Author Topic: PMR #1 Drilling Engine - Mike's 4th Engine  (Read 9777 times)

Offline b.lindsey

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #15 on: February 15, 2019, 09:44:46 PM »
 Mike, it wouldn't hurt to call and ask them. I suspect they will given how much you had to take off due to the inclusions/voids.

Bilk

Offline mikehinz

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #16 on: February 20, 2019, 01:38:17 AM »
Just a quick update on the flywheel.  Since I had to install my 4J today for the work I was doing on my spindle adapter repair, I went ahead and chucked up the flywheel leaving enough of the rim exposed to indicated it in.  I also used a small steel block as a spacer to firmly seat the other side of the flywheel that had been previously trued up, against the inside face of the 4J chuck jaws. 

After doing so I took a cut on the exposed side of the rim and on the outer face of the hub.  Surprisingly and very much unlike the other side of the flywheel I only had to take off about .030 in order to clean it up. 


The last pix shows the just completed side against the print.  It looks a bit like it's not cleaned up but that's just some oil in a couple of places.


The flywheel rim width ended up being .43".  The rim is a bit off center since I had to take so much from the first side.  However, I think I'll leave it as it as if it gets to bothering me too much, I'll order a new flywheel casting from PMR or perhaps Martin Pattern and Model. 

Nexts I plan to make a simple mandrel out of some 3/8" drill rod and Loctite it in place.  Then I'll take some very light cuts to make the rim and sides of the rim run true to the hub.  Hopefully that will work OK without too much ringing and chatter! 

All for now.

Enjoy!

Mike.
MIke
Wichita, KS, USA

Offline mikehinz

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #17 on: February 24, 2021, 08:06:03 PM »
Well, after a very long absence from any work in my shop or posting on this forum, due to various issues in life, I've made it back!  Over the last few weeks, I've made a fair bit of progress on the PMR #1 kit and I'll catch up on my progress over the next few days and hopefully soon get caught up to present day. 

It's good to be back working in the shop again!
MIke
Wichita, KS, USA

Offline mikehinz

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #18 on: February 24, 2021, 08:12:19 PM »
Just to show finishing up the flywheel:

I used Loctite 638 and glued in a piece of drill rod and then mounted the same in a collet block and inclined it in my mill vise just to get the clearance required to make the drill and tap for the set screw. 

First milled a flat:


Then tapped the hole :


So the flywheel is now completely finished.

Mike

MIke
Wichita, KS, USA

Offline mikehinz

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #19 on: February 24, 2021, 08:44:35 PM »
Next is getting some fairly major work done on the frame.

Since it had been quite some time since I'd made the fixture for the frame, I mounted it in the mill vise and indicated a ground rod laid in the slides just to make sure that it was reasonably square with the world.



Milling the top of the slide surfaces to the required dimension from the top of the cylinder mounting flange as per the prints.



Milling the area between the bearing bosses as per the print.  I had to use an extended end mill to reach the areas.  i never like using those extended end mills as the tend to chatter with the slightest bit of pressure.



After milling the area between the slide surfaces to the dims called out in the print, I used a Starrett adjustable parallel to confirm the dimension.



Milling a groove on the rough bearing surfaces to be used to determine the centerline of the TBD bearing surfaces.  I measured the height off the slide surfaces and added/subtracted as necessary to get to the centerline of what will be the cylinder.



I took the groove 'forward' and 'down' to assure that a 3/16" pin's center would be exactly where the center of the bearings would need to end up.



Drilling and tapping the required 5-40 holes for mounting the spaces for the top slides.  Locations were determined from the centerline of the frame and per the print, assuring that the holes were equally distanced from the end of the slide surfaces.



Bolted the fixture plate on my 90 degree angle plate and make sure the frame was level horizontally.



And vertically as measured from the slide surfaces:



Found center in y from the edge of the fixture plate as I'd previously determined that the frame was within .001" on center of the fixture:



Then to position in x, I clamped a 123 block on the slide surfaces, found the edge and then figured out where I need 0 from there.



Used my boring head to create the round mounting area for the cylinder.  I'd just started cutting in this pix.   The flat area was from a previous operation.  I put that feature there with an end mill so i had a reference for the operations when the frame was mounted horizontally. 



