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John Stevenson	04/06/2011 21:35:38
5068 forum posts 3 photos	Posted by NJH on 04/06/2011 19:43:38: David did say, in his post on" The thread that crashed and burned", that 50% of the responders wanted CNC in the mag. ( Tony & John how many replies did you make? ) That was 50% wanted CNC from the poll results not 50% of answers in the post. Not 50% ONLY want CNC - different animal which goes to show moost was a braod spectrum of articles. That also includes me, i don't want full CNC. John S.
John Coates	04/06/2011 21:37:19
558 forum posts 28 photos	Posted by John Stevenson on 04/06/2011 21:35:38: That also includes me, i don't want full CNC. Neither did Bill Clinton - he just had Monica smoke the cigar for him !
John Stevenson	04/06/2011 22:06:03
5068 forum posts 3 photos	So David, who make the decisions, says a full special won't happen and like it or not he calls the tune. We have scribe a line, we often have long running articles like letters to a grandson or whatever it was so what about a 2 - 3 pager every issue called CNC corner. You don't have to read it if you don't want but so far 50% of the readers who have bothered to fill the poll in say they would like to see it. Also if you know that it's going to be relegated to those 2 - 3 pages then it's manageable. ????????? John S.
Steve Garnett	04/06/2011 22:37:42
837 forum posts 27 photos	Posted by Chris Trice on 04/06/2011 18:29:47: I believe I suggested that in the original thread on too much CNC. Great minds....? (and no rude comments from everybody else either!) Posted by David Clark 1 on 04/06/2011 21:19:25: A full CNC special will not happen. A small A5 booklet about CNC might be included as an add on FOC. I must admit that I could see a few potential problems with this, although I was trying to ignore them. One of them was how on earth you sell it to W.H.Smiths. I can just imagine the conversation: DC: (for it is he) "We're doing a special - it's about CAM. Would you like an exclusive deal to handle it?" WHS: "Why isn't it going in the regular magazine?" DC: "Well, we put three articles related to it in one edition, and World War Three appeared to break out on the forum. A few people didn't mind at all, most said it was too many, and we felt that a handful of respondents might be going to brick our windows." WHS: "So why do the special?" DC: "Really, it's because a couple of naive people though that this might ameliorate the situation - what the heck, they may even have been right about that. I'm hoping they are, anyway. So with a bit of luck, you won't get that many bricks though your windows..." WHS: "Hold the line please - we need to consult a couple of people - we won't be long". 10 minutes passes - DC is pacing nervously around his telephone, which has turned eerily silent. Suddenly it clicks back into life. WHS: "Hmm.... we've taken what you said on board - and we'll get back to you about it..." DC: " Would it help if we only paid £10 per page to the contributors, and paid the rest to your insurance company for additional premiums?"
John Stevenson	05/06/2011 00:09:36
5068 forum posts 3 photos	Damn it, give me the extra and I'll go round and brick the windows of anyone that complains - can't be fairer than that can I ? John S.
Richard Parsons	05/06/2011 08:29:24
645 forum posts 33 photos	The problems of coldness in the workshop. Over here from mid-September to early March it gets COLD. Often as low as -30°C or lower. We have the answers which are · 3 (no more) layers of clothing, which can include ‘Long Johns’ or Swambo’s tights is she is not looking. Good insulation and an inner door which was a curtain made of ‘Bubble wrap’ (Cheap). · A ‘Kandelo’, My previous workshop was a 10’ by 8’ wooden shed and I built a portable ‘Kandelo’ (it was moved outside in summer) What is a Kandelo? It is a wood/rubbish/coal (if you can get it)/dirty oil/etc burning storage heater. Mine was made in part of a 40 Gallon oil drum and had 8 ‘circulations’ on 2 levels. When I had built my new ‘workroom’ I sold the shed and Kandelo to some wood workers, who used it as an office/warming room. Whilst the owner and his helpers were at lunch, the next door mob tried to unfreeze their Propane/butane bottles. The shed, the Kandelo and the ‘next door mob’ are no longer with us! If the editor wants I will write up how to do it and throw in the oil burner for good measure.
