture, above. These are 3/16" size, but they have other sizes. You can also get them
finished, already bored and threaded. Being a bit of a cheap skate, (it's the "more time than
money" syndrome), these are a good deal at about $3.50 for the tree.

I cut them off with a jewelers saw, but there is enough space between the els to use a
hack saw too.

They are put in the four jaw and the saw cuts cleaned up. The els are uniform enough to
use the same jaw settings for all of them once the first one is centered up. The only jaw that
has to be changed is the one that holds against the saw cut. Some have a little flash that
has to be knocked off before they go in the chuck.

Once a saw cut end is faced off, the el can be drilled and tapped on that end, then reset in the
chuck for the other end.

Not having any miniature pipe taps, I use a 10-32 tap to thread these. They will need a
little sealant or teflon tape when the pipes are screwed in.

The pipes and other straight fittings are made from 3/16 C360 brass rod. This works fine
for lengths of pipe that are not any longer than twice as long as your drill bit. For longer
pieces of pipe, PM Research has that too. I have a problem with it, and it's one
of the few products they sell that I don't like. They make their model pipe from what I'm
pretty sure is C260, which is one of the worst kinds of brass to turn or thread on a lathe.
It would be fine for soldering, but is crummy for threading.

Here are some of the fittings needed. There will be more, but they don't each need a picture.

So, some painting, some fixing, and in the shot above, some plumbing, done. The lubricator
will go on the end of that piece of pipe, and I should be able to get started on that tomorrow.

Thought I might get this engine done by Christmas, but, not so sure about that now.
Just call me pokey.

Thanks for checking in!

Dean

 

[zeeprogrammer]

That's really good stuff there pokey. ;D

Why the second turning on the plug you made?
How did you cut the bigger piece off? Jeweler saw again?
The one pic shows a plug being inserted and the other hole already plugged and filed. The next pic must be the other side. Is that right? I can't see any evidence of the plug. Very nice!

Thanks for the detail on the pipes and fittings. Very helpful.

And gosh...I know you make mistakes too. ;D

 

[Deanofid]

That's really good stuff there pokey. ;D

Why the second turning on the plug you made?

Just coincidental to roughing out the piece, Zee.

How did you cut the bigger piece off? Jeweler saw again?

Yep

The one pic shows a plug being inserted and the other hole already plugged and filed. The next pic must be the other side. Is that right? I can't see any evidence of the plug. Very nice!

Yes, right again. And thank you!

Thanks for the detail on the pipes and fittings. Very helpful.

And gosh...I know you make mistakes too. ;D

And you don't know the half of it!

Dean

 

[cobra428]

Dean,
That's some fancy maneuverings :bow:

Tony

 

[Twmaster]

Nice job hiding those misdrilled holes. Also, here I was about to buy a tap/die for 3/16 model pipe. I have taps/dies for 10-32...

Again, thanks for the tips. Hopefully we'll see that run my Christmas!