Laser Centering Jig for Deckel using Dan Gelbart's concept
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    Default Laser Centering Jig for Deckel using Dan Gelbart's concept

    I've been pondering over making a Laser Centering Jig patterned after Dan Gelbart's concept.

    For anyone not familiar with Dan's idea, here's a video, he discusses it at 2:10 and talks about it for about 3 minutes. Ignore his choice in mill, if you watch the later part of the video he shows that he has better taste in lathes. Very clever guy.



    I have ordered this DIY laser ponter kit, to use for mine.

    DIY Red Laser Pointer-ScientificsOnline.com

    I'm pondering a design that could be used for both the ER40 collet nut, as well as the vertical head spindle, which is almost exactly the same size at the top of the taper on the spindle nose.

    There is a small area, that i think I can turn a thin ring that could register on that area at the top of the taper. and use magnets to secure it to the spindle.

    On the ER40 chuck, it would slip over the outer diameter of the collet nut, and have a small step to register on the face of the nut itself.

    Also thought about circular vs. rectangular design, and it seems the reason Dan's uses a rectangular design is to get space for the laser and batteries itself.

    I'm going to replace the 2 x AAA batteries with a smaller watch battery, so will get a small holder to replace the one in the kit. I will also use a mini-toggle or similar instead of the momentary switch in the kit.

    Here's Dan's patent, in case you haven't seen it.

    Laser centering jig - Gelbart, Daniel

    If you google you'll find others that people have made, some with mixed results, some good. I think the shape has a bit to do with it, and am planning to copy Dan's design in the video kinda sorta...there have been a number of jigs that have a shank and fit into a collet, but the problem with that style is you need to retool to use the jig. If the jig fits over the tool, you can use the same tool without having to retool for each centering.

    Comments?

    Cheers,
    Alan

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    Went over to SIMS yesterday, being the bottom feeder I am...I picked up these pieces of aluminum. The piece I was mostly after is the 2" thick, 4"x6" 7075 T6. A friend took it last night and is going to cut it on his band saw to 1" thick, which I plan to use for the frame portion. This is 10 lbs. of aluminum at $2/lb. SIMS charges the same for 7075 as they do 6061, but unfortunately didn't have much 7075. A friend took this piece last night and is cutting it in half, and I will use a 1" x 4" x 6" piece for the frame portion. The small pieces are scarce at SIMS so I grabbed those thin pieces, and a piece of 3/8" plate and a 4" round.

    sims-scrap-run.jpg

    Here is the spindle nose and collet chuck. Ironically, these are almost exactly the same size. ~2.500" on diameter of collet nut and the top register of the taper. There is just slightly over .125" of width, so I will leave a small .125 piece so it will fit over the spindle, when not using the collet chuck.

    fp1-vertical-spindle-nose.jpgcollet-chuck-nut.jpg

    This is how I plan to make the frame. Not entirely sure if I will mill all the way through, but I think it would be better to just mill a pocket and use a cover on the top. I will use the vertical index attachment to mill the radius on the 3 cuts (both sides of the pocket and the outside), and mill out the center. Will start milling once I get my 7075 back. Excuse the drawing, I didn't have a compass so used a divider holding a pencil freehand to draw the radius. The bushing will be hardened as it will only have .125" around the top, so it can spin freely with the spindle, when attached to the spindle nose. I will use 4140 HT for that.

    Cheers,
    Alan
    Attached Thumbnails Attached Thumbnails laser-centering-jig-frame.jpg  

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    Have made some progress, and now I get to modify my original sketch above...to add a slot. I am also forgetting about using the bushing to simplify it. I need to think about how I will mount it, but planning to put a 1" slot in the frame, and secure 2 pins in this holder, so it will rotate to change angle.

    I had this ~1.500" aluminum, but unfortunately I can't get that in a collet as my collets only go to 1-3/8", so I used chuck, turned a 1" diameter, then drilled and reamed a hole 3/8" hole for 2.100" in length, and drilled a larger .810" hole (1.625" in length), just large enough to allow the circuit board to fit in.