Richard Parsons	05/06/2011 08:52:26
645 forum posts 33 photos	As to CNC articles I have no objections to them. I do not use CNC kit myself because I have no CAD package that works. I have tried the ‘free’ version of Alibre but it is always arguing with ‘silver-light’, I have ditched it. Apart from that I think I got hold of a Hungarian-ised version – EEK! Does anyone know of a diagrammatic representation of the ‘G’ code instructions to act as a ‘halfway house’ between the drawing and the ‘G’ code instructions? Are there any ‘G’ code subroutine libraries in the public domain? Are there any ‘G’ code library management software available? Ps if you are using MS Word do not use bullet points Dick
David Clark 1	05/06/2011 09:18:59
3357 forum posts 112 photos 10 articles	Hi Steve Garnett Who said we would be doing a special CNC exclusive to Smiths. I sid we might do an A5 magazine. If we did it would be free with the current MEW. Nothing about it being a special was mentioned. regards david Edited By Diane Carney on 06/06/2011 00:43:25
Chris Trice	05/06/2011 09:43:47
1376 forum posts 10 photos	I think you misunderstood David. Steve is saying he agrees that a CNC special WON'T happen and why by suggesting the conversation that would take place if you did pitch it to Smiths.
Steve Garnett	05/06/2011 11:20:47
837 forum posts 27 photos	Posted by David Clark 1 on 05/06/2011 09:18:59: Who said we would be doing a special CNC exclusive to Smiths. Only me, postulating the possibility in the above post, as Chris has pointed out. Read the bit before the dialogue carefully... I was just hoping that this was better than throwing teddies out of prams! Edited By Steve Garnett on 05/06/2011 11:22:54
Andrew Johnston	05/06/2011 11:40:45
7061 forum posts 719 photos	Paaah, it's much more fun throwing teddies! Mind you this is all WI stuff compared to the tantrums, hissy fits and teddy throwing that I've seen on the flying field, particularly in competitions. If nothing else the 'controversial' threads seem to attract a lot more posts than the more technical ones; that might say something? Regards, Andrew
John Stevenson	05/06/2011 11:59:19
5068 forum posts 3 photos	Posted by Richard Parsons on 05/06/2011 08:52:26: Does anyone know of a diagrammatic representation of the ‘G’ code instructions to act as a ‘halfway house’ between the drawing and the ‘G’ code instructions? Are there any ‘G’ code subroutine libraries in the public domain? Are there any ‘G’ code library management software available? Dick I think there are a lot of misconceptions out there as regards G code, many seem to think it's another language and the lack of G Code speak will not let you use CNC which could not be further from the truth. Let me take you thru something I do on a regular basis but although it's regular they are never the same, so basically many one off's which others tell us that CNC is no good for. I do a lot of electric motor repairs for three different companies not the rewind bit, that's their bowl of rice but repairing shafts , bearing housings ripped off splines etc. One oft repeated job is brush rings for largish DC motors, usually fork truck motors which can cost up to £7,000 to replace so they will repair them. The brush ring comes in with all the brush boxes hanging off and what is left of the insulated ring is burnt away. Repair consists of making a new ring out of Tufnol, putting all the holes and slots in and fitting the old brush boxes back on, old way takes about two to two and a half hours. First off make a sketch as good as possible then grab a sheet of Tufnol and band saw a circle out. Hold in chuck and trepan centre out if circular or if square with rounded corners onto the rotary table on the mill and work out arcs and straight lines. Mill out curved slots and curved counterbores, layout hole positions and drill. Cut outer diameter or shape to suit and then fasten brush boxes back on. As I say for a simple one all circular and all holes could be just under two hours. Funny shaped ones with lugs and curved slots possibly up to three hours, that's the old way. New way is make the same sketch as before but now draw this in CAD, export as a DXF and into a simple CAM system, something like Cut2D, look to see what is the smallest hole and choose a cutter smaller than this or equal to, I tend to use cheap 3mm single flute router cutters from Silverline at £1 each, very cost effective. Tell cut 2D to profile the holes, you don't drill if the hole is larger than the cutter, then do the curved slots and