# PM Research #4 Build Log



## vederstein

Recently I received a PMR #4 1/4 hp steam engine kit as a gift.  Not knowing how to build this thing, I asked if anyone knew of some build logs.

Nobody responded.

So I'm forging ahead.  Since apparently there aren't any PMR #4 builds on the Internet (just finished engines), I'll document my build here.

Those that know this engine and it's brother, the #6CI, this is not a model engine.  It's a full sized 1/4hp reproduction of an engine from about 120 years ago.  So lets face it, you're not going to build this thing on a Sherline or SIEG mini-lathe.

You need some decent sized equipment.  Luckily I have a large enough Chinese (Harbor Freight) mill-drill and a 78 year old 12" x 36" Sebastian lathe.






(This isn't mine, but mine looks just like it.)






In 2012 I built the PMR #6CI.  This engine uses many of the same components.  Unfortunately, with my relative inexperience, a casting issue, and bad decisions at the time, I has a running engine, but it leaked way too much to be of much use.

Perhaps I'll be more successful with this build.

More to come...

...Ved.


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## vederstein

I started with the base.

It's a cast iron non-critical part, so it's a good starting place to see how the CI cuts.


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## vederstein

Then I started on the Frame.

DO NOT DO WHAT I DID HERE!!!

The first operation, facing the legs went ok.

The second operation (turning the OD of the Cross Head) was difficult to center, but I got there.

The third operation (facing the cross head) is where all hell broke loose.  The part wasn't held good enough in the chuck and flew out.  The casting hit the back wall, then the floor.  The leg broke off.

I tried welding the legs back on, but no luck.  I have the part re-ordered, the that's a $100 U.S. dollars down the drain.

I guess I'll have to figure out something else when I try this part again.


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## vederstein

After my dismay at the Frame.  I went onto the Cylinder, Steam Chest, and caps.

First the caps.  Then the Cylinder.  Finally, I transfer punched the hole locations from the Caps to the Cylinder.

In the last picture in this post, you can see my totally botched Frame in the background.


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## Herbiev

Great build. Love the clear pics. Keep em coming please.


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## barnesrickw

My South Bend pre WWII looks like that too.


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## AlbertdeWitte

Hi There

Sorry I was absent from this site for some time

When I ordered my kits I was very much tempted to build #4 as well, but I got the 6CI instead. #4 is the vertical brother of #6 just as you said, however many of the parts are the same and same in size so that should be easy for you.

I am on the brink of completing #6, just over 4 month in my spare time. Then it will be the Red Wing. I called mashining of #6 a "walk in the park" which obviously was not the case, but will be compared to the Red Wing

I also built #5 with Boiler 2 and #1

Where are the leaks on your #6?

From your photos you are doing a great job here

Keep it up and all the best.

You are also welcome to mail me on [email protected]


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## vederstein

AlbertdeWitte said:


> Hi There
> 
> Where are the leaks on your #6?



Albert,

Here's the list of issues (mostly my fault and inexperience) from my #6CI build:



The main bearing caps were not aligned. I finally realized the problem long after I completed the engine.  When I initially machined the base, I clamped the casting to the bed of the mill and machined the face.  The casting was a bit warped, and when I unclamped it, it sprung back to its original position warping the machined surface.
To maintain straightness on the crankshaft, I bored a slip fit to the shaft when pressing on the crankshaft journal.  Then I knurled the mainshaft and pressed them onto the crank plates.  The knurled press fit didn't hold.  Eventually I has to cross drill the shaft and press in a pin.
My connecting rod casting was quite warped from PMR.  I straightened it with some persuasion (hammer) before I machined it.
The steam chest portion of the cylinder casting had a significant sink in it.  In the end I made a sleeve and held it in with JB weld, but that is the source of my leakage.  The engine runs on 15-20 psi, but there's so much leakage through the steam chest, that I cannot really use the engine for any real purpose.
I really hope this build of the #4 turns out better.


I have a large enough boiler to make some real power, I just need an engine that is good for it.


Thanks,


...Ved.


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## vederstein

Another Sunday, more progress on the engine:

I received the replacement frame.  The entire day was devoted to it.  I went slowly.  I have no desire to blow another $100 on another scrapped casting.

Since the facing of the legs went ok last time, I used the same setup except I extended my live center to give some support:


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## vederstein

After about 1-1/2 futile hours of trying to mount this thing to my 4-jaw chuck and/or my 8" faceplate, I gave up and decided to use the engine's base as a jig to mount the frame for machining:


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## vederstein

Now, cast iron as an engineering material is great in compression.  It's fair (at best) in tension and sucks in bending.  It can be quite brittle.

So I backed up the base casting with some temporary supports prior to chucking into the lathe:


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## vederstein

And with that casting re-enforcement, it's off to the races!!!!!

(The bar in the bore during the facing operation was just a safety in case the part became dislodged like how I ruined the first Frame casting.)

And that's it for this week.


