Clever, that just proves that I'm as useless at hardware than I am (according to me) godlike at software.·A friend of mine works at a hospital and I bet he can get me one of those old (don't know the real name) spike on a spring, wrapped in a tube, for "plotting" when measureing bloodsugar. And if I'm lucky, it'll make a tiny, but efficient "divot" which requires less hitting and punching.
- I bet they didn't think of copper and fiberglass PCBs when they made that device.
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Why do·they call it a spacestation? There's hardly "space" for anything in there.
You need to use the right tool for the job. I get excellent results with a Dremel in a Dremel drill press and I use high speed tungsten carbide drill bits (the same as the production board shops use). These drill bits are designed to run at 50,000 RPM and higher - so turn the speed on the Dremel to it's maximum setting and you're good.
Paul Baker said...
Lemon:
Do you have a dremel? how about getting a dremel drill press?
Beau:
I do in essence·the same thing, I use a hand drill with a 1/32" bit and the trigger speed control set to barely rotate at full depress, then I put the bit in the dremel and drill away. I quickly learned that even at the lowest speed, the dremel will skid across the surface without a divot. I use the dremel because it is much easier to control by gripping with both hands and doing a straight plunge. Though a jewelers drill with snake attachment would be even easier.
I ordered this http://www.toolworld.dk/images/69094.jpg·two weeks ago, but due to·two major·snowstorms it haven't arrived yet. It's supposed to be a 1.5 HK whith adjustable speed. Until it arrives, I'm stuck on a homemade drill made from a 15500 RPM motor from an RC plane, geared down to·around 600 RPM whith load. But handling the thing is like trying to navigate a spaceshuttle using a compas.
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Why do·they call it a spacestation? There's hardly "space" for anything in there.
Paul Baker said...
Has anyone thought of a project to do smt soldering involving an X-Y table and a Z axis arm holding a soldering iron? It would likely still require manual application of the flux and the solder to the iron tip. I'd imagine the most fool-proof way to program a solder action would be to do what assembly line robot programmers do; dry run the action and the controller would repeat the action. This could alieviate bad eyesight/shaky hand problems. To cut on component cost you could eliminate the drive of the X axis and simply use it as a manual positioning axis.
I'd love to see ideas for the Z axis. What about solder/paste feed?
If any one·actually makes such a device and orders one of my 3 axis stepper motor controller kits·(unipolar motors only) for $75, I will refund the entire amount (and postage) in return for a picture showing the device connected to my contoller.
If you're pushing solder paste around, the normal solution is a timed shot of compressed air into a syringe, behind a diaphragm to encourage the paste to the right end of the syringe.
This is pretty poorly controlled, since the paste it rather thermally sensitive. It's also fussy - I once dropped a syringe of the stuff, and it snapped the (tapered) nozzle off. I transferred the remains of the paste into a regular syringe, with a similar sized needle. It started out fine, but after a while, got harder and harder to squeeze any out. Turns out, the straight needle was changing things, squeezing the flux out in preference to the solder, so after a while, the paste was less flux, more solder, and wouldn't move.
Just a cautionary tale, that solderpaste doesn't necessarily flow like you'd expect.
(Using a lead screw pressing on a diaphragm might (or might not) get you a more consistent shot size, and avoid the need for compressed air - I can't imagine that the paste could tell the difference between my hand pressing on teh diaphragm and that...
You'd probably want to do this all with the board prewarmed - even if just with a couple of halogen lamps - the flux is a lot runnier & stickier when warm. When it's cool, it really doesn't want to stick to anything. I'd suggest anyone thinking about automating this buy a syringe of the stuff and having a play, before building something that doesn't quite work [noparse]:)[/noparse]
But yeah, an automated soldering beastie would be handy. Then, of course, there's the temptation to turn it into a full (if simple & slow) pick & place machine. Feature creep - it's not a plan, it's a way of life [noparse]:)[/noparse]
I would imagine the simplest means for automatic dispensing is to use a small DC air compressor like one used for an aquarium and connect it to one of these http://www.heinc.com/jensen/syringeadapters.html·either by timed application or with a flow meter, then momentarily run it in the opposite direction to stop the flow (this would be for flux application).
I think solder paste, while enticing in the concept, has too short of a shelf life and variation of properties during the shelf life to be useful, additionally through personal experience, wave tip soldering produces vastly more reliable results than solder paste when using an iron. I found that the amount of paste on the pad effects the amount of time for reflow and·this could compromise consistant results·in an automated system.
