Re: [Emc-users] OT: Concrete Lathe
On 11/16/2011 01:28 PM, Dave wrote: Looks like most of the Datron mills actually have solid granite bases - most of them are not a composite polymer-granite dust mix. I have bought some epoxy resin to repair boat hulls and the best price I can find for non-blushing epoxy resin is about $75 per gallon including the hardener with shipping. So a gravel/epoxy composite or granite dust/expoxy composite frame is going to be a lot more expensive than basic concrete which is going for about $150 per cubic yard around here delivered in a mix truck. Making an epoxy/gravel composite would also take some experimenting as epoxy tends to self heat as it is sets and it can get very hot. I have no idea how they control curing in thicker structures with epoxy. I have had a cup of mixed epoxy get so hot, that I was not able to hold onto to it. (too much activator in the mix). The hotter it gets during a cure, the faster it sets so it can become a tail chasing exercise on thicker parts. That is why most boat hulls are laid up in thin layers - usually less than 1/8th inch per layer. Andy I think we got these old imperial measurements from you guys! Apparently we are rather resistant to change.But I'm still waiting for the UK to adopt the Euro...any day now .. right??;-) Dave Dave, There are application epoxies that are designed to cure in bulk, and do not exhibit the high heat generation that a typical laminating epoxy does when mixed up and kept in a container in large amounts. The epoxy I used to use to make molds and plugs was a greenish color and had metal dust and a few other additives in it to make the final product strong. Had a very slow cure rate, something like 48 hours for the initial cure, and then you had to finish with a heat cure to get to the final hardness. Prior to the heat cure, the epoxy never got much warmer than a human's body heat. Laminating epoxies, like the ones you mentioned above, have much shorter cure times, because they use the exothermic heat generated by the chemical reaction to hasten the cure, moreso than the much, much slower curing molding epoxy like I use. Of course, there are laminating epoxies that don't quite fit that mold (no pun intended), like the Epon epoxy I use to glue up the bamboo rods that I make. That epoxy has a 7 day cure at 65 degrees F, though you can, and I do, heat cure it. Mark -- All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On 16 November 2011 18:28, Dave e...@dc9.tzo.com wrote: Making an epoxy/gravel composite would also take some experimenting as epoxy tends to self heat as it is sets and it can get very hot. I have no idea how they control curing in thicker structures with epoxy. Valen has an interesting thread on cnczone about a new head for his mill: http://www.cnczone.com/forums/general_metal_working_machines/118358-phenolic_basalt_head_our_hm45.html -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On 11/17/2011 5:21 AM, Mark Wendt wrote: On 11/16/2011 01:28 PM, Dave wrote: Looks like most of the Datron mills actually have solid granite bases - most of them are not a composite polymer-granite dust mix. I have bought some epoxy resin to repair boat hulls and the best price I can find for non-blushing epoxy resin is about $75 per gallon including the hardener with shipping. So a gravel/epoxy composite or granite dust/expoxy composite frame is going to be a lot more expensive than basic concrete which is going for about $150 per cubic yard around here delivered in a mix truck. Making an epoxy/gravel composite would also take some experimenting as epoxy tends to self heat as it is sets and it can get very hot. I have no idea how they control curing in thicker structures with epoxy. I have had a cup of mixed epoxy get so hot, that I was not able to hold onto to it. (too much activator in the mix). The hotter it gets during a cure, the faster it sets so it can become a tail chasing exercise on thicker parts. That is why most boat hulls are laid up in thin layers - usually less than 1/8th inch per layer. Andy I think we got these old imperial measurements from you guys! Apparently we are rather resistant to change.But I'm still waiting for the UK to adopt the Euro...any day now .. right??;-) Dave Dave, There are application epoxies that are designed to cure in bulk, and do not exhibit the high heat generation that a typical laminating epoxy does when mixed up and kept in a container in large amounts. The epoxy I used to use to make molds and plugs was a greenish color and had metal dust and a few other additives in it to make the final product strong. Had a very slow cure rate, something like 48 hours for the initial cure, and then you had to finish with a heat cure to get to the final hardness. Prior to the heat cure, the epoxy never got much warmer than a human's body heat. Laminating epoxies, like the ones you mentioned above, have much shorter cure times, because they use the exothermic heat generated by the chemical reaction to hasten the cure, moreso than the much, much slower curing molding epoxy like I use. Of course, there are laminating epoxies that don't quite fit that mold (no pun intended), like the Epon epoxy I use to glue up the bamboo rods that I make. That