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## AlbertdeWitte

vederstein said:


> Albert,
> 
> Here's the list of issues (mostly my fault and inexperience) from my #6CI build:
> 
> 
> 
> The main bearing caps were not aligned. I finally realized the problem long after I completed the engine.  When I initially machined the base, I clamped the casting to the bed of the mill and machined the face.  The casting was a bit warped, and when I unclamped it, it sprung back to its original position warping the machined surface.
> To maintain straightness on the crankshaft, I bored a slip fit to the shaft when pressing on the crankshaft journal.  Then I knurled the mainshaft and pressed them onto the crank plates.  The knurled press fit didn't hold.  Eventually I has to cross drill the shaft and press in a pin.
> My connecting rod casting was quite warped from PMR.  I straightened it with some persuasion (hammer) before I machined it.
> The steam chest portion of the cylinder casting had a significant sink in it.  In the end I made a sleeve and held it in with JB weld, but that is the source of my leakage.  The engine runs on 15-20 psi, but there's so much leakage through the steam chest, that I cannot really use the engine for any real purpose.
> I really hope this build of the #4 turns out better.
> 
> 
> I have a large enough boiler to make some real power, I just need an engine that is good for it.
> 
> 
> Thanks,
> 
> 
> ...Ved.



Hi There Ved

Thanks for your response.

I had a similar problem with the base so I did not clap it down. I've machined the bearing clocks clamped together in the milling machine, made bushes for the crank and upon reaching .001 in size I mounted them on the frame, super grued and then drilled, tapped and fitted, which turned out a perfect alignment.

If you missed my posts:
http://www.homemodelenginemachinist.com/showthread.php?t=24595&page=2

I notice you do not use a back plate in the lathe which I think is important to clamp castings in those funny shapes we find ourselves trying to clamp.

What I also like to do when it comes to fitting eg heads, inside heads or bearing blocks are the following steps:

I Clamp items in machine vise or stepper blocks with bolts, glue the parts together lightly with super glue, locate centers, drill centre drill, drill through the thread sizes, drill hole size to meet required depth and then tap, all in one position in the milling machine, I the repeat the steps for all holes. This ensures accurate drilling and tapping, also preventing the taps to start scew treading. I also put in the screws as I go along.

On the cylinder I used a back plate to clamp it in the lathe, boring both the cylinder bore and the valve chest. I prefer not to drill and reem as per plan. I made a boring bar for the valve and the result was a perfect fit with no leak. You may consider re boring it and making a purpose fit valve for it.

My connecting rod was rather a misaligned casting on which I had to do a lot of work grinding and sanding it till aligned, turned out to be fine, but a lot of work I can assure you, #4 uses the same rod correct?

I am very interested in your boiler, that one thing I must still consider building. Do you mind sharing it with me?

Until next time Happy machining!!

Albert


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## vederstein

Albert,

Thanks for the notes.  I'll use them on parts I haven't worked on yet.

As for the boiler,  I have a small, not very well organized, build log here:

http://www.homemodelenginemachinist.com/showthread.php?t=24487

And here's a picture at the Louisville Maker Fair from Sept 19, 1015:


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## AlbertdeWitte

Any time Ved

I'm adding few photos on securing the head to the cylinder


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## vederstein

First of all, I apologize that many of these photos aren't as clear as the previous photos.  The camera I was using ran low on power, so I used my wife's camera.  It's actually a better camera, but apparently not in action shots.

Now this engine has lots of round things.  So today was quite circular.

First, the lower valve heads:


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## vederstein

Then onto the upper valve head:


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## vederstein

The piston rod  gland nut is kind of tricky.  I don't have a 1/2-20 die, so I single pointed the thread.  I don't single point very often, but in this case is went ok...


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## vederstein

Ahh, Crank Plates - stepping away from brass, which is a treat to machine and back to cast iron which is grainy, dirty, and not particularly pleasant.

After the lathe work, I took the parts to my mill.  Two issues arose.  First, my rotary table with 3" chuck is too small to hold the crank plates.  So I bit the bullet and cut a piece of 5/8" brass bar stock to fit a pin upon which the crank plates would slip fit onto.

The other issue is that my mill/drill is a round column.  So my Z-axis travel wasn't enough to fit the drill and/or reamer.  Raise the column and I lose my centering on the rotary table.  Several years, I took a Bison 2" chuck and made a little stud on the back that I can use for these occasions.

And that concludes week 3.

...Ved.


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## AlbertdeWitte

Great machining there Ved

At this rate you will finish soon!!


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## vederstein

Onto the main bearings:

These took several hours to do because there are two of them and the shaft hole positions relative to the mounting holes must be as exact as possible.

I started via milling the bottom face, but I quickly realized this was a bad idea because of the tool marks left on the casting.  So I did my main facing on the lathe.


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## vederstein

Bearing blocks continued:

Then it was back to the mill.

Much of the time was spent milling edges (both parts at the same time as possible) to qualify edges.  Then I could saw off the bearing caps from the body.

Note that I stamped the bearings "A" and "B" and filed a notch into each part to ensure the bodies and caps are matched and oriented to each other.


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## vederstein

Bearing Blocks Continued (2):

After cutting the caps from the blocks.  There was more machining and cleaning up to qualify edges:


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## vederstein

Bearing Blocks Continued (3):

After milling most the edges, the bearing cap was drilled.  Then the block was transfer punched, drilled & tapped.  I could then assemble the incomplete bearings.

After more milling to size,  I then drilled and reamed the bearing journal.

The journal wasn't perfect, but much much better than on my earlier engine.  After a little deburring and working in the shaft, the bearings line up pretty good with very little perceptible binding or backlash (slop).


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## vederstein

Time for some internal reciprocating parts.

First the steam valve.  I differed from the plane and used some 5/8" brass stock instead of the CRS bar that came with the kit.  The reason for this is twofold:


I think the brass will wear against the cast iron better and will break in sooner.
I have several feet of 5/8" 360 brass round and can afford to screw up a piece or two.


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## vederstein

Onto the piston.