After drilling pilot hole in the center, i used some feeler gauges to make sure that the slide surfaces and centerline of the cylinder ended up at the proper locations.



Drilled the center hole plus the bolt pattern for mounting the cylinder plus drilled and tapped the 2-56 holes for the backing gland.  I just use the DRO on the mill, but since my DRO is an old Sony with limited features, I lay out what I need in CAD and then just use the x,y coordinates generated to move the mill table as needed.  This works well for me.



The frame almost done, except for the bearing surface that need to be at 45 degrees plus of course getting the required 3/8" thru the bearing area for the crankshaft.



This should do it for this post.

Mike
MIke
Wichita, KS, USA

Offline mikehinz

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #20 on: February 24, 2021, 08:55:21 PM »
A few pix of finishing the bearing caps.   I'd previously flattened the bottoms and cleaned them up a bit on my belt sander.

Drilling the thru holes for the bolts.  Caps are mounted on each end of the mill vise to make sure they're well gripped on the vise.  I'd zero'd the DRO on the left rear of the mill vise so I just swapped the caps whenever I finished one.



I set the caps at 45 degrees with an angle block and spot face and drilling and tapped for the oil cup locations.



Top side of the caps finished.



Turned the caps over and made sure that they were flat.  I'd put them on top of parallels but since they were rough on that side, i wanted to be sure.



Milling the bottom feature on the caps.  This locates the bearing caps at the correct position on the frame. 



And finally the caps completed as shown from the bottom surface.  The hole is the oil cup mounting hole that I drilled thru. 



And that's it for the posting for today.  More tomorrow hopefully.

Mike
MIke
Wichita, KS, USA

Offline propforward

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #21 on: February 25, 2021, 01:09:14 AM »
Well, after a very long absence from any work in my shop or posting on this forum, due to various issues in life, I've made it back!  Over the last few weeks, I've made a fair bit of progress on the PMR #1 kit and I'll catch up on my progress over the next few days and hopefully soon get caught up to present day. 

It's good to be back working in the shop again!

Glad to see you back. Your work on the engine is top shelf - very nice indeed.
Stuart

Forging ahead regardless.

Offline cnr6400

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #22 on: February 25, 2021, 02:39:02 AM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: :popcorn: :popcorn: :popcorn:
"I've cut that stock three times, and it's still too short!"

Offline bent

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #23 on: February 25, 2021, 05:52:51 PM »
Looking good!  No apologies for delays required, it's been quite the year+ for me too.  Hope to get back to hobby machining soon,  maybe once the weather warms a bit.

Offline mikehinz

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #24 on: February 25, 2021, 06:40:28 PM »
This series of pix shows how I machined the bearing cap surfaces on the frame. 

First was to get the frame, which is mounted on the fixture plate to a 45 degree angle.  I do have an adjustable angle plate, but pure laziness and sloth made me just clamp the fixture place in my Kurt vise.  The angle block is just shown for reference.  I actually turned it over and used a DTI to make sure the angle was correct.



Then i swept the 3/16" pin with the DTI to make sure the frame was actually square with the mill.  I didn't show it, but I knew that the center of the 3/16" pin is exactly on the bearing hole centerline.  So I touched off of the top of the pin and then did the arithmetic to get the bearing surfaces and the notch to the correct depths. 



After milling the features on the top, measuring the .500" slot with using an adjustable parallel.  I did manage to actually hit the dimension on the nose!  Miracles do occur!



Drilling the hole pattern on both sides for the bearing caps.



Then threading the holes 3-48 using a spring loaded tap follower and a very small tap handle.   I do like working with cast iron as it machines and taps easily.



The bearing caps fitted.  Everything went together well. The bearing caps are even with the frame on the inside, but not on the outside, but I think that this is what's intended on the prints.



So that does it for getting the bearing caps onto the frame.  Everything came out good so far!

Mike

MIke
Wichita, KS, USA

Offline mikehinz

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #25 on: February 25, 2021, 07:28:20 PM »
On to making the hole thru the frame and bearing caps for the crankshaft.  I was somewhat afraid of this operation as the surfaces are a bit uneven and there's the existing groove for locating the c/l.  In any case, here we go!