epoxy has a 7 day cure at 65 degrees F, though you can, and I do, heat cure it. Mark Very interesting I am always learning things from this list. :-) Thanks, Dave -- All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On 15.11.11 19:30, perotter wrote: Some DATRON mills are polymer-concrete. I think they are concrete with a polymer used like rebar would be. I also think that all of the 1st ones were concrete, but some are now granite.These mill are for high speed milling. When I visited ANCA, a couple of decades ago, they just called it cement-filled plastic, I think. (Or perhaps that's just as much as I understood at the time.) But now their website also talks of polymer-concrete. So it's been in use in the CNC machine tool industry for at least 20 years, then. For us, it might be easier to build machines with a fabricated steel exterior, filled with epoxy-granite. The effect should be similar, I think. (The method seems to be popular with users of micro-mills, especially poured down the column.) Epoxy has another use in machine building, e.g. for installing ballscrew end bearings. The mounting holes can be bored oversize, the ballscrews aligned, and epoxy used to fix the bearings, in a more modern alternative to the babbit metal method used in the 1916 example in Kirk's OP. (Building a solid but imprecise base, then adding precision by later alignment, has a lot of appeal for a DIY machine.) Erik -- Leibowitz's Rule: When hammering a nail, you will never hit your finger if you hold the hammer with both hands. -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On 11/16/2011 3:06 AM, Erik Christiansen wrote: On 15.11.11 19:30, perotter wrote: Some DATRON mills are polymer-concrete. I think they are concrete with a polymer used like rebar would be. I also think that all of the 1st ones were concrete, but some are now granite.These mill are for high speed milling. When I visited ANCA, a couple of decades ago, they just called it cement-filled plastic, I think. (Or perhaps that's just as much as I understood at the time.) But now their website also talks of polymer-concrete. So it's been in use in the CNC machine tool industry for at least 20 years, then. For us, it might be easier to build machines with a fabricated steel exterior, filled with epoxy-granite. The effect should be similar, I think. (The method seems to be popular with users of micro-mills, especially poured down the column.) Epoxy has another use in machine building, e.g. for installing ballscrew end bearings. The mounting holes can be bored oversize, the ballscrews aligned, and epoxy used to fix the bearings, in a more modern alternative to the babbit metal method used in the 1916 example in Kirk's OP. (Building a solid but imprecise base, then adding precision by later alignment, has a lot of appeal for a DIY machine.) Erik Looks like most of the Datron mills actually have solid granite bases - most of them are not a composite polymer-granite dust mix. I have bought some epoxy resin to repair boat hulls and the best price I can find for non-blushing epoxy resin is about $75 per gallon including the hardener with shipping. So a gravel/epoxy composite or granite dust/expoxy composite frame is going to be a lot more expensive than basic concrete which is going for about $150 per cubic yard around here delivered in a mix truck. Making an epoxy/gravel composite would also take some experimenting as epoxy tends to self heat as it is sets and it can get very hot. I have no idea how they control curing in thicker structures with epoxy. I have had a cup of mixed epoxy get so hot, that I was not able to hold onto to it. (too much activator in the mix). The hotter it gets during a cure, the faster it sets so it can become a tail chasing exercise on thicker parts. That is why most boat hulls are laid up in thin layers - usually less than 1/8th inch per layer. Andy I think we got these old imperial measurements from you guys! Apparently we are rather resistant to change.But I'm still waiting for the UK to adopt the Euro...any day now .. right??;-) Dave -- All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On Mon, 14 Nov 2011 11:38:49 -0800 Kirk Wallace kwall...@wallacecompany.com wrote: On Mon, 2011-11-14 at 20:37 +0200, Viesturs Lācis wrote: 2011/11/14 BRIAN GLACKIN glackin.br...@gmail.com: THere is also an extensive set on threads on CNCzone for building a Epoxy granite mill. It took me 3 months last winter to read first ~160 pages of that thread. I find it very very interesting and I am sure that I will do some practical experiments some day. My impression from that thread combined with that small amount I read about these concrete lathes is that epoxy-granite has more advantages than concrete. BTW this also is discussed in that thread. I really recommend anyone who is interested in this to take a look at it, but be warned - it will take a long time to read it, because last time I was there, it had almost 4000 posts. And most of them - more than few sentences. Viesturs Just a side note. What I got from the concrete lathe idea is that, with the most basic materials on hand, a useful machine could be made and possibly make a better life for those in need. An epoxy concrete material may be out of reach for a third world environment. I'd like to see if any of this has really been applied in real life. I can see how the Berkley stove could be easily implemented, http://darfurstoves.org/ except the sheet steel would need to come from outside. It seems one small issue or material could stop the whole project. A real challenge would be, how to make something useful from plain old dirt. IIUC - epoxy concrete has very good dampening characteristics. I suspect one could cast the main structure in concrete with rebar then embed the critical components in epoxy concrete. Dave -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