The piston's not too hard to make except for a couple of caveats:



Fit the piston to the actual cylinder bore.  I over-bored the cylinder a few thousanths.  So I measure both ends of the cylinder.  When I got close to size, I continually fit the cylinder to the piston (while it was in the lathe) to check for fit.
I used my 2" Bison chuck to hold the piston for machining the opposite side so I didn't mar the piston walls.


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## vederstein

Sometimes you just can't win.

I guess I shouldn't be too surprised, because the same thing happened on the large(ish) Stirling - my cylinder bore is somewhat tapered.

It's strange though, the open ends match, but the center is a bit smaller.  Perhaps it's due to the casting flanges or that my lathe is nearly 80 years old.  I don't know. 

Anyways, it's several hours with a cylinder brake hone to fit the cylinder to the piston.  (The issue isn't the piston because is fits into each end of the cylinder, but gets stuck about 3/4" in.

At the time of this writing, there's improvement, but I've stopped for now (too annoyed: time to stop for the day).


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## charlesfitton

Sorry for this - but is the piston tapered?


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## AlbertdeWitte

vederstein said:


> Sometimes you just can't win.
> 
> I guess I shouldn't be too surprised, because the same thing happened on the large(ish) Stirling - my cylinder bore is somewhat tapered.
> 
> It's strange though, the open ends match, but the center is a bit smaller.  Perhaps it's due to the casting flanges or that my lathe is nearly 80 years old.  I don't know.
> 
> Anyways, it's several hours with a cylinder brake hone to fit the cylinder to the piston.  (The issue isn't the piston because is fits into each end of the cylinder, but gets stuck about 3/4" in.
> 
> At the time of this writing, there's improvement, but I've stopped for now (too annoyed: time to stop for the day).



I had the same problem VED and I easily corrected it with a "Flap Wheel"disk grinder, was like in and out and 100%


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## vederstein

charlesfitton said:


> Sorry for this - but is the piston tapered?



The piston goes in either either end and either way, so I don't think the piston is tapered.

All evidence is that the bore is hourglass shaped.

It'll take time, but I'll get it to fit.

...Ved.


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## willburrrr2003

Ved, this is a great build thread!  Thanks for all the pics of working parts in your lathe!  Hope things go well with your cylinder bore.  If you can't get the hourglass issue fixed, could you sleeve it?

Regards,

    Will


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## vederstein

Week 4?

After about another 45 minutes of honing, I got the piston to flow freely though the bore.  The bore was definitely hourglass shaped.  Every few minutes I'd remove the part and check for fit.  When running my finger inside the bore, I could feel the flared bore at the end.

Doesn't matter now.  It's good.

Onto finishing the crankshaft.  First the crank pin.  The tolerances on this are tight and therefore I broke out my good micrometer for measurements.

The prints call out a sharp corners on the crank journal, but my carbide tips have what I consider a too large radius.  So I used a small cutter and hand held the tool to undercut the corner a tad (fifth picture).


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## vederstein

Then using the earlier brass mandral, I pressed the crank pin to the crank plates.

Then I could machine the crank shafts.  I don't have a keyway cutter, so I used an 1/8" endmill.


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## vederstein

Issues will arrise, I guess even with my careful measurements, one of the press fits for the crank pin wasn't strong enough and came loose.  But instead of risking damage to the cast crank plates, I decided to fuse (TIG weld without filler metal) the pin to the crank plate.

After a little bit of working, the crank runs pretty good in the bearings (with the upcoming flywheel it free spins).  Much better than my earlier engine.


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## vederstein

On to the flywheel.

It's both an easy part (not many dimensions are critical) and a hard part (those chips are _*hot!!*_).


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## vederstein

I don't have a broaching kit for the flywheel keyway, so I did an alternative that I've seen done, but never have had much luck myself:

Take a parting tool and clamp it sideways.  With the lathe back gear engaged (to lock the spindle) "whittle away" at the keyway via running (by hand) the blade in and out of the bore.  

For this I took 0.002" cuts.

This time was better than my previous tries, but I still had some issues. :wall:  To compensate, I'll grind away the interference on the key.  The rest is drilling and tapping the thread to lock the key in position.

With the upcoming U.S. holiday, I'll probably a couple week before I get back to this project.  Have fun!


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## vederstein

Now onto the Connecting Rod.  It's a brass casting and I'm sure quite expensive if I screwed it up.  Therefore I took my time and measured two, three, four times before cutting.  And I always "sneaked" up on the final dimension.

The biggest issue was once again my round column mill and Z-axis travel.  For facing the sides of the Conrod to width, I used a extra long, spiral, two fluted, 3/8" end mill that I have.  It deflects a lot, so getting the width correct was a slow process of 0.005" to 0.010" cuts.

In the end I'm pleased with it. When I tested it on the crankshaft, there's just a little bit of drag.


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## vederstein

Conrod #2...

At the small end of the rod, notice that I left material at the end.  This was to support the small end's ears while drilling and reaming.  After I took the rod out of the mill, I manually cut out the extra material with a hack saw and filed the surface smooth.


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## AlbertdeWitte

Hi Ved, its coming on just fine!


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## vederstein

Thanks Albert.

It will be some time before I get back to this project, but a working engine by the end of the year doesn't seem unreasonable.  Painting won't happen until March or April when it's warm enough here to wash and paint the parts outside.

...Ved.


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## AlbertdeWitte

Hi Ved

I am busy with the final touches on mine and should start painting in the next 2 weeks if all goes to plan. I am using 2K epoxy paint for my models which dries in any weather.

