Author Topic: MEM Corliss Attempt  (Read 3750 times)

Offline Larry

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Re: MEM Corliss Attempt
« Reply #45 on: July 06, 2019, 05:22:45 AM »
CYLINDER FOOT - The kind comments are appreciated. I plan to make the cylinder foot from 2 pieces & fasten together with screws. A piece of 3/4" scrap aluminum was cut to approximate size for the "T" sections. The pictures below will show the milling set up.

Raw material cut from 3/4" piece of scrap aluminum.
Milling surface with small face mill to square up the sides.
Milling one side of the "T" section.
Milling opposite side of the "T" section.
Finished "T" section - will cut in half.
"T" section cut in half for 2 feet - finishing ends.
Finished "T" section blanks - slot will be cut next.

Offline b.lindsey

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Re: MEM Corliss Attempt
« Reply #46 on: July 06, 2019, 02:24:14 PM »
Always good to see your updates Larry. Those look great so far.

Bill

Offline Larry

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Re: MEM Corliss Attempt
« Reply #47 on: July 15, 2019, 04:07:55 AM »
CYLINDER FOOT (continued) - The next operation was to cut the 1" x 5/16"  opening in the "T" section. I started by using a 1/2"  2 FL end mill at full depth. Disaster almost happened - the end mill began to pull out of the collet. Fortunately I caught it when the cut was deeper than my mark. I have had this happen when cutting steel but didn't think it would happen in aluminum - but it did. I should have known better. I then changed to a 3/8" end mill and cut the depth in .050 increments. The width was cut in .025 increments. As a result the depth of one opening is .035 more than the specified .313 on the drawing. I don't think this will affect the strength although it is a slight appearance factor.

8956 - "T" section in mill vise to cut opening.
8957 - "T" section with first cut.
8959 - "T" section with first cut to correct depth.
8961 - "T" section with opening partially finished.
8962 - "T" section with opening partially finished.
8964 - "T" section with opening complete.
27242 - "T" sections with openings complete. (Note depth of openings in the 2 pieces.)

Online Kim

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Re: MEM Corliss Attempt
« Reply #48 on: July 15, 2019, 05:41:54 AM »
Those look very nice, Larry!

Interesting on the mill pulling out of the collet.  Do other people have this problem?  The only time I ever experiences something like that was when I forgot to tighten the collet!  I had it finger tight and had intended to come back and tighten it down, but forgot - till I noticed the depth changing. And for me, it got shallower, not deeper, since the forces pushed the mill up, not down.

What kind of collet are you using?  is it fitting right?  Is there some swarf stuck in the grooves preventing it from closing down properly?  This seems kind a bad to have your end mill move on you while it's in the collet!

Kim

Offline john mills

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Re: MEM Corliss Attempt
« Reply #49 on: July 15, 2019, 09:57:12 AM »
Kim i have seen cutters  move if cutting on the sides .But i would not expect to have problems with these size of cuts even in steal.

the collet must be the right size for the cutter.and the collet chuck spotlessly cleaned.changing cutters with out
dismantling and cleaning is asking for swaf to end up where it is not wanted.then the collet and body can get marked briused and won't run true or may not tighten properly .check that the collet is not worn,if a cutter has
been moving it could also be slipping and can wear the collet. the nut needs to be tightened .
When i programmed cnc machines i did a lot of cutting out profiles in tool steel with ripper cutters i was very aware
of the possibility of slipping so with threaded cutters i was able to use collets with theaded nuts with the cutter screwed into but with the size cuts  and material used hear there should not be any problems.
 

Offline Elam Works

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Re: MEM Corliss Attempt
« Reply #50 on: July 15, 2019, 04:09:16 PM »
Kim,

Yup, Under high side loading I have had helical endmills pull out of spring collets. Once leaving a 'mark of shame' in a table from a 1/4 endmill. Even with something like a industry standard ER16 collet holding a standard helical (not high helix) endmill. But also have had it happen with fairly shallow taper TG collets when trying to see how big a chip load I could create; i.e. intentionally pushing the limits with much bigger endmills (CAT 40 taper spindle). For that reason I really don't like the DA series collets except for drilling (angle too steep) and for heavy roughing cuts still use a cutter with a Weldon flat and a set screw. Especially since marking the table! In the UK, I believe they had cylindrical shank endmills that has a thread on the tail end just to stop them from pulling out of collets, though the EU has done its best to homogenize everything and eliminate individuality. It is pretty rare in model making, except when cutting soft metals with 2-flute endmills and a full slotting cut. Those tend to squirm around a bit and therefore are more prone to wiggle their way out of a collet. That is if the cutter does not choke on the chips and brake. For a similar reason I have found vibration on a side milling cut (even if not a heavy cut) is more prone to drive a taper up into the machine spindle and make it stick, that a heavy direct thrust from a large drilling op.


