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Thread: 10"x12" Scratch built lathe

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    Member hoss2006's Avatar
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    Quote Originally Posted by Bubba View Post
    Sure was and as I remember, he made the auger also.

    I think he lives in Texas????

    Been scratching my brain trying to remember his handle at least, hoped it would jog somebodys memory.
    gd.marsh's auger?
    http://www.cnczone.com/forums/bencht...ml#post1028786
    Hoss

    Gosh, you've... really got some nice toys here. - Roy Batty -- [URL]http://www.g0704.com[/URL]


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    Yep, thats the one! Us old folks don't remember some things to good!

    Art
    AKA Country Bubba (Older Than Dirt)


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    Thanks guys! Gary definitely created a very impressive auger. From the research I've been doing most turning centers seem have some sort of flat swarf conveyor. Mostly they're metal links, but I'm just shooting for a simple small way to get chips out of my machine. Does a flat belt conveyor make any sense to put in this machine or should I shoot for an auger style?



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    Quote Originally Posted by jakemestre View Post
    Quick Update but nothing crazy.
    I machined the X axis motor plate and bolted everything together. It looks great. The turret no longer falls, even when there's no power. I've printed a couple different pulley ratios to see how well the machine performs before I spend money on metal versions. I think I'm going to go with a 1:1 with 20tooth pulleys unless somebody says otherwise.
    Nice printed pulleys! I'm seeing more and more printed parts on this forum and frankly I'm getting jealous, need to get to work on a printer!!!!

    I only have one question with respect to those printed pulleys though. Would it not be better to clamp the pulley to the shaft instead of the embedded nut / set screw approach? The support for that nut just looks thin. Other than that the pulley ought to last long enough to verify acceptable operation.

    I also started molds for carbon boxes for electronics. This way I can make a custom shape to fit the stand, maximize space, and optimize shielding. I'll be laying up the box later today or tomorrow assuming I don't sand through the DuraTec.
    At this point I'm leaning towards an enclosure out of fiberglass or carbon, but I can do it out of metal too. I've got a really awesome epoxy that's chemical proof(which I've also tested against my coolant/oil). Everything is up in the air with the enclosure. The only things I know are that it will have one sliding door for easy part changes, and one gull type door for toolchanges at home position.
    Steel is the easy way to get shielding in an electronics enclosure. It is also far easier to update in the future, even doing something as simple as drilling a 7/8" hole for a cord grip. You look like the type of guy that will find reason to modify this machine in the future.

    You do have me confused here though as you start out talking about an enclosure for the electronics but then end sounding like you are talking about the machine enclosure. If you are talking about the machine enclosure here then I'm off track. In that regard I see you having little choice but to go with steel. The reason is pretty simple you need ballistic protection if something lets loose in the lathe. From the stand point of spitting out stuff that can do a lot of damage a lathe is far different than a milling machine, so from a personal safety standpoint you need a robust steel enclosure.
    The main reason for this post is that I need help with the chip conveyor. I've never really taken one apart, or for that matter had a good look to see how they work. Does anybody have any good links or images of a good conveyor?
    Unfortunately no pics. I've only worked on a couple in my life and let me tell you they get nasty! There are several approaches I've seen over the years. You can go the auger route, the flat conveyor route (with flaps) or the rake route. I might suggest keeping the conveyor simple no matter what you do, I especially don't like conveyors that try to turn a belt up an incline.

    It is probably a bit late to suggest this but the conveyor really needs to be designed in from the beginning.
    I picked up some 4" wide conveyor from Mcmaster that's got little triangles on one side and smooth on the other. I'm not entirely sure how to get chips out and keep coolant in. Any links/photos/advice would be extremely appreciated.
    Thanks guys,
    Jake
    Just going slow up hill will allow chips to drain some. Obviously the conveyor needs a certain amount of length to do this well and you could get swamped if your operation are heavy chip producers.