-Original Message- From: dave dengv...@charter.net Sent: Nov 15, 2011 10:37 AM To: emc-users@lists.sourceforge.net Subject: Re: [Emc-users] OT: Concrete Lathe IIUC - epoxy concrete has very good dampening characteristics. I suspect one could cast the main structure in concrete with rebar then embed the critical components in epoxy concrete. Dave http://www.datron.de/en/products/machine-tools.html Some DATRON mills are polymer-concrete. I think they are concrete with a polymer used like rebar would be. I also think that all of the 1st ones were concrete, but some are now granite.These mill are for high speed milling. I had forgot about them until this topic came up.Looks like they have expanded their line. -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
2011. gada 15. Nov. 17:39 dave dengv...@charter.net rakstīja: IIUC - epoxy concrete has very good dampening characteristics. I suspect one could cast the main structure in concrete with rebar then embed the critical components in epoxy Yes, epoxy-granite has superior vibration dampening properties - 6 times better than cast iron. The thing about using it together with concrete - concrete is shrinking for weeks after pouring as the moisture dries out, so special additives need to be used. Otherwise vibration can make all the embedded inserts loose. Viesturs -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
I've seen cement as the pilars of a big Tricept type parallel machine. They use special type of concret with epoxi or similar aditives. I've heard of similar termal expansion coefficientes for steel an concret, and of the good vibration absorbing properties of concret. I think that the aditives, can help both on the tensile strength and on the vibration disipation part too. Just my two cents, Javier On Mon, Nov 14, 2011 at 5:20 AM, Dave e...@dc9.tzo.com wrote: Concrete is fine for compression loads. You can mix 5000 psi concrete pretty easily. However it has very poor tensile strength. They say 10-15% of the compressive strength. Fiberglass has a much higher tensile strength. That is why concrete has to be pre-stressed to be used for tensile applications. If it was a great material for machine frames, the machine makers would be using it. My lathe has a bunch of it in the base- the block is about 3feet wide - 12 feet long and 14-16 tall. But I think they put it in the base to brace the structural steel frame and take the ring out of the frame so it would be difficult for it to resonate. Dave On 11/13/2011 10:50 PM, Jack Coats wrote: It was Lucien I. Yoeman that patented this back during WW1, not WW2, for shell turning. http://xa.yimg.com/kq/groups/13335163/1942903983/name/MM++lathe+How+to+Build21a.pdf has a picture of the lathe and team that built it. I found his patents on patents.google.com some time ago. Good but not overly enlightening reading. No reason not to use this technique to build just about any machinery that could use a very stable base (lathe, mill, laser cutter, plasma cutter, etc) The cement is great because it doesn't take rocket science to get a stable base that hold together. A friend sells chemical additives for putting in concrete to change it's properties but for most projects a simple 1,2,3 mix or sacked concrete mix works well. To make the concrete stronger, use less water, rather than more. My suggestion is to build one (or more) as an experiment. Most of what is needed doesn't need steel reinforcing, but putting it is doesn't hurt. A local manufacturer makes steps for fire stairs, he puts in bolts and leaves the threads exposed about an inch. He uses stainless steel to ensure they don't rust. So if you want to cast in some attachments for long term use, stainless is a good option. If it is just for use for a 'few years' galvanized or cement covered is OK. ... Just my thoughts. ... Jack Whatever you do, work at it with all your heart... Colossians 3:23 On Sun, Nov 13, 2011 at 8:46 PM, Chris Reynolds c_reynolds2...@yahoo.com wrote: I belong to that group, there is some interesting information there. I was under the impression that during WWII using concrete in casting large machine parts was used because of lack of raw materials, and fairly common. I've always thought it would be fun to experiment with this technique, not only for a lathe but for a mill as well. Chris There is a yahoo group re-developing making a lathe from concrete. They are baseing their stuff on a guy that made lathes for turning large projectiles for the Navy. He had a couple of patents. Basically he had a jig to hold his metal pieces that define the critical dimensions. He poured the lathe, waited a couple of days, un-did the forms. installed the jig and some metal pieces, then poured a low temp metal alloy he developed (formula is lost) that didn't shrink or expand when cooled to hold the metal pieces in place in the concrete. Anyway, email me directly if you want to get the link to the group (I just don't have it at hand or I would put it here). ... Jack -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list
Re: [Emc-users] OT: Concrete Lathe
THere is also an extensive set on threads on CNCzone for building a Epoxy granite mill. I gave up trying to follow that thread 2 years ago. They may have a readers digest version of it somewhere now.. -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On Sun, 13 Nov 2011 23:20:31 -0500 Dave e...@dc9.tzo.com wrote: Concrete is fine for compression loads. You can mix 5000 psi concrete pretty easily. However it has very poor tensile strength. They say 10-15% of the compressive strength. Fiberglass has a much higher tensile strength. That is why concrete has to be pre-stressed to be used for tensile applications. (massive snip Well stated! Speaking of prestressed; it is strong simply because of the steel in it; usually cables held at a given tension while the concrete cures. IIRC concrete for prestress goes about 7Ksi in compression after a 30 day cure. That was 50 years ago when I had a summer job in a testing lab. It is my understanding that SiC dust is used in very high strength concrete to increase strength. ftp://ftp.wsdot.wa.gov/dotshare/eforms/update/350_040.PDF The above has some interesting information on mix design and testing. Hmmm! 20 Ksi concrete sounds like interesting stuff. Dave -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On 14 November 2011 04:20, Dave e...@dc9.tzo.com wrote: Concrete is fine for compression loads. You can mix 5000 psi concrete pretty easily. However it has very poor tensile strength. They say 10-15% of the compressive strength. This might well not matter in most machine tools, though, as the important thing is stiffness, rather than strength. (has anyone ever seen a broken frame on a lathe or a mill?) 500 psi (to use your quaint units) is probably plenty. Imagine a lathe with a 10 square headstock block. That's going to take 22 tons of cutting force to snap it off. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
2011/11/14 BRIAN GLACKIN glackin.br...@gmail.com: THere is also an extensive set on threads on CNCzone for building a Epoxy granite mill. It took me 3 months last winter to read first ~160 pages of that thread. I find it very very interesting and I am sure that I will do some practical experiments some day. My impression from that thread combined with that small amount I read about these concrete lathes is that epoxy-granite has more advantages than concrete. BTW this also is discussed in that thread. I really recommend anyone who is interested in this to take a look at it, but be warned - it will take a long time to read it, because last time I was there, it had almost 4000 posts. And most of them - more than few sentences. Viesturs -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On Mon, 2011-11-14 at 20:37 +0200, Viesturs Lācis wrote: 2011/11/14 BRIAN GLACKIN glackin.br...@gmail.com: THere is also an extensive set on threads on CNCzone for building a Epoxy granite mill. It took me 3 months last winter to read first ~160 pages of that thread. I find it very very interesting and I am sure that I will do some practical experiments some day. My impression from that thread combined with that small amount I read about these concrete lathes is that epoxy-granite has more advantages than concrete. BTW this also is discussed in that thread. I really recommend anyone who is interested in this to take a look at it, but be warned - it will take a long time to read it, because last time I was there, it had almost 4000 posts. And most of them - more than few sentences. Viesturs Just a side note. What I got from the concrete lathe idea is that, with the most basic materials on hand, a useful machine could be made and possibly make a better life for those in need. An epoxy concrete material may be out of reach for a third world environment. I'd like to see if any of this has really been applied in real life. I can see how the Berkley stove could be easily implemented, http://darfurstoves.org/ except the sheet steel would need to come from outside. It seems one small issue or material could stop the whole project. A real challenge would be, how to make something useful from plain old dirt. -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
I belong to that group, there is some interesting information there. I was under the impression that during WWII using concrete in casting large machine parts was used because of lack of raw materials, and fairly common. I've always thought it would be fun to experiment with this technique, not only for a lathe but for a mill as well. Chris There is a yahoo group re-developing making a lathe from concrete. They are baseing their stuff on a guy that made lathes for turning large projectiles for the Navy. He had a couple of patents. Basically he had a jig to hold his metal pieces that define the critical dimensions. He poured the lathe, waited a couple of days, un-did the forms. installed the jig and some metal pieces, then poured a low temp metal alloy he developed (formula is lost) that didn't shrink or expand when cooled to hold the metal pieces in place in the concrete. Anyway, email me directly if you want to get the link to the group (I just don't have it at hand or I would put it here). ... Jack -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
