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Re: Flywheel for Stirling engine
The "best" way will depend on the operator's preference! If there's a
machined surface anywhere on the flywheel you received, it's usually handier to start by using it as a reference for subsequent machining. If it's rough all over & you've got a face plate, start by mounting it on the face plate with the shaft hole reasonably centered & the edges roughly parallel to the face plate. Depending on how rough the casting is, you may want to do a little shimming to minimize the amount of metal to remove. Try to visualize the finished flywheel inside the casting. While it's on the face plate, bore the center hole & face the exposed surface. Next step is to reverse it & face the other surface - since there's now a machined surface against the face plate, the other surface will be parallel. Final step is to turn the periphery. If you don't have a face plate, you can do it by using a drill press to make an accurate center hole, then use that hole to mount it for subsequent machining. Roy --- In 7x12minilathe@..., "dabmetal01" <dabmetal01@...> wrote: What would be the best order of operations for the flywheel and how do you |
Re: First prototype of the laser edge/center finder done!
If nothing else, the laser pointers make superb cat toys! It's even
more fun with 2 lasers & multiple cats;-) Roy --- In 7x12minilathe@..., Victoria Welch <wrlabs@...> wrote:
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Re: First prototype of the laser edge/center finder done!
You could say, "It's been enlightening!"
Part of my thinking was to post a link to Small Parts; they carry a lot of hard to find, nifty items. As a satisfied customer, it's in my best interest to keep them viable. Roy --- In 7x12minilathe@..., "born4something" <ajs@...> wrote:
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Re: First prototype of the laser edge/center finder done!
Victoria Welch
On Monday 16 April 2007, Ian Foster wrote:
G'day John, Vikki, Roy Derek et al.Hi Ian es all, I've been kind of busy for the past couple days but reading the mail as I can. With the one from MM coming, truthfully I don't know if I will consider proceeding with this or not. It has been fun, but there is limited $$$ involved :-(. I'd love to see what the sapphire balls would do though and experimenting with different filters / waveguides. I am thinking that the laser pointers are just too inconsistent quality wise, there may be some answer to that but the only other options I have seen are ungodly expensive. And, as noted, I spent more than the cost of the MM unit on cheap laser pointers alone at this point. Perhaps it could just be a hobby exploration over time, who knows? Thanks to everyone who provided feedback and food for thought! Take care, Vikki. -- Victoria Welch, WV9K/7 "Being Muslim is not a religion. Islam is an ideology that is fixated on the death or conversion of everyone. It isn't intolerance or bigotry to reject, despise or attempt to destroy such a contemptible way of thinking." --Mormon Doc |
Re: First prototype of the laser edge/center finder done!
G'day John, Vikki, Roy Derek et al.
I think this thread should come to an end before we feel the ire of those who would want to "sit back and sift". Even though discussion has drifted away from the topic it has generated a healthy forum on an engineeering subject and perhaps broadened the understanding of some. I know others will "stick tp their guns". One good turn deserves another. Regards, Ian |
Cummins Lathe for sale w/ extras
If classified aren't allowed in this group, Can the administrators
please delete this. I joined this group a while back when I bought the lathe and learned a lot. My hobby has progressed to making parts larger than the 7x12 can deal with....and I've had to get pretty creative with attachments and tooling trying to work on a hub for my racecar that was 6.4" in diameter. Anyway, I just bought a new Atlas 10" lathe, and I no longer need the mini-lathe. So its up for sale. Here's the list of stuff I've got. Cummins 7X12 lathe Seig DRO setup A bag of spare gears, change gears, belt, etc... 4" 4 jaw chuck Quick Change Tool Post with tool holders Assorted tooling I don't have any tailstock centers to include but I will include a tailstock chuck Steady rest & carriage rest Faceplate I haven't used it much lately but it needs the typical maintanence: lube the gears, adjust the gibs, etc.... but it works great. Please email me with offers or questions, as I don't quite know what the whole package is worth. lbhsbz@... |
Re: First prototype of the laser edge/center finder done!
