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  1. #1
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    Grid O' Holes

    I'm thinking about making some more generic (universal?) fixture plates than the ones I currently use.

    Do you use a grid of holes fixture plate? What do you think of yours?

    Are there accessories you wish were available?

    Are there things you think could make it better?

    What are the things you don't like about your "universal" fixture plate?
    Bob La Londe
    http://www.YumaBassMan.com

  2. #2

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    Re: Grid O' Holes

    I have an SMW plate in 6061. Took me a bit to get used to using it but at this point I don't know how I would get along without it and my pair of mod vises. I have other setups and fixturing devices but for the overwhelming majority of what I do, its the mod vises and the fixture plate. Only thing I find myself wanting is a mod vise with more travel. When I start a job and have to size my raw material, it gets old having to constantly reposition the vise(s) to compensate for .5-2" of difference in material dimensions from one orientation to the next. Obviously there is a practical limit to how much travel a workholding device like that can have but I would think 1-2" should be doable.

  3. #3
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    Re: Grid O' Holes

    Quote Originally Posted by soofle616 View Post
    I have an SMW plate in 6061. Took me a bit to get used to using it but at this point I don't know how I would get along without it and my pair of mod vises. I have other setups and fixturing devices but for the overwhelming majority of what I do, its the mod vises and the fixture plate. Only thing I find myself wanting is a mod vise with more travel. When I start a job and have to size my raw material, it gets old having to constantly reposition the vise(s) to compensate for .5-2" of difference in material dimensions from one orientation to the next. Obviously there is a practical limit to how much travel a workholding device like that can have but I would think 1-2" should be doable.

    Thank you. That's very helpful. I have looked at Saunders Machine Works plates. They have some nice features. I used to buy Carr Lane CL5-TVLP Tiny Vise edge clamps from them (they no longer sell them) for use on my own fixture plates.

    The Saunders plates are close, but not quite right for my use. I could use them to set up 2-4 parts for many jobs, but in some cases I can make 9 parts in one setup with the plates I use now. It might be that I can't figure out a more flexible system that is capable of the same part density, but I begrudge the time I spend swapping fixture plates and edge clamps. (I need to buy more edge clamps)

    Just so you know. I am impressed with the Mod Vise. Its a neat design. Not as flexible as an Infinity Vise, but not bad at all. They both have the same issue of having to move the "moveable" jaw by loosening the hold down bolts. I no longer use my shop made Infinity Vise either.
    Bob La Londe
    http://www.YumaBassMan.com

  4. #4
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    Re: Grid O' Holes

    Just my opinion,..
    but I've never seen the need for a fixture plate.
    It seems like another un-needed step in the process.

    In 20 years, On both my little TORMACH, and on big full-sized CNC's, I just use the T-slots.
    I've never run across a setup that couldn't be easily handled by using the T-slots in the table.

    G54 and G55 are gonna be wherever you set them.

    It's kinda like buying a Radius turner.
    It's cool to have...but do you REALLY need it?

    Am I wrong?

  5. #5
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    Re: Grid O' Holes

    I always thought about using dedicated fixture plates to setup 4th axis on one and multi vise setups on another and other configurations on other plates. Then move them on and off mill with overhead lift. This would speed up changing of setups. Because I never did much production I kind of left that idea behind. Then Over time I become comfortable with just using the t slots and resetting fixtures, vises and 4th axis using slot keys to align everything. If I did need to repeat a setup quickly I also use t slot stops to locate everything very close to where it was. The cost was another factor.

    I rely on the aligned t slot and keys to avoid having to tram in a vises, 4th axis and multi part fixture setups. And find this method fast, accurate and easy to keep clean.

    I often wondered how much time is spent aligning vises and other fixtures with no t slot. And also how you keep all the holes and threads clean over time.
    Another concern was rust or other goo building up under plate if it was just left on there for months.

    All that said I do like options and would put one to use if I made it or purchased one.

  6. #6
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    Re: Grid O' Holes

    Quote Originally Posted by RussMachine View Post
    Just my opinion,..
    but I've never seen the need for a fixture plate.
    It seems like another un-needed step in the process.

    In 20 years, On both my little TORMACH, and on big full-sized CNC's, I just use the T-slots.
    I've never run across a setup that couldn't be easily handled by using the T-slots in the table.

    G54 and G55 are gonna be wherever you set them.

    It's kinda like buying a Radius turner.
    It's cool to have...but do you REALLY need it?

    Am I wrong?

    I doubt you are wrong about what your experience was, and there really isn't any one part I couldn't make just as you describe. However I do some production work now (never thought I would) and I begrudge part density on the table. If I can throw two or four vises on the table that means I can make 2 or 4 parts (generally). In that same work space I can make as many as a dozen with a fixture plate setup on the machine. I have one part that I make a dozen at a time. Recently I made a 100 mold order for a distributor. By laying out the fixture plate (stock file) in cam I was able to throw three pieces of rough saw cut stock on the machine, and pull off nine blanks ready to go on the high speed machines. Then on the small high speed machines I had made fixture plates (dropped them in the vise for this one) that would hold 4 prepped blanks each. Every time I finished a cycle I pulled 2 complete molds out of each machine. Since fixtures were all laid out in CAM with the parts it was pretty seamless. It wasn't a savings of minutes. It was a savings of hours. Lots of hours.

    Maybe I can machine two parts as fast per part as I can machine twelve, but I can't make 120 tool changes faster than I can make 20. I can't prep 12 piece of stock faster than I can prep 3. And I can't load 12 pieces faster than I can load three.

    No you aren't wrong. We just maybe don't look at it the same way, and that's okay.

    As to the radius turner. That's a custom shop tool. You can set it for for any radius within its range. A form tool (if you have enough power and rigidity) is much faster. I use a form tool on the middle weight lathe for putting a radius on pins. If I had to work on a wide range of radii I would have to have dozens of form tools. (Yes I know the trick about using a round over cutter. In fact I do use one as a form tool.) A ball turner however can make any radius in its range. If I made different size custom round knobs all the time on the manual lathe with a different radius on each one I think I would feel like I needed a radius or ball turner. I'd probably rough them with a regular turning tool, but I'd finish with a ball turner. Actually I kind of do that even with a form tool on some of the larger insert rods I make. The form tool can't really cut the whole large radius so I knock the corners off and the chamfer tool and then let the form tool scream to finish it.
    Bob La Londe
    http://www.YumaBassMan.com

  7. #7
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    Re: Grid O' Holes

    Quote Originally Posted by mountaindew View Post
    I always thought about using dedicated fixture plates to setup 4th axis on one and multi vise setups on another and other configurations on other plates. Then move them on and off mill with overhead lift. This would speed up changing of setups. Because I never did much production I kind of left that idea behind. Then Over time I become comfortable with just using the t slots and resetting fixtures, vises and 4th axis using slot keys to align everything. If I did need to repeat a setup quickly I also use t slot stops to locate everything very close to where it was. The cost was another factor.

    I rely on the aligned t slot and keys to avoid having to tram in a vises, 4th axis and multi part fixture setups. And find this method fast, accurate and easy to keep clean.

    I often wondered how much time is spent aligning vises and other fixtures with no t slot. And also how you keep all the holes and threads clean over time.
    Another concern was rust or other goo building up under plate if it was just left on there for months.

    All that said I do like options and would put one to use if I made it or purchased one.
    I get some staining under the plates I currently use. It looks the same as an old machine table. Right now I consider my fixtures plates (and even my edge clamps) to be sacrificial, so hole longevity is probably not an issue, but I only have holes for edge clamps in specific configurations right now. I expect if I had a grid of holes I'd have a box of plastic push in plugs next to the machine. As to setting up vises. I do not use Keys because the stock keys never seem to be right for best use of the vise on the machine. Well aligned takes a few minutes, and good enough often takes less time than changing the hardware to mount it if I don't plan to leave it on the machine long. I can even line up two vises pretty quickly. I design my fixture plates with keys because I did design them to maximize use of the machine envelope. The I put a pin in the spindle, drop the pin into a register, clamp down the plate, and set the work offset.

    I'm thinking of more of a fixture plate system. They would be less sacrificial and more quickly configurable than swapping plates.

    My current system isn't bad, but I am a one man shop and I plan to stay a one man shop until they find my body draped over a machine or laying on the floor next to it. If I can spend a few hours today saving minutes everyday it doesn't take long at all to make it pay.

    P.S. I have considered a 4 sided tombstone with a 4th axis and fixtures on all 4 sides. I think it might be a toss up at that point between doing that or preloading with fixture pallets.
    Bob La Londe
    http://www.YumaBassMan.com

  8. #8
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    Re: Grid O' Holes

    hy
    ... 3 axis : just put vice in there, tighten it, probe, and rotate program in xy plane; no need to aling vices, or other prismatic stuff
    ... rotary : no need to align it's face, simply probe it, then rotate program in xy plane; this approach suits most 4th axis setups
    ... trunion : probe and rotate : 1st rotation brings the upper surface of material paralel to xy plane, then 2nd aligns it with x/y axis; mostly, those 2 rotations occur simultaneosuly

    manual alignment belongs to era before cnc's; reason why is not largely used on cnc's, is because of all those isues related to probes and custom macros, path that only few dare to walk, because, if don't do it yourself, then it costs a bit too much

    I consider my fixtures plates (and even my edge clamps) to be sacrificial
    the more things you consider sacrificial, and the more things you can repair/craft on your own, the better; onestly, i consider a good machinist not one that does parts, but one that has a large tolerance about sacrificing expensive stuff, yet still being able to fix all those / kindly

  9. #9
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    Re: Grid O' Holes

    In the grand scheme of things everything is sacrificial. To be fair I would prefer to sacrifice some things a lot more slowly than others.
    Bob La Londe
    http://www.YumaBassMan.com

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    Re: Grid O' Holes


  11. #11
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    Re: Grid O' Holes

    Quote Originally Posted by deadlykitten View Post
    hy
    ... 3 axis : just put vice in there, tighten it, probe, and rotate program in xy plane; no need to aling vices, or other prismatic stuff
    ... rotary : no need to align it's face, simply probe it, then rotate program in xy plane; this approach suits most 4th axis setups
    ... trunion : probe and rotate : 1st rotation brings the upper surface of material paralel to xy plane, then 2nd aligns it with x/y axis; mostly, those 2 rotations occur simultaneosuly

    manual alignment belongs to era before cnc's; reason why is not largely used on cnc's, is because of all those isues related to probes and custom macros, path that only few dare to walk, because, if don't do it yourself, then it costs a bit too
    I dont understand what your talking about when probing and rotating program on axis. But I will take your word for it.

    I guess im thinking fixture pallets are used in production to change a machine over to a new very different setup. With all fixtures in place ready to go.
    And fixture plates are the grid of holes often used to hold odd shaped parts or a bunch of parts using fasteners or some other strategy.

    I use vise keys and alignment slot for easy vise jaw alignment with x or y axis and avoid the need to sweep the Jaw face with an indicator and adjust or zero out the indicator sweep for jaw alignment.
    Same for 4th axis. I only need to sweep face on z axis to confirm or adjust 4th axis to be parallel to z axis and shim if its off slightly.

    All probing I do is for offset locations for programs. those programs on my cnc will not make parts correctly if the fixture is not aligned to a given axis unless they are simple one sided machined parts made from larger material or cookie cutter style tool paths.

    I also use multi part fixture plates with vice keys to avoid sweeping the plate with indicator to zero out and align with axis. I use this on both mill and router.

    The fixture plates I mentioned above are big plates with hundreds of holes for mounting vices, 4th axis or multi part sacrifice fixture plates.
    I noticed many people talk about using a smw style plate to protect and avoid damage to the machines axis surface from an error in a program or some other human caused problem. I would consider this also if I was running a high speed high dollar machine but I would still wonder if I was stacking up errors by using one and just how much protection it would provide when a endmill plunges right thru it at 100 ipm.

  12. #12
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    Re: Grid O' Holes

    hy dew let's consider these scenarios :
    ... some flanges where machined on a lathe, and each one has 5 holes of diameter 15; next operation, on a mill, requires to finish those holes at 16+0.03; is needed to align each hole, in order to be able to finish them:
    ...... use a special fixture, that guarantess that all flanges will be mount with identical phase orientation, thus program will be identical for each flange
    ...... don't use a fixture, but simply clamp the flange anywhere on the table, then, using a probe macro, determine position for each flange, and holes phasing; this macro executes within <15 seconds, thus there is no longer a need to craft a special fixture, unless there are many many flanges the program will no longer be identical, but shifted & rotated
    ... is needed to machine a hole inside a plate, with a perpendicular condition; there is a vice on a 5axis machine, but when clamping that plate, the vise jaw lifts enough to be out of spec, in regard to the perpendicular condition; one may start to hammer the plate, and dial it, etc, or simply probe it, and rotate the axis, until the plate will be paralel to xy plane

    please, what is a smw style plate ?

    plates will raise the part from the table; kind of is better to use low height fixtures and low overhang tools, but most of the times there are compromises, because, for example, is easy to achieve modularity by using a plate, or even more

  13. #13
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    Re: Grid O' Holes

    Pallets or plates made and sold by suanders machine works or other similar system, Carr lane and others make them also.
    Just a big plate with hundreds of threaded holes.
    what I thought was the topic

  14. #14
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    Re: Grid O' Holes

    ...the #1 problem with holes in table....cleaning out the coolant, chips, rust. etc from previous jobs by the time you need to use them.

  15. #15
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    Re: Grid O' Holes

    Quote Originally Posted by mountaindew View Post
    Pallets or plates made and sold by suanders machine works or other similar system, Carr lane and others make them also.
    Just a big plate with hundreds of threaded holes.
    what I thought was the topic
    '

    "Grid O' Holes" was the teaser, but not necessarily the "be all" and "end all" of the topic of fixture plates and efficient parts density.
    Bob La Londe
    http://www.YumaBassMan.com

  16. #16
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    Re: Grid O' Holes

    hello again bob under the umbrella of things related to shorter setup time, there is also the one related to using probes / 3d tasters that have tir; for example, when finding tir of 0.1(or higher), using a test indicator, many will try to adjust it; in reality, is possible to use a probe/taster, with accuracy level of 0.01, even with tir of 0.5mm

    classical method involves lowering tir, then using a gauge ring to calibrate

    alternative way, is to leave tir as it is, then calibrate inside the ring, but taking those huge errors into account; for example, if calibration was done for a tir of 0.5, then that calibration is still valid, until the tir is no longer 0.5

    for this to work, is required to use the probe/taster in a stationary spindle; there are machines that can not handle a probe without rpm, and for those there is really needed to have low tir; as for those that can gauge with stationary spindle, then any tir variation can be handled without tir adjustment

    so voila, just another small trick, to shave time from setup operations as long as erorrs are taken into consideration, there is no longer needed to minimize them, thus palpator tir alignment operation is no longer needed



    other thing that i often do, is using the 3d taster not dialing the needle to 0, but only moving it a bit; difference is that at 0 the taster behaves absolute, while at <>0 it behaves relatve; going towards 0 requiers more time from the moment when contact between palpator and fixture/material occured, while going towards <>0, requires more/less time, like more if you go beyond 0, and less if you go before 0; i use to go before 0, like only for the needle to move a few divisions on the dial; doesn't matter how many, only what matters is to always move the dial for the same amount of divisions

    there are setups, where origin can be found by using the taster in absolute, or in relative; diference is not big, yet it can be more accurate to use the relative mode, as springs inside the taster won't be compressed too much; to really know those differencies, a calibration process should occur at 0, and another at <>0; thus even if there are errors, take them into account with a precision that is high enough to deliver actual setups, without really going the extra step for eliminating those errors

    for example, that random machine/instalation is accurate at plus/minus 0.005, but it always shows values shifted with 5mm; you may decide to fix it, or to use it as it is, by always substracting 5mm from whatever value it shows; as for probes and tasters, such erorrs can be handled automatically by a macro : just imagine how much time you gain / kindly

  17. #17
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    Re: Grid O' Holes

    time expired, so here is another reply, about plates :
    ... using only 1, is comon in shops that do change fixtures often
    ... using 2, is good for shortening setups that require an important amount of time for preparation; for example, is better to prepare outside the machine, while the machine is cutting, and when the program ends, simply loose time only with changing fixtures inside the machine, not also with part preparation on the fixture, that has been done meanwhile
    ... using 3 and above, is specific to shops that need a high level of modularity : for example the top plate upper face is setup custom, lower face is designed to suit a quick change system with the middle plate, and the middle plate is designed to suit a more general quick change sistem with the base plate; like this, the master plate can mix with 10 intermediate plates, that each one can mix with other 10 plates; complexity increases when hidraulic or pneumatic clamps are being used from this consideration, also table level is a plate : most vmc stick with the t slot model, but 5th axis machines may have interchangable tables, in order to reduce overhang; custom configuration may be ordered before purchase, as basic table will not suit whatever needs of a client, yet it may be cheaper to craft it yourself / kindly

  18. #18
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    Re: Grid O' Holes

    Quote Originally Posted by Bob La Londe View Post
    '

    "Grid O' Holes" was the teaser, but not necessarily the "be all" and "end all" of the topic of fixture plates and efficient parts density.
    I often think in pictures "graphically" and your topic description made me think only of the big plates with lots of holes. I do multi part fixture plates with custom layout to hold as many parts as I can fit with a clamping systems "mighty bites" or others. I use vice or table mount mini pallets with all the holes to mount parts using small toe clamps or direct bolt down to surface. I tend to do surface ops and avoid profile ops that would need to cut into fixture plate to finish a part that mounts to it. The custom plates are I design to be slightly cut into to complete profile of parts.
    I see big shops and others often use ground pins and clamp systems in a more generic fashion and make many different parts on same plate or pallet. Just by changing the layout of the pins and clamps.