Happy machining


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## vederstein

On to the cross head.  This is a casting with no obvious ways to machine it.  It doesn't have any cast in bosses for holding the part.

The last time (on the PMR #6) I made this part my initial thoughts were "How the hell am I going to machine this thing?!?!"  This time around my intial thoughts were "How the hell am I going to machine this thing?!?!"  

So first I spotted/drilled/tapped where the piston rod connects.  This gives me a place to attach a threaded rod for chucking into the lathe.  Against the drawings, I drilled all the way through the cross head.  This gave me a place to apply the live center.


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## vederstein

Cross Head #2

It took a couple of trial fits, but the cross head fits acceptably in the engine frame.

Then it was back to the mill for drilling the connecting rod journal and facing the width.

I drilled/reamed the journal first.  This allows (with the help of a 5/16" rod) flip the cross head for the width facing.  Again, I fit the parts to the connecting rod instead of strictly by the drawing.


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## vederstein

The last part for today was the Cross Head pin.  It's a comparatively simple part, so the pictures should be self explanatory.

After I finished the pin, I could temporarily assemble the bottom end of the engine. (short block?)  It moves freely with no noticeable knocks.  Thus far, I'm quite pleased with it.

(If you're curious, the red stuff on the Con Rod is engine assembly lube.  I have a bottle left over from when I overhauled the turbocharger on my Corvair.)

...Ved.


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## vederstein

Next is the eccentric strap.  This is another CI casting with not obvious holding position, so after some pondering on the cut order, I forged ahead.

First I drilled the strap.  After cutting the casting in two, I used a fly cutter to clean up the sawed surfaces.

Then after tapping the holes, it was off to the lathe to bore the inner diameter...


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## vederstein

Eccentric Strap #2

After facing the strap to width, it was back to the mill for drilling out the push rod connection point.

With that part completed, it was on to the eccentric.  This part is fairly simple, the most important thing is fitting the part to the eccentric.  It took a few trials, but in the end it fits good.


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## vederstein

A running engine is within grasp.  The last components are the valve linkages.

I'm fortunate enough to have a mini-mill that I converted to CNC.  So for the upper and lower linkages, I used the CNC to mill the radius and drill the holes.

After profiling each end of the provided bar stock, I used a hack saw to cut the linkages in two.  Then I could clean up the sawed edge and drill for the linkage bar.

Now for the slot in the link I used a slitting saw.  THESE THINGS SCARE THE HELL OUT OF ME!!!!  I was well out of the way when cutting the slot.

There was some filing necessary to get the parts to move freely, but it's all good.


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## vederstein

There's no use in showing pictures of bending bars and fitting parts, but in the end I have created life!!!!!

There's still more to do, like painting and making the oil cups, gaskets, and lagging.  But I couldn't resist trying to run the engine.

There's nothing like seeing a creation run for the first time.  It's exhilarating.  After a few minutes of running, the engine will barely run on about 3-4 psi, but it idles reliably at 5 psi (as shown in the video).

th_wav

[ame]https://www.youtube.com/watch?v=XaADnRmfXCs[/ame]


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## 10K Pete

It lives, it breathes, it's wonderful!!!  woohoo1woohoo1

Lookin' great!

Pete


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## AlbertdeWitte

Congratulations Ved!!
th_wav


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## vederstein

I would like to thank all those people (especially Albert) for following this thread.

Unless something truly interesting comes up, I probably won't be adding much to this.  For looks, I plan on strips of balsa wood as lagging and I'll show that, but from here on out updates will be scarce.

Again,  thanks for all you followers.

...Ved.


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## AlbertdeWitte

You are welcome Ved, I was watching your steps and realized many similarities as far as methodology goes between the 2 of us.

I painted mine on Saturday and now for final polishing and assembly. I will post few pictures of that on my thread. I will share the link with you.

I also converted an old wiper motor into a little generator which works well. I am now busy with the lamp pedestal...will see how it comes out

However, stay in contact with me on [email protected]

Regards




vederstein said:


> I would like to thank all those people (especially Albert) for following this thread.
> 
> Unless something truly interesting comes up, I probably won't be adding much to this.  For looks, I plan on strips of balsa wood as lagging and I'll show that, but from here on out updates will be scarce.
> 
> Again,  thanks for all you followers.
> 
> ...Ved.


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## AlbertdeWitte

Hi Ved

Like I said

Few extra touches is outstanding....

http://www.homemodelenginemachinist.com/showthread.php?t=24595&page=3


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## abowie

Apologies for hijacking an old thread but I've found all of this very useful and want to add my 2c worth with my own PM4 build.

Firstly, many, many thanks to Vederstein. I've read all of the posts in great detail and they've helped me enormously with my build.

Also, thanks to all of you others who have contributed to this thread. Many times, wondering what to do, I've been helped out by your advice.

There's very little on the 'net on the machining for this kit. This is by far the most comprehensive thread I have found.

There's also a Youtube video series on the PM6 by GI Customs here.

And this on the PM6 by Don Giandomenico.

So. Here we go!


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## abowie

In mid 2020, courtesy of covid, I found some YouTube videos on making a small model steam engine.

It was the PM Research PM1, and both Blondihacks  and  Joe Pieczynski have excellent video series detailing it's manufacture.

I ordered one, and mostly, by copying what Joe and Quinn did I managed to make it. AND IT WORKS!!

Making this model improved my machining skills by an order of magnitude.

