• Pins vs Square keys

    From Bob La Londe@none@none.com99 to rec.crafts.metalworking on Sat May 30 15:22:55 2026
    From Newsgroup: rec.crafts.metalworking

    I've had a few vises that came with square keys on the bottom very
    aligning a vise quickly to a t-slot. Generally I take them off and
    store them away (lose them) and never think about them again.

    Keys have a few problems. The first is those on the vises I can afford
    are never perfectly parallel to the jaws and the t-slots. They need to
    be taken off, machined, and then put back on. The other is they almost
    never line up with the best t-slot for best use of the vise. On vises
    with bolt slot hold downs I guess its no big deal, but I actually prefer
    vises with a slot in the side that require a hold down clamp. I've even machined my own slots in vises to make mounting them easier and more
    flexible. (on some knee mills you can move the head to best position
    for the vise, but...) T

    All of that being said I have an application where keying might be
    useful. My personal standard setup for the Tormach mill is a pair of 6
    inch wide grinding (screwless) vises with the jaws machined away
    (machined in place) to maximize the use of the work 9.5 inch Y axis work envelope. I recently took them off to mount that monolithic piece of
    aluminum for the college race team guy's gear box, and now I need to put
    them back on. I've got a big piece of 4140GT TGP that I use as a
    straight gage when pairing vises. It usually gets me within .001 across
    its length. Then I can tap in the rest of the way, but for most of my
    work within .001 over the 18" X envelope of the machine is plenty good
    enough. Its not as good as the machine is capable of, but its not far
    off. Nobody notices if the top of two plates are a thousand off from
    each other with the slight chamfer from de-burring. I can always chase decimal places if necessary by other methods.

    Anyway, I was thinking about keying those vises specifically for that
    machine before I put them back on. That way I won't be so reticent to
    remove them when a project could benefit from their dismissal. I can
    drill, ream, and press in pins very quickly. It will be a bit of a time
    suck to slot the bottom, tap that modestly hard steel, and then machine
    up some square keys.

    Is there a reason pins would be a bad idea? Hold down force is against
    the flat of the table, not the side of the pin. I have plenty of pins
    on hand, and the diameter tolerance is quite good. The length tends to
    be 10 thou over, but the diameter is usually 0.000 - +.0002. Far better
    than I can position the holes. I figure I would pull them gently
    against the side of the t-slot, lightly clamp down the vises, and then
    bump them as needed for position. I'm not even against taking a light
    cut along the steps I machined in the jaws if necessary after the vises
    are tightened down.
    --
    Bob La Londe
    CNC Molds N Stuff

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  • From Bob La Londe@none@none.com99 to rec.crafts.metalworking on Sat May 30 15:33:45 2026
    From Newsgroup: rec.crafts.metalworking

    On 5/30/2026 3:22 PM, Bob La Londe wrote:
    I recently took them off to mount that monolithic piece of aluminum for
    the college race team guy's gear box, and now I need to put them back on.

    During the whole time they were cutting their gear box and since I have
    been roughing blanks manually in the back on the South Bend 10x54. It
    really has improved my manual skills for quick work, but my time is
    better spent letting the Tormach do rote work like that wile I work on
    other stuff. I also have some stock mold designs optimized for cutting
    on the Tormach with it 5120RPM spindle. I need to cut some of those too.

    I rough to length on the manual mill anyway, but I was fully prepping
    hinged blanks in the back. That is time consuming.
    --
    Bob La Londe
    CNC Molds N Stuff
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  • From Bob La Londe@none@none.com99 to rec.crafts.metalworking on Sat May 30 16:35:04 2026
    From Newsgroup: rec.crafts.metalworking

    On 5/30/2026 3:22 PM, Bob La Londe wrote:
    Is there a reason pins would be a bad idea?-a Hold down force is against
    the flat of the table, not the side of the pin.-a I have plenty of pins
    on hand, and the diameter tolerance is quite good.-a The length tends to
    be 10 thou over, but the diameter is usually 0.000 - +.0002.-a Far better than I can position the holes.-a I figure I would pull them gently
    against the side of the t-slot, lightly clamp down the vises, and then
    bump them as needed for position.-a I'm not even against taking a light
    cut along the steps I machined in the jaws if necessary after the vises
    are tightened down.