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    Member gd.marsh's Avatar
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    Quote Originally Posted by jakemestre View Post
    Thanks guys! Gary definitely created a very impressive auger. From the research I've been doing most turning centers seem have some sort of flat swarf conveyor. Mostly they're metal links, but I'm just shooting for a simple small way to get chips out of my machine. Does a flat belt conveyor make any sense to put in this machine or should I shoot for an auger style?
    Jake,
    I got the idea for the auger from a video of a HAAS machine but I believe you're right, most of the newer machines seem to use a conveyor. Mine does work well, although to be more effective you would have to make sure all surfaces inside the enclosure are significantly angled toward the auger. My enclosure has too much flat surface at the bottom so even though some chips are washed into the auger by coolant flow, most need to be swept into it after the job is done. The wash-down hose does a fine job accomplishing that though & I can have my machine completely cleaned up in about 10 minutes with very little labor involved.
    Not sure I ever added a picture of the completed auger in my thread but this is the extension that moves the chips up hill to drop in the trash can. It basically fills up and holds chips until more are pushed in behind & they eventually move up & drop into the can. That really helps to allow for coolant to drain back into the collector rather than winding up in the trash can as well. For the record the extension is made from a 5" diesel exhaust flare.

    BTW, EXCELLENT WORK ON YOUR LATHE!

    Attached Thumbnails Attached Thumbnails 10"x12" Scratch built lathe-img_0269-jpg  


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    Hey Jake, Id like to start off by saying that I have been following along with your thread and have enjoyed your build so far, wonderful work on the turret changer!

    But I am concerned about your stand and chip conveyor, as someone has already suggested you need to add bracing diagonally. Remember that a triangle is the strongest shape you can build and its relatively easy to add them in afterwards.

    My real concern though; is that you'll run out of space inside your enclosure. If you keep the lista where it is and add more bracing above it you wont have much space left for your conveyor. IMHO there is enough engineering to do just building the lathe, forget the conveyor and toolbox and build a removable chip catch pan and a flood coolant setup into that space instead.

    You'll have plenty of space to add bracing now and if you really want a conveyor later you have the space to put it in too.



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    Registered jakemestre's Avatar
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    First off, You guys are awesome for all your help.
    Second off, Sorry it's been so long since my last post. I've been having a really hard time with the control boards for my new 3D printer. I have ideas about 3D printing tech that I want to get to prototype stage and patented as soon as possible.
    I've made a bit of progress on the lathe though. I'll post a separate update, but I wanted to respond to everyone first.

    Quote Originally Posted by wizard View Post
    Nice printed pulleys! I'm seeing more and more printed parts on this forum and frankly I'm getting jealous, need to get to work on a printer!!!!

    I only have one question with respect to those printed pulleys though. Would it not be better to clamp the pulley to the shaft instead of the embedded nut / set screw approach? The support for that nut just looks thin. Other than that the pulley ought to last long enough to verify acceptable operation.

    Steel is the easy way to get shielding in an electronics enclosure. It is also far easier to update in the future, even doing something as simple as drilling a 7/8" hole for a cord grip. You look like the type of guy that will find reason to modify this machine in the future.

    You do have me confused here though as you start out talking about an enclosure for the electronics but then end sounding like you are talking about the machine enclosure. If you are talking about the machine enclosure here then I'm off track. In that regard I see you having little choice but to go with steel. The reason is pretty simple you need ballistic protection if something lets loose in the lathe. From the stand point of spitting out stuff that can do a lot of damage a lathe is far different than a milling machine, so from a personal safety standpoint you need a robust steel enclosure.

    Unfortunately no pics. I've only worked on a couple in my life and let me tell you they get nasty! There are several approaches I've seen over the years. You can go the auger route, the flat conveyor route (with flaps) or the rake route. I might suggest keeping the conveyor simple no matter what you do, I especially don't like conveyors that try to turn a belt up an incline.

    It is probably a bit late to suggest this but the conveyor really needs to be designed in from the beginning.


    Just going slow up hill will allow chips to drain some. Obviously the conveyor needs a certain amount of length to do this well and you could get swamped if your operation are heavy chip producers.
    Wizard,
    You SHOULD be building a 3D printer... lol They're pretty useful for basically everything. I needed a special mount for a T5 bulb light the other day, so I just designed it and printed it. Presto.
    On the pulleys I was shooting mostly just to see how many teeth were engaged and which size belt I needed without spending $100 on all the wrong stuff.
    On the conveyor, I think I'm leaning towards an auger now. They seem dead simple, pretty easy to clean, and quite frankly I can't wrap my head around how to keep the chips only on top of the conveyor. Swarf goes EVERYWHERE, and all I see is headache with a small scale conveyor. I've left space for a conveyor or auger in the design, I just haven't gotten around to precisely modeling it.
    I didn't explain very well what I'm doing with control boxes, panels, and such. It will become more clear as soon as I finish molds. Drilling carbon for any random shape is no big deal, and the shielding properties are awesome. I know that making things out of metal is the most straightforward method, but I want to have a little flair in this machine. I also have a bunch of resin that's going to expire if I don't use it so the materials are cheaper for me than metal. It's also a fun exercise in mold making and carbon layup. Who else can say they've got a carbon encased lathe? lol. Thank you very much for all your help.
    Jake