I finished the kit in October 2020. The Devil, as they say, finds work...

Joe Pie's next series is to be the miniature lathe offering from PM research. I bought it, but it's terrifyingly small and complicated. I need to buy some tiny tooling,  so I'm waiting until Joe gets started so I can copy him.

In the meantime I wanted something bigger. After perusing PM's catalogue, I ordered the PM4 as well.


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## abowie

So. Why bother to post this?

Well, to be honest, because the PM4 kit presents some challenges to the novice home machinist (people like me).

Parts of it are too big to fit in our little lathes.

Some of the design has flaws that can lead to failures in components.

And the castings require us to think outside the square to produce acceptable tolerances, and a machine that will run.

I love a challenge!


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## abowie

I started out with the cylinder. Fairly straightforward setup in a 4 jaw.

I elected to use an angle grinder to remove the surface scale layer to make initial machining easier and to get the top surface approximately flat.

To make setup easier I machined up a mandrel out of  round bar. 

This is a clever trick I picked up from Quinn, and for more detail see how she did this with her PM1 build (link to Youtube above).

The main diameter was a fairly close fit to the ID of the casting, and on one end I turned it down to 1/2" so it would fit into my drill chuck in the tailstock. You mount the mandrel in the chuck, slide the bore over it and you are 95% centred for the 4 jaw.

All that weight off centre meant that I had to run the lathe slowly but I got the bore to dead on 1.500" and the top surface flat.


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## abowie

As I needed to do the valve cylinder bore and drill holes in the mill, I opted to machine the other face parallel at the same time.


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## abowie

I used the chamfer on the end of my drill chuck to centre the piece. I double checked the centre with an edge finder and it was very accurate.


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## abowie

So I bored the valve.

I then glued the cap (prepared earlier) onto the cylinder with good quality cyanoacrylate glue and drilled the holes for the lower cylinder cap.


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## abowie

The main body casting is tricky. It is nearly too big for my mill and completely too big for my lathe.

And it has no easy registration surface to work with.

I used a very large file to smooth off the top rib on the cross slide bore as best as I could. I then set the casting up on the mill bed so that this part was horizontal on the X axis.

Then I tweaked it using aluminium shims under the foot until the foot was as close to horizontal in the Y axis as I could get. I always feel a bit dubious about using the level box, but it is yet to let me down badly. In retrospect, for better accuracy I probably should have used a dial gauge.

Then I machined the upper foot flat and square. Once I had done this I flipped it over and did the other foot using the first as a register. On assembly (see later) I am actually about 20 thou out on the length of the Y axis but the frame sits well on the base and if I want I can drill out the mounting holes in the foot to correct the error.


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## abowie

I made a drill extension and drilled the afore mentioned mounting holes.


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## abowie

While I was thinking about how to machine the rest of the body, I tackled the cross slide.

Now on the PM1 kit there is a sprue on one of the smaller castings that allows you to mount it in the lathe. You then cut the sprue off when you've finished.

Looking at the combined valve eccentric follower and crosshead casting in this kit, I made a fatal error, and cut off what I thought was a sprue. Unfortunately it was the boss for attaching the valve rod to the eccentric follower. My first mistake, and more later on how I fixed this.

See how nicely that sprue worked?


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## abowie

It's really quite a pretty part.


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## abowie

I repaired the eccentric follower by drilling the arms and making a new boss. I thought a car main cap design would look appropriate, along with studs and nuts.


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## abowie

About this time in the build I found this thread. It was so helpful to be able to read through the ideas and setup for the parts. There aren't a lot of threads on the PM4 /PM6 builds and some of the parts are quite difficult.

I decided to do the valve caps in brass for a little bling, although I did the valve itself in CRS.

For some reason I ended up needing 4 attempts at the valve as I kept getting the OD undersize for some reason that I never did entirely work out.


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## abowie

Others have been dubious about the 5 piece crankshaft design, and so was I. Nevertheless I made it to plan.

Everything machined nicely to tolerances, and pressing the main shafts into the flats was fine, but when I pressed the journal into the web discs BOTH of them cracked, and I'm certain I had the press fit tolerances spot on.

More on this later.


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## abowie

I read the cautionary tale at the beginning of this post and decided that a steady rest was a necessity for machining the bore. But I have a Workman 6125 lathe and its swing over just isn't big enough to spin the part. Nor will its steady rest fit around the top of the body.

So what do you do when your lathe isn't big enough? Phone a friend!

My brother in law is a diesel mechanic. And he has a HUGE lathe.

Swing over is about 2ft/600mm. The backplate is the size of a manhole cover and weighs about 40kg. I'm 6'1" and 110kg and fairly strong and putting it in place was very difficult.

Here is the frame, dwarfed by the lathe.

After I'd spent some time carefully machining the bore to spec he laughed and pulled open a drawer, which was FULL of adjustable reamers. He had 1" to about 3 1/2" covered. By that stage I didn't need it.


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## abowie

Once the frame was machined I was able, by cutting down a drill bit, to JUST drill the holes in the top.


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## abowie

Now unfortunately, on to my next, major mistake.

And I apologise that I have no photos.

I came to machine the conrod.

It's a pretty good casting, but there isn't any suitable reference surface that I could find. After a lot of thought I fixed it into a 2" toolmaker's vice, trued it up as best I could and made a light skim cut along one side of the shaft to act as a reference.

I then set out square and concentricity for the face machining and the bores using that skim cut as the reference. This was difficult, and I ended using edge finders etc to try to find the midline.

