Author Topic: Flyboy Jim's PM Research #5  (Read 6056 times)

Online gbritnell

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Re: Flyboy Jim's PM Research #5
« Reply #75 on: November 12, 2019, 04:08:26 AM »
I have built a couple of PM's models and while I find them nicely done and supplied I just wish they would allow a little more finish stock on the castings.
gbritnell
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Online crueby

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Re: Flyboy Jim's PM Research #5
« Reply #76 on: November 12, 2019, 04:44:17 AM »
Excellent!!   :popcorn:

Online b.lindsey

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Re: Flyboy Jim's PM Research #5
« Reply #77 on: November 12, 2019, 01:44:12 PM »
I found that bore to be one of the trickier operations. Nicely done, especially on the Sherline!!

Bill

Offline Flyboy Jim

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Re: Flyboy Jim's PM Research #5
« Reply #78 on: November 12, 2019, 02:07:26 PM »
I found that bore to be one of the trickier operations. Nicely done, especially on the Sherline!!

Bill

Thanks Bill and Chris..

Machining this casting has been quite the challenge for both my Sherline mill and the operator.  :thinking: Very enjoyable.

Since you both are my "unofficial Sherline mentors" I spend a lot of time reading you two's Sherline build threads. Actually, I reread my own as well, since I can't always remember how I did some particular operation (something to do with that "CRAST" disease).  :shrug:

Jim
Sherline 4400 Lathe
Sherline 5400 Mill
"You can do small things on big machines, but you can do small things on small machines".

Online crueby

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Re: Flyboy Jim's PM Research #5
« Reply #79 on: November 12, 2019, 04:08:15 PM »
 :happyreader: I do the same thing sometimes - know that I made a part like that once....   :headscratch:

 :popcorn: :popcorn:

Offline bent

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Re: Flyboy Jim's PM Research #5
« Reply #80 on: November 12, 2019, 09:41:21 PM »
Hmm, nice approach.  I think I'd use a boring head for the recess, but only because I don't have a rotary table...yet.  :popcorn:

Offline Flyboy Jim

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Re: Flyboy Jim's PM Research #5
« Reply #81 on: November 13, 2019, 02:30:15 AM »
Hmm, nice approach.  I think I'd use a boring head for the recess, but only because I don't have a rotary table...yet.  :popcorn:

I thought about using the boring head also, but found it difficult to adjust in small increments to the exact circumference I needed. Getting the bore to the exact size I needed was a challenge. It worked out great though. I got it to .002" less than the .750" I needed, so decided not to press my luck. With the end mill I could mill out to the exact circumference I needed. Then I took .010" bites at a time and just went around and around until I got the recess to a depth of .062.

I hope you're able to get a RT soon. It really does open up a whole new realm of machining possibilities!

Jim

 
Sherline 4400 Lathe
Sherline 5400 Mill
"You can do small things on big machines, but you can do small things on small machines".

Offline mike mott

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Re: Flyboy Jim's PM Research #5
« Reply #82 on: November 13, 2019, 02:59:52 PM »
Nicely done on the boring and facing Jim. I'm impressed with that much distance away from the clamped surface that the casting was rigid enough to do the recess without some form of supplementary support. Of course nothing to say about your skill in pulling it off. :whoohoo:

Mike

 
If you can imagine it you can build it

Offline Flyboy Jim

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Re: Flyboy Jim's PM Research #5
« Reply #83 on: November 15, 2019, 04:07:06 AM »
Nicely done on the boring and facing Jim. I'm impressed with that much distance away from the clamped surface that the casting was rigid enough to do the recess without some form of supplementary support. Of course nothing to say about your skill in pulling it off. :whoohoo:

Mike

Thanks Mike,

If the bore needs some additional truing, I might be able to use these hand reamers that I bought at an estate sale a while back. That is, if they'll work with cast iron and if I actually learn how to use them!  :shrug: Need to learn more.



Decided not to drill for the cylinder, at this point, since there are some critical alignment requirements that need to be met and I'm not sure how to factor those in yet. Don't want to back myself into a corner.

So I mounted the top of the frame in the 4 jaw and took a light (very light) cuts on the base to finish truing it up (was only a few thousands off, relative to the top).



Did a little milling of the sides of the base in preparation for drilling the holes for mounting the frame to the base. 

Not a lot of progress...........but progress just the same.

Jim
Sherline 4400 Lathe
Sherline 5400 Mill
"You can do small things on big machines, but you can do small things on small machines".

Offline mike mott

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Re: Flyboy Jim's PM Research #5
« Reply #84 on: November 15, 2019, 05:55:29 AM »
Nice work there Jim. Those reamers aren't to shabby either.

Mike
If you can imagine it you can build it

Online crueby

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Re: Flyboy Jim's PM Research #5
« Reply #85 on: November 15, 2019, 01:24:39 PM »
Great progress Jim.  When you do get to boring the cylinder, I would suggest holding it by the top end so you can bore the cylinder and true the base in one chucking.

Offline Flyboy Jim

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Re: Flyboy Jim's PM Research #5
« Reply #86 on: November 15, 2019, 02:06:25 PM »
Great progress Jim.  When you do get to boring the cylinder, I would suggest holding it by the top end so you can bore the cylinder and true the base in one chucking.

Thanks Mike and Chris. Also thanks for the tip Chris, I've got it duly noted.  :ThumbsUp: While going through Bill's build thread, I've noticed that there's a lot of operations needed for the cylinder. At least it's bronze and not cast iron.  :whoohoo:

Speaking of cast iron. I was milling (or trying to mill) the mold seam mark on the edge of the base (you can see it in the last picture above). Man is that little nub hard!  :wallbang: Might be time too order that Foredom system I've always wanted.  :cartwheel:

Jim
« Last Edit: November 15, 2019, 02:10:35 PM by Flyboy Jim »
Sherline 4400 Lathe
Sherline 5400 Mill
"You can do small things on big machines, but you can do small things on small machines".

Offline Hans

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Re: Flyboy Jim's PM Research #5
« Reply #87 on: November 15, 2019, 03:43:01 PM »
Jim, I would hit that seam with a 4-1/2" grinder.

~Hans

Offline bent

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Re: Flyboy Jim's PM Research #5
« Reply #88 on: November 15, 2019, 07:01:09 PM »
Was going to say the same as Hans, but I'd use a stone on a dremel tool, or a hand stone, or a file and take the fins/gates/parting lines off.  That's called fettling...or fondling if you're Jo. ;D

Online crueby

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Re: Flyboy Jim's PM Research #5
« Reply #89 on: November 15, 2019, 07:07:54 PM »
Second grinders/sanders on those, hard spots/sand/etc can really chew a mill up.


Now, if you NEED an excuse to by another tool like the Foredom, I'll back you up that its a good reason!   ::)

I do have another brand flex shaft tool, also have a Foredom that I picked up later. The off brand one has worked well for many years, it just chews through brushes on the motor faster than I'd like. Still working though! Very handy tools for carving work. I don't use it much for the engines, tend to use the 1" belt sander for those things. Another nice one is the little air-powered handpieces like the TurboCarver, which takes dental burs, runs around 400,000 rpm. Not for removing lots of material, but great for fine detailing, I use it for shaping valve ports.