    Quote Originally Posted by gd.marsh View Post
    Jake,
    I got the idea for the auger from a video of a HAAS machine but I believe you're right, most of the newer machines seem to use a conveyor. Mine does work well, although to be more effective you would have to make sure all surfaces inside the enclosure are significantly angled toward the auger. My enclosure has too much flat surface at the bottom so even though some chips are washed into the auger by coolant flow, most need to be swept into it after the job is done. The wash-down hose does a fine job accomplishing that though & I can have my machine completely cleaned up in about 10 minutes with very little labor involved.
    Not sure I ever added a picture of the completed auger in my thread but this is the extension that moves the chips up hill to drop in the trash can. It basically fills up and holds chips until more are pushed in behind & they eventually move up & drop into the can. That really helps to allow for coolant to drain back into the collector rather than winding up in the trash can as well. For the record the extension is made from a 5" diesel exhaust flare.

    BTW, EXCELLENT WORK ON YOUR LATHE!
    Gary,
    Thank you so much. Your design will probably be a basis for mine if that's alright? Everything in my lathe will basically be at 45degree angles and very easy to washdown. I knew that going into this build if I didn't make everything crazy sloped chips would accumulate everywhere. I like your idea of the diesel flare. Very solid. Thanks for your kind words.
    Jake

    Quote Originally Posted by Wizbaa View Post
    Hey Jake, Id like to start off by saying that I have been following along with your thread and have enjoyed your build so far, wonderful work on the turret changer!

    But I am concerned about your stand and chip conveyor, as someone has already suggested you need to add bracing diagonally. Remember that a triangle is the strongest shape you can build and its relatively easy to add them in afterwards.

    My real concern though; is that you'll run out of space inside your enclosure. If you keep the lista where it is and add more bracing above it you wont have much space left for your conveyor. IMHO there is enough engineering to do just building the lathe, forget the conveyor and toolbox and build a removable chip catch pan and a flood coolant setup into that space instead.

    You'll have plenty of space to add bracing now and if you really want a conveyor later you have the space to put it in too.
    Wizbaa,
    Thanks, I'm glad my build is worth following. That turret has been a really rewarding project.
    I think I know what I'm going to do with the auger and I've left enough space to mess around. I could be wrong, but I'm don't think that designing the enclosure and auger will be that difficult since I've got solid models of everything. Besides, half the fun is trying to get everything to fit in the smallest package possible!
    For bracing I'm actually going to make a flat carbon plate instead of a square tube x. That will save a bunch of space on the back of the machine. It will also form a wall to keep things from going behind the machine(which inevitably will happen when I drop that irreplaceable miniscule bolt).
    Thanks,
    Jake



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    Default Various Components

    Hey guys,
    A little update. As I said before I've been working at my new 3D printer to get it up and running. I've managed to squeeze some parts in between jobs and printer. This is a new hot end I based off an open source design by Pico. I made quite a few of them since cycle time was under 20 minutes.

    It's only about the size of a AA battery


    Onto the lathe...
    Got everything covered:

    Pulleys are real now. I had to machine a square pocket on one pulley to accept the nut for the ballscrew. There just wasn't enough space in the machined pocket for stacked height.

    4130 spindle cartridge was quite a job to machine. It's 6" in diameter with a 4" hole that's 1.65" deep. I wish I had a good lathe to turn stuff like this. All the machining was done on the mill and it was about a 8hr job front and back.

    Molds for the electronics box ready to polish and assemble. After the box is built I'll be able to make the carbon box to house all of the electronics and computer.

    I have more molds but I can't really talk about them. That's all for now, thanks for reading.
    Jake



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    Thanks for the update...Keep'em coming!



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    Hi Arizonavideo i run a cnc Manual combination unser linuxcnc bobcad is my cam so if you have questions ...

    Gesendet von meinem SM-N9005 mit Tapatalk



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    I hadn't been paying much attention to the benchtop machines forum.. Wow, I've been missing out!