For the solder,·I think using a stepper motor to pull solder wire through a pair of rollers would be effective, through there may be some tight clearance issues since you would want the output of the roller to be very close to the iron tip, though an additional set of non driven rollers between the driven set and the spool could effectively straighten the solder enough to back the feeder away from the tip. A specially modified solder tip may improve the system, one with a V groove channel on the side. The solder wire would make contact with the groove, melt and flow via gravity down to the tip.
I've always been facinated with the operation of mechanical systems but do not have experience designing or constructing them, so these ideas may or may not work.
Not sure about the aquarium pump - I just measured the force I need to run the syringe I have here - it's a 16mm internal diameter syringe of Electrolube paste, labelled SMSP (and, interestingly, it says '0-10oC' on it - I don't know if that's a storage or operation temperature.)
Anyway, it takes 5-10Kgf to do its thing. That's going to take a lot more than an aquarium bubbler... (You'll also need to release the pressure sharply, to stop dribbling). The leadscrew plan feels simpler.
If you want to use solder wire, rather than paste, you have the problem of it trying to push the component around. All rather tricky. I suspect that there's no clear winner here. It'd be a fun project, though.
(Pick&place machines are gently dropping in price. Ebay 4357177726 looks like it was a good buy for somebody...)
A "big" project that I have had on the back burner is to build a primary XYZ CNC machine built exclusively to machine the parts for a secondary
CNC. - Make sense?!
Which came first... The ruler or the machine that made the ruler?
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Beau Schwabe - Mask Designer III
I suggest the #69-#60 set. The 10 piece set is $7.15 plus shipping and they work great in a Dremel with a Dremel drill press. I've drilled about 300 holes and I'm still on my first bit. Each drill bit is good for a few thousand hits.
You really only need these drill bits for the component holes. You can use cheaper drill bits to drill 1/8 inch mounting holes.
Beau Schwabe said...
A "big" project that I have had on the back burner is to build a primary XYZ CNC machine built exclusively to machine the parts for a secondary CNC. - Make sense?!
Yep. Have you seen: http://www.buildyouridea.com ·? that is what he did, but the first machine made "lost foam" patterns for the casting of the gibs for the second machine. A really cool method of casting is documented there...
Beau Schwabe said...
A "big" project that I have had on the back burner is to build a primary XYZ CNC machine built exclusively to machine the parts for a secondary
CNC. - Make sense?!
Which came first... The ruler or the machine that made the ruler?
I have a complete set of drawings of every part involved in a hand made CNC machine for the same purpose. At first the plan was to·cut the parts from hard plastic, then use that machine to make a more precise and more roubust machine, then machine no. 2 would make the precision parts for a no. 3 machine, this time in iron or steel, and then I'de design a new CNC machine using the experience from the first 3, and let machine no. 3. create the parts.
At this point I've got, as I said, the parts needed for the first machine, hand drawn in 2D and 3D, but actually making the 400 (+/-) parts for the assembly is not going to be easy, so I am trying to find a student who can make the parts for free as a project for his/her school - but even whith the parts pre-made, I'm not sure it will·work, since I've never designed and build·such a complex machine, and doesn't know for sure that it'll be able to cut anything but bread'n butter.
Does any of you guys know how much force would be required for a machine trying to·mill in metal - the tests I've made seems to indicate that a high RPM drill·trailing along a·0.1' thick steel plate, will need to handle around 5 pounds of thrust in the XZ axis and up to 7 pounts the the Y axis, but thats using a scale weight attached to a tool which was ment to be drilling, not milling.
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Why do·they call it a spacestation? There's hardly "space" for anything in there.
Just to throw my 2 cents worth into this conversation, have you heard of Lindsay Publications?· They have a series of books on building practically a complete machine shop from scratch.· Very cool stuff, I bought the set but have gotten stuck (too lazy and or too little free time!) at getting some foundry sand for castings......
Here's the link. This guy Gingery who wrote the series was a serious thinker and machinist.
Michael Chadwick said...
Just to throw my 2 cents worth into this conversation, have you heard of Lindsay Publications?· They have a series of books on building practically a complete machine shop from scratch.· Very cool stuff, I bought the set but have gotten stuck (too lazy and or too little free time!) at getting some foundry sand for castings......
Here's the link. This guy Gingery who wrote the series was a serious thinker and machinist.
The forces, or more imprtantly the rigidity of the machine depend on the precision of your requirement. Even small commercial milling machines weigh a few thousand pounds and have in the order of 3 to 5 HP positioning motors, and typically 10 to 20 HP spindle motor. Machines that are insufficiently rigid for the application will exhibit flexing during cutting, causing unacceptable chatter, and you do speak of cutting steel, so...........
