Engines > From Kits/Castings
PMR #1 Drilling Engine - Mike's 4th Engine
b.lindsey:
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
mikehinz:
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.
mikehinz:
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!
mikehinz:
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
mikehinz:
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
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