Author Topic: Flyboy Jim's PM Research #5  (Read 10114 times)

Online propforward

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Re: Flyboy Jim's PM Research #5
« Reply #195 on: February 14, 2020, 05:09:19 PM »

Stuart, yes.............I can't put it off much longer. I've been working on my plan on just how to hold the Frame for drilling the Crankshaft holes.  :headscratch:


That's really the core of making these things isn't it? These castings are just so awkward. It's part of the challenge that attracted to castings and want to try making engines this way.
Stuart

Offline zeeprogrammer

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Re: Flyboy Jim's PM Research #5
« Reply #196 on: February 14, 2020, 05:50:17 PM »
Zee, if you look at the last picture, you can see where I drilled 5/32" for 1/8" and then on through at 1/16". That creates a bit of an oil cup for oiling the Crankshaft.

 :facepalm: I get it now. I don't think I'd finished my 1st cup of coffee when I asked.
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Offline Flyboy Jim

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Re: Flyboy Jim's PM Research #5
« Reply #197 on: March 15, 2020, 04:04:06 AM »
Holy cow! I can't believe it's been this long since I had something useful to post on my build. Got busy with some other life things and then a lot of fumbling with the next steps.

First I had to mount the Frame casting horizontally so I could mill, drill and tap the holes to mount the Slide Valve Bearings (this shot was taken after I had drilled the holes).



Then I had to make sure it was level to the mill table.

 

Drilled and successfully tapped two of the holes. The problem was that they needed to be drilled #50 for a 2-56 tap. I had to keep enlarging them in order to get the tap to go through. Finally ended up drilling #46 to get the tap to go through.



So far so good. One Slide Valve Bearing and Slide Valve Cap mounted.



That's when things started going south. I almost had the 3rd hole tapped and then the tap broke off in the hole. Heck!  :facepalm: Using a 1/8" end mill I was able to mill the tap out. Whew! Turned a brass insert and Loctited into the hole. Then drilled#50 and tapped the hole 2-56.........easy! Got my tap order in from McMaster Carr and tapped the 4th hole. Heck again..............this tapped broke like the other one.....also in a #46 hole. Did the same solution as for hole #3.

Next I noticed that the bolts in the #50 drilled holes had a heck of a lot less play than the #46 holes in the cast iron did. The solution to that was to drill out holes #1 and 2 to 1/8" and put inserts in them as well.







It's nice to be back making a little headway.............even if it is slow headway. I've come to the conclusion that I'm not to fond of working with cast iron.

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 zeeprogrammer

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Re: Flyboy Jim's PM Research #5
« Reply #198 on: March 15, 2020, 12:57:50 PM »
Glad to see you back at it.
Nice save!

I'm a little confused about the drill sizes you used.
For a 2-56, I would have used a #50 in brass (or aluminum) or a #49 in iron (or steel).
A #46 is nearly the size of a 2-56.
(My reference book may have errors though).

If I use the equation I got from Marv...

Dt = Dm - (2*K) * (dot / n)

Dm = 0.086 (major diameter of a 2-56)
K = .649519 (a constant)
dot = .5 (50% tap for iron, 75% for brass)
n = 56 (thread count)

Dt = .074401

A #49 is .073 (or .001401 from Dt)
A #48 is .076 (or -.0016) from Dt)

Hm. Dt is right in the middle. Which to use?




Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Zee-Another Thread Trasher.

Online crueby

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Re: Flyboy Jim's PM Research #5
« Reply #199 on: March 15, 2020, 01:26:03 PM »
Yeah, 46 is too big. My guess is hard spots in the iron, you notice if the drills had trouble getting through too? I much prefer cast bronze to cast iron parts.

Offline Flyboy Jim

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Re: Flyboy Jim's PM Research #5
« Reply #200 on: March 15, 2020, 02:03:13 PM »
Yeah, 46 is too big. My guess is hard spots in the iron, you notice if the drills had trouble getting through too? I much prefer cast bronze to cast iron parts.

Yep...... I'm with you Chris when it comes to cast iron. It seemed to drill just fine and when I ultimately ran a 1/8" end mill through that went well also. I'm wondering if 2-56 is just too delicate to tap cast iron. I've got holes for the Cylinder and Crankshaft Bearing Caps to drill and tap 2-56 yet, so I'm a little concerned. I'm thinking about bumping the tap up to 3-48 with the proper sized hole. For the record the second broken tap was a new one from McMaster Carr.

Zee..........your book is correct. As I kept having to go to a larger and larger drill size my effort became more of an experiment on how large of a hole I'd have to go to to get a 2-56 tap to go through, knowing I could always bump up to 3-48. Breaking a tap (2 taps) wasn't in the plan. >:(

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 Bear

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Re: Flyboy Jim's PM Research #5
« Reply #201 on: March 15, 2020, 02:09:55 PM »
Jim, great work. I liked seeing the photos that I think show the interplay between the Sherline lathe and mill. Am I seeing that on some processes, you are merely transferring the chuck with the part from the lathe to the mill. If so, I guess that would be very helpful with attaining tolerances. Is this correct?

