V2 rocket guidence system 70 years ago - Page 1
Forum section: electronics / projects

author: Homer J Simpson
author_rank: Super Contributor
timestamp: December 20, 2013, 05:17:53 am
content: Interesting YouTube video on V2 rocket gyro and guidance system.Up and running after 70 years.KT

author: Macbeth
author_rank: Super Contributor
timestamp: December 20, 2013, 06:28:45 am
content: Very interesting. I remember making a visit to the Imperial War Museum (London) when I was 11 years old with my class. The one thing that utterly fascinated me was the cutaway V1 flying bomb (or "doodlebug"). It was an amazing network of metal pipes and "stuff", the complexity astounded me, so much I wondered why they went to all that effort just to blow the bloody things up?V2 is of course a whole other level.I highly recommend visiting the Imperial War Museum to anyone - we have one in Manchester now as well. I must go and check it out as it's relatively local.

author: dannyf
author_rank: Super Contributor
timestamp: December 20, 2013, 10:55:10 am
content: Look at all those (digital) computers on board that thing. I am amazed.

author: amyk
author_rank: Super Contributor
timestamp: December 20, 2013, 12:56:33 pm
content: Anyone find it a little sad they produced all those parts just to destroy and be destroyed?And here's another related video of Mike's teardown and running of an avionics gyroscope:

author: Bored@Work
author_rank: Super Contributor
timestamp: December 20, 2013, 02:39:22 pm
content: The successor of this Oemig company still exists. In their company history they directly skip from 1922 to 1948http://www.groschopp.de/en/company/history/Ups.

author: nctnico
author_rank: Super Contributor
timestamp: December 21, 2013, 12:03:37 am
content: Recently there was a TV series called 'Nazi Megastructures' which focusses on the technical achievements the Nazis made in that time (*). One of the episodes is about the V2 rocket program.(*) Do note that these achievements have cost many prisoners their lives while being abused as slaves in horrific conditions.

author: TheBay
author_rank: Unknown
timestamp: December 21, 2013, 12:58:35 am
content: Interesting video, LOL at the Atten PSU in the last part of the video, notice he flicks it from independent to parallel to give it a bit more current to get it all goingQuote from: Homer J Simpson on December 20, 2013, 05:17:53 am

author: SeanB
author_rank: Super Contributor
timestamp: December 21, 2013, 06:20:13 am
content: Not bad for the gyro to still run after 70 years, though the bearings do need to be stripped, cleaned and repolished, they are running incredibly rough. On power down it should run for a half hour or more with no power. Currently it will give poor accuracy and will have a lot of precession. I saw the little gyro units that were the heart of the original 747 IMU stripped down at SAA Technical years ago, in a clean room area, where they were being run on final test. They could detect the rotation of the earth around the sun easily, let alone the rotation of the earth on it's axis.

author: nctnico
author_rank: Super Contributor
timestamp: December 21, 2013, 11:41:30 am
content: According to the video most of the noise was coming from the frequency controller. I wonder what is in there because it still works after 70 years. Perhaps the bearings could use some TLC as well. OTOH it was quite dissapointing because the parts didn't to much. I'm pretty sure the Americans (NASA) have at least one complete V2 somewhere in storage. At the end of WW2 they obtained several...

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: December 21, 2013, 12:20:07 pm
content: Quote from: nctnico on December 21, 2013, 11:41:30 amFrom what I could see it was using a rotary converter - basically a universal motor and generator on the same shaft, so this is where most of the noise would be coming from

author: SeanB
author_rank: Super Contributor
timestamp: December 21, 2013, 01:19:58 pm
content: Rotary converter will have a lot of bearing noise, fan noise and that will be typical of them running at 30 000 RPM. The noise from the regulator box though is probably simply stray magnetic fields causing eddy currents in the case material causing the movement of the case. Likely because they use a straight inductor inside with an open ( large air gap) magnetic core which causes the case to be noisy. Motor is pretty much as noisy as any other aircraft motor, I have some 28V fans that are very loud, but they sure do move a lot of air for the volume they occupy. 400Hz fans scream.Just that when turned off the gyro is very noisy, one with that much noise will not be a very good unit in service on any aircraft.

author: dannyf
author_rank: Super Contributor
timestamp: December 21, 2013, 01:33:10 pm
content: QuoteThat has to be wrong: our NASA experts on this board have proclaimed that it is not possible to fly a rocket without "digital" computers. So what you saw with your own eyes clearly don't exist.

author: ovnr
author_rank: Frequent Contributor
timestamp: December 21, 2013, 01:37:33 pm
content: Quote from: dannyf on December 21, 2013, 01:33:10 pmYes, because flying a missile or ICBM is exactly as complicated as a soft landing on the moon. Thanks for the lesson on orbital mechanics.

author: SeanB
author_rank: Super Contributor
timestamp: December 21, 2013, 01:42:13 pm
content: I hate to burst their bubble, but you can make a pretty reasonable autopilot that uses absolutely no electrical parts aside from a few light bulbs for panel illumination. Was a very popular thing on the Dakota and was quite reliable. Ran on vacuum off one of the engines and needed some compressed air to drive the actuators for the hydraulics, but no electricity used at all. Gave altitude hold, attitude hold and steered to a bearing.Missiles are pretty complex electronics and mechanics, and you throw them away after at best a single full use, though often they have thousands of hours of running on them in test or in simulation. Pretty complex internals there.

author: walshms
author_rank: Regular Contributor
timestamp: December 21, 2013, 06:24:26 pm
content: Quote from: ovnr on December 21, 2013, 01:37:33 pmEducation is the penicillin that fights the plague of ignorance.

author: nctnico
author_rank: Super Contributor
timestamp: December 21, 2013, 09:32:52 pm
content: And how about the proximity fuze? Another non-digital invention from WW2:http://en.wikipedia.org/wiki/Proximity_fuze

author: dannyf
author_rank: Super Contributor
timestamp: December 21, 2013, 10:21:10 pm
content: QuoteIt couldn't have possibly existed, per our NASA experts here.

author: G0HZU
author_rank: Super Contributor
timestamp: December 21, 2013, 11:33:13 pm
content: dannyfYou do realise that to fly to the moon and back the computer does more than just keep the rocket stable during takeoff?It has to plot and control the speed and trajectory around the moon to make sure the craft doesn't veer off course as it slingshots back to earth. It also has to maximise efficiency of the whole system to save fuel etc.On the last thread you compared flying a spacecraft to riding a bike, now it's launching unmanned V2 missiles.But you still argue a human could do all the tasks of the NASA computers (both on earth and the spacecraft) that help to keep it on course etc? Some of these trajectory calculations were recalculated hundreds of times in order to keep the spacecraft within the tight flight trajectory of a few degrees.How could a human do all this? How could a human know their exact speed and location (and flight angle) in space without computers? Maybe you think they just look out of the window and aim at the moonAre you for real? (either way you are the most amusing character on the forum)