Author Topic: Newbie building a PMR 6CI  (Read 9829 times)

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #45 on: July 20, 2018, 02:23:10 AM »
The week of 7/30/17 produced some very important holes.  If anybody's eyes are bleeding, I've done you a favor.  I just don't have that many images to provide for this week.

I test fitted the inner valve head before committing to anything.



All my lovely pieces set out and ready for orientation markings.



This close-up looks a little rough, but you can see my dykem with scribing.



Holes successfully transferred.



“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 #46 on: July 20, 2018, 03:26:15 AM »
The week of 8/6/17 produced very little overall change.  Essentially I milled the flats of my cross slide and drilled the mounting holes.

With so many ways for this to go terribly wrong, I balanced the need to ensure the part was well oriented in the vise.  I had this piece of aluminum which I clamped tight against the bore of the part and used my calipers to ensure it was running true.




Here is another look at the setup.  Mounting the cross slide to the cylinder allows me to ensure there is no unwanted rotation.  You might also notice that I've drilled two small holes in the bottom of the cylinder.  These will have globe valves to facilitate draining of the cylinder when you are done running the engine on steam.  I DO plan to run this on steam ultimately.



Here I am making sure that rotation doesn't happen.  It's a decent setup pic, but how freaking cool does that head look bolted on?  I just love it.  :mischief:



You can see this effort coming together well.  There is a need to have a very specific height from this bottom to the center of the bore, so a great deal of effort has been made to complete this relatively small bit of metal removal.  You can also see two bolt heads which will normally be out of site, holding the cylinder to the head to the cross slide.



I'm getting closer here.  I just love seeing the horizontal milling cutter in action or just ready to do work.  It removes metal like a beast and you don't often see horizontal action.



All done and height verified.  There's a bit of swarf for all of you!



This is a little better view of the finished work.  I have two horizontal cutters and I figured out this one produces a much better finish.  I really enjoy using it.



I failed to get a shot of all 4 holes complete, but the other three look a lot like this one!   :Lol:



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

Offline crueby

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Re: Newbie building a PMR 6CI
« Reply #47 on: July 20, 2018, 03:37:44 AM »
Impressive work, looking great!!


 :popcorn:

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #48 on: July 20, 2018, 02:13:05 PM »
Impressive work, looking great!!


 :popcorn:

It's very nice of you to say.  This fantastic community has a lot to do with why I chose to post here!   :praise2:

Last night I realized that I'm either missing a series of images, or I didn't do much in the last year.  It will require a bit more effort to know for sure.  I may get you all caught up sooner than anticipated.

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

Offline Brian Rupnow

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Re: Newbie building a PMR 6CI
« Reply #49 on: July 20, 2018, 11:16:59 PM »
Vdub--Very nice work, and great documentation. Your enthusiasm really comes through on your posts. I can remember feeling the same way 10 years ago when I bought my first lathe and mill.---Brian Rupnow

Offline zeeprogrammer

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Re: Newbie building a PMR 6CI
« Reply #50 on: July 20, 2018, 11:42:36 PM »
Your enthusiasm really comes through on your posts. I can remember feeling the same way 10 years ago when I bought my first lathe and mill.

Same here. And what I like is that kind of enthusiasm can be contagious. It's certainly helping me.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Baner

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Re: Newbie building a PMR 6CI
« Reply #51 on: July 22, 2018, 06:08:48 AM »
I just read through your build log. Excellent work! Castings can be quite a challenge and you're handling them like a pro. I'm loving your machine tools too. There's a certain pleasure in using old iron.

I didn't notice anyone post, and you may have learned since, but when machining cast iron cover the machine ways with a paper towel or rag. Cast iron chips are abrasive and they'll accelerate wear if allowed to get under machine slides. Cleaning it off can be hard because it's so fine. Best to cover up. Same goes when Dremel grinding on the lathe, or even using abrasive paper to polish. Need to preserve those machines!

Dave.   

 

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #52 on: July 22, 2018, 03:21:21 PM »
Your enthusiasm really comes through on your posts. I can remember feeling the same way 10 years ago when I bought my first lathe and mill.

Same here. And what I like is that kind of enthusiasm can be contagious. It's certainly helping me.

Thank you everybody.  It's always nice to hear people validate your work and to one degree or another, I expected that.  However, this particular recognition I certainly didn't expect.  To think that my sharing keeps somebody else excited about the hobby is definitely more than I would have known to hope for!   :stir:

I just read through your build log. Excellent work! Castings can be quite a challenge and you're handling them like a pro. I'm loving your machine tools too. There's a certain pleasure in using old iron.

I didn't notice anyone post, and you may have learned since, but when machining cast iron cover the machine ways with a paper towel or rag. Cast iron chips are abrasive and they'll accelerate wear if allowed to get under machine slides. Cleaning it off can be hard because it's so fine. Best to cover up. Same goes when Dremel grinding on the lathe, or even using abrasive paper to polish. Need to preserve those machines!

Dave.   

 

Again, it is very nice to hear such praise.  I certainly don't feel like I deserve it today.  Over the past couple of days I took a cross head which was well set up for success and made a last second change that rendered it beyond what I'm willing to accept.  I believe I will be able to use it to continue forward in the build, but I think I'll take the opportunity to create a replacement from a chunk of steel.  That should be fun and definitely a very new experience for me.

