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Thread: Cut out oblong

  1. #21
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    I feel your pain. That is a lot of metal (4340 steel no less) to remove with hand tools. And the Dremel is not much better as it is for small jobs. Doing this completely with hand power will take forever and probably not be all that accurate.

    You say "without expensive tools". A belt sander is not all that expensive and it can remove a lot of metal in a controlled manner. Use a hack saw to cut off a length that is about 91 or 92 mm long. No way to avoid making that cut. You could cut off the bulk of the sides with the hack saw as well; again that is a lot of work but I have done worse. Take breaks.

    Then start with a 50 or 60 grit belt on the belt sander. The steel will heat up so have a can of water to cool it. Work on the saw cut end and the other end if necessary until you get within about 0.5mm of the 90mm finished length. Work on the two sides, again until it is about 0.5mm large. Then switch to a finer belt, perhaps 80 grit and get closer with it. Make frequent checks for square, parallel, and the actual size. Switch to a 100 grit when you are approaching the final size and perhaps a 150 grit for finishing. You can use a bit of oil on the finer grit belts to get a better surface finish. With careful work and frequent measurements you can probably get it within +/- 0.2mm. Perhaps +/-0.1mm. Even better is possible with care and patience.

    With some careful purchases you can keep the cost of tools and materials under $150.

    Another possibility would be filing it. A pair of 12" files, one coarse and the other fine could be used. It would help a lot if you had a bench vise to hold it as you work. Again, checking the size and for square frequently would be key to success. I like the 12" size file. Smaller ones are harder to control and take more time and effort so I don't recommend them. Over 95% of my filing is with a 12": I only use smaller ones when there is a definite reason to do so. A hack saw and the files would run around $50 but a good bench vise can easily cost over $100; some are well over that.



    Quote Originally Posted by Drilldept View Post
    Well, I only have a drill press, a dremel and hand tools. I wounder if this could be done with accuracy by using a drill press and drilling multiple holes like a straight line and finish it off using a hacksaw? I imagine that it will lack accuracy and that I will have a hard time getting rid of the excess material between each hole? 4340 isn’t as hard as stainless to machine, but it’s still hard.

    I need to be able to make straight cuts. What’s the best solution for this without using expensive tools?

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  3. #22
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    I didn't think about that. Heck you can get one for $25 or so. And $5 for some safety glasses. PLEASE don't try it without eye protection. Please! PLEASE! It would be faster than a belt sander. But you would still need to finish up with something more delicate if any precision is desired.



    Quote Originally Posted by AARONT View Post
    Bust out the angle grinder.

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  5. #23
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    hammer + anvil, even with fancy tools would be my goto for this shape. ok, flat dies in powerhammer with kiss blocks, but same concept.

  6. #24
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    If all I had was what he has I would get a 4flute center cut 1/4"- 5/16" end mill to spot the rod for drilling.Close spacing and drilling will get rid of most of the material.Since we don't know what type drill press he has kinda hard to know for sure if it is up to the task but most 1/2" chuck 1/2hp or larger drill presses will plunge cut without much trouble.You can then cut the webs with a hack saw rather quickly.

    With the right speed you may be able to plunge most of the remaining web left.
    The work must be held very ridged and a fence to keep every thing in line.Follow up with a chisel and lastly a file.If you are careful and cut close to your reference line you should not have much material to remove.
    Single end Chinese EMs are cheap.

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    Now I'm reminded of what a tool salesman called "six pack milling" for clearing out excess material in a mold frame when we'd recently gotten a large mill. I'm not sure we ever tried it but the idea was interesting. The proposition was to drill large holes adjacent to each other down to close to bottom depth. You'd be left with all the pillars in between holes. Then you'd center on each of the pillars and drill them down. That might be something the guy could do on the drill press if he planned his hole layout and clamped things down.

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    One should not undertake vast projects with half vast equipment

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    A sharp file and a big cup of coffee.

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    Quote Originally Posted by metalmagpie View Post
    A sharp file and a big cup of coffee.

    One place i worked, another mechanic who anticipated a long job that day would take his "go fast" pills before he came in. One day he arrived prepared but the engine block wasn't back from the machine shop.

  12. #29
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    Quote Originally Posted by TGTool View Post
    One place i worked, another mechanic who anticipated a long job that day would take his "go fast" pills before he came in. One day he arrived prepared but the engine block wasn't back from the machine shop.
    If he'd taken the pills at the right time, he could have done the block work in his shop with the drill press...

  13. #30
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    Quote Originally Posted by TGTool View Post
    Now I'm reminded of what a tool salesman called "six pack milling" for clearing out excess material in a mold frame when we'd recently gotten a large mill. I'm not sure we ever tried it but the idea was interesting. The proposition was to drill large holes adjacent to each other down to close to bottom depth. You'd be left with all the pillars in between holes. Then you'd center on each of the pillars and drill them down. That might be something the guy could do on the drill press if he planned his hole layout and clamped things down.
    Actually a great strategy for removing a lot of stock in the right use.
    Drills are very fast stock removal tools, the small holes make it easy to remove the the left standing slivers or towers with pliers.
    It is kind of a special use deal.
    Problem one is that it only works nicely with pockets. Problem two it leaves a floor that still must be finished as it id full of drill points.

    Sort of the same I could see using a drill press with a clamped on rail to plunge mill to depth stepping by hand along the long axis of the part.
    Move the rail or stop block "guide" sideways and repeat. One could keep the rail clamped and have some "spacer" stock for each sideways stepover.
    Not sure how many will understand what I'm saying here. All hand fed and held against a stop rail.. (you will know if you took too big of a bite)
    Not a real flat floor but then get out the "German precision milling device" and only a few thou to fix by hand.
    I should not admit as a machinist but have done this. Sometimes you find yourself in a place where all you have is a hacksaw, bench grinder, drill press, and some dull files.
    Bob

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    Quote Originally Posted by Bill D View Post
    Grab it in vise grips. Drive about 25mph on a paved road, concrete if possible. lean out door and apply work to the ground with firm pressure Check for fit every 200 feet or so. Be careful to make full even contact so the ends do not get overdone.
    Could this be shaved down on a gun range with enough accuracy?
    Bil lD.
    THIS is how you do it!

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    In B 4 the Lock


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