Chevy V8 Scale Engine Plane

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GRAYHIL

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Hi All
One of the first things I used to see with apprentices on milling machines was them hammering the !!!! out of the job trying to get the parallels to fit snug between vice and job. I used to go over , tap the job once and it was done.
The secret I explained was a reasonably light tap and NO rebound of the mallet off the job.
Graham
 

GRAYHIL

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Hi All
One of the first things I used to see with apprentices on milling machines was them hammering the !!!! out of the job trying to get the parallels to fit snug between vice and job. I used to go over , tap the job once and it was done.
The secret I explained was a reasonably light tap and NO rebound of the mallet off the job.
Graham
 

GRAYHIL

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Now I am totally confused must be my age
Graham
PS
It is about vices and parallels
 

doc1955

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Hi All
One of the first things I used to see with apprentices on milling machines was them hammering the !!!! out of the job trying to get the parallels to fit snug between vice and job. I used to go over , tap the job once and it was done.
The secret I explained was a reasonably light tap and NO rebound of the mallet off the job.
Graham
 

doc1955

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Hi All
One of the first things I used to see with apprentices on milling machines was them hammering the !!!! out of the job trying to get the parallels to fit snug between vice and job. I used to go over , tap the job once and it was done.
The secret I explained was a reasonably light tap and NO rebound of the mallet off the job.
Graham
Ok now I messed up LOL
I was just going to say also I see new to the trade people tighten the crap out of a vise and over time it will ruin the vise. If you keep your part or material low in the vise just sticking up high enough to get the job done it isn't necessary to tighten the crap out of it.
 

john g

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forget the vice ! mill one side in the vice , then mount that surface on a angle plate . mount the angle plate on the machine table, not in the vice ! your part will be as square as the angle plate . I have been doing it this way for 40 plus years ( retired gage maker, routinely worked to very close tolerances +/- .0001 ) John
 

ALEX1952

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I agree with your comment but! how many of us have to ease fettle etc to get something to run correctly even a tool room which would have high end machines could get a job back from the end user not to remake just to make things easier, in other words to fit it that's it from me as I think we are in danger of going of at a tangent to the main topic.
 

SailplaneDriver

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Thanks for all the help guys. I think I have my vise issues under control. Now to get on with this build.

I did the block left bank with no drama.

IMG_20190506_175718.jpg


Not so lucky on the right bank. The arrow shows where I spot drilled an incorrect hole. Likely not a problem since its only about a tenth deep. The circle is a hole that is .060 off. I dialed in the DRO at 2.228 instead of 2.288. Since this one is very close to the cylinder I think I will have to drill it out and plug it. I could use JB weld or Loctite 603 to hold in the plug. What do you guys think?
Right Bank Oops.jpg
 

SailplaneDriver

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That would be easier. I'll have to remember to adjust it when I make the head. Out of curiosity, would the plug option work as I described it?

Right bank is almost done except for that one hole needs to be tapped and the 2-56 hole. I've hogged out the valley for that side but note of my 1/4 end mills have a long enough LOC. Have to order one.
 

stevehuckss396

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Just use a center cutting endmill to start a new hole in the correct location. Drill down with the endmill until you are lower than the bad hole and then drill your hole with the correct drill bit. Use an endmill about the size of the drill or a hair bigger.
 

SailplaneDriver

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The incorrect hole was drilled to full depth. If I understand what you suggested, I would need to use a much longer screw/stud for that hole. Is there enough material to go around .750 deep in that area? To get .500 of depth as on the plans, I would need to go 1.0 deep. The spot drilled hole I am going to ignore or fill with JB Weld if it looks like an issue.
 

doc1955

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Just drill a hole a couple thread sizes larger put a piece of ready rod in place with Locktite and mill or file flush to the engine block face then drill and tap the correct size in it. Its the same as using a threaded insert.
 

SailplaneDriver

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Thanks Doc. I looked at the hole location in more detail. There is not enough room from the hole to the edge of the block to go much larger; the center to edge is only .104. If I leave .030 from the edge, the largest major diameter thread that would fit is #6. I can try and make a 6-40 plug out of 6160 and screw it in. Anything larger and I risk tearing when I mill the side of the block. I don't have much faith that it would survive being threaded in so I'll try a test run on some scrap. Steve's option of milling a hole is problematic since the miniature end mills have a larger shank and LOC is not long enough to go .500. If the test doesn't work, I think I'll just leave it where it is and adjust one of the heads. Fortunately it wasn't the adjacent hole on the other side of the cylinder or it would likely have intercepted the exhaust port on the head.

Wow! Amazon just delivered the longer 1/4" end mill I ordered yesterday afternoon, less than 24 hours and standard shipping. Can't beat that. I need the longer LOC on this new end mill to finish the valley areas.
 

doc1955

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I'm not sure you understood what I was saying. Just put a hole on location and put a plug in ant theen the correct thread size. You don't even have to clean up all the wrong hole as long as the one you put in on location has about 3/4 of the circumference. Ive corrected hole locations this way and as long as you have more than I'd say about 60% it will work.
 

stevehuckss396

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You wrote that you spot drilled an incorrect hole. I did not know that it was drilled full depth.
 

SailplaneDriver

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I'm not sure you understood what I was saying. Just put a hole on location and put a plug in ant theen the correct thread size. You don't even have to clean up all the wrong hole as long as the one you put in on location has about 3/4 of the circumference. Ive corrected hole locations this way and as long as you have more than I'd say about 60% it will work.
I think I understand. The maximum major diameter that will fit at the correct hole location is .148 if I keep .030 edge clearance. The largest thread that will fit in that diameter is #6, only one size above the required #4. I can go bigger if I offset the plug. The incorrect hole is .060 away from the correct location. See the diagram below. The yellow circle is about the biggest I can fit and it has a .156 diameter and doesn't help. An alternative is to reduce the edge clearance to .020 which would get me to .176 and up to a #8. How likely is 6160 to tear out with .020 clearance?

upload_2019-5-8_14-59-36.png
 

SailplaneDriver

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You wrote that you spot drilled an incorrect hole. I did not know that it was drilled full depth.
I did one of each as shown in the photo. I caught the one that was spot drilled but not the other. My eyes are not calibrated well enough to catch .060 at an angle and my scribe mark was scratched over by chips.
 

SailplaneDriver

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Steve, did you use a chucking reamer to get the .230 diameter holes for the lifter bushings? I could try and make a boring bar and do them that way but it would be a long reach for a skinny bar.
 
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