Author Topic: Newbie building a PMR 6CI  (Read 9224 times)

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #15 on: July 13, 2018, 03:59:45 AM »
Remember how I said chunks of time go by sometimes?  Well, we're now picking back up on 1/1/17.  At one point, I picked up this lovely 1946 Burke Army milling machine.  It's a 3 phase motor, and I had to wait for some Christmas money to get the VFD so I could spin it on a 220V breaker.



I also met a real machinist who practically laughed at my little machine.  I didn't take offense.  He also hooked me up with quite a few horizontal machine cutters.  I've learned that most people don't bother with horizontal machines anymore.  I also got a very pleasant surprise when I bought the machine.  After we agreed on the price, we all learned together that it had a vertical attachment.  I use the vertical attachment probably 85% of the time.



With the milling machine up and running, I was anxious to clean off the top of my base.  However, before I did that, I used this file to clean up the bottom of the base.  Please don't take notice of the fact the tang is not covered by a handle!   :naughty: :-[





Here is one of those things I'm sure I didn't specifically see somebody else do, but I suddenly thought of how well it would work to ensure my parting tool was perfectly perpendicular to the work.



This would become one of my crank rods.  As much as I hate to admit it, the whole reason I had to turn these is because I failed to sneak up on a press fit diameter on the crank disks so that I could simply use 5/8" CRS.  Worse yet, I then failed to sneak up on the diameter of the crank rods, and later I will have rebuilt these!    >:( :(



“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair

Offline propforward

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Re: Newbie building a PMR 6CI
« Reply #16 on: July 13, 2018, 04:56:31 PM »
Looks like it is coming along nicely. That mill is a beauty - what a find!

I now work in a decent size manufacturing concern, with a lot of machinists. Machinists do tend to snicker at our little home machining projects, but they have a very different set of goals to the home model maker. I've found the guys at my place to actually be genuinely interested in what I do at home on these projects. They have a bit of a giggle too but it's all good, they are a wealth of knowledge when it comes to needing help on fixturing and set ups. They seem to be somewhat impressed - or pleased - something positive anyway - that one of the design engineers actually has a try at some "real work".

Anyway - off topic a bit there. Nice looking engine, I shall follow along with interest.

Time can get away from us can't it? Happens to me a lot. It's been over 2 years since I worked on a model engine, but I'm coming back to it at last. But that's another story.
Stuart

Offline Stuart

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Re: Newbie building a PMR 6CI
« Reply #17 on: July 13, 2018, 05:14:57 PM »
try a blue maker they do not rub off like the black ones when you reapply them
My aim is for a accurate part with a good finish

Offline Ian S C

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Re: Newbie building a PMR 6CI
« Reply #18 on: July 14, 2018, 11:32:05 AM »
There is probable a need for greater skill, setting up and using to a high standard on a small hobby mill than a large industrial one.
Ian S C 

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #19 on: July 14, 2018, 05:25:34 PM »
Thanks for the encouragement guys.  I would definitely agree with you about "real machinists."  This guy I know snickered a bit about my machine, but he is really nice and very helpful.  At one point I realized he was taking time to answer my simple questions when he needed to be focused on a deadline, so I've given him a break from me.  I need to call him soon.

While the project hasn't turned out perfectly, I still think he'll be impressed.  When he heard I was doing this project as my first step into machining, he was skeptical for sure.

I'm trying to "bang out" some of these posts so I can get you all caught up with where I am now.  I have quite a bit of the parts made, or very close at this point.  There is a need to purchase more stuff again, so we'll just see how it all plays out.

“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #20 on: July 15, 2018, 04:53:31 AM »
Happy freakin' Birthday to me!  1/22/17 I returned home from a "Polar Bear Campout" with our Boy Scout Troop.  If memory serves, it was about 50 degrees, so we didn't exactly earn a Polar Bear patch.

However, this week was very eventful for my project.  First, I began by shaving down my pillow blocks.  I really enjoy the action of my simple little machine.



I was very pleased with the finish I got on the pillow block and pillow block cap.




Here I began preparing for the work on my cross head.  Basically I just took the very high spots off with my bench grinder.  Rough work.  Anything to get me back to shaving metal properly more quickly!   :whoohoo:



Same deal on my cylinder.  At the time of this writing, my cylinder is complete with tapped holes, etc and I actually just finished the valve today, so it's crazy seeing this early stage.  Sometimes I take for granted just how much I have already achieved.



You certainly have to have a base for such an engine, and no time like the present...



By the end of the week, I had marked out the holes on the pillow blocks for mounting to the base.



“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #21 on: July 15, 2018, 06:03:19 AM »
The week of 1/29/17 saw some decent progress too.  Before I was able to save up enough money to get a set of collets, I used this old drill press.  This is NOT a recipe for precision, but I've often done what I felt necessary when I felt the risk to reward ratio was reasonable.



Here I've marked out the pillow blocks holes for tapping using the black marker method.



At this early stage I just had to lay out some of the parts.  It always helps to envision the future.



I spent a fair bit of time mounting the cross head to the face plate.



Additional attempts at precision here.  Again, a fair bit of time was spent.  By this time I had learned how easy it is to have things go wrong if you don't spend the time mounting parts well up front.



The moment has come.  Again I get to shave cast iron.  I just love  :Love: this process.  Yes, I'm also going to share with you these stages images I love so much.



There's that intermediate stage as the surface comes to full realization.