    Well, I decided to try pins. One vise is already drilled and reamed. I Figured there were two benefits to going with pins. There is more room
    to relocate them if I don't like the position, and they really won't
    interfer very much with changing to square keys if I decide pins aren't working out.

    Okay... I plan to use green Loctite, so moving them will require heat,
    but other than that. I don't want them vibrating out since there is
    nothing holding them in except a light interference fit
    --
    Bob La Londe
    CNC Molds N Stuff
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  • From Jim Wilkins@muratlanne@gmail.com to rec.crafts.metalworking on Sat May 30 21:12:16 2026
    From Newsgroup: rec.crafts.metalworking

    "Bob La Londe" wrote in message news:10vfo00$15ec6$1@dont-email.me...

    Is there a reason pins would be a bad idea?

    My Microcentric pie jaw lathe chuck uses pairs of 1/8" dowel pins to locate the top jaws, with one clamping screw between them. Kinematically they
    should be as good as the machining of the tee slots, which you could check
    for tight or loose spots with an adjustable parallel. You aren't roughing
    out iron castings which might shift a vise secured to the oily table only by bolt tension.

    The RF-31 that replaced a worn-out drill press for the company had tee slots that weren't quite parallel to table travel, and the large drill press vise (18 vs 80 Lbs) I ordered for it had no slot underneath. I milled a close fitted key at home and found with it that the table slot had loose and tight places, which I filed to an even slight drag all over.

    The quill on the RF-31 shifted when clamped, limiting it to ~0.005" vertical adjustment. The Clausing can do 0.0005".

    To align the vise jaws and X axis I clamped the key in its tee slot and
    milled the top slightly narrower, thus parallel to table travel, closed the vise on it upside down and milled the matching press-fit slot in the bottom.

    I set the ram position to make the largest collet-sized endmill slightly
    clear behind the rear vise jaw with the table fully forward. Thus the work
    can be lifted out or the table moved rapidly.

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  • From Bob La Londe@none@none.com99 to rec.crafts.metalworking on Sat May 30 18:31:35 2026
    From Newsgroup: rec.crafts.metalworking

    On 5/30/2026 6:12 PM, Jim Wilkins wrote:
    "Bob La Londe"-a wrote in message news:10vfo00$15ec6$1@dont-email.me...

    Is there a reason pins would be a bad idea?

    My Microcentric pie jaw lathe chuck uses pairs of 1/8" dowel pins to
    locate the top jaws, with one clamping screw between them. Kinematically they should be as good as the machining of the tee slots, which you
    could check for tight or loose spots with an adjustable parallel. You
    aren't roughing out iron castings which might shift a vise secured to
    the oily table only by bolt tension.

    The RF-31 that replaced a worn-out drill press for the company had tee
    slots that weren't quite parallel to table travel, and the large drill
    press vise (18 vs 80 Lbs) I ordered for it had no slot underneath. I
    milled a close fitted key at home and found with it that the table slot
    had loose and tight places, which I filed to an even slight drag all over.

    The quill on the RF-31 shifted when clamped, limiting it to ~0.005"
    vertical adjustment. The Clausing can do 0.0005".

    To align the vise jaws and X axis I clamped the key in its tee slot and milled the top slightly narrower, thus parallel to table travel, closed
    the vise on it upside down and milled the matching press-fit slot in the bottom.

    I set the ram position to make the largest collet-sized endmill slightly clear behind the rear vise jaw with the table fully forward. Thus the
    work can be lifted out or the table moved rapidly.



    These are going on a CNC mill, so a rapid to full Z height or any other
    safe clearance area is as fast as I can turn the MPG, or already done
    when I walk up if I add it to the end of the program, which I do. The
    M30 macro at the end of every program does a G53 to Z zero at full
    speed, along with a redundant spindle off and coolant off command.

    I was getting a little cocky. Everything was just working the last few
    days. Turning parts, machining. CNC programs. Just working. The
    first of the two vises went perfectly. On the second one I hit hard
    spots and ruined the tip on every screw machine length split point
    letter D drill in the shop except those in tool holders on CNC machines.
    Its one of those I buy in multiples because it gets used all the time.
    I didn't want to drill the pin hole with a hand grind, because I
    wanted better accuracy than MY hand grinds can give you. I have two
    empty holes in the second vise because of "problems." Finally I ran
    across a .248 reamer I forgot I own. I broke the surface and cleaned up
    the hole by pecking donw 1/8 inch with an end mill, then I spotted with
    a center drill, and then I drilled it with a.242 (letter C) drill. From
    what I was reading .007 was to much maybe for an HSS .249 reamer so I
    risked the .248 reamer. finished with the .249 reamer, and set the pin.