Hi,
Well I'm not a physicist although I am an engineer of the electronic variety. My thinking is that the laser wavelength is around 600nm from memory and will readily detect edges of quarter wave. That's probably an order of magnitude finer than the surface finish on most machined surfaces so most surfaces would appear to be a myrriad of "edges". I think these things are simply using the fact that laser beams don't spread much and are the cheapest source of a narrow beam. Also, these LED lasers are not as spectrally pure as their more expensive cousins which would muddy any interference pattern technique. John --- In 7x12minilathe@..., "tbarker_xxx" <tbarker@...> wrote: thread so maybe somebody can answer a question I've had about laser edgeand depending upon the user's eye to do the alignment, but that doesnot seem to take full advantage of the characteristics of a laser.Why are these units not taking the reflected image and splitting it sothe beam? Since the travel distance as the beam moves onto an edgewould be different the split beam should show very noticableinterference (assuming of course that the difference in travel distance is nota multiple of the wavelenght and that seems unlikely).repeatable precision-edge- detection. I've thought a bit about what opticsto mass produce, although it is probable something that would a bithard to prototype in a home shop.Just theimagine filing energetically and dislodging a handle such that ifunexpectedly.tang is driven up inside your wrist on the next power stroke. thatonhelped or that cheap wood is just so springy that it comes down theMcIntyreshank tightly?!? Short of pounding it off with a hammer of somesort,I think it is there to stay.workbench. andDerek Bok |
Re: Thread cutting mystery...
John,
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You and Roy hit the nail on the head. I'm cutting an approximation of a 1.5mm metric thread...something I've never done before. I thought that engaging the half nuts at the same number on the threading dial every time would do the trick! My gear setup is 40, 50, 65,55 for an actual TPI of 16.923. I'll try again without disengaging the halfnuts (that's gonna be tricky!) Thanks again for the help fellas. Jim Dana Point, CA --- In 7x12minilathe@..., "born4something" <ajs@...> wrote:
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Re: First prototype of the laser edge/center finder done!
Hi Roy,
Yeah, but once Vikki's commercial number from MM arrives I think she'll find new games to play. Vikki's had the fun of sussing out how far you can push a $1 laser and it's been an interesting thread. :-) John --- In 7x12minilathe@..., "roylowenthal" <roylowenthal@...> wrote: no ideagreatestwere to even start looking for something like that.liberty zeal,dangers to liberty lurk in insidious encroachment by men of wellmeaning but without understanding." -- Justice Louis Brandeis |
Re: Thread cutting mystery...
Hi Jim,
I'd try keeping the half-nuts engaged and reversing up - as opposed to using the threading dial. If the problem persists you must have some sort of slippage (on keyed gears???). Are you doing non-native threads (metric on an imperial lathe or vice verca)? John --- In 7x12minilathe@..., "kettletrigger" <kettletrigger@...> wrote: lathe, but it always went fine back then. Today I learned the hard lesson of running a testpiece even though I thought it would work fine¨Cruined a nice part in the process. f cuts. I made no changes whatsoever to the top slide or cross slide (other than retractingit for clearance then setting back to "zero") and made sure to catch the thread dial on "1" forevery pass. Those five passes should have all been in the same groove, but it'soffsetting a couple of thous each pass. It's as if something in the gear train is slipping but I'vechecked everything a bunch of times. I'm really stumped on this one, any ideas would beappreciated.
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Re: First prototype of the laser edge/center finder done!
Small Parts has them:
Roy --- In 7x12minilathe@..., Victoria Welch <wrlabs@...> wrote: laser. idea were to even start looking for something like that.liberty when the government's purposes are beneficient . . . the greatestwell meaning but without understanding." -- Justice Louis Brandeis |
Re: Thread cutting mystery...
What thread pitch are you trying to cut?