    This is after I parted that off, which was slightly long and I put it in a collet and cleaned up the end as I snuck up on the 3/8" lens hole (.410" in length).

    laser-holder-stock-part.jpg

    This is what I ended up with for what will be the top end of the holder.

    laser-holder-top-end.jpg

    The other end, with the lens hole. The thickness is about .410 in length for the lens hole, enough for a 10-32 set screw.

    laser-holder-lens-end.jpg

    Drilled a #21 on the Deckel and tapped with a 10-32.

    laser-holder-tapping.jpg

    And this is what I have so far. I need to put some type of pins in each side of the holder, so that it can pivot. One thing I like about the ER40 collets is how much they collapse. This drill is about .030" undersize for the collet but it will still collapse enough to hold it securely. Makes it easier if you are using drill bits in them.

    laser-holder-set-screw.jpg

    I will now modify the frame design to hold this holder. The better way would have been to desolder the circuit board from the lens, mount the circuit board in the pocket and run wires to the lens. I don't trust my de-soldering and soldering on such small connectors though, so going this route. It leaves me with a 1" diameter holder, which is quite larger than the brass lens which is 3/8" on the smaller diameter. I contemplated making the holder square to make it easier to mount, but pins will allow this to pivot fine and I could turn this on the lathe which is faster than milling each side.

    I got the 7075 cut at a friend's shop, and cleaned it up on the Nichols and Deckel. I found a 1/2" arbor with a 1/4-20 thread on the end. I'm going to use that with a 1-1/2" 1/4-20 bolt/washer to secure the plate so I can hold it in the vertical index attachment. I just recently got the drawbar for it, so I can use the collets with it. I have a 1/2" collet.

    Cheers,
    Alan

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    Hi Alan,

    Thanks for the pointer: I found it very interesting to watch Dan Gelbart's series of videos about building prototypes. Lots of interesting things there, for example I didn't know about flextures. Gelbart's home shop is full of a lot of pricey stuff, including a laser spot-welder, a CNC water-jet, a CNC Weiler lathe, a 100-ton press, and so on. I did a bit of reading about the guy, very interesting story. He built up a company specializing in precision optical devices and sold it for a billion dollars. So his home shop is done using different standards than most of us!

    Cheers,
    Bruce

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    Quote Originally Posted by ballen View Post
    Hi Alan,

    He built up a company specializing in precision optical devices and sold it for a billion dollars. So his home shop is done using different standards than most of us!

    Cheers,
    Bruce
    He might know about optics...but I don't think he knows much about milling machines.

    Cheers Ross

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    Quote Originally Posted by ballen View Post
    I did a bit of reading about the guy, very interesting story.
    He is a very interesting guy, he has LOTs of patents, a number of them which use lasers.

    https://www.google.com/search?tbo=p&...%22&gws_rd=ssl

    Quote Originally Posted by AlfaGTA View Post
    He might know about optics...but I don't think he knows much about milling machines.
    I would tend to agree with you, but he seems to have modified it quite a bit. I'm dumbfounded why he has that mill amongst such other machines? He seems like a very clever guy, and as stated in my original post, I can't account for his taste in milling machines. Those are not like the low end mills they make, but it's an interesting choice.

    The laser centering jig is kinda controversial I 'spose, some machinists think it's just a gimmick, but I think it could save time depending on what one is doing.

    For instance, he often remarks about being accurate to 50 microns, which is close enough for a lot of stuff I would do, but I wouldn't want to hold all of my work at 50 microns, that's about .002" AFAIK. So, it probably has it's place and/or requires more time to get better accuracy (I haven't watched all his videos but have seen him refer to 50 microns in 1 second). I would challenge the 1 second setup time, but it looks like it could be quick.

    He seems like more of a person who does prototypes than he is a machinist. Still, I find his ideas and techniques to be interesting.

    Cheers,
    Alan

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    Yes. i watched the video....What i saw does not correlate to 50 microns....maybe that close per side.....but if he is calling TIR...i am not buying.
    I like the gadget...for drilling holes likely good enough, but if the work calls for going on the mill i would look to hold closer....or why bother.
    Problem is how inaccuracy compounds.

    Did not see this feature, but think the design would be better if the angle of the beam could be changed,....a thumbscrew adjustment perhaps
    so the circle could be adjusted without changing the work height....

    Cheers Ross

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    Seems to me like a major limiting factor is the width of the laser beam...

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    Quote Originally Posted by AlfaGTA View Post
    Yes. i watched the video....What i saw does not correlate to 50 microns....maybe that close per side.....but if he is calling TIR...i am not buying.
    In trying to understand the 50 microns, I think I understand better that Gelbart is using 50 microns for -/+, so it is really within .001". I watched a video of another person who made one of these and he said it was within .001" on his testing. That is probably close enough for most work I do. The reason I say that is because that is how accurate my machine is.

    Quote Originally Posted by AlfaGTA View Post
    I like the gadget...for drilling holes likely good enough, but if the work calls for going on the mill i would look to hold closer....or why bother.
    Problem is how inaccuracy compounds.
    Right, the thing is that we are all limited to the accuracy of our own machines, and none of them are perfect and have some TIR runout on the spindle. That is where the accuracy of the laser comes into play, from the spindle itself. But we are all only as accurate as the machines we use, without compensating to get better accuracy. This is the art of being a great machinist, one that can bring the tolerance in closer than the machine being used.

    Quote Originally Posted by AlfaGTA View Post
    Did not see this feature, but think the design would be better if the angle of the beam could be changed,....a thumbscrew adjustment perhaps
    so the circle could be adjusted without changing the work height....
    This is exactly why I made the holder, so that it can pivot and change the angle. The worst case would be when the spindle is at the bottom of the Z axis, i.e., the lower position of the table, and the other extreme would be when the table/work is close to the top position. Being able to adjust for both of those could be needed at some point. The patent linked to in the OP of the thread shows a screw to adjust the angle, as you suggest. Most of the designs do incorporate some type of adjustment for the angle of the light by pivoting the lens.

    I have noticed on some of the other ones made, they leave the laser hanging low and that changes the angle needed quite a bit, and in some cases doesn't work well at specific distances. Keeping the lens up close to the spindle seem more logical, and how Gelbart did his.

    Quote Originally Posted by Colt45 View Post
    Seems to me like a major limiting factor is the width of the laser beam...
    No, actually this doesn't seem to be a problem. The bigger problems seems to be in the strength of the laser light from the lens. Many of the cheaper models are not very powerful and the light/ring it projects is not as visible. One person recommended using a 5mw laser to get around that problem, which my DIY kit is. The better more expensive laser pens sold do have this higher power, they are often more expensive, like in the $40-$50 price range.

    If you think about this, the ring should be accurate for the entire width of light projected. The laser is not what determines that accuracy, it is the spindle and how accurate your spindle is. IOW, it will be just as accurate on the outer width of the projected light, as it is in the center or the inside edge of the laser beam. You are not measuring from the width of the beam, you are merely lining up visually, which is on your part or existing layout markings.

    This jig is only useful for a given, known point to center off of. If you had a blank part with no markings you will still need to do the layout where you want to drill/mill. Where it will come in handy is when fixturing to center drill pins, existing holes, or work that has already been laid out and scribed. It is only good for centering over existing parts/marks. But for that I see it as being a time saver. Currently I use the standard centering gauge with the spring pin on the end, lining up the edge and then moving the spindle over half the diameter of the spring pin. This would save time in doing that for me.