Unfortunately I was not successful, and have ended up with the crank end being about 35 thou offset sideways from the top end.

It's a pity because both the bores seem to be spot on in terms of parallel and diameter.  I have done a trial build, and by trying different orientations of conrod frame and crank I can get it all to go together but it's not good enough to allow me to tighten everything down. If I do it binds.

I have ordered another casting from the ever helpful guys at PMR.

My plan is to machine the shaft between centres this time, as per the video series by GI Customs. That ought to give me a solid centre to work from.


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## abowie

I followed Ved's approach to the bearing pillars and caps and machined both raw castings together, then cut them apart. They came out really well.






I wanted to ensure that they ended up perfectly concentric when I bored them.

So I made up a mandrel that fitted the bores with 1 thou clearance and spaced them the correct distance apart on the casting referenced from the drawings.


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## abowie

I mounted the base onto my mill bed using two vices. 

I referenced the side of the pillar with a gauge to get the bore perfectly vertical. I centred the cutter on the bore using an edge finder in the bore.

Then using a newly purchased 5/8" reamer, I bravely cut the bores.

The resulting surface isn't perfect; there was some chatter that has left very shallow grooves, but it is a really good fit for the crank. I wonder if I had used a straight flute reamer whether the result might have been better.

I have decided that I deliberately made the grooves to aid with oiling...


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## abowie

Back to the crankshaft.  I did what Ved did, and fused the parts together with TIG.

One positive of this is that with the crank bolted down into the pillar blocks prior to welding it has turned out perfectly true.

Sadly it looks ugly.

So I have bought a big chunk of cast iron, and I plan to make a one piece centre section, then press shafts into it. 

I have cut the rough shape on the mill, but I don't have a long enough cutter to do the journal so until that arrives it's sitting in my 4 jaw on the bench, waiting.


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## abowie

So this is where I am at present.

I've made most of the rest of the simple parts like the valve linkages, rods , piston and rod etc etc.

I still haven't done the eccentric because my 4 jaw is occupied. But I'm probably 95% done.

To those reading this thanks for your interest, and to Ved and the others of you who have helped with advice and ideas thank you so much.


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## abowie

I thought the crank caps would look better with nuts and studs.  Several burned and sanded fingertips later..


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## abowie

I did a little bit of painting.  Clear lacquer for the flywheel. I cut the keyway using the "cutoff tool in the lathe toolholder" technique.

I may yet hand paint the spokes red.

I have used brake caliper paint for the red. It is really good on the raw cast iron.

I sandblasted the castings for my PM1 kit, but just degreased the current ones.

I'm toying with the idea of using silver on the base and maybe the cross slide, although I may blue that and the eccentric +/- the follower.


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## Eccentric

Wow, that is a big steam engine.  I really enjoy the PM research kits.


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## abowie

Yes. It stands 19" high and is a full scale model of a unit you could buy in the 1890's. Presumably to power your butter churn or something.


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## abowie

Rather than machine the base in the lathe, I did mine on the mill. There are a couple of pics of it above where I am boring the crank.

I have a set of very old, very large files that I bought at a garage sale.

These are really good for truing up rough castings.

I blued up the underside of the base and then filed it flat until it didn't rock when placed on my mill bed.

Then I clamped it down to the bed and trued it up using the long edge of the cavity in the centre as my X axis. The casting was rough and upsetting my dial gauge so I placed a piece of flat steel along that edge and held it on with magnets so I had a smooth surface.

I decided to clamp it on the rough top casting first to drill the 4 holes that allow it to be mounted to a solid surface.

Then I moved the clamps one at a time so I could mill the top flat and drill and tap the other holes. With a DRO on a mill this is just child's play.


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## abowie

I had ordered a couple of big pieces of HSS in order to finish the rod journal on my replacement three piece crankshaft. Because of the amount of stick out needed (about 3") I wanted something as rigid as possible.

The larger of the two, 20x20x180mm arrived on Friday, and it is HUGE! I intended to use it only to rough out the basic journal diameter from the really rough octagon I'd produced on the mill.

I had to machine out one of my quick change holders to 20mm to hold it. It was slow going but I managed to produce a nice round 5/8" diameter.

Now I had to decide how to machine the journal to final diameter. I simply don't have a tool that is long and narrow enough to make the cut while being rigid enough.

I had also ordered a 16mm square piece of HSS but that still hasn't arrived. The crank has been taking up my 4 jaw chuck and I want to get it done and out of there.

So I decided to make up what was essentially a giant parting tool.

I milled up a 20 x 10 x 150mm piece of mild steel as a mount, and cut a 40mm long 10mm slot in one end. I then TIG welded a piece of 10x10mm75mm HSS blank into it, and sharpened the end.

Unfortunately the the 30mm or so sticking out snapped off in short order. So I ground the end of the mild steel to a point so the HSS was sticking out, shaped the HSS to form a cutter, and it performed flawlessly. I was able to get a very nice consistent 0.499" diameter on the journal and got the 0.560" width spot on.

So now I can chuck it up in the 3 jaw, centre drill it for the crank journals and finish it to final dimensions.


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## abowie

Today I drilled the central holes for the shafts.

I decided against using the reamer, and set the crank up in my 3 jaw and bored the hole to 0.624". 

I turned one side and skimmed the edges so it's all square with the centre bore, then cut it off in the bandsaw.

It is too hot in my shed to do any more today. I will do the other side and make the shafts when we get a cool change.