There's actually a lot going on this pix.  I bolted the fixture plate onto the 90 degree angle plate and spaced it up with some 123 block.  The 3/16" pin is held into the previously milled groove with some longer 3-48 screws to make sure it stays in place.  Then I swept the pin vertically in both axis to make sure the frame is straight and luckily it was as I was pretty careful when i made the fixture plate.  Lastly I centered the spindle over the pin and locked the mill table down once I was on center.



Then I milled a flat area with a 3/8" end mill just to make sure that I had a flat surface to start on.  I didn't show the pix, but I think used a 5/16 EM to make the initial hole thru the top most area on the frame and then used an extended 1/4" EM to mill thru the bottom area of the frame. 



Since I now had a (hopefully) straight hole thru both sides of the frame and bearing cap area, I then drill thru 1ith a 23/64" bit.  And since the previously made holes with the end mills were straight, the bit should also remain straight thru both existing holes.



Then finished the hole feature by reaming thru with a .375 reamer.  The crankshaft is spec'd to be .374" so there should be clearance, plus when the crank is made it can be tested against the frame to be sure.



And finally checking the fit with a piece of on-size drill rod.  The drill rod fit well when the caps were tightened down and the rod could be rotated by hand, so I declared success on this operation!  This turned out to be a relief to me as I had feared that something might go horribly wrong somewhere during this process.



All for now.  I'll post more tomorrow or the next day as I progressed on the other parts of the engine.

Enjoy!

MIke.



MIke
Wichita, KS, USA

Offline samc88

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #26 on: February 25, 2021, 09:47:52 PM »
Nice work so far Mike

Offline mikehinz

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #27 on: February 26, 2021, 03:28:47 PM »
Now we're back to some of the smaller parts that need to be checked for fitment against the frame once done.

First is the crosshead.  The raw casting was pretty good, that is more or less straight and square and had plenty of material that could be removed so it was relatively easy to get to the final part.  I measured the width and estimated how much need to come off each side.  The raw part could be gripped security just by placing it in the vice as shown.



Then I turned the part 90 degrees and finished the top of the slide area.  First one side:



Then the other side.  Confirmed the thickness dimension as that's fairly important as it has to slide between guide surface on the frame and the top slide. 



Further workholding on the part becomes tricky from this point on, so I made a couple of AL bits that allowed the part to be held in the vise as required by the just milled flat surfaces.  Alternatively, if you didn't care about maintaining the original appearance of the part, the enter area could have been milled flat and held securely after that operation.  I wanted to try to maintain the original appearance.



Part being held by the little fixtures resting on parallels.  This was milling the side of the circular area flat and to dimension.



Then bluing the part, finding the center of it, pretty much by eye and starting the spot drilling/drilling/reaming ops to get to .25"



.25" pin shown thru the part to verify the hole was correct.



Squaring the part up in preparation for bringing it to length.



Milling the part to length and sacrificing a bit of the fixtures in the process.  I didn't get a pix of what I had done previously, but I'd marked the length from the center of the hole as per the print, and simply milled to down to that mark.



Next I needed to mill the slot for the connecting rod into the part.  I had to think about this a bit as the measurement for the slot is taken from the centerline of the hole, but there was no way to get that measurement without a pin in place.  So what ended up doing was to pin a .25" pin in the hole, set the vise stop rod, find the edge of the pin, then remove the part, remove the pin from it and place the part back in the vise against the stop rod. 



Milling the slot.  I used an under-width end mill and then moved off the centerline equally in the y axis to bring it to the final width.  Surface finish was good in the slot.



Gauging the slot width with a pin. 



And the finished part on top of the print.  I actually did drill and tap the 10-32 hole in the end of the part, but failed to take a pix of that op.  But nothing tricky about it as it was easy to find the location and this material, although a bit sticky, drill and taps easily.



So, this part is finished and I confirmed it fit within the frame slide area. 

All for now.  Enjoy!

Mike



MIke
Wichita, KS, USA

Offline bent

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #28 on: February 26, 2021, 03:48:54 PM »
I think it adds a lot to the look of an engine to keep as much of the "as cast" surface as possible.  Good job, in my book.

Offline Johnmcc69

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Re: PMR #1 Drilling Engine - Mike's 4th Engine
« Reply #29 on: February 26, 2021, 03:49:31 PM »
 :ThumbsUp:
 Great set up's & fixturing Mike!

 John

 

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