    Cheers,
    Alan

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    I don't mind his choice in machines, I've owned 8 of them.
    This is however showing a real lack of knowledge on lasers.
    It works on a OD as shown through multiplication of the angle.
    No way on God's green earth you hit 50 microns on a flat surface.
    To many problems in the way here.
    People hear the word laser and think OMG accurate, ti's not so.
    For the most part lasers suck for accurate measuring of edges or locations at tenths.
    Bob

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    Quote Originally Posted by CarbideBob View Post
    This is however showing a real lack of knowledge on lasers.
    I 'spose you're right, even though Dan Gelbart has over 200 patents, many of which use lasers in them for all type of specific tasks in imaging.

    https://www.google.com/search?tbo=p&...%22&gws_rd=ssl

    For your needs it doesn't seem that it would be the right tool. For me I still feel it will save me some time...

    Cheers,
    Alan

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    Default Laser center finder

    Quote Originally Posted by traditional-tools View Post
    I 'spose you're right, even though Dan Gelbart has over 200 patents, many of which use lasers in them for all type of specific tasks in imaging.

    https://www.google.com/search?tbo=p&...%22&gws_rd=ssl

    For your needs it doesn't seem that it would be the right tool. For me I still feel it will save me some time...

    Cheers,
    Alan
    Hi Folks:
    For all of you building a laser center finder, here are some notes:
    1. The laser has to be focussed to a very fine spot (under 0.1mm) so a regular laser pointer is useless. Focus it to a minimum spot about 150 mm away. Since the spot is oval, orient oval spot with long dimension tangential to the circle created to get a finer line. You can buy a laser module that can be focussed on Ebay for a few bucks, for example: 2pcs Focusable 3 5V 650nm 5mW Red Laser Dot Diode Module 12x35mm | eBay
    2. The tilt of the beam has to be adjustable by tilting the module or a small mirror. A fixed angle is a poor choice. I posted a link to a fully detailed design on the YouTube video where I show the device.
    3. Note that the posted design slips over the chuck or toolholder, so you don't have to remove tool to check centering.
    4. Make sure design is balanced so you can use it at high speed. Design and test it to withstand much higher speeds as the highest used.
    5. You can easily get 25um (0.001") and even better by using some simple tricks. For example, to center a hole on a bar or shaft place piece of paper under shaft and adjust height or beam angle till you just see two tiny spots of light on paper, each one on one side of shaft (e.g. shaft blocking almost the whole circle). This will give you accuracies down to a few microns in a dim room.
    6. For all of those who felt sorry for me because of my choice in a milling machine:
    The machine shown (Jet) is what I use as a drill press. I have a Makino KE55 CNC mill , Moore jig borer and other fancy machines. This video is part of a course to teach students so I chose machines they will be familiar with. I don't show any of the fancy machines (like a 1um accuracy aerostatic lathe/grinder) in these videos.
    Cheers,
    Dan Gelbart

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    Hi Dan,

    Thanks for showing up here and commenting. Not sure if you are familiar with these forums, but I think you might find some of the discussions here to be interesting. I learned a number of things from your videos. For example the demos showing that solvent cleaning techniques don't remove the last monolayer of hydrocarbons was eye-opening.

    I posted a link to a fully detailed design on the YouTube video where I show the device.
    Could you please post that link here as well?

    [EDIT]

    Found the link: https://drive.google.com/?tab=wo&aut...nU3V0E

    Cheers,
    Bruce
    Last edited by ballen; 11-21-2014 at 02:54 AM.

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    Hey Dan,

    I recently watched your videos and thought they were great.
    Thanks for making them available on youtube

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    Quote Originally Posted by dangelbart View Post
    Hi Folks:
    For all of you building a laser center finder, here are some notes:
    1. The laser has to be focussed to a very fine spot (under 0.1mm) so a regular laser pointer is useless. Focus it to a minimum spot about 150 mm away. Since the spot is oval, orient oval spot with long dimension tangential to the circle created to get a finer line. You can buy a laser module that can be focussed on Ebay for a few bucks, for example: 2pcs Focusable 3 5V 650nm 5mW Red Laser Dot Diode Module 12x35mm | eBay
    2. The tilt of the beam has to be adjustable by tilting the module or a small mirror. A fixed angle is a poor choice. I posted a link to a fully detailed design on the YouTube video where I show the device.
    3. Note that the posted design slips over the chuck or toolholder, so you don't have to remove tool to check centering.
    4. Make sure design is balanced so you can use it at high speed. Design and test it to withstand much higher speeds as the highest used.
    5. You can easily get 25um (0.001") and even better by using some simple tricks. For example, to center a hole on a bar or shaft place piece of paper under shaft and adjust height or beam angle till you just see two tiny spots of light on paper, each one on one side of shaft (e.g. shaft blocking almost the whole circle). This will give you accuracies down to a few microns in a dim room.
    6. For all of those who felt sorry for me because of my choice in a milling machine:
    The machine shown (Jet) is what I use as a drill press. I have a Makino KE55 CNC mill , Moore jig borer and other fancy machines. This video is part of a course to teach students so I chose machines they will be familiar with. I don't show any of the fancy machines (like a 1um accuracy aerostatic lathe/grinder) in these videos.
    Cheers,
    Dan Gelbart
    I missed this post, but glad that you came over to reply Dan.

    I haven't finished my jig as I've been working on other stuff.

    Kudos to you on the KE55, from what I've seen of those they are very nice machines.

    Hope you come back when you have time, but I see this was your only post on Practical Machinists in 3 or 4 months, so I suspect that you may not come back.

    I thank you for your great videos.

    Alan

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    Welcome Dan.

    Nice to have another Weiler E series owner on the board. I have an E-50.

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    [QUOTE=AlfaGTA;2398360]He might know about optics...but I don't think he knows much about milling machines.
    Just to defend myself: this is not my milling machine, this is my drill press. The video was intended for student so I opicked a machine familar to them. My milling machine is a Makino KE55.
    Dan

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    [QUOTE=dangelbart;2507866]
    Quote Originally Posted by AlfaGTA View Post
    He might know about optics...but I don't think he knows much about milling machines.
    Just to defend myself: this is not my milling machine, this is my drill press. The video was intended for student so I opicked a machine familar to them. My milling machine is a Makino KE55.
    Dan
    Sorry about the rough landing Dan (Jet pun intended). Pull up a chair and enjoy. I think you'll find us to be a pretty good group of folks

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    I thought it was pretty cool that he had what looked to be a Quad vise on the table there. Doesn't/didn't Metalcutter (Stan Dornfeld) make those? I always liked the look of those, for an all mechanical vise (non-hydraulic). Overall I quite liked his attitude, pace of explanation, and interesting ideas.

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    Quote Originally Posted by dangelbart View Post
    Just to defend myself: this is not my milling machine, this is my drill press. The video was intended for student so I opicked a machine familar to them. My milling machine is a Makino KE55.
    Dan
    Dan,

    Just have to ask...because your comment aligns with what Ross had kind of implied above in one of his posts, that the centering device could be useful for drilling.

    I'm just curious if you use the centering device on your Makino at all, or is that not needed given that you have CNC on it?

    For me, I have an older Deckel FP1, and I use my machine for drilling and milling...I don't have the luxury to have a dedicated mill to be used for drilling only. It would seem that the centering device is not as useful on the KE55, or is it? IOW, do you ever use device on it? I am the type of person your video was aimed at, I believe, and have learned quite a bit from your prototyping videos.

    Glad to see you surface at PM, this is a great place and I think you will find that you fit right in here with your way of thinking...PM does require some thick skin as it's has such a diverse set of members.

    Would love to see a video of the KE55 with an explaination of it's features. Is the interface in English on yours? I wasn't sure if the KE55 was like the KEV55 with the interface in Japanese only or not. Rumor the ROM can be swapped out easily...but my experience with Japanese products is that nothing is 100% when doing so...things like the panel and such, internal markings on the machine if parts need to be replaced, etc...it would seem you have an english interface?

    EDIT: BTW, I saw this green laser the same seller had on ebay: http://www.ebay.com/itm/121211797564

    Cheers,
    Alan


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