Furthermore, a CNC lathe should be quite a bit easier to build than a mill. However, in my humble opinion (I have one a commercial mill & lathe) to make a "real" home made unit will be a lot of work unless you downgrade your requirements so far that the machine becomes essentially useless for metal cutting.
An XY positioner with a Z axis with limited force requirements (a fraction of a pound) is very much in the realm of a mechanically inlined hobbyist.
Thanx for some valuable input Peter. A CNC lathe/mill for working in Delrin/Plexi and other plastics might be a bit more in reach for me at this point, though a bigger, better and meaner machine for steel works is still my long term objective.
At this point I'm considering if a drill that can drill from/at any angle could do the trick - a mechanism locking the drill into position would require much less powerfull positioning motors, the spidel motor and the motor driving the drill down (or which ever direction it's facing) would ofcause still require the same power.
- I'm not sure if this would even work.
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Why do·they call it a spacestation? There's hardly "space" for anything in there.
Lemon, there are newer generation milling machines that operate exactly the way you are describing. They use a concept of mounting the cutting tool and motor on a movable frame suspended by a triad of extendable connecting rods. The length of each of these rods is individually controllable, and hence any x, y and z positions within its range are possible. By adding multiple degrees of this concept, the orientation of the spindle can also be controlled; virtually any motion can be described.
Yup, my first and only minute of clarity this year. With my quota of good thinking already spent, I might aswell put my breain back in the jar. ;o)
I'll start building a full scale model for writing and testing firmware this month - if it works, or at least if some of it works, I'll post the result in a while (in a long while posibly).
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Why do·they call it a spacestation? There's hardly "space" for anything in there.
Comments
- I bet they didn't think of copper and fiberglass PCBs when they made that device.
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Why do·they call it a spacestation? There's hardly "space" for anything in there.
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Why do·they call it a spacestation? There's hardly "space" for anything in there.
http://www.use-enco.com/CGI/INSRIT?PMAKA=201-2536&PMPXNO=953096&PARTPG=INLMK3
or less
http://www.use-enco.com/CGI/INSRIT?PMAKA=201-2826&PMPXNO=951820&PARTPG=INLMK3
and steppers motors are easy to salvage from old printers, fax machines or copiers.
I'd love to see ideas for the Z axis. What about solder/paste feed?
If any one·actually makes such a device and orders one of my 3 axis stepper motor controller kits·(unipolar motors only) for $75, I will refund the entire amount (and postage) in return for a picture showing the device connected to my contoller.
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---
James Newton, Host of SXList.com
james@sxlist.com 1-619-652-0593 fax:1-208-279-8767
SX FAQ / Code / Tutorials / Documentation:
http://www.sxlist.com Pick faster!
This is pretty poorly controlled, since the paste it rather thermally sensitive. It's also fussy - I once dropped a syringe of the stuff, and it snapped the (tapered) nozzle off. I transferred the remains of the paste into a regular syringe, with a similar sized needle. It started out fine, but after a while, got harder and harder to squeeze any out. Turns out, the straight needle was changing things, squeezing the flux out in preference to the solder, so after a while, the paste was less flux, more solder, and wouldn't move.
Just a cautionary tale, that solderpaste doesn't necessarily flow like you'd expect.
(Using a lead screw pressing on a diaphragm might (or might not) get you a more consistent shot size, and avoid the need for compressed air - I can't imagine that the paste could tell the difference between my hand pressing on teh diaphragm and that...
You'd probably want to do this all with the board prewarmed - even if just with a couple of halogen lamps - the flux is a lot runnier & stickier when warm. When it's cool, it really doesn't want to stick to anything. I'd suggest anyone thinking about automating this buy a syringe of the stuff and having a play, before building something that doesn't quite work [noparse]:)[/noparse]
But yeah, an automated soldering beastie would be handy. Then, of course, there's the temptation to turn it into a full (if simple & slow) pick & place machine. Feature creep - it's not a plan, it's a way of life [noparse]:)[/noparse]
Steve
I think solder paste, while enticing in the concept, has too short of a shelf life and variation of properties during the shelf life to be useful, additionally through personal experience, wave tip soldering produces vastly more reliable results than solder paste when using an iron. I found that the amount of paste on the pad effects the amount of time for reflow and·this could compromise consistant results·in an automated system.