    After the first vise went so easily the second one nearly whooped me.
    Now to order a box of new split point letter D drills. LOL.
    --
    Bob La Londe
    CNC Molds N Stuff
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  • From Bob La Londe@none@none.com99 to rec.crafts.metalworking on Sat May 30 18:36:17 2026
    From Newsgroup: rec.crafts.metalworking

    On 5/30/2026 6:31 PM, Bob La Londe wrote:
    On 5/30/2026 6:12 PM, Jim Wilkins wrote:
    "Bob La Londe"-a wrote in message news:10vfo00$15ec6$1@dont-email.me...

    Is there a reason pins would be a bad idea?

    My Microcentric pie jaw lathe chuck uses pairs of 1/8" dowel pins to
    locate the top jaws, with one clamping screw between them.
    Kinematically they should be as good as the machining of the tee
    slots, which you could check for tight or loose spots with an
    adjustable parallel. You aren't roughing out iron castings which might
    shift a vise secured to the oily table only by bolt tension.

    The RF-31 that replaced a worn-out drill press for the company had tee
    slots that weren't quite parallel to table travel, and the large drill
    press vise (18 vs 80 Lbs) I ordered for it had no slot underneath. I
    milled a close fitted key at home and found with it that the table
    slot had loose and tight places, which I filed to an even slight drag
    all over.

    The quill on the RF-31 shifted when clamped, limiting it to ~0.005"
    vertical adjustment. The Clausing can do 0.0005".

    To align the vise jaws and X axis I clamped the key in its tee slot
    and milled the top slightly narrower, thus parallel to table travel,
    closed the vise on it upside down and milled the matching press-fit
    slot in the bottom.

    I set the ram position to make the largest collet-sized endmill
    slightly clear behind the rear vise jaw with the table fully forward.
    Thus the work can be lifted out or the table moved rapidly.



    These are going on a CNC mill, so a rapid to full Z height or any other
    safe clearance area is as fast as I can turn the MPG, or already done
    when I walk up if I add it to the end of the program, which I do.-a The
    M30 macro at the end of every program does a G53 to Z zero at full
    speed, along with a redundant spindle off and coolant off command.

    I was getting a little cocky.-a Everything was just working the last few days.-a Turning parts, machining.-a CNC programs.-a Just working.-a The first of the two vises went perfectly.-a On the second one I hit hard
    spots and ruined the tip on every screw machine length split point
    letter D drill in the shop except those in tool holders on CNC machines.
    -aIts one of those I buy in multiples because it gets used all the time.
    -aI didn't want to drill the pin hole with a hand grind, because I
    wanted better accuracy than MY hand grinds can give you.-a I have two
    empty holes in the second vise because of "problems."-a Finally I ran
    across a .248 reamer I forgot I own.-a I broke the surface and cleaned up the hole by pecking donw 1/8 inch with an end mill, then I spotted with
    a center drill, and then I drilled it with a.242 (letter C) drill.-a From what I was reading .007 was to much maybe for an HSS .249 reamer so I
    risked the .248 reamer. finished with the .249 reamer, and set the pin.

    After the first vise went so easily the second one nearly whooped me.
    Now to order a box of new split point letter D drills. LOL.

    P.S. I had an RF-30 a long time ago. (Might have been a 31, I don't
    recall.) It was capable of making parts, but it was as you noted not
    top tier. I ran it for a while with a Kwik 200 master holder in the R8 spindle, but ultimately I decided that wasn't enough faster than the
    regular R8 tooling to justify the loss of clearance. I sold it to a guy
    who wanted it to machine lower receivers. It should be good enough for
    that. They have a lot of tolerance. As long as the pin holes are close
    to the right size and line up from one side to the other they generally
    work. When he showed up to buy it the darn thing wouldn't turn on, so I
    made him a deal on it. First trouble I ever had with it. LOL.
    --
    Bob La Londe
    CNC Molds N Stuff
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  • From Jim Wilkins@muratlanne@gmail.com to rec.crafts.metalworking on Sun May 31 07:54:48 2026
    From Newsgroup: rec.crafts.metalworking

    "Bob La Londe" wrote in message news:10vg3ai$18310$1@dont-email.me...
    ....