The threading dial only aligns for multiples of 1/2 tpi; if you're doing a metric approximation (with an SAE leadscrew) you'll have to keep the half-nuts engaged during the entire process. Roy --- In 7x12minilathe@..., "kettletrigger" <kettletrigger@...> wrote: lathe, but it always went fine back then. Today I learned the hard lesson of running a testpiece even though I thought it would work fine¨Cruined a nice part in the process. cuts. I made no changes whatsoever to the top slide or cross slide (other than retractingit for clearance then setting back to "zero") and made sure to catch the thread dial on "1" forevery pass. Those five passes should have all been in the same groove, but it's offsettinga couple of thous each pass. It's as if something in the gear train is slipping but I'vechecked everything a bunch of times. I'm really stumped on this one, any ideas would beappreciated.
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Re: Thread cutting mystery...
--- In 7x12minilathe@..., "kettletrigger"
<kettletrigger@...> wrote: lathe, but it always went fine back then. Today I learned the hard lesson of running a testpiece even though I thought it would work fine¨Cruined a nice part in the process. cuts. I made no changes whatsoever to the top slide or cross slide (other than retractingit for clearance then setting back to "zero") and made sure to catch the thread dial on "1" forevery pass. Those five passes should have all been in the same groove, but it's offsettinga couple of thous each pass. It's as if something in the gear train is slipping but I'vechecked everything a bunch of times. I'm really stumped on this one, any ideas would beappreciated. jim; have you checked the engagement of the half nuts? it looks like the cut is wandering within the same groove. just one idea. don |
Re: Thread cutting mystery...
If nothing is slipping, it may mean you have the gears set up for
metric threads. How many tpi were you trying to cut? How many tpi did it actually cut, as measured with a thread gauge (no estimating here...)? What was the gear setup? Is the thread indicator gear engaged properly? John --- In 7x12minilathe@..., "kettletrigger" <kettletrigger@...> wrote: lathe, but it always went fine back then. Today I learned the hard lesson of running a testpiece even though I thought it would work fine¨Cruined a nice part in the process.cuts. I made no changes whatsoever to the top slide or cross slide (other than retracting itfor clearance then setting back to "zero") and made sure to catch the thread dial on "1" forevery pass. Those five passes should have all been in the same groove, but it's offsettinga couple of thous each pass. It's as if something in the gear train is slipping but I'vechecked everything a bunch of times. I'm really stumped on this one, any ideas would be appreciated. |
Thread cutting mystery...
It's been a couple of years since I've done any screwcutting on my lathe, but it always went
fine back then. Today I learned the hard lesson of running a test piece even though I thought it would work fine¨Cruined a nice part in the process. Here's a photo of the problem I'm having: That's a 1.5" diameter piece of aluminum with five successive test cuts. I made no changes whatsoever to the top slide or cross slide (other than retracting it for clearance then setting back to "zero") and made sure to catch the thread dial on "1" for every pass. Those five passes should have all been in the same groove, but it's offsetting a couple of thous each pass. It's as if something in the gear train is slipping but I've checked everything a bunch of times. I'm really stumped on this one, any ideas would be appreciated. Jim Dana Point, CA |
Re: Database of past messages
THANK YOU TONY !!!