For the solder,·I think using a stepper motor to pull solder wire through a pair of rollers would be effective, through there may be some tight clearance issues since you would want the output of the roller to be very close to the iron tip, though an additional set of non driven rollers between the driven set and the spool could effectively straighten the solder enough to back the feeder away from the tip. A specially modified solder tip may improve the system, one with a V groove channel on the side. The solder wire would make contact with the groove, melt and flow via gravity down to the tip.
I've always been facinated with the operation of mechanical systems but do not have experience designing or constructing them, so these ideas may or may not work.
Anyway, it takes 5-10Kgf to do its thing. That's going to take a lot more than an aquarium bubbler... (You'll also need to release the pressure sharply, to stop dribbling). The leadscrew plan feels simpler.
If you want to use solder wire, rather than paste, you have the problem of it trying to push the component around. All rather tricky. I suspect that there's no clear winner here. It'd be a fun project, though.
(Pick&place machines are gently dropping in price. Ebay 4357177726 looks like it was a good buy for somebody...)
Steve
Steve
CNC. - Make sense?!
Which came first... The ruler or the machine that made the ruler?
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Beau Schwabe - Mask Designer III
National Semiconductor Corporation
(Communication Interface Division)
500 Pinnacle Court, Suite 525
Mail Stop GA1
Norcross,GA 30071
I suggest the #69-#60 set. The 10 piece set is $7.15 plus shipping and they work great in a Dremel with a Dremel drill press. I've drilled about 300 holes and I'm still on my first bit. Each drill bit is good for a few thousand hits.
You really only need these drill bits for the component holes. You can use cheaper drill bits to drill 1/8 inch mounting holes.
http://www.buildyouridea.com ·? that is what he did, but the first machine made "lost foam" patterns for the casting of the gibs for the second machine. A really cool method of casting is documented there...
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---
James Newton, Host of SXList.com
james@sxlist.com 1-619-652-0593 fax:1-208-279-8767
SX FAQ / Code / Tutorials / Documentation:
http://www.sxlist.com Pick faster!
Post Edited (James Newton) : 3/4/2005 12:47:21 AM GMT
At this point I've got, as I said, the parts needed for the first machine, hand drawn in 2D and 3D, but actually making the 400 (+/-) parts for the assembly is not going to be easy, so I am trying to find a student who can make the parts for free as a project for his/her school - but even whith the parts pre-made, I'm not sure it will·work, since I've never designed and build·such a complex machine, and doesn't know for sure that it'll be able to cut anything but bread'n butter.
Does any of you guys know how much force would be required for a machine trying to·mill in metal - the tests I've made seems to indicate that a high RPM drill·trailing along a·0.1' thick steel plate, will need to handle around 5 pounds of thrust in the XZ axis and up to 7 pounts the the Y axis, but thats using a scale weight attached to a tool which was ment to be drilling, not milling.
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Why do·they call it a spacestation? There's hardly "space" for anything in there.
Here's the link. This guy Gingery who wrote the series was a serious thinker and machinist.
http://www.lindsaybks.com/dgjp/djgbk/series/index.html
Plus there·is a bunch of·obscure·and interesting information on the web site.......
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Why do·they call it a spacestation? There's hardly "space" for anything in there.
The forces, or more imprtantly the rigidity of the machine depend on the precision of your requirement. Even small commercial milling machines weigh a few thousand pounds and have in the order of 3 to 5 HP positioning motors, and typically 10 to 20 HP spindle motor. Machines that are insufficiently rigid for the application will exhibit flexing during cutting, causing unacceptable chatter, and you do speak of cutting steel, so...........
Furthermore, a CNC lathe should be quite a bit easier to build than a mill. However, in my humble opinion (I have one a commercial mill & lathe) to make a "real" home made unit will be a lot of work unless you downgrade your requirements so far that the machine becomes essentially useless for metal cutting.
An XY positioner with a Z axis with limited force requirements (a fraction of a pound) is very much in the realm of a mechanically inlined hobbyist.
Peter (pjv)
At this point I'm considering if a drill that can drill from/at any angle could do the trick - a mechanism locking the drill into position would require much less powerfull positioning motors, the spidel motor and the motor driving the drill down (or which ever direction it's facing) would ofcause still require the same power.
- I'm not sure if this would even work.
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Why do·they call it a spacestation? There's hardly "space" for anything in there.
Good thinking on your part!
Peter (pjv)
I'll start building a full scale model for writing and testing firmware this month - if it works, or at least if some of it works, I'll post the result in a while (in a long while posibly).
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Why do·they call it a spacestation? There's hardly "space" for anything in there.