    I made a tool that locks in a 1/2" hole by screwing in a 1/4-28 bolt but it may not scale down in length and be too much work for your welding table
    pins.

    It's a puller for a 1/2" bronze bushing in a blind hole in the end plate of
    a hydraulic pump. The working part is a sleeve with a raised rim on the end that catches the bushing. Lengthwise slits ending in drilled holes let it compress to fit in. The area of the holes was bored larger than 1/4" to
    flex, by cut and try to balance strength and stiffness; the first try was
    too weak.

    The area beyond the holes was tapped 1/4-28 with a taper tap run only deep enough that the fingers expand to grip the bushing when the bolt passes through. This was too fussy for multiple parts, leaving the OD large and turning it down to an interference fit in the hole with the bolt in place might be easier. A smaller stub on the end compressed in a collet would
    remove thread clearance and hold the split fingers securely.

    The bolt extracts the bushing. The end of the bolt was also tapered to start in the compressed threads. I didn't spring temper it and multiple cycles
    might have cracked it.

    It was a lot of work to save a bushing I could have drilled out and wouldn't reinstall if I could successfully fit a new one, though it avoided risk to
    the end plate. Its most valuable use has been as a pocketable example of my custom tool making ability at job interviews.

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  • From Bob La Londe@user16941@newsgrouper.org.invalid to rec.crafts.metalworking on Sun May 31 12:33:09 2026
    From Newsgroup: rec.crafts.metalworking


    "Jim Wilkins" <muratlanne@gmail.com> posted:

    "Bob La Londe" wrote in message news:10vg3ai$18310$1@dont-email.me...
    ....

    I made a tool that locks in a 1/2" hole by screwing in a 1/4-28 bolt but it may not scale down in length and be too much work for your welding table pins.

    It's a puller for a 1/2" bronze bushing in a blind hole in the end plate of a hydraulic pump. The working part is a sleeve with a raised rim on the end that catches the bushing. Lengthwise slits ending in drilled holes let it compress to fit in. The area of the holes was bored larger than 1/4" to flex, by cut and try to balance strength and stiffness; the first try was too weak.

    The area beyond the holes was tapped 1/4-28 with a taper tap run only deep enough that the fingers expand to grip the bushing when the bolt passes through. This was too fussy for multiple parts, leaving the OD large and turning it down to an interference fit in the hole with the bolt in place might be easier. A smaller stub on the end compressed in a collet would remove thread clearance and hold the split fingers securely.

    The bolt extracts the bushing. The end of the bolt was also tapered to start in the compressed threads. I didn't spring temper it and multiple cycles might have cracked it.

    It was a lot of work to save a bushing I could have drilled out and wouldn't reinstall if I could successfully fit a new one, though it avoided risk to the end plate. Its most valuable use has been as a pocketable example of my custom tool making ability at job interviews.


    Think holdfast. Typically pins and blocks just work as workstops.

    A common welding table hold down clamp, just looks like a bar clamp. Remove the fixed jaw and weld a round stub. On the end of the bar.
    --
    Bob La Londe
    CNC Molds N Stuff
    --- Synchronet 3.22a-Linux NewsLink 1.2
  • From Jim Wilkins@muratlanne@gmail.com to rec.crafts.metalworking on Sun May 31 13:11:43 2026
    From Newsgroup: rec.crafts.metalworking

    "Bob La Londe" wrote in message news:1780230789-16941@newsgrouper.org...

    Think holdfast. Typically pins and blocks just work as workstops.

    A common welding table hold down clamp, just looks like a bar clamp. Remove the fixed jaw and weld a round stub. On the end of the bar.
    --
    Bob La Londe
    CNC Molds N Stuff
    --------------------------------------
    I replaced the plastic stops on my B&D Workmate with dowels stepped to fit the holes, and they make good clamps. My welding table is a damaged street drain grate with openings large enough to insert the whole bar clamp.

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