Look at that beautiful finish.  It truly never gets old for me.



By the end of the week I was able to get the cylinder mounted to the face plate, ready to be machined.



“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair

Offline propforward

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Re: Newbie building a PMR 6CI
« Reply #22 on: July 15, 2018, 11:55:51 AM »
Looking really good - I am enjoying seeing the stage by stage pictures.
Stuart

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #23 on: July 15, 2018, 03:25:19 PM »
The week of 2/5/17 was also pretty exciting.  I was able to bring the ends of my cylinder to dimension and begin boring my cross head.



Since my lathe is VERY basic, I found it helpful to manually add a gauge to my saddle travel to assist in obtaining the precision needed while trimming down the length of the cylinder.  The only issue with this method is that I have to be VERY careful not to bump the magnetic base.  Yes, I learned this from experience multiple times.   :zap:



Look at that finish!  I know..  broken record.  Anyway, you can see the less than perfect nature of the holes for the piston and valve.  We'll take care of that later.



Happy with the results, it's time to move on



Within this same week, I was also able to begin spinning my cross head.  I had already learned how carbide tips don't appreciate interrupted cuts.  I'm using a homemade boring bar with a small piece of HSS.  Later I will learn that the design sucks as it doesn't allow me to bore right up to the end of the length of the bar.

“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #24 on: July 15, 2018, 03:29:25 PM »
I'd really like to thank everybody for your kind words so far.  This project has been so much fun, and being new to all of this, I had to get over the fact that I continue to make mistakes.  I found this forum while looking for Corliss plans and I really liked the community.  That is why I decided it was time to start sharing my experience.

Nobody yet has even mentioned how unbelievably disgusting my work space is.  Yes, you have seen bottles of old antifreeze in the background.  It took me quite a while to remember the exact right Saturday of any given month so I could take them to the waste disposal facility.

Finally, please don't encourage me about step by step pictures.  Believe it or not, I'm sparing everybody A LOT of extra pictures!   :LittleDevil:

“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #25 on: July 15, 2018, 04:19:46 PM »
The week of 2/12/17 brought more excitement as I began to fit big pieces together.

Here we have the end of the cross head and bore essentially complete.  I'll still need to improve the finish of the bore and actually as I type this, I'm preparing to do just that.



This is a pretty bad picture, but shows an important process.  In order to ensure I kept a consistent depth of cut on the cylinder side of the cross head, I utilized my dial indicator as previously shown.



I truly am a simple creature.  It still fascinates me to see how I'm making a perfectly smooth cut at one point in the diameter of the part, yet not even penetrating the outside layer in another.  This is the case despite my strong efforts to ensure the part is centered, square, etc.  I'm sure this is par for the course with cast parts, but...   :shrug:



There's the same location of the part after taken to dimension and you can see that we have a wonderfully consistent cut across the diameter.



Cross slide with inboard head in place.  The dimensions came out very nicely.  It is a snug fit internally and the outside diameter is right on the money.



The two parts separated for illustrative purposes.



“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair

Offline zeeprogrammer

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Re: Newbie building a PMR 6CI
« Reply #26 on: July 15, 2018, 04:23:08 PM »
I had already learned how carbide tips don't appreciate interrupted cuts.

 :facepalm: I'd forgotten that. I wish I'd read this two days ago. But I'd lucked out and managed to make the part. (A flywheel rim from plate.)

I'm enjoying the thread.  :ThumbsUp:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #27 on: July 16, 2018, 03:35:28 AM »

 :facepalm: I'd forgotten that. I wish I'd read this two days ago. But I'd lucked out and managed to make the part. (A flywheel rim from plate.)


Yeah, I've certainly had success turning interrupted cuts with it, but I at least know intellectually that it's not ideal.

I'm really glad y'all are enjoying the thread.  I've been getting quite a bit of work done these past few weeks and I can't wait to get this thread caught up with the project.

“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #28 on: July 16, 2018, 04:15:27 AM »
The week of 2/19/17 saw the completion of the boring of the cylinder and creating precise holes in the crank disks for the crank pin.  I have to be honest and say that the method of aligning the two crank disks was taken straight from rcdon's web page.

I used my dial indicator to ensure the boring bar was running true before spinning the cylinder about it.




..and here's the result.  One more hole to be reamed and quite a few holes to be drilled and tapped.



I think this method for alignment of the drill on center was satisfactory.  I've since learned of a very simple concept where a longer rod with a point sits in your tool holder and pushes into your center punch.  It rotates a short distance from the work on a fulcrum showing a much exaggerated display of how far out of center you are as the long end wobbles.  I need to make one of these soon!



This is pretty much just a zoom out of the last picture.  You can get a good look at my messy work space and less than restored lathe!



Now comes the center drill.



After working through a couple of drills, stepping up from a smaller drill, I ran a reamer through and called it good! :cartwheel:



“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #29 on: July 16, 2018, 04:29:16 AM »
The week of 3/5/17 didn't produce very many pictures, but I did get my valve port reamed.

I decided to trace the cylinder on a sheet of paper, get the center of the cylinder marked out and measure the distance to the center of the valve port.  I was very happy with the results.  Maybe there is a better way, but I couldn't think of one.



Once again, here are the results.  Yesterday I got the proof that the valve port was a consistent diameter throughout as I tested my complete valve!   :whoohoo:



“It is difficult to get a man to understand something, when his salary depends on his not understanding it.” - Upton Sinclair