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## Richard Hed

abowie said:


> Today I drilled the central holes for the shafts.
> 
> I decided against using the reamer, and set the crank up in my 3 jaw and bored the hole to 0.624".
> 
> I turned one side and skimmed the edges so it's all square with the centre bore, then cut it off in the bandsaw.
> 
> It is too hot in my shed to do any more today. I will do the other side and make the shafts when we get a cool change.
> 
> View attachment 122440
> 
> View attachment 122441


Just curious.  Do you live in city?  Do you have access to lots of cheap water?  If you have lots of cheap water, you can build yourself an "air conditioner" useing several techniques.  If the water is cold out of the faucet, you simply run it to a radiator like a car radiator, use a fan to blow it around, and put the warmed water on your lawn or trees.  Another method is more difficult but uses less water.  It's the evaporative method in which you circulate water in a radiator but the water goes to a set of pipes which are wrapped with cotton cloth.  A fan is necessary to evaporate waater dript on the cotton.  The cooled water circulates to your radiator and you put your fan behind it.  Where I live there is lots of water, but it comes out of the ground luke warm in the summer when you needs it.  42Deg is time for a couch and a beer.


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## stanstocker

Funny, it's expected to hit a high around 40 here too, just in F rather than C.  Getting old enough to dislike cold...  We rarely get over 35C in the summer here, but it's usually with very high humidity just to make sure you really get the full effect.  Looks like you're making good progress, that is one large engine in my book!  I'm looking forward to getting to the smaller model version PM sells, hopefully this spring during our wet season.


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## Richard Hed

stanstocker said:


> Funny, it's expected to hit a high around 40 here too, just in F rather than C.  Getting old enough to dislike cold...  We rarely get over 35C in the summer here, but it's usually with very high humidity just to make sure you really get the full effect.  Looks like you're making good progress, that is one large engine in my book!  I'm looking forward to getting to the smaller model version PM sells, hopefully this spring during our wet season.


Generally I live in the Philippines during the winter months.  I am not making that engine at this time but looks interesting.


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## larryg

In the above picture you can see how I modified the union in the valve linkage.  I threaded the rod from the valve and threaded the union to receive it, 10-32.  This worked out very well for me to tune the valve position while the engine is running.  You have to add a bit of length to each piece to allow adjustment.
I also have a build thread here and an album of pictures that have languished for a year as other life events have consumed me.



			https://www.homemodelenginemachinist.com/media/albums/pm-research-4-build.257/
		


Build thread,  Larrys PM Research #4

lg
no neat sig line


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## Richard Hed

larryg said:


> View attachment 122461
> 
> 
> In the above picture you can see how I modified the union in the valve linkage.  I threaded the rod from the valve and threaded the union to receive it, 10-32.  This worked out very well for me to tune the valve position while the engine is running.  You have to add a bit of length to each piece to allow adjustment.
> I also have a build thread here and an album of pictures that have languished for a year as other life events have consumed me.
> 
> 
> 
> https://www.homemodelenginemachinist.com/media/albums/pm-research-4-build.257/
> 
> 
> 
> lg
> no neat sig line


Nice log.  Luv ur setups.  Where in Oregon r u?  I live in Moses Lake.


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## larryg

Richard Hed said:


> Nice log.  Luv ur setups.  Where in Oregon r u?  I live in Moses Lake.



Thank you.  I'm just south of Salem, just over the hill from the Enchanted Forrest.


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## Richard Hed

larryg said:


> Thank you.  I'm just south of Salem, just over the hill from the Enchanted Forrest.


Enchanting.


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## abowie

larryg said:


> View attachment 122461
> 
> 
> In the above picture you can see how I modified the union in the valve linkage.  I threaded the rod from the valve and threaded the union to receive it, 10-32.  This worked out very well for me to tune the valve position while the engine is running.  You have to add a bit of length to each piece to allow adjustment.
> I also have a build thread here and an album of pictures that have languished for a year as other life events have consumed me.
> 
> 
> 
> https://www.homemodelenginemachinist.com/media/albums/pm-research-4-build.257/
> 
> 
> 
> Build thread,  Larrys PM Research #4
> 
> lg
> no neat sig line


That's how they did it on the smaller PM1 kit I built, and I was a bit surprised to see the roll pin setup.


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## abowie

Richard Hed said:


> Just curious.  Do you live in city?  Do you have access to lots of cheap water?  If you have lots of cheap water, you can build yourself an "air conditioner" useing several techniques.  If the water is cold out of the faucet, you simply run it to a radiator like a car radiator, use a fan to blow it around, and put the warmed water on your lawn or trees.  Another method is more difficult but uses less water.  It's the evaporative method in which you circulate water in a radiator but the water goes to a set of pipes which are wrapped with cotton cloth.  A fan is necessary to evaporate waater dript on the cotton.  The cooled water circulates to your radiator and you put your fan behind it.  Where I live there is lots of water, but it comes out of the ground luke warm in the summer when you needs it.  42Deg is time for a couch and a beer.



Because South Australia is so dry (similar climate to Northern California) you can actually buy commercially made evaporative air cooling systems. They're essentially a big plastic box packed with water absorbing material and a big fan.

Yesterday is not the first time I've considered fitting one to my shed.


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## Richard Hed

abowie said:


> Because South Australia is so dry (similar climate to Northern California) you can actually buy commercially made evaporative air cooling systems. They're essentially a big plastic box packed with water absorbing material and a big fan.
> 
> Yesterday is not the first time I've considered fitting one to my shed.