Also, thanks for pointing out about the cast iron.  I've been a touch on the anal side about clearing it from the ways, but seeing the words typed, I realize I need to do more.  I've seen others with paper/cloth covering the ways and I convinced myself that they were just being unnecessarily cautious.  It's time to change that thought process.   :embarassed:

“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 #53 on: July 22, 2018, 07:38:03 PM »
The week of 7/16/17 saw a little bit of advancement.

This is an example of a wonderfully useful and simple shop made tool.  This tap guide helps make sure the tap cuts threads perpendicular to the surface.



Now I can mount both of the valve heads to the cylinder.



“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 #54 on: July 22, 2018, 08:12:43 PM »
About a month went by and the week of 8/20/17 saw some movement on the eccentric yolk.

At this point I did not yet own a height gauge so I had to get creative in finding the center.  I know this setup may look a bit ridiculous, but it did wind up being effective.




A brass connecting rod will be bolted through a hole drilled here, so I had to find center again.  Yes, the casting is less than perfect so you do have to go to a bit of extra effort in finding the "proper" center.  I'm certain this is just what to expect from casting as opposed to feeling like there is anything wrong with the castings.  In that way, castings may save time, but aren't necessarily simply easier.



Let's start with something simple.  After ensuring the yolk was properly vertical in the vise, it was time to drill.



Since I've already completed the dimension of the width of the yolk, determining the center here is a definitive measurement from an edge.  I rather enjoy the process of finding center.  Interestingly enough, with all of the mistakes I make often I decide to do the math for centering in my head and it rarely winds up being a problem.  Though, I generally know if I need to double check myself.



Without a DRO, it makes sense to find center, make a center indentation, spot face and drill through up to the size of the threading size drill all in one go.  Then, I also drill the larger size for the bolt to slip through all the way down to the center mark I made earlier.  If I'm very careful, it will stop right in exactly the correct place, leaving the larger size hole on the back strap of the yolk and the smaller size where I need to cut threads.  I prefer doing as many operations as possible with the yolk set up parallel rather than trying to make sure it is perfect again later.  The chances that it would be perfect are slim.



There's the part with holes drilled to size and ready to be sawn.  Notice the larger sized hole from this side.



The same part from the other side, and notice the smaller size hole here.



“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 #55 on: July 22, 2018, 08:38:40 PM »
The week of 8/27/17 saw the completion of the eccentric yolk.

Please feel free to have a laugh at this slitting saw.  I decided to save some money to get further along in the project more quickly.  This piece of junk likely took 10 times longer to get through the material, having to run it so slowly and take such light passes.  I've since replaced it.



Slitting saw work complete.  I'm quite pleased with the overall result.  If you look closely, you'll see just a bit of a chamfer at the lead in to the holes of the clamped piece.  It's almost like I planned it that way.  Well, I actually did!   :old:  With a quick clean up from a milling bit and some tapping, they'll be ready to be clamped together and bored out.



The yolk clamped together after threads cut, waiting for the boring operation.  <insert Keith Appleton joke about boring vs. boring here>




I was very excited to finally be putting my boring head to work.  My little milling machine doesn't have a terrific amount of Z axis travel and there wasn't much room to spare.  But, it was enough to get the job done!   :whoohoo:



There she is in all her glory.  I'll save you the need of asking the question.  Yes, I do consider it complete and yes I do realize that there is still some crust in surface on this side.  When I was milling this part, yet another mistake was made, leading me to have to make a decision.  I decided that there is enough good and smooth surface area here to work well.  Also, while there will certainly be contact made on the side, the force is not horizontal in nature, so I think it's a reasonable compromise.  I'll always see the flaw and remember that this whole project was a giant learning process for me. :embarassed:



“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 #56 on: July 22, 2018, 08:54:39 PM »
The week of 9/3/17 offered another foray into the wonderful world of turning brass.  My god is brass an absolute joy to machine.

But first, I apparently spoke too soon in my last post.  There was another operation to perform on the yolk.  And, in that regard, the part is honestly not complete to this day.  Though I've drilled this hole for the oiler, I haven't yet tapped it.  The reason for this is that I can put off buying that tap, while still mostly completing the part and also I'm not certain what size I'll necessarily wind up using.



I read about this process in the George Thomas' book Workshop Techniques a while back.  For those who aren't already familiar, I'm using a "bar" (drill) of the proper size, to rotate the part around in the vise, milling a bunch of successive flats in order to create a radius.  It's actually extremely effective.





Next, I drilled a hole which will become the back of an open slot.  It may look odd now, but keep watching.



Here's my awesome slitting saw in action again.



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

Offline crueby

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Re: Newbie building a PMR 6CI
« Reply #57 on: July 22, 2018, 09:34:04 PM »
Looking great. Brass is my favorite too, wonderful stuff. Milling the end round like that works great, just have to be sure the bar is tight down to the top of the vise, no chips under it. Works great for larger curves too, can use a smaller bar in large hole for half round caps, just press down on the cap to center the bar in the arc.




 :popcorn:

Offline vdubjunkie

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Re: Newbie building a PMR 6CI
« Reply #58 on: July 23, 2018, 04:05:44 AM »
Looking great. Brass is my favorite too, wonderful stuff. Milling the end round like that works great, just have to be sure the bar is tight down to the top of the vise, no chips under it. Works great for larger curves too, can use a smaller bar in large hole for half round caps, just press down on the cap to center the bar in the arc.




 :popcorn:

That's a good tip.  I hadn't thought of changing the arc with a smaller bar, but it does make sense.

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

Offline b.lindsey

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Re: Newbie building a PMR 6CI
« Reply #59 on: July 23, 2018, 02:09:39 PM »
More great pictures and progress. Keep them coming :)

Bill