Talk:Portal:WRV1
From TeamFrednetWiki
Cool stuff Joerg - keep it coming! --Anders Feder 05:05, 5 December 2008 (EST)
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Parts needed for WRV1 build
Joerg has made an excellent progress designing the WRV1 and also developing the tools needed to build the wheels and other components. There are a few more we need to purchase to complete the prototype. If anyone has access to these parts and would like to donate some to the effort, please contact Joerg directly to arrange shipment of them to him. Also, if you are able to contribute funds toward this development, please use our Chipin donation link to contribute toward these parts (mention "WRV1" in your email message to us about the donation). Note that the current exchange rate for Swiss Francs is close to 1:1 with US$.
4 Motors (268348 EBCLL SL assembled with 110316 GP13A) from MaxonMotor Switzerland.
Details:
4 Stück RE-max 13 Ø 13 mm (268348) mit Getriebe GP 13 A Sinterlager , Metall (110316) für die Konstruktion eines weiteren Funktionsmodells
Pos. 1) xxxxxx (Kombinations Nr. noch ausstehend)
bestehend aus:
Motor: 268348 EBCLL SL 1WE 0.75W Getriebe: 110316 GP13A SL i = 275:1
Preise in CHF exkl. MWST, Lieferung und Verpackung
Stückzahl Preis/Stk. 1 - 4 122.60 5 - 19 108.20
Total cost for 4 motors needed to complete the prototype is ~ US$500 (plus VAT). Can anyone help with funding this purchase?
--fjb 13:37, 4 March 2009 (EST)
Date formats
This seems as good a place as any to start talking about date formats.
One part of the world uses DD-MM-YYYY, and then another part (in the U.S.) tends to use MM-DD-YYYY (or worse, MM-DD-YY). I believe that both of these styles are inferior to my preferred style which is simply YYYYMMDD (no slashes, no dashes, no separators). The reason for this is mathematically obvious: my format allows the date to be used as a mathematical quantity directly, without any conversions, in standard mathematical comparisons. Further, this format is numerically consistent, in that (as with all numerical quantities) the field that changes fastest (the day) is rightmost, and the field that changest slowest (the year) is leftmost.
So let's hereby establish a standard format for all dates in the wiki as YYYYMMDD ... or (if you must have separators) YYYY-MM-DD. We should include this in our "wiki standards page" somewhere in the wiki too, if someone would like to get that underway. --fjb 16:03, 31 January 2009 (EST)
2008-02-01
I use the format YYYY.MM.DD HH:MM since over 20 years, but this was always considered as unusual, i did not use that format in public. So Fred you are running into open doors!
As i can easily live with the "-" instead of the "." as separator I will always use the format in all documents. I think it would make sense to publish it on in a more public way.
Jörg
I agree that YYYY MM DD is the superior format - it sorts so nicely! By the way, Alex did note it 'officially' over here. --Anders Feder 09:03, 1 February 2009 (EST)
Questions re WRV1
Q1 Do you have an estimate of present configuration mass and power consumption?
Q2 What power consumption and storage capacity is presently installed? (if none, what do you envision installing and what is its mass?)
Q3 What solar power supply rating do you envision utilising, what will its weight be along with orientation hardware?
Q4 What is the effective functionality of the wheel suspension springs, i.e. what can the WRV1 NOT do if the springs were eliminated?
Q5 What is the logic for designing in springs for a low speed vehicle intended to operate under lunar 'g'?
--DerekSmith 16 Aug 2009 13:32 (GMT)
Improved Grip and Obstacle Management
I have been working with systems to improve grip and traction over variable surfaces. One of the most effective I have developed is the 'Floppy Bag'. Take a partially inflated soft ball and press it against an irregular surface. The contact surface will conform to the irregular surface beneath it, and as pressure is applied from above, the ball will become semi rigid and 'grip' that surface and at that point the ball can be used as a grip point against that surface
Try this as a simple example of concept experiment - remove the tracks and springs from the WRV1 wheels, and replace them with a strip of small bubble wrap. Bubble wrap bubbles are 'floppy bags' and conform to the shape beneath them when the load is applied. Obviously this material is not suitable for half a km over lunar regiolith, but it should demonstrate superior grip and traction performance over any other system short of a cogged track !!
Another major advantage of the 'Floppy Bag' system is in load spreading, particularly valuable on non stable surfaces due to the elimination of the generation of any point source forces which occur with rigid wheels. The principle can also be scaled up to any size required and floppy bags can be stowed and deployed for additional purchase as and when required. The bags can be fabricated from many materials to give abrasion resistance and thermal protection and the internal pressure may be controlled by either active or passive systems.
I hope that posting the concept here is sufficient to prevent any person or company from ever patenting the ides, thus leaving it open to the world for free and unrestricted use.
--DerekSmith 16 Aug 2009 13:47 (GMT)
Flip-over and heat-over protection
Could the wheels be larger for the occasion if rover may fall on the roof on landing or on the rough landscape?
Robot does not have "up" and "down" unlike human vehicle, it can drive both sides up.
It would be an advantage if the rover shape would be symmetrical to horizontal axis.
Also thermal engineering needs to be reviewed: simple motors may overheat in vacuum since there is no air to cool them.
At least some thermal sensors must be at critical points of the rover.
For heat protection i provide aerogel, best known insulator; heat, UV, radiation resistant. Contact me.
--Vaino n 15:48, 25 August 2009 (EDT)
Portalization of WRV1 portal
Thanks Marc for the WRV1 portal. It is very nice. Joerg's time is dedicated to the WRV1 development of this awesome prototype, blueprints and this kind of stuff. Best, --Tristancho 20:50, 13 September 2009 (UTC)