counterbores. Then do the inside shape but leave 4 tabs on 0.5mm thick by 3mm long to hold the inner so it doesn't flip up and break the cutter, same on the outside. Tell Cut2D to generate the code and save to a memory sick. Now grab a sheet of Tufnol literally nail it to the MDF sacrificial bed on the router, guess where the centre is, touch the cutter on the top surface and zero all axis, raise the cutter and press GO Average brush ring at 8" diameter and 10mm thick will take about 10 minutes to cut, snap out from the tabs and clean up and reassemble the boxes as before. From sketch to finish is now under one hour. I have not even seen the GCode at any point nor do I need to. For these brush rings there are so many different shapes and many are very close to another that it's easy to get mixed up so other than a couple that are regular repeats I delete the files afterwards because it's quicker to draw a new one than cut, copy, paste, scale and make mistakes. Years ago we had to write code or alter it but things have moved on and programs are so much better today. Andrew Johnson in the thread "How would you make this part" spent 40 odd hours programming his bevel gear, OK a lot of that was his learning curve but using a modern program, which wasn't out when Andrew was doing this, I 'drew' the gear and got all the information from the screen and the code in 10 minutes. This when entered into the CNC told me it wanted 1 hour and 58 minutes to cut and again I had never seen the G Code. So you can use them for one off's and not repetition and contrary to popular belief you don't need to know GCode. John S. Edited By John Stevenson on 05/06/2011 12:05:39
NJH	05/06/2011 14:56:29
2314 forum posts 139 photos	Hi John I'm not teasing you about CNC here I can see that you have a very good reason for using it in your quoted tasks. What sort of price is a set up to do those sort of things? Regards Norman
John Stevenson	05/06/2011 15:21:25
5068 forum posts 3 photos	Norman, Prior to CNC they were willing to pay 2 - 2 1/2 hours labour plus a bit of materials, the fact I can now cut this down to an hour only off sets the extra cost of machinery. Why rock the boat I'm often asked to code a job for others with no CAM packages, usually simple job but probably involve a lot of arc's etc, one job that springs to mind is exhaust flange plates that bolt to cylinder heads for the guys making their own headers. From being given say a gasket I can draw and code this within an hour so I charge one hours labour John S.
NJH	05/06/2011 17:16:58
2314 forum posts 139 photos	Sorry John I wasn't wishing to pry in to your commercial dealings. What I was getting at was I assume you must have a comprehensive CNC set up and I was wondering just what sort of investment in equipment is needed to go down that route. (Again please don't tell me what yours cost but what lathe , mill, computer, software packages etc. you think necessary ) I know there are various mods for conventional lathes but I'm thinking here purpose built stuff - not the esoteric kit F1 workshops use of course but the sort the dedicated amateur / small jobbing pro might find useful. This is only my curiosity really so please don't take too much time ( I think I've used up all the spare room in my workshop and emptied my "playtime" account even if I did get interested in the process ) Regards Norman
David Clark 1	05/06/2011 17:56:58
3357 forum posts 112 photos 10 articles	Hi John Using Q parameters on Heidenhein you can write a program that you only need to input the the two hole centres and the two radii and it can calculate the whole thing as it runs. I also did the same with hexagons. Just needed cutter radius and AF and it did the lot, any size within the machine capacity that you want.. regards David
John Stevenson	05/06/2011 22:49:52
5068 forum posts 3 photos	David, Don't muddy the water, we are trying to convince some people how simple it is Norman, Now these are just my views on it and remember there are many ways to do the same job and there will also be many views on you question of what is necessary. I'll deal with milling machine first as mill and lathe are two totally different animals, a lot of people think that a lathe is just a two axis mill but nothing is further from the truth. First off you need a mill be it a converted X2, X3 type and by this I mean to take in all makes from the various people, You can buy older redundant Denfords and Boxfords ex education, for not a lot of money if you can get in on the ground floor. Top of the range