Moog Hydra Point mills are hydraulic cylinder actuated. On May 14, 2012 10:52 AM, "dave" <dengv...@charter.net> wrote:
> On Mon, 14 May 2012 14:03:51 +0100 > andy pugh <bodge...@gmail.com> wrote: > > > On 14 May 2012 13:41, Dave <e...@dc9.tzo.com> wrote: > > > There were/are some manufacturers of hydraulic cylinder driven > > > milling machines. > > > > I used to drive a servo-hydraulic tensile-testing machine. The > > actuator was extremely stiff and extremely fast. And _extremely_ > > expensive. > > That particular one used a leaky piston and leaky end-seals (actually > > hydrodynamic bearings) with separate scavenge pumps. > > The truly expensive part was the Moog Valve, which is an > > electromechanical proportioning valve, which applied differential > > pressure to either side of the piston. That was my first introduction > > to PID. It was necessary to re-tune the PID for each design of tensile > > specimen, as the stiffness changed. > > It could run at 20 tons / 5mm / 50Hz. The hydraulic power pack was the > > size of a small car. > > > > At work they have test rigs using the same style of actuator Those > > run 20 tons / 250mm / 50Hz. The hydraulic power pack is 20 x 20hp > > pumps feeding an 8" dia 10,000psi ring-main. The pipe fittings look > > expensive. > > > http://www.toyota-motorsport.com/slideshowpro/albums/album-20/lg/Full-Car_Road_Simulator1.jpg > > Is an example. > > > > Sunstrand made some horizontal mills with a hydraulic piston on X. Y > and Z were manual. Decently stiff mills and really good for production > but took too long to set up for one-offs. > > Many years ago I did some instrumentation for the test jig for the > first reusable release bar (Decoto Aircraft/Grumman) for carrier > catapults. The jig was 6 x 6" CD with a 3" CD plate welded on. Nice > sized accumulator probably at 4000 psi or so. Loading rate on the bar > was something like 1.0E+6 pounds/sec. There was a nice thump that could > be heard throughout the facility when a test was fired. > > Note: Decoto is now GE Aerospace after being Smith Aerospace and who > knows what else. > > Dave > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