It was Lucien I. Yoeman that patented this back during WW1, not WW2, for shell turning. http://xa.yimg.com/kq/groups/13335163/1942903983/name/MM++lathe+How+to+Build21a.pdf has a picture of the lathe and team that built it. I found his patents on patents.google.com some time ago. Good but not overly enlightening reading. No reason not to use this technique to build just about any machinery that could use a very stable base (lathe, mill, laser cutter, plasma cutter, etc) The cement is great because it doesn't take rocket science to get a stable base that hold together. A friend sells chemical additives for putting in concrete to change it's properties but for most projects a simple 1,2,3 mix or sacked concrete mix works well. To make the concrete stronger, use less water, rather than more. My suggestion is to build one (or more) as an experiment. Most of what is needed doesn't need steel reinforcing, but putting it is doesn't hurt. A local manufacturer makes steps for fire stairs, he puts in bolts and leaves the threads exposed about an inch. He uses stainless steel to ensure they don't rust. So if you want to cast in some attachments for long term use, stainless is a good option. If it is just for use for a 'few years' galvanized or cement covered is OK. ... Just my thoughts. ... Jack Whatever you do, work at it with all your heart... Colossians 3:23 On Sun, Nov 13, 2011 at 8:46 PM, Chris Reynolds c_reynolds2...@yahoo.com wrote: I belong to that group, there is some interesting information there. I was under the impression that during WWII using concrete in casting large machine parts was used because of lack of raw materials, and fairly common. I've always thought it would be fun to experiment with this technique, not only for a lathe but for a mill as well. Chris There is a yahoo group re-developing making a lathe from concrete. They are baseing their stuff on a guy that made lathes for turning large projectiles for the Navy. He had a couple of patents. Basically he had a jig to hold his metal pieces that define the critical dimensions. He poured the lathe, waited a couple of days, un-did the forms. installed the jig and some metal pieces, then poured a low temp metal alloy he developed (formula is lost) that didn't shrink or expand when cooled to hold the metal pieces in place in the concrete. Anyway, email me directly if you want to get the link to the group (I just don't have it at hand or I would put it here). ... Jack -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
Concrete is fine for compression loads. You can mix 5000 psi concrete pretty easily. However it has very poor tensile strength. They say 10-15% of the compressive strength. Fiberglass has a much higher tensile strength. That is why concrete has to be pre-stressed to be used for tensile applications. If it was a great material for machine frames, the machine makers would be using it. My lathe has a bunch of it in the base- the block is about 3feet wide - 12 feet long and 14-16 tall. But I think they put it in the base to brace the structural steel frame and take the ring out of the frame so it would be difficult for it to resonate. Dave On 11/13/2011 10:50 PM, Jack Coats wrote: It was Lucien I. Yoeman that patented this back during WW1, not WW2, for shell turning. http://xa.yimg.com/kq/groups/13335163/1942903983/name/MM++lathe+How+to+Build21a.pdf has a picture of the lathe and team that built it. I found his patents on patents.google.com some time ago. Good but not overly enlightening reading. No reason not to use this technique to build just about any machinery that could use a very stable base (lathe, mill, laser cutter, plasma cutter, etc) The cement is great because it doesn't take rocket science to get a stable base that hold together. A friend sells chemical additives for putting in concrete to change it's properties but for most projects a simple 1,2,3 mix or sacked concrete mix works well. To make the concrete stronger, use less water, rather than more. My suggestion is to build one (or more) as an experiment. Most of what is needed doesn't need steel reinforcing, but putting it is doesn't hurt. A local manufacturer makes steps for fire stairs, he puts in bolts and leaves the threads exposed about an inch. He uses stainless steel to ensure they don't rust. So if you want to cast in some attachments for long term use, stainless is a good option. If it is just for use for a 'few years' galvanized or cement covered is OK. ... Just my thoughts. ... Jack Whatever you do, work at it with all your heart... Colossians 3:23 On Sun, Nov 13, 2011 at 8:46 PM, Chris Reynolds c_reynolds2...