    As for 5axis stuff that is above my paygrade! I do follow people like kern precision that has multi axis machines with big cabinets of tools for spindle and other racks for vises and other types of hot swap fixtures as I call them. From what I see you can set one up on a Monday and run it all week and come back to 50 pallets of different complete parts at end of week. With one big program. Or keep stocking the pallets with fresh stock and make endless parts and the machine never stops cutting.

    Anyway good topic for discussing

  19. #19
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    Re: Grid O' Holes

    Oh you poor tormach guys...
    Nothing is simple from the kitty kat.

  20. #20
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    Re: Grid O' Holes

    Quote Originally Posted by deadlykitten View Post
    hello again bob under the umbrella of things related to shorter setup time, there is also the one related to using probes / 3d tasters that have tir; for example, when finding tir of 0.1(or higher), using a test indicator, many will try to adjust it; in reality, is possible to use a probe/taster, with accuracy level of 0.01, even with tir of 0.5mm

    classical method involves lowering tir, then using a gauge ring to calibrate

    alternative way, is to leave tir as it is, then calibrate inside the ring, but taking those huge errors into account; for example, if calibration was done for a tir of 0.5, then that calibration is still valid, until the tir is no longer 0.5

    for this to work, is required to use the probe/taster in a stationary spindle; there are machines that can not handle a probe without rpm, and for those there is really needed to have low tir; as for those that can gauge with stationary spindle, then any tir variation can be handled without tir adjustment

    so voila, just another small trick, to shave time from setup operations as long as erorrs are taken into consideration, there is no longer needed to minimize them, thus palpator tir alignment operation is no longer needed



    other thing that i often do, is using the 3d taster not dialing the needle to 0, but only moving it a bit; difference is that at 0 the taster behaves absolute, while at <>0 it behaves relatve; going towards 0 requiers more time from the moment when contact between palpator and fixture/material occured, while going towards <>0, requires more/less time, like more if you go beyond 0, and less if you go before 0; i use to go before 0, like only for the needle to move a few divisions on the dial; doesn't matter how many, only what matters is to always move the dial for the same amount of divisions

    there are setups, where origin can be found by using the taster in absolute, or in relative; diference is not big, yet it can be more accurate to use the relative mode, as springs inside the taster won't be compressed too much; to really know those differencies, a calibration process should occur at 0, and another at <>0; thus even if there are errors, take them into account with a precision that is high enough to deliver actual setups, without really going the extra step for eliminating those errors

    for example, that random machine/instalation is accurate at plus/minus 0.005, but it always shows values shifted with 5mm; you may decide to fix it, or to use it as it is, by always substracting 5mm from whatever value it shows; as for probes and tasters, such erorrs can be handled automatically by a macro : just imagine how much time you gain / kindly

    Speaking of probes... I found I got quite good accuracy locating holes by: 1-Probe, 2-Zero DROs, 3-Rotate probe 180degrees, 4-probe again. 5-Divide DROS by 2. 6-Move spindle to new zero. 7-Set work offset of hole center.

    Its not perfect, but its pretty darn good. Never used a 3D taster, but the above method works also works for edge finders, well except that its continuously rotating of course.

    Whether or not its good enough depends on your acceptable tolerances and on your next operation.

    Another thing I use a lot for finding the end of a piece of stock (and positioning it) quickly is a half ground tool in a tool holder. This is more for one off and job shop type work though. It quickly allows you to locate your saw cut end before you machine it off, and is ok sometimes for repositioning a work piece for non critical re-machining. To be fair I do use it for production work as well. Setting up a piece of bar stock in each wo on a fixture plate can be very fast this way if you haven't machined reference marks on your fixture plate. You could use a precision ground pin, but a half ground pin or tool allows you to put the edge of the stock right at the limit of your work envelope for certain jobs. Also, by using half ground tool there is no simple math for you to make a basic mistake. You will be within the backlash and flex of your machine (and your ability to grind a tool).
    Bob La Londe
    http://www.YumaBassMan.com

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