    Thanks for documenting this stuff here, I'm sure it'll inspire a few nice lathes! I'm tempted So many projects, so little time.. I'll just live through your success.



  12. #92
    Registered jakemestre's Avatar
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    Default VFD/Motor questions

    Hey guys,
    More questions. I need a second opinion on motors. First off I'm comparing my machine to the little Haas Office Lathe which uses a 7.5hp motor. Haas says it can be run from 220V single phase power, but I'm not entirely sure how they do this in such a small package. From my investigations 3hp is really the upper limit of easy/inexpensive spindle motors. At least for the 220V 1ph which is the best I've got in my shop. If I want to step it up to 7.5Hp I've got to get a rotary phase converter at around $1500, or screw with the line input and current limit on a huge Variable Frequency Drive at around $800-1000. A 7.5hp motor looks like it's around $7-800. All in all much more costly than I'm comfortable spending right now.
    So I took a closer look at 3hp motors and drives. My current little lathe is set up with the Lenze AC Tech SMVector drive, but didn't quite understand the relationship between motor-drive when I installed it. Just today I figured out I have no torque because I'm using a continuous duty motor and running it at 5% of rated speed. If I haven't already messed up the insulation I probably will soon. An inverter duty motor is around $500, and I can use my SMVector drive to get constant 10ft-lb torque down to 90RPM with 1:1 belt ratio. If I add in a step pulley with 2:1 ratio I'll have about 20ft-lb of torque. That's only 2ft-lbs less than a 7.5hp setup costing thousands. If anybody sees anything wrong with this conclusion please speak up. I'll order a motor over the weekend if I don't hear from anyone.
    The headstock is almost done, I'll post pictures when it's installed.
    The molds for the electronics box are polished and I'm waiting on more consumables to do a vacuum infusion early next week. As soon as the box is made I can wire things up and start tuning.
    I'm trading a sheet metal shop some CNC training for a sheet metal enclosure. Again a case of not having the correct tools. I hate using an angle grinder to cut sheet metal, it's such a pain to get everything straight. Better to call in the big guns. Now I just have to design the thing.
    That's all, If you know much about VFD's and big motors any help would be appreciated. Have a good one guys.
    Jake



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    Quote Originally Posted by jakemestre View Post
    And a close up of the hirth. This things is like a jewel in person. Though it definitely doesn't need so many bolts. (they just look cool)

    Jake
    Jake,

    Can you tell me a bit more about how you made the hirth coupling? I've been looking for a source online, but they seem hard to find.
    Do you have a CAD model / drawing.
    What angles did you use on the teeth and how did you achieve that?



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    Quote Originally Posted by jakemestre View Post
    Hey guys,
    More questions. I need a second opinion on motors. First off I'm comparing my machine to the little Haas Office Lathe which uses a 7.5hp motor. Haas says it can be run from 220V single phase power, but I'm not entirely sure how they do this in such a small package.
    Inverters have become surprisingly small in recent years. As for single phase operation you need a rectifier front end on the drive that can handle the current, that is the only major difference between a single and three phase powered inverter. I'm not sure about how the HAAS is specified as far as supply current goes but 7.5 hP will be about 25 amps single phase, taking into account the rest of the machine they probably are suggesting a 50 amp service, this is a reasonable single phase load.
    From my investigations 3hp is really the upper limit of easy/inexpensive spindle motors.
    Depends upon the motor, ultimate spindle speeds and the expected torque range. On a lathe the weight of the motor is of little concern so it can be an old fashion AC induction Motor. Your drives might become more expensive though carefully shopping is important here too. When it comes to drives volume is everything and frankly most of the worlds volume motor wise is in the smaller sizes, say sub 5 HP. So yes a drive for a 7.5 HP motor, one that is single phase capable is a jump in price.