@yahoo.com wrote: I belong to that group, there is some interesting information there. I was under the impression that during WWII using concrete in casting large machine parts was used because of lack of raw materials, and fairly common. I've always thought it would be fun to experiment with this technique, not only for a lathe but for a mill as well. Chris There is a yahoo group re-developing making a lathe from concrete. They are baseing their stuff on a guy that made lathes for turning large projectiles for the Navy. He had a couple of patents. Basically he had a jig to hold his metal pieces that define the critical dimensions. He poured the lathe, waited a couple of days, un-did the forms. installed the jig and some metal pieces, then poured a low temp metal alloy he developed (formula is lost) that didn't shrink or expand when cooled to hold the metal pieces in place in the concrete. Anyway, email me directly if you want to get the link to the group (I just don't have it at hand or I would put it here). ... Jack -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
[Emc-users] OT: Concrete Lathe
Posting this in case someone might find it interesting: http://www.lathes.co.uk/multimachine/ http://flowxrgdotcom.files.wordpress.com/2011/07/new-method-of-building-lathes.pdf http://www.lathes.co.uk/multimachine/multimachine.pdf -- Kirk Wallace http://www.wallacecompany.com/machine_shop/ http://www.wallacecompany.com/E45/index.html California, USA -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
I have a large lathe that is made from heavy steel weldments - 1-2+ thick plate steel and the base was framed in structural steel and concrete was poured into it. I don't believe it has any cast iron in it at all. The turret might be cast, but if it is, I can't tell. The tailstock and the slide are also fabrications of 3/4 or 1 thick plate. The lathe is really heavy, over 20,000 lbs.. I'm sure that the concrete is most of the weight. The lathe was made by Monfort and is an early 90's model. Dave On 11/12/2011 3:31 PM, Kirk Wallace wrote: Posting this in case someone might find it interesting: http://www.lathes.co.uk/multimachine/ http://flowxrgdotcom.files.wordpress.com/2011/07/new-method-of-building-lathes.pdf http://www.lathes.co.uk/multimachine/multimachine.pdf -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
There is a yahoo group re-developing making a lathe from concrete. They are baseing their stuff on a guy that made lathes for turning large projectiles for the Navy. He had a couple of patents. Basically he had a jig to hold his metal pieces that define the critical dimensions. He poured the lathe, waited a couple of days, un-did the forms. installed the jig and some metal pieces, then poured a low temp metal alloy he developed (formula is lost) that didn't shrink or expand when cooled to hold the metal pieces in place in the concrete. Anyway, email me directly if you want to get the link to the group (I just don't have it at hand or I would put it here). ... Jack -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On 12 November 2011 23:21, Jack Coats j...@coats.org wrote: There is a yahoo group re-developing making a lathe from concrete. They are baseing their stuff on a guy that made lathes for turning large projectiles for the Navy. This appears to be that yahoo group, and that lathe. then poured a low temp metal alloy he developed (formula is lost) Possibly one of these? http://www.alchemycastings.com/lead-products/fusible.htm Cerrosafe sounds fun, it shrinks on initial cooling so you can remove it, then expands back to the exact original dimension. -- atp The idea that there is no such thing as objective truth is, quite simply, wrong. -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On 11/12/2011 05:57 PM, andy pugh wrote: On 12 November 2011 23:21, Jack Coatsj...@coats.org wrote: There is a yahoo group re-developing making a lathe from concrete. They are baseing their stuff on a guy that made lathes for turning large projectiles for the Navy. This appears to be that yahoo group, and that lathe. then poured a low temp metal alloy he developed (formula is lost) Possibly one of these? http://www.alchemycastings.com/lead-products/fusible.htm Cerrosafe sounds fun, it shrinks on initial cooling so you can remove it, then expands back to the exact original dimension. I have about 15 lbs of planer knife babbitt, that I got from a salvage yard. It's a low melt alloy, that doesn't shrink when poured. -- -Mark Ne M'oubliez ---Family Motto Hope for the best, plan for the worst ---Personal Motto -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
Re: [Emc-users] OT: Concrete Lathe
On Sat, Nov 12, 2011 at 7:57 PM, Mark Cason farmerboy1...@yahoo.com wrote: On 11/12/2011 05:57 PM, andy pugh wrote: On 12 November 2011 23:21, Jack Coatsj...@coats.org wrote: There is a yahoo group re-developing making a lathe from concrete. They are baseing their stuff on a guy that made lathes for turning large projectiles for the Navy. This appears to be that yahoo group, and that lathe. Search on Yoemans Lathe for the early concrete lathe described above. The Yahoo group Multimachine has a very active thread on developing a smaller version of the original behemoths. Brian -- RSA(R) Conference 2012 Save $700 by Nov 18 Register now http://p.sf.net/sfu/rsa-sfdev2dev1 ___ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
