Author Topic: PM Research Engine Number 1  (Read 6548 times)

Offline propforward

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Re: PMR #1 - Props first casting project
« Reply #15 on: September 22, 2018, 11:51:56 PM »
Yes, thatís a chuck spider from Edge Technologies. Itís a 3 armed device, with strong magnets, that holds different ground parallels, to put behind thinner jobs and hold them square to the chuck. Itís the first time I used it today - works rather well.
Stuart

Offline Ye-Ole Steam Dude

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Re: PMR #1 - Props first casting project
« Reply #16 on: September 22, 2018, 11:52:37 PM »
Hello Stuart,

Good start and will be fun to follow this build.

Have a great day,
Thomas

Offline propforward

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Re: PMR #1 - Props first casting project
« Reply #17 on: September 22, 2018, 11:55:19 PM »
Thanks Thomas! I shall be pleased to hear any comments of yours as we go along, thanks for checking in.

Here is more on the spider:

http://www.edgetechnologyproducts.com/chuck-stop-set/

Bit pricey, but fair value. I never had much luck setting up with parallels. Could never seem to get thin items square. I got mine in a sale somewhere - might have been Shars.
« Last Edit: September 23, 2018, 12:34:17 AM by propforward »
Stuart

Offline crueby

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Re: PMR #1 - Props first casting project
« Reply #18 on: September 22, 2018, 11:56:43 PM »
http://www.edgetechnologyproducts.com/chuck-stop-set/

Bit pricey, but fair value. I never had much luck setting up with parallels. Could never seem to get thin items square. I got mine in a sale somewhere - might have been Shars.
Slick unit, thanks!

Online b.lindsey

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Re: PMR #1 - Props first casting project
« Reply #19 on: September 22, 2018, 11:57:39 PM »
Stuart, no I mean using grub screws instead of turning down the bottom and threading it. Tap the body of the oil cup below the reservoir 2-56 and then loctite the grub screw in place after drilling through it.

Bill

Offline crueby

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Re: PMR #1 - Props first casting project
« Reply #20 on: September 23, 2018, 12:00:53 AM »
Stuart, no I mean using grub screws instead of turning down the bottom and threading it. Tap the body of the oil cup below the reservoir 2-56 and then loctite the grub screw in place after drilling through it.

Bill
Now thats a clever trick!

Online b.lindsey

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Re: PMR #1 - Props first casting project
« Reply #21 on: September 23, 2018, 12:03:22 AM »
It works well Chris. I think you get stronger threads and also threads up to the very bottom of the oil cup.

Bill

Offline propforward

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Re: PMR #1 - Props first casting project
« Reply #22 on: September 23, 2018, 12:21:02 AM »
Oh I see! Yes that makes a lot of sense. I can see how you would get better engagement that way. Thanks for the tip!
Stuart

Offline zeeprogrammer

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Re: PMR #1 - Props first casting project
« Reply #23 on: September 23, 2018, 12:50:37 AM »
I don't quite understand Bill's suggestion re grub screw and oil cup so take pictures!

I like that spider but as you say, a bit pricey. Can those parallels also be used in a vise? How thick are they?
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline crueby

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Re: PMR #1 - Props first casting project
« Reply #24 on: September 23, 2018, 01:09:25 AM »
Rather than turning threads on a post at the bottom of the cup, drill and tap a hole for a screw into the bottom of the cup. Drill a through hole in the grub screw and loctote it into the threaded hole in the bottom of the cup. The grub screw forms the threaded post.

Offline propforward

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Re: PMR #1 - Props first casting project
« Reply #25 on: September 23, 2018, 06:59:27 PM »
Well, I just got done milling the steam chest out, and I must say I'm happy with how this has gone. I had to put together a coordinate diagram for it, and then carefully keep track of my handwheel positions, because I don't have DRO's (not likely to add these in the foreseeable future), and also made sure to write down diagrams to remind me which way to turn the handles (sounds obvious but I've fallen foul of that before).

Anyway, I'm 2 thou over on the depth of the chest, which is within my general tolerance goal of Ī0.005 so I'm pleased. Looks decent too, in my opinion.

Now I'm trying to decide how to center the slots in the bottom of the chest. I can easily do that from the sides of the steam chest, but then how to center the bore in relation to that? Need to give that some thought. I have a feeling that if I center the slots in relation to the casting OD, that everything will line up well enough. Have to double check dimensions on the valve etc, make sure everything will work if I do that. Also need to get some small milling cutters, so this is it for now. Got to go and do some  chores. Leaving the cylinder where it is for now, because I want to mill the slots, and also drill the holes for the cover before moving it.

« Last Edit: September 23, 2018, 07:22:15 PM by propforward »
Stuart

Online b.lindsey

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Re: PMR #1 - Props first casting project
« Reply #26 on: September 23, 2018, 07:31:01 PM »
That finish turned out well Stuart. You are making some good progress already!!

Bill

Offline crueby

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Re: PMR #1 - Props first casting project
« Reply #27 on: September 23, 2018, 08:03:06 PM »
Very nice!  Glad I am not the only one who maps out the moves.   :popcorn:

Offline propforward

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Re: PMR #1 - Props first casting project
« Reply #28 on: September 23, 2018, 08:49:46 PM »
Thanks much. It was quite fun - the chest filled up with chips of course, so I patiently kept milling and carefully keeping track of location. Then when I vacuumed out the chips at the end, was absolutely delighted with the result. Shouldn't take much to get the base and flange smooth to make good seals.

I have to use a map for the milling pattern on something like this, or I'll end up in a world of hurt - or at least a ruined part. :D Don't need that at this stage!
Stuart

Offline Tennessee Whiskey

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Re: PMR #1 - Props first casting project
« Reply #29 on: September 23, 2018, 10:25:50 PM »
Looking great Stuart. I centered my ports to the bore by doing it and then turning it ninety degrees from the way you are holding yours, inserted a plug and centered from that.

Whiskey