Where I live it is very dry, summer and winter.  Those evaporative coolers are prevalent here, howeveer, they are not the type I am talking about.  People swear by them but I know enough about thermodynamics that I thimpfk it must be mostly psychological with a tiny bit of reality.  When water evaporates, it sucks out the heat from what ever it is evaporating from.  (boiling water may be viewed that the steam is removing heat).  But then the wagter vapor is blown into your home or whatever--that means that heat that is taken out of the absorbing material is blown right into yuour home.  The water has such a high heat of transition from water to vapor that it actually DOES cool a bit but the major place that is actually cooled is in th eabsorbing medium.  What I am proposing is to take advantage of that mechanism, that is, putting pipes inside the absorbing medium which cools th ewater inside the pipes and is circulated into a radiator in your room then heat exchanged by means of a fan.  Much more efficient but a pain in arse to make--not terrible but definitely a day or two's work.  Why this idea is not commercially available, I can only guess that the setup wojuld require some kkind of hole in your house (or an krackt open window for two hoses), the hoses being traipsed around, the radiator and it's setup. 

There is a third option involving a regular airconditioner--that is, an improved one using the same method of evaporation.  As you know, airconditioners take water out of the air and drip it outside==well this is a terrible ineficiency.  If hyou capture that water and spray in on th e cooling coills on the outside of your window (or whatever), the cooling coils cool MUCH faster thus saving yuour airconditioner the work of compressing ghe internal gasses to a higher pressure (which releases the heat from your house to the outside).  In horribly hot places this would be a great alternative to letting the water drip out on the ground.  If one doesn't have enough moisture in the air, use distilled water.

I have a friend in Tamworth.


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## Nikhil Bhale

We use the below type of evaporative coolers in my part of India. We have dry hot summers with temperature going up to 48C. These work best in low humidity conditions. We call them desert coolers.






Three sides covers are made of two layers of mesh with dry grass filled in between. This cooler is kept in a big tub of water. Water is circulated from bottom to top by a pump. The top water collector has holes from which it drips on the grass. Fan sucks in air through this grass and helps in evaporation.

Regards
Nikhil


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## Richard Hed

Nikhil Bhale said:


> We use the below type of evaporative coolers in my part of India. We have dry hot summers with temperature going up to 48C. These work best in low humidity conditions. We call them desert coolers.
> 
> View attachment 122474
> 
> 
> Three sides covers are made of two layers of mesh with dry grass filled in between. This cooler is kept in a big tub of water. Water is circulated from bottom to top by a pump. The top water collector has holes from which it drips on the grass. Fan sucks in air through this grass and helps in evaporation.
> 
> Regards
> Nikhil


We call them "swamp coolers".


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## abowie

Weather has now returned to sensible.

I finished the build by making the oiler cups and completing the centre section for my replacement crank.

The oilers are huge in comparison to the ones on the PM1 kit


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## TubeTech

abowie said:


> Because South Australia is so dry (similar climate to Northern California) you can actually buy commercially made evaporative air cooling systems. They're essentially a big plastic box packed with water absorbing material and a big fan.
> 
> Yesterday is not the first time I've considered fitting one to my shed.


Rusting lathe ways and other tooling is the consequence of evaporative cooling - Beware.


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## Anatol

TubeTech said:


> Rusting lathe ways and other tooling is the consequence of evaporative cooling - Beware.



evaporative cooling will increase humidity - which is usually pleasant in very dry hot climes. May experience is that evaporative cooling will not work in humid air. So how can ambient moisture from evap cooling be more than, say normal humidity in, say, southern England?


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## Richard Hed

Anatol said:


> evaporative cooling will increase humidity - which is usually pleasant in very dry hot climes. May experience is that evaporative cooling will not work in humid air. So how can ambient moisture from evap cooling be more than, say normal humidity in, say, southern England?


Yes, particularly in a moist area, the evaporative cooling wojuld not work very well.


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## abowie

So you may recall that I made a mess of the conrod, with one end being about 35 thou off centre. With this error the cross slide keeps jamming when I assemble the model and it won't spin freely.

I ordered a new casting from PMR and it arrived last week.

I made short work of it this time.

I decided to turn it between centres until I had some nice straight parallel sides to register from. Once that was done, it was a piece of cake.

This one is correct to within 2 thou alignment.


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## abowie

Oh dear.

A cautionary tale.

So right at the beginning of the build you may recall that I stood the frame up in my mill to drill the 4 mounting holes in the feet.

Then, when I couldn't fit the frame in my lathe I made up a plate with some studs to bolt the frame to, then bolted that plate onto the backplate on the BIG lathe.

As the casting was pretty rough I used a mandrel to get an approximate centre for boring the cross slide bore. And bore it I did.

BUT. 

The bore was not centred realtive to the mounting holes. But the crankshaft pillar mounting holes on the base are located in relation to the mounting holes for the frame. 

Which is off centre. SO THAT'S WHY IT DOESN'T WORK.


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## abowie

All of this has a happy ending, however.

*I have fixed the problem.*

I haven't fixed the model, although I will over drill the mounting holes and that ought to fix the misalignment.

But I have fixed the problem with my lathe being too small.

I have bought this:

50mm spindle bore, 380mm swing over, 1000mm bed. 2 axis DRO plus 3rd DRO on compound. Built in coolant. Foot brake. Power X and Y axis. Cam lock chucks. Thread cutting gearbox up the wazoo. AU$3300 at auction from the local trade school.

It weighs 980kg. Installation is going to be fun. Watch this space!


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