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I most always sit back and sift for useful info. and much can be learned in doing so. The topic on the copyrights was getting foolish and wasting space that could be used for intelligent dialog. Doug Tony Smith <ajsmith@...> wrote: What a lot of hoo-ha about nothing, as the saying goes. 99.99% of the message on these boards really aren't worth saving, including this entire thread. Having a decent search interface, or an index, or perhaps a list of 'best of' threads would be nice. However, if you were going to do that, you might as well do what other have done, and call it a book. As far as who owns copyright, you do for your messages. By posting you grant Yahoo the right to publish them (with no royalties) or do whatever they like until you or they delete them. Yahoo doesn't really care (much) about a 3rd party setting up a database, so long as they don't pretend to be Yahoo, claim affiliation etc. The copyright & TOS (no, not Star Trek) pages are linked off the main groups page. If a poster has a problem with the 3rd party database, then it's between them. Personally, if you feel that your messages are so valuable that you'd be willing to fire off C&D letters or start lawsuits, perhaps you should stop posting. 'rroll99' has exactly 3 messages in my inbox, the one complaining about copyright, one asking for a book suggestion, and one saying thanks re the book. Not worth getting excited about. Perhaps I can sue all the other members of this group for having my copyrighted messages on their computer systems. You can all sue me in return. Besides, the whole point is spreading knowledge, and anything on this lists would be fairly well known anyway. I doubt anything new & earthshattering would appear on a message board that is mainly "I'm a newbie, how do I..." posts. There a few websites that have cherrypicked lists for useful messages, see for a example. It just mangles the emails a bit. Look at all the Usenet stuff, it eventually all ended up on Google. Useful? Maybe. Go write a book instead. Taking from many is called research, isn't it? Plus you'll get a pat on the back, and not (as many) accusations of copyright theft. Tony -----Original Message----- --------------------------------- Ahhh...imagining that irresistible "new car" smell? Check outnew cars at Yahoo! Autos. |
Re: Database of past messages
Patrice,
I think Druid has put to words what I believe as well. As for the search engine on this list, it is lacking but it does as good as can be expected on a free for all site like this. I see the problem as an organization problem. I don't see that we have an index to help newcomers and to help the long timers. Newcomers always ask the same quetions over and over, ME INCLUDED. And it is difficult for anyone to find a thread that they remember is on here somewhere that had the information they NOW need. This site is no different in that respect than other yahoo groups. As an alternative Patrice, maybe putting together a useful index that has hyperlinks back to this list would be as useful as anything. To get to the meat of the info.(the thread with the actual discussion) the user STILL has to be a member here. A very comprehensive Index and/or table of contents would be very useful, although maybe difficult to BUILD as well as MAINTAIN. As 'designated users' see a thread that might be a good reference, they can add a link to it from the TOC or Index. When general users have questions, they could first refer to the TOC/Index to do their searching for key words. New users could be directed to existing 'beginnerish' threads to answer their questions when appropriate. There's LOTS of reference information on this site. As I catch threads of possible future interest, I save a link to my palm pilot. On some, I copy the content directly and usually include a reference to the thread it came from in case I need more information. This also helps ME when I'm out in the workshop away from the computer. My 2c worth. Sorry, I'm a database programmer, I just think this way. Rance --- In 7x12minilathe@..., Druid Noibn <druid_noibn@...> wrote: removed the "copyright" from your site - however, as with the best of intentions, this generates another problem and a violation of the copyright law - your previous posting of "copyright" was a also a violation, called theft. courts will not hear a case unless it is registered. By not citing the copyright holder or the original author(s) you are placing in public domain work in which you might not have the authority to do so. and/or the original authors save for the logo and possibly the "look and feel?" as "public domain" in which case the public at-large have full use of it. However, it does not grant the copyright. complicated. Commercial use is sometimes a fine hair to split under the "Fair Use" principle. Most often restricted to educational institutions - If one were to copy a document for a class, a reasonable copying fee is permitted. A charge greater than this is deemed commercial and would be seen as unfair and potentially theft. intentions, it does have ramifications due to the ne're-do-wells who benefited from the work of others. permission is required and 2) full citation to the copyright owner (saving this, the original author) must be stated. Next disclosing information from a "members-only" group (one needs to be a member to post) is not a good idea. proceed is likely the best.
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Re: Database of past messages
Clint D
OK guys, its time to put this topic to rest. No need for any more comments.
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I as a moderator dont have a problem with any kind of info put out on the net as long as its a benefit to all. Personally, I dont think the creator of website in question had any malice intent. So, lets put this to rest now before the group owner gets upset and involved. to many other important topics going on for this type of OT Clint Tony Smith wrote: What a lot of hoo-ha about nothing, as the saying goes. 99.99% of the |
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