-Doug

Offline Larry

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Re: MEM Corliss Attempt
« Reply #51 on: July 18, 2019, 04:47:19 AM »
Kim-

I use a #2 MT collet in my mill and the 1/2" size gets used the most. My collets came with the mill when I bought it over 40 years ago so I suspect there is some wear. More than likely the situation as described by Doug was the main cause.

Offline Larry

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Re: MEM Corliss Attempt
« Reply #52 on: July 18, 2019, 05:12:49 AM »
CYLINDER FOOT (Continued) - Mounting holes were marked & drilled in the top of the "T" section. The base plate mounting holes were drilled & tapped for #5-40 screws in the bottom of the "T" section. Base plates were cut from a piece of 1/8" x 1 1/4" aluminum flat bar. Edges were milled to 1 1/8". Holes were marked & drilled. Center holes are 82 degree CSK for #5-40 FH screws.

8966 - Drill holes in "T" section.
8968 - Drill 4 holes in "T" section.
18698 - "T" sections with 4 holes.
8970 - Base plates (1/8") - finish end.
8972 - Base plates (1/8") - finish long edge.
02973 - Base plates (1/8") cut to size.
8973 - Drill holes in base plate.
8978 - 82 degree CSK holes for #5-40 FH screws in base plate.

Offline Larry

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Re: MEM Corliss Attempt
« Reply #53 on: July 18, 2019, 05:23:56 AM »
8980 - Drill hole for #5-40 screw in "T" section bottom.
8982 - Tap hole for #5-40 screw in "T" section bottom.
8984 - "T" section & base plate complete.
8986 - "T" section & base plate assembled.
8988 - Cylinder feet under block.

Offline vcutajar

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Re: MEM Corliss Attempt
« Reply #54 on: July 18, 2019, 11:58:38 AM »
Quietly following along your progress Larry.  :ThumbsUp: :ThumbsUp:

Vince

Offline scc

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Re: MEM Corliss Attempt
« Reply #55 on: July 18, 2019, 08:10:49 PM »
Me too! :popcorn:            Terry

Offline Larry

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Re: MEM Corliss Attempt
« Reply #56 on: August 04, 2019, 03:23:59 AM »
OUTRIGGER BEARING PEDESTAL - A piece of scrap 1/2" aluminum was machined to 1" x 1 3/8". The side cut outs were chain drilled and milled 3/8" x 1 1/8" in successive steps using a 3/8" 2FL end mill. The 4 mounting holes were marked and drilled using a #29 (.136) drill.

1/2" scrap aluminum marked to be machined.
1/2" aluminum block machined to 1" x 1 3/8".
Side cut outs are chain drilled.
Cut outs machined to 3/8" x 1 1/8" in successive steps.
Cut outs complete.
Drilling 4 mounting holes.
Completed part.

Offline Larry

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Re: MEM Corliss Attempt
« Reply #57 on: September 10, 2019, 12:26:34 AM »
CRANKSHAFT BEARING - I just happened to have a piece of 1/2" x 1" brass bar stock. How often does that happen? I cut off 2 pieces and machined to size - 3/4". Layout crankshaft hole - drill & ream to .375. Layout bolt holes - drill #30 (.128) - CSK 5/16" x 1/8" deep using a 5/16" end mill. Mill a .188" wide x .125 deep step on each top corner using the 5/16" end mill in machine. Drill #60 (.040) oil hole in top center of bearing block (not on drawing).

9016 - Cut off 2 pieces of 1/2" x 1" brass bar stock and machine to 3/4".
9020 - Layout crankshaft hole & drill .368 with "U" drill .
9021 - Ream crankshaft hole to .375".
9023 - Layout 2 bolt holes & drill #30 (.128).
9025 - CSK 2 bolt holes with a 5/16" end mill x 1/8" deep.
9027 - Mill a .188" wide x .125" deep step on each top corner using the 5/16" end mill in machine.
125313531 - Drill a #60 (.040) oil hole in top center of bearing block (not on drawing).

Offline Larry

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Re: MEM Corliss Attempt
« Reply #58 on: September 10, 2019, 12:40:18 AM »
CRANKSHAFT BEARING (continued) - Turn a filing button and file top radius to .375". Polish to remove tarnish.

9032 - Turn a filing button from a piece of 3/4" diameter steel rod.
132521347 - File top radius to .375". I removed most of the excess stock using a narrow sanding belt and filed to finish.
9034 - Polish to remove tarnish - completed part.

Offline Johnmcc69

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Re: MEM Corliss Attempt
« Reply #59 on: September 10, 2019, 01:58:38 AM »
 :ThumbsUp: :popcorn:
 Looking good Larry! Keep those parts coming!

 John