are the turnkey machines like the KX1, KX3 and the Tormach. So the price here is very flexible and can't really be defined. We then need a dedicated computer to run it, an older desktop that still has a parallel port will do fine, these can be had for anything from free to £90, not worth paying more and a modern computer probably won't have a parallel port anyway. We are now into the realms of software, the controller program to run on the computer I use, Mach3 costs about £100 to license it. There is a free controller that runs on Linux called EMC which is free. The last two bits of software are CAD for drawing your part and CAM for turning the drawing into code that the controller can read. CAD can cost from free to £5,000 depending on what you want to do. Draftsight from Solid Works is free and is a very powerful program not unlike Autocad, they give it away to get you to move on to full 3D at £5K but if you are happy with Draftsight it's a marvellous deal. Again CAM can cost from free to £50,000 [ no misprint ] again depending on what you want to do. CNC Code maker, Cambam, Lazycam and the wizards inside Mach are all free. Paid programs around £100 to £150 cover Cambam Pro, Cut2D, and Sheetcam and possibly the level 1 hobby version of Dolphin. So for a milling machine, leaving out the flexible cost of the machine you can actually get started for free if you go the Linux / EMC / Draftsight / Cambam route. I'll do lathes later. John S.
Martin W	06/06/2011 00:00:06
940 forum posts 30 photos	John It is a pity that this information hasn't, as far as I am aware, been presented in MEW in this type of format. Rather than showing screen shots of computer screens with code etc. a simple explanation of what is required and the relative costs would encourage some to take the plunge into the CNC way of producing widgets etc. While I can't justify the expense of going down the CNC route, nor do I have the room, I would certainly be interested in reading an article along these lines. Not so much about what is produced but the setting up the component parts and how they interact plus relevant/typical costs for a small workshop environment. In one of my earlier post I classed myself as a CNC Luddite, not because I can't see the advantage of CNC but more because what I produce doesn't warrant CNC and while I am still learning I get great pleasure in hand mangling bits of metal. Cheers Martin
NJH	06/06/2011 10:41:41
2314 forum posts 139 photos	Thanks John This just what I was hoping for - I await the lathes post with interest. I think my position and attitude mirrors Martins and I endorse all that he has said. How about an article in this vein for MEW - I'm sure those readers with " traditional interests" ( sounds better than Luddites!) would find this acceptable. It might earn you a few bob too! Cheers Norman
blowlamp	06/06/2011 11:14:50
1885 forum posts 111 photos	Posted by Martin W on 06/06/2011 00:00:06: John It is a pity that this information hasn't, as far as I am aware, been presented in MEW in this type of format. Rather than showing screen shots of computer screens with code etc. a simple explanation of what is required and the relative costs would encourage some to take the plunge into the CNC way of producing widgets etc. While I can't justify the expense of going down the CNC route, nor do I have the room, I would certainly be interested in reading an article along these lines. Not so much about what is produced but the setting up the component parts and how they interact plus relevant/typical costs for a small workshop environment. In one of my earlier post I classed myself as a CNC Luddite, not because I can't see the advantage of CNC but more because what I produce doesn't warrant CNC and while I am still learning I get great pleasure in hand mangling bits of metal. Cheers Martin I have supplied an article along these lines to David at MEW, but I don't know if or when it might be published. In it, I've tried to show how a part can be draw quite simply in an (affordable) CAD program and transfered to an (affordable) CAM program, to produce the instructions (G-code) for the CNC milling machine/router to run. As John S. points out, there's virtually no need to look at, let alone fiddle with the code once the CAM has produced it. The whole point of a CAM program, is to relieve you of the tedium of figuring out the right numbers and appropriate instructions and allow you to concentrate on other, more important things. Martin.

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