    Generally it is a good idea to talk to a sales engineer when trying to implement a large inverter on a single phase supply. If you go back to the part about the rectifier mentioned above the sales engineer will have knowledge about rectifier capacities in the larger drives. As such he can specify a drive with a large enough of a rectifier to handle the single phase currents. Often this means a drive that is larger than what is required for single phase operation.
    At least for the 220V 1ph which is the best I've got in my shop. If I want to step it up to 7.5Hp I've got to get a rotary phase converter at around $1500, or screw with the line input and current limit on a huge Variable Frequency Drive at around $800-1000.
    You will have to setup the drive anyways so I'm not sure why setting the current limit and or accelerations is a big deal. The fact is these parameters take out a lot of the mechanical wear in a machine when across the line startups are done.
    A 7.5hp motor looks like it's around $7-800. All in all much more costly than I'm comfortable spending right now.
    So I took a closer look at 3hp motors and drives. My current little lathe is set up with the Lenze AC Tech SMVector drive, but didn't quite understand the relationship between motor-drive when I installed it. Just today I figured out I have no torque because I'm using a continuous duty motor and running it at 5% of rated speed. If I haven't already messed up the insulation I probably will soon. An inverter duty motor is around $500, and I can use my SMVector drive to get constant 10ft-lb torque down to 90RPM with 1:1 belt ratio. If I add in a step pulley with 2:1 ratio I'll have about 20ft-lb of torque. That's only 2ft-lbs less than a 7.5hp setup costing thousands.
    Gear ratios are a wonderful thing. This is why some of the largest mills out there, lathes too, use a gear box of some sort. If you are willing to pop the belts off you can get much of the same benefit from belt drives. However I would go with a 5 to 1 reduction myself as the minimal reduction.

    By the way there are two ways to mess up your insulation in an AC motor driven by an inverter. One is the high voltage spikes or noise damaging the motors insulation. The other is the lack of cooling. Many so called inverter rated motors are so called because the new insulation resists breakdowns from those high voltage spikes. That is a good thing! These motors still can suffer from over heating of the windings at low speed due to the lack of cooling air flow. This is why many motors running off inverters have a separate fan motor to cool the main motor.

    This is why I would prefer to see you use an optional ratio of at least 5 to 1 on any belt drive with a 3600 RPM motor. It keeps you motor speed up hopefully allowing better cooling. The bad part here is that this impacts your maximal speed with a run of the mill AC induction motor. If you go with a motor capable of 120 HZ operation and a corresponding high rotor speed, you can recover much of your operating range. You will still need the one to one range. 120 Hz should give you about 1440 on the spindle. This assumes the motor can handle 7200 RPM without grenading. You can buy motors that can handle that rotor speed but they aren't cheap.

    Today the economical way to implement a variable speed drive is to go with a 1800 RPM motor. At 120 HZ this means you have a 3600 RPM motor. The rotor can handle this no problem on most motors. You would need to change up your gear/belt ratios again due to the lower motor RPMs
    If anybody sees anything wrong with this conclusion please speak up. I'll order a motor over the weekend if I don't hear from anyone.
    Well hopefully I'm not to late. Above I gave you a rough idea of how to get what is possible with off the top of my head thinking. However you might want to put more effort into engineering this. You need to specific what your top end RPM and torque requirements are along with up your low end RPM and torque requirements. Usually torque at the low end is more important so this should be given priority.

    Once you have firm values for low end torque and RPM you can work on the motor size and belt ratios to give you that performance figure. I would figure on needing at least two different belt ratios though you may surprise yourself. Give yourself some margin for losses and unexpected operating conditions too. You may find that you don't have a torque/RPM solution for one belt reduction (using a reasonable motor size), in that case you will need a jack shaft to afford yourself another reduction in speed or a gear box in the head stock itself. In the end everything is dictated by the ultimate cutting performance you want. It gets a bit complicated but you really need to figure out what sort of metal removal rates you can settle for and the power required to do that rate. The web and Machinery's Handbook can help here.
    The headstock is almost done, I'll post pictures when it's installed.
    The molds for the electronics box are polished and I'm waiting on more consumables to do a vacuum infusion early next week. As soon as the box is made I can wire things up and start tuning.
    Are you making just about everything here yourself? Making a fiber glass panel box is an interesting diversion I guess.
    I'm trading a sheet metal shop some CNC training for a sheet metal enclosure. Again a case of not having the correct tools.
    You will never have the correct tools all the time. You are lucky though that your have something of value to trade.
    I hate using an angle grinder to cut sheet metal, it's such a pain to get everything straight. Better to call in the big guns.
    If you can stand the noise a circular saw can do the job. Looks a big ugly afterwards though.
    Now I just have to design the thing.
    That's all, If you know much about VFD's and big motors any help would be appreciated. Have a good one guys.
    Jake
    I can't say I know a lot. Most of the units we use at work are installed and run the motors at one speed for just about ever. It is a different use than spindle control. The problems are the same which largely comes down to making sure you have the torque required at the lowest operating speed. Your big problem will likely be not having that torque without going to a really large motor or multiple belt reductions.