As you and others have said in my thread regarding lathe choice, the milling machine appears to be a necessity.


Offline Flyboy Jim

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Re: Flyboy Jim's PM Research #5
« Reply #202 on: March 15, 2020, 02:24:15 PM »
Jim, great work. I liked seeing the photos that I think show the interplay between the Sherline lathe and mill. Am I seeing that on some processes, you are merely transferring the chuck with the part from the lathe to the mill. If so, I guess that would be very helpful with attaining tolerances. Is this correct?

As you and others have said in my thread regarding lathe choice, the milling machine appears to be a necessity.

Good observation Bear. You've just discovered what, for me, is one of the big advantages of the Sherline lathe and mill combination. There are times when I've started with a part in the 3 or 4 jaw chuck on the lathe, then move it to the mill for an operation or 2, then back to the lathe for more work. All while not disturbing the part in the chuck. I'm sure it can be done with other lathes and mills, but have no experience with that. Something else I appreciate is the accuracy of the zero resettable dials. I make lots of use of that feature............sort of a "poor man's DRO".  :)

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 zeeprogrammer

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Re: Flyboy Jim's PM Research #5
« Reply #203 on: March 15, 2020, 02:35:01 PM »
When I had the mini-lathe and mini-mill, I could transfer chucked parts between them.
The biggest issue was taking the chuck off (or on) the lathe because of how it was bolted on. (Tough to get fingers onto the nuts.)
That's why I wanted my next lathe to have a cam-lock for the chuck.
Makes it much easier to swap the chuck but I hadn't counted on how heavy the chucks are. (Not to mention the risk of dropping such things.)
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Bear

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Re: Flyboy Jim's PM Research #5
« Reply #204 on: March 15, 2020, 02:36:35 PM »
Jim, great work. I liked seeing the photos that I think show the interplay between the Sherline lathe and mill. Am I seeing that on some processes, you are merely transferring the chuck with the part from the lathe to the mill. If so, I guess that would be very helpful with attaining tolerances. Is this correct?

As you and others have said in my thread regarding lathe choice, the milling machine appears to be a necessity.

Good observation Bear. You've just discovered what, for me, is one of the big advantages of the Sherline lathe and mill combination. There are times when I've started with a part in the 3 or 4 jaw chuck on the lathe, then move it to the mill for an operation or 2, then back to the lathe for more work. All while not disturbing the part in the chuck. I'm sure it can be done with other lathes and mills, but have no experience with that. Something else I appreciate is the accuracy of the zero resettable dials. I make lots of use of that feature............sort of a "poor man's DRO".  :)

Jim

Thank you. Still considering the Sherline lathe. However, I am also considering the HF 7x12 lathe. I know, night and day  :)

Offline Bear

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Re: Flyboy Jim's PM Research #5
« Reply #205 on: March 15, 2020, 02:37:47 PM »
Thanks for the additional input, Zee.

Offline Flyboy Jim

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Re: Flyboy Jim's PM Research #5
« Reply #206 on: March 15, 2020, 03:53:18 PM »
When I had the mini-lathe and mini-mill, I could transfer chucked parts between them.
The biggest issue was taking the chuck off (or on) the lathe because of how it was bolted on. (Tough to get fingers onto the nuts.)
That's why I wanted my next lathe to have a cam-lock for the chuck.
Makes it much easier to swap the chuck but I hadn't counted on how heavy the chucks are. (Not to mention the risk of dropping such things.)

To add to what Zee said. The Sherline chucks screw on and off so easy to swap back and forth. Not too heavy either. :ROFL:

By the way have I mentioned lately that I'm a "Sherline fanboy"?  :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".

Offline Kim

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Re: Flyboy Jim's PM Research #5
« Reply #207 on: March 15, 2020, 05:30:08 PM »
Bummer of a time with the taps there, Jim :(
But it looks like you've made the best of it.  It's never fun when taps break, but you worked out ways around it and have been able to move on.  And that's half the battle in this hobby.  Figuring out how to get around these kinds of issues!

Enjoying your build!  :popcorn: :popcorn:
Kim

Offline Flyboy Jim

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Re: Flyboy Jim's PM Research #5
« Reply #208 on: March 16, 2020, 01:43:51 AM »
Thanks Kim.

Got in a short session this afternoon. Milled the Vee ( geeez every time I tried to type "Vee" ....... auto correct kept changing it to "Zee".........I feel haunted  :-\)  grooves in the Valve Slide Bearings for the Valve slide.







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 #209 on: March 16, 2020, 01:51:20 AM »
Excellent!   :popcorn: :popcorn: :popcorn: