Pacific Vapor Engine from Morrison & Marvin Castings

[kvom]

We need a Merlin build here.

[Dave Otto]

Hi guys
When I first built the drive gear assembly for the pump there were quite a few comments about how the gear covered up the nice lettering on the base of the engine. I really wanted to stay true to that advertisement that I had used to model the pump assembly.

Well after looking at it for a while now and watching it run I have decided to go ahead a put some spokes in the cast iron bull gear. I feel that it will give the engine more visual interest both running and static. Being able to see the Pacific logo will also be a plus.

Some of the early California engine builders used webs between the flywheel spokes for counter weights. Mery is one that comes to mind. I decided that the web approach would be a good way to create the boss where the drive pin will be located.


The gear was modeled in Alibre to see how it would look. I printed one at work so I could put it on the engine and think about it for a while. I kind of liked it.


Starting out a pair of soft jaws were machined to hold the gear.


Then the gear was indicated in.


The first side of the gear is machined. I used a .03 radius carbide bull mill for all operations. This way I could use this cutter to surface the radius in and not have to change tools. A, (Z Level finish) tool path was used with a .005” step down. I’m a long time user of BobCAD and really liking the current version #31, I believe it is their best yet.


The gear was flipped over indicated in, and machined.


Here it is fresh from the mill to see how it is going to look.


After a little bench work to remove the tool marks and a light bead blast. I’m quite pleased with how it looks on the engine.
One other concern I had was how to keep that large machined solid gear looking nice, now it can be painted with just the outer rim left bare.


Thanks for checking in.
Dave

[Art K]

Dave,
The job on the gear is great. Looks good on the engine as well. I have to admit not owning any bull endmill. Standard and a few radius emill's.
Art

[cnr6400]

That last photo is great Dave, and fine work on the gear and other engine and pump parts. Staying tuned here! 

[kvom]

I see a few chips in a couple of the photos.  Dave's work is slipping.   

Gear is great anyway.

[Steamer5]

Hi Dave,
 Just been back to check the before shot!
This steps it up yet another level! Very very nice.

Cheers Kerrin

[fumopuc]

Hi Dave, very impressive. Ist there any picture of the operation itself available, with the cutter ?

[Kim]

Wow Dave! That looks amazing!  Very slick indeed.
So, I'm not familiar with the term Bull Mill.  What's different about a bull mill compared to a regular end mill?
Kim

[Jasonb]

Sounds like what we call a radius end mill, just the corners of the tips have a convex radiused, I have freehand ground them from blunt standard cutters when wanting an internal fillet as they remove metal far faster than a round nose (which we call bull nose) cutter.

Wheel looks good Dave

[yogi]

Beautiful gear Dave! 
It adds even more character to an already impressive masterpiece! 

[Tennessee Whiskey]

Beauty on top of beauty   

Eric

[Ye-Ole Steam Dude]

Hello Dave,

OK, that gear is way too pretty to cover up any part of it with paint, how about anodize it? 

Have a great day,
Thomas

[zeeprogrammer]

Your finishes are always astounding.
I'd like to know more about your bead blasting system and other tips/techniques for getting those awesome finishes.

P.S. Chips on the table? tsk tsk

[Dave Otto]

Thanks for all the very nice comments guys.

Yesterday was a busy day for us, my daughter graduated from BSU with her degree in Mechanical Engineering, her mom and I are very proud of her. She already has a great job at a local robotic and industrial automation company where she has worked for the last couple of years first as a summer intern and then an engineer in training. https://thehouseofdesign.com/

As Jason has indicated a bull end is just a different name for a flat end mill with radiused corners. Lots of times it is nice to have both the flat cutting ability and the radius combined in one tool. They are very nice for 3d surfacing in some applications.

Achim, I didn’t take any pictures of the cutting operation but I have attached a picture of the tool path used to radius the spokes. Because of the radius on the tool the steps are blended and only take a quick rub with some sanding cloth to remove the tool marks.

Zee, I have also attached a picture of my little blast cabinet. It’s nothing very fancy, I built it many years ago. The upper box with the arm holes I purchased at an employee auction. It was a small self contained bench top unit for doing very fine cleaning of vacuum system components; all I got was the sheet metal box. I fabricated stand and lower hopper and assembled what you see here. A small gun was purchased and I had scrounged a foot pedal air valve. The fancy stainless steel cyclone separator was added later down the road. It came off a piece of high tech equipment that a friend was scrapping out.

But what matters is the media, I use very fine glass bead (https://www.mcmaster.com/3337k59) to obtain that nice satin look. The prep work is done with fine files, sanding sticks and sanding cloth rolls.

Thanks again guys, I will try to do a better job of the swarf-less machining that I seem to be known for.

Dave

[fumopuc]

Hi Dave, thanks for the toolpath picture, it makes it easier for me to understand.