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Introduction -
Roland Friestad
May 9, 1999
From: Roland Friestad I have great hopes for this forum and the future of Low-Cost CNC/CAD/EDM/DRO etc - Although one of the things I've found is that the definition of Low-Cost varies a lot depending on who's doing the defining - To introduce myself: I'm a professional engineer and tool & die-maker with a background in Aeronautical and Mechanical Engineering. That means I can use P.E. after my name, something that combined with anything from $0.50 to $1.00 will get a cup of coffee in anything but the most expensive restaurants. I was on the design staff of Piper Aircraft and was Chief Engineer of Bellanca Aircraft - I also spent some time at UNIVAC working on the computers used on the first moon landing craft - That's where I first became aware of the use of computers for actually moving and controlling real-life equpment - I've been hooked ever since I dropped out of the corporate rat-race over 25 years ago and started a small manufacturing company specializing in short-run metal stamping, making parts for other companies - I have come to prefer to work for smaller companies rather than the "big boys" who generally expect you to be suitably respectful of their size - I could write a book about those experiences - I got into CNC as soon as I could afford to buy my first Bridgeport CNC mill about 20 years ago - It revolutionized my thinking about building dies and tooling - The local Technical School talked me into teaching CNC programming since I had the first equipment in the area - I taught for about 20 years on evenings and weekends - The classes were held at my shop and the students needed to get into my CNC mills to run their projects and "smoke test" their programs - It seemed that a die building project was always in the mills when they wanted to run their own projects - That's when I searched for a small CNC machine to use for teaching - What I found was equipment that appeared to be terribly over-priced for their capabilities and size - So, fancying myself a designer I built my own retrofits, using commercial mills and lathes as the basic frames - I know enough electronics to be dangerous and the assembly language computer programming I was taught at UNIVAC is so hopelessly out of date that I needed to find a company to provide the CNC motion - I located a small outfit run by two guys working out of their basement and contracted with them to build the first CNC controller for me - They have since grown into what is now CENTROID - The first CNC machines were successful as teaching tools and other teachers wanted similar machines so I started building them - The project got out of hand and what started as a sort of "hobby project" has become a fairly large part of my small business with approximately 400 machines done up to now - These include CNC lathes, mills, routers, laser welders, rotary tables, and some very special custom machines - In 1989 I started writing a series of articles for HOME SHOP MACHINIST magazine on retrofitting these machines, providing drawings and resources for those who wanted to get into CNC in a low-cost way - This continued for several years but I've been sort of inactive with the articles for the last few years - I'm working on a whole new series to be published, the first of which is a home-built DRO for small mills - Don Fergle and myself have presented the CNC Seminars at N.A.M.E.S. for the last two years - It is satisfying to see the standing-room-only crowds at these seminars - I"ve been talking to the N.A.M.E.S. directors about an expanded program for the next year's exhibition - Will advise when they let me know if it is going to happen - I'm pleased to see the growing interest in these areas and will try to contribute as much as possible - I see various areas that need work and would hope that we can all progress together by combining efforts and sharing information - I feel that my own expertise is in the areas of mechanical design and machining rather than that of programming and electronics - Consequently I would be more than willing to coordinate and share with those who have complementary capabilities - One thing that I have been thinking about for a couple of years is the possibility of hosting some sort of get-together for those who want to build or retrofit milling machines or lathes - I've got a fairly complete machine shop and lots of space - While I build and sell systems to schools for training of CNC operators and programmers, the hobbyist movement is where my personal sympathies lie - Those of you who might want to participate in such a get together at my shop can let me know via this forum - I am thinking of about a week long project where you could bring your machines along and spend time making parts and sharing ideas using my shop and equipment - A lot of these projects would probably be of interest also to the readers of HOME SHOP MACHINIST and I could write them up for publication if everyone agreed - I apologize to be so long-winded about this - I'll try to keep it shorter in the future but it's kind of nice to know that I'm not the only one out there with these kinds of interests - Roland Friestad <cardinal.eng@...> |
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Re: Intro
Dennis Mino
Brian, I think it's www.teachcnc.com
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try that......... ----- Original Message -----
From: Brian Fairey <bfairey@...> To: <CAD_CAM_EDM_DRO@...> Sent: Sunday, May 09, 1999 10:52 AM Subject: Re: [CAD_CAM_EDM_DRO] Intro From: Brian Fairey <bfairey@...>Loved system.the Aussies I met. ThenFirst, it used some 2.4 amp drivers with a 450 oz in steppe r motors. system.I built 5 amp drivers for it then converted it to the present servo freeMilling a 3" diameter bore with a 3/8" end mill is a joy. cncprogram that do that. last you need to learn about various stepper coderetofits information. While there d/l a copy of Stepster for a free G discussion of shop built systems in the above catagories.interpreter. discussion of shop built systems in the above catagories. |
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Introduction and plea for help
"Ian W. Wright" <[email protected]
Hello group,
With a bit of luck, this list will be the best thing in my life (sad eh?) As some of you know already I repair and restore high class watches and small clocks and I am wanting to find a way of making small parts easily and accurately. A typical problem might be that a complicated chronograph may come in, having suffered the attentions of an 'expert', with one or more of its internal operating levers missing. At the moment the only way I can reliably make a new part is to cut and fit it gradually bit-by-bit using the remains of the movement as a guide - a very hit-and-miss affair. I have worked out that, by taking digital photos, importing them into Autocad and drawing over them, I can design the required new part to a high degree of accuracy and confirm that it will work OK before I cut any metal BUT I then have the major problem of transferring the designed shape onto the metal and cutting it accurately - a scribed line in my scale of things can be half the width of the finished part! So, I have been playing about for some time with ideas to make a wire EDM and a miniature CNC miller - each with a table size of only about 6" x 6". However, I have continually fallen at the first fence as I don't seem to be able to get a stepper interface working properly. The steppers I have are marked 'Step-Syn' type 103G770-0344, 24 volt, 0.22 Amp, 1.8 deg/step, 5 wire. I have tried a number of published stepper driver circuits but these are mainly for low voltage motors and seem to give up when I try to hang a power darlington output stage on them to handle the higher voltage. I must admit to not having tried Dan's circuit yet but, after so much wasted time and expense, I'm a little sceptical of paying out for 24 transistors on a maybe! (Sorry but I am the archetypal Yorkshireman - deep pockets and short arms!) I tried running an emulation of this circuit on an electronics workbench program and it seemed to work, although with apparently jittery outputs - then I moved and reconnected a wire I had connected to the wrong place and it stopped working! Can anyone advise me on the practical solutions they have found and, also, can anyone tell me how the feedback circuits of a wire EDM work - I'm sure this is really the machine I need for most of the work I want to do. Some of the watches etc. I have been working on recently are on my web site at Best wishes Ian -- Ian W. Wright LBHI Sheffield Branch Chairman of the British Horological Institute. Bandmaster and Euphonium player of the Hathersage Brass Band. UK. See our homepage at:- or or 'Music is the filling of regular time intervals with harmonious oscillations.' |
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Rhino Segue
On Sun, 09 May 1999 12:14:31 -0300, James P Crombie
<jpcrombie@...> wrote: But if you are doingI agree, Rhino is a stellar goodie (I was lurking on the beta testers list during it's development, and I must say the developer guys are also a bunch of nice chaps, no fat-heads, ifyagetmedrift). The reason for chiming in was to mention something that is IN Rhino already, and that is: interface drivers for a couple of the high-end 3-D measurement tools, ya know, them gimbled arm thingies you use to digitize in 3-D. Now, THERES a grand other possible group project, eh? Develop a low-cost, workable resolution 3-D digitizing arm. Woooheee, you are about to enter the "dream and drool zone". AGAIN, the reason why these things are sooooo spendo is that to market an industrial-grade digitootzy, and get the high resolution demanded, the bearings and other components get spendy real fast, but for us HSM types, being able to input a shape into Rhino at say 0.005" res and then refine and dump out lofts or sections of the contours to our handy dandy routers/mills would we vewy noice indeed. BTW, Rhino, especially for what the program does, is actually NOT terribly expensive. I think I saw one early adopter vendor selling copies for around $400 IIRC. Not cheapo, to be sure, but not like a license for a full copy of Autocad, neither. Gar |
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Re: interface board
On Sun, 9 May 1999 10:00:50 -0500, "Steve Lindsay"
<slindsay@...> wrote: Gar.... 360 will work!Gotcha; yeah, I know, anything really will work, as long as you have enough precision in the numbers so you don't bump a count due to roundoff, but it's sure messy to be working with (and displaying the results of) native resolutions of 0.00069444444444", doncha tink? B) Specially when, if HP would just listen to us home machinists (hee hee), they could just MAKE one perfectly suited for us! I just don't unnerstand why they don't consult with us hobbyists when doing their marketing surveys. B) Back when I was writing the program the most HP had for linear encodersYeah, agreed; like I said, I really DO appreciate their being both a supplier and specially a reasonably priced supplier of the optic media, and on their web pages they're not REALLY tryna "hide" the fact that HP's sensors are key to their products, it's just that they coulda put links there to HP's website where the HEDS sensors and app notes for them are available, so as to help out their clients. But I also understand the business concept of presenting yourself as a sole supplier or rather "one-stop shopping", so it's not really any serious complaint I was alludin to, ifyagetmedrift. No biggie. BTW, the HP link to their motion stuff is: Punch in the part number "heds-9200 opt 360" to go directly to: "HEDS-9000/9100/9200 Extended Resolution Series" I noticed when checking this link to make sure it was still alive, that them bozos have ADDED a 300 cpi sensor to their repertoire, but NO 250 cpi one!! Da noive a dem guys. Sheesh. Time for a write-in campaign, eh? :) Gar |
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Re: Intro
Brian Fairey
Dan cant find www.teachnc.com
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Brian. Dan Mauch wrote: From: "Dan Mauch" <dmauch@...> |
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List
Good morning listees. I am happy to report that we now have 98 members, and
growing. One of things I might comment on it that if possible include the URL on items mentioned in your postings, this would make it easier for everyone to find the item, and stop a lot of extra "do you have the address/URL" postings. Hello lurkers, how about telling us something about what you are doing, or want. Guys keep up the good work. bill |
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Re: Cadadvance ver 6.5
James P Crombie <[email protected]
I havn't bothered to download it myself, I already have to many cad p rograms :-) I do most of my work in Rhinocad3D. If I need to dimension the drawing, then I export it to TurboCad 2d, another freebie striped-down cad program. But if you are doing complex 3d surfacing then Rhino is the best program out there. Dennis Mino wrote: From: "Dennis Mino" <dmino@...>-- --------------------------------------------------------------------- James P Crombie Summerside PEI Canada My Astronomy stuff RhinoCad 3D Stuff --------------------------------------------------------------------- |
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3D Modelling
Here's what i would like to do...
I'm a chiropodist (like a podiatrist) - am involved in the manufacture of custom foot orthoses (supports) - the current process is to take a plaster of paris bandage/cast the foot in the orientation you want(to obtain negative cast)/fill this cast with plaster(to obtain the positive model)/modify the model by adding plaster to various areas to achieve the correction desired/vacuum mold a heated plastic blank over the modified plaster model/grind and finish the support The way i see it, there are several areas that a scanner/cnc mill could be involved - what i would like to do is scan the foot(or cast of the foot)/modify the image on the computer(this is where having a computer's accuracy and repeatability would be most beneficial i think)/ then mill the positive cast/finish in the normal manner the mill could just produce the orthosis, but, due to the nature of some of the materials (ie carbon graphite, etc) it would be much more practical to mill the positive cast, then use it to make the orthosis in the traditional way any info or links or direction would be greatly appreciated Chris Ellacott |
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Re: interface board
Steve Lindsay
Gar.... 360 will work! In the setup screen in the dro program
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you can enter a number to count by.... and it supports a number up to 14 places right of the decimal. The 360 cpi would quaduture to 1440 and 1440 divided by 1" is 0.00069444444444 Enter this number into the dro axis setup. To get to the setup screen after the program starts....hit R "Read Encoders" and then X or Y or Z to get to that axis setup. In this setup you can also tell it how many numbers to display right of the decimal on the readout screen so all 14 places don't clutter your screen. Back when I was writing the program the most HP had for linear encoders was 200 and then HP told me they don't make the strips and I would have to find another company that made them. I do have a HP big encoder book and called lots of those numbers in the back finding a company that would sell what encoders I was after (since HP won't sell direct). Later I found US digital. They are just another reseller of HP stuff but I thought their web pages layout describing what HP had was helpful... At least compared to the luck I was having calling all the suppliers/resellers in the back of HP encoder book. Also the way I understood it they were making the linear mylar strips. I haven't looked at US Digitals web pages for a long time but if they are coming across like they are big stuff without HP I would find it cold too. Steve Digital Read Out 4.0 (encoder reader) Date: Sat, 08 May 1999 23:52:42 -0700 I trust most everyone realizes that pretty much all US Digital does is |
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Re: Cadadvance ver 6.5
Dennis Mino
Where's the web page for this?
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Thanx. ----- Original Message -----
From: Dan Mauch <dmauch@...> To: <CAD_CAM_EDM_DRO@...> Sent: Sunday, May 09, 1999 8:45 AM Subject: [CAD_CAM_EDM_DRO] Cadadvance ver 6.5 From: "Dan Mauch" <dmauch@...>nice tho it is a bit dated. I runs fine under win98. So if you need a free$1989 cad program I would recommend d/ling a copy of it.discussion of shop built systems in the above catagories. |
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Re: Intro
Dan Mauch
Welcome to the group. I visited Perth/Fremantle about 10 years ago. Loved
the Aussies I met. I have retofitted my 8x36 200mmX900mm vertical mill to a servo CNC system. First, it used some 2.4 amp drivers with a 450 oz in steppe r motors. Then I built 5 amp drivers for it then converted it to the present servo system. Milling a 3" diameter bore with a 3/8" end mill is a joy. I would start by d/ling a dempo copy of Desknc for Dos at www.deskam.com This is a fine low cost G code interpreter. You can also go to www.teachnc.com and read about G code instructions. From there it it a simple mater to convert autocad dxf files to G code. There are sveral free program that do that. last you need to learn about various stepper motor/servo systems and how they work and what their limitations are. You will also want to visit www.metalworking.com for other pictures of cnc retofits information. While there d/l a copy of Stepster for a free G code interpreter. Dan |
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Re: Scanning to G code
Dan Mauch
I have played with several methods to convert bit mapped images to G code. I
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tried several of the scan to cad programs and none of them worked to the degree that I would like to see. I tested the first version of deskart from www.deskam.com you can d/l a demo copy from them. I wanted to make very tiny images about .5"x.5" The first version I tried tookbitmapped digital pictures then load them into deskart then shrink the size down to .5X.5 . I have a small sherline mill that I have converted to CNC. I tried machining machinable wax with the image. The results were poor. There were several problems. Some were mine some were with the software. Here is what I found. Deskart did not have an anti gouge control and was somewhat limited. On my part the .014 cutter was too big for that size image. I wanted 300 dpi so what i really needed was a .003 diameter cutter. Second the sherline max speed is about 3000 RPM which is too slow. I need about 50,000 RPM. Subsequently, Deskart has been revisedand version 2 is now out. It has antigouge control and sveral new features. I hope to test this in the next week. Dan -----Original Message-----
From: Jon Elson <jmelson@...> To: CAD_CAM_EDM_DRO@... <CAD_CAM_EDM_DRO@...> Date: Saturday, May 08, 1999 10:42 PM Subject: Re: [CAD_CAM_EDM_DRO] 3D modelling From: Jon Elson <jmelson@...>any info/links to help me - want to take a 3D object, digitize it (?laser/video) into the computer, modify it, then mill this modified object - budget is VERY low, so shareware & surplus sound good done a few 2-D objects. I remembered about 10-15 years ago, a big craze (and small business)putting people's pictures on T shirts. I thought, "Yeah, I'll take digital pictures of my kids fromseveral positions, use a program to convert the pictures to a 3-D point cloud, and then write atoolpath generator. I could franchise this and make a bundle! Yeah!" Well, I talked to somepeople about it, and downloaded some of the 2-D to 3-D mapping programs, and then askedspecific questions of these outfits. The response was unanimous. Yes, they all wanted to dothis, and yes, they'd all tried it, and no, their software really didn't perform well. Onecompany said they actually got it to work (the face is shown in wire frame on their web page) but thatit took an experienced CAD/CAM operator well over 8 hours to massage that face into reasonableshape. The hair is hopeless! But, for that, you could fudge it with canned versions of thebacks of people's heads, and no one would ever know.camera has come out, but it is around US $10000. Slightly out of my budget.is simple enough for the 2-D to 3-D mapping programs to work, then it is possible. Youdon't tell me more about what you want to do, so that's as good as I can do.discussion of shop built systems in the above catagories. |
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Re: Just On-board
In a message dated 99-05-09 02:13:59 EDT, you write:
<< On Sat, 8 May 1999 14:59:59 EDT, Jonty50@... wrote: >>I'm currently constructing a 48" x 96" x 24" gantry style router. Neat, we should compare notes; BTW, I musta been dreamin when I posted the bed dimensions on mine. It's 4' X 4' X 2' for me, NOT the enormous 8' Y that Jon is working toward. I just never even HOPED to have room for such a monster, let alone find the parts necessary for it. But I musta harbored Freudian desires for same, given my misstyping. B) So my intro shoulda read 4' X 4' X 24". << Yeah, the thing is outtahand. It takes up way too much space in the two car garage that I have for a shop. I'm using a 6" x 6" x 1/4" wall rectangular steel tube 6' long as the gantry. The gantry rides on two 2" x 4" x 1/4" wall rectangular 6061-T6511 aluminum tubes that are 10' long each. The framework that holds it all together is made from 4" x 4" x 1/4" square steel tube that I salvaged from a dumpster. My NEMA 34 step motors are also salvaged from a couple of mainframe printers. The parts aren't really such a problem. The Bishop Wisecarver V wheels, wheel mountings and track were around $600 for the lot. I have a little over $1000 in it with around another $600 to spend on the driver board and miscellaneous items. Add in a bit more for a "fudge factor" and I figure an all up price of around $2000 - $2500 all told. Not bad for such a heavy duty machine. >I've found that Bishop Wisecarver makes the least expensive quality >linear motion components. I like their "V" stuff, but never went for pricing. Give us an example of "least expensive quality" if can think of a simple one, eh? Tanx. << The V bearings run around $20 each, it basically takes 4 per axis. I've found that the B-W track is not necessary, the wheels do very nicely riding on 1/4" diameter hardened steel rod ( I use music wire) that can be just pressed into a 1/8" deep slot milled in an aluminum bar or rectangular tube. Very smooth motion, even smoother than the B-W track. Jonathan jonty50@... |
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CNC
Is anyone working or going to work on building the CNC that has been in Model
Engineers Workshop ? I have stated on it, found 3 stepper motors and a power supply and have a base plate being trimed up from a larger piece. It has tasken several days to change the measurements from metric to inch but have about go it done. Now i am redrawing it and puting the measurements back on . Several in our club are thinking about making one but so far i am the only one that has started on it. Would like to here from someone else who has started on it. bill hinkle in Oklahoma where the wind blows somwtimes ps: seven miles from the big storm. |
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Re: Stepper Controls
Brian Fairey
Boondog say that the parallel port card is coming soon?? Or did you mean the 8255 card?
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Brian, Ont, Canada. Bob Bachman wrote: From: Bob Bachman <bobach@...> |
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Re: I'm New here
In a message dated 5/8/99 8:22:10 PM Hawaiian Standard Time, pencad@...
writes: << Now, my project I want to do I to assemble a laser cutter of approx. 40-50 watts, CO2 powered laser. >> Hello folks. Peter Tsukamoto here. I have just joined and am most impressed with the potential of this group. I look forward to reading the posts everyday. In regards to the laser project Don is attempting, my only input would be to use extreme caution around a laser processing machine. If any of the laser energy inadvertently got directed into a persons eyes, that would be the end of that persons vision. I doubt the laser goggles sold by the laser makers would be enough to prevent damage. At the very least, a visit to a metal shop that has a metal cutting laser and observing the shielding techniques would be warranted. Peter |
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