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    Registered jakemestre's Avatar
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    Whow! Thank you! This is exactly why I decided to post a build log of this project. The collective knowledge on this forum is fantastic. I'll keep working on this aspect of the design. I know it's really a key element, and if I have to bite the bullet I will. I started a spreadsheet with pros/cons broken all the way down to torque/$ for each of 3 and 7.5hp systems in vector and inverter setups. Since I can close the loop in LinuxCNC with an encoder on the spindle, I'm not sure I need to really dole out for Vector. I'll call an applications engineer at one of the drive companies on Monday. Any drives you recommend? Thank you again Wizard!
    Jake



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    Quote Originally Posted by pippin88 View Post
    Jake,

    Can you tell me a bit more about how you made the hirth coupling? I've been looking for a source online, but they seem hard to find.
    Do you have a CAD model / drawing.
    What angles did you use on the teeth and how did you achieve that?
    Good morning,
    Originally the turret design was developed by Dieter Freind which was updated by Josh Updyke. They're available for free over on grabcad. I utilized the base design but changed it to have an aluminum plate housing (not the best idea I've ever had), a modified turret, and an air cylinder that holds does the locking. If I had to redo this I would weld a housing out of steel. The Hirth joint is inside of that solidworks assembly and uses a 15degree taper. That can be cut using a simple taper mill. The design is tricky if you've never done them, but not that hard one you understand the methodology. I changed the taper to 10degrees because I happened to have that taper mill lying around. It's also the taper on all the other parts of this turret. Honestly I like 10 a little better for my design because I've got about 1000lbs of force to unlock. I'll keep you posted on how it works under cutting loads (if I see any sticking or such). I noticed your signature has mini-lathes, this design may need to be scaled to be successfully used on a mini. I doubt the turret would even work well on my 9x20. Too much swing from stick tools would interfere with the ways. I hope this answers your questions.
    Jake



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    Thanks Jake,

    I had another version of those plans which was in a different format. Got the ones you linked now, they are better.
    The one thing I can't see in the model - how does the drive pulley engage the shaft? I presume it is keyed (with a sliding fit to allow the shaft to move axially without moving the pulley)
    The rear spring plate must also be attached firmly to the shaft yes? How have you done that?

    I'm planning a scratch build much bigger than a mini lathe. I picked up some THK HSR30 rails with long blocks. I'm working on design and will post a thread soon looking for tips on optimising swing and tool placement, I'm still a little unsure on how best to size and layout a turret face plate.

    Last edited by pippin88; 02-22-2014 at 09:54 PM.


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    Jake,

    Is it possible to give more details (specs) about the tapered end mill you used on the turret parts?
    Thanks in advance.

    JoeyB

    A doughnut a day keeps the doctor away.


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    Quote Originally Posted by joeybagadonuts View Post
    Jake,

    Is it possible to give more details (specs) about the tapered end mill you used on the turret parts?
    Thanks in advance.

    JoeyB
    Here's a link to Tapered End Mills over at MSC. You can also pick them up at your local tool distributors (which I recommend over places like MSC) . They have a taper to the flutes rather than being straight. I got a HSS mill for about $15 at my local place. Useful tool for making weird stuff on a 3 axis that would typically call for a 5 axis machine. Then again if you've got a 5 axis machine at your disposal you'd better be writing a program to cut the tapers with a normal endmill!
    Jake



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    Default Post 100

    Wow, that happened fast. 100 posts and over 16,000 views, that's crazy. Anyway, I've got a small update. Straight on to it.

    Those bearing surfaces were quite challenging to machine. +0 -.0002 on the races was no small task on my sloppy 9x20. I had to creep up on the value and sand everything smooth in the end. I used a mic and telescoping gages in multiple locations to get to diameter. Those two parts were a royal pain in the butt.
    Now I need to grind the main spindle. None of the shops in town admit to being able to OD grind. So:
    I picked up a small toolpost grinder.

    Now I just need to figure out how to grind. I'll also have to make a fixture to hold it on the lathe cross slide. I found a great site on how to do that. I'll grind a few practice pieces before I go to work on the main spindle.

    Looks like I'm going to have to also figure out a micro height adjust on the tailstock. I'm glad I made that cutout on the enclosure now... I'm also going to chuck it up in a 4jaw to make sure I'm perfectly concentric. Anybody on here do much OD grinding and have suggestions?
    Jake



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