Sunday, August 29, 2010

bug: mamba max pro firmware 1.29 - torque limit test fails on "crawler" setting.

for firmware 1.29 on castle mamba max pro ESC:

- the motor torque limit test does not work when the basic/reverse type setting is set to crawler reverse and the drag brake is set to 213% (full crawler). Not sure though if both settings are responsible for the bug. The motor would not spin at all and the red and green led light up steady (test running indicator), this means there is a bug according to the info i have. Upon the next connection, the program detects the run was a success, which i highly doubt actually was. The test failed. i tried 3 times re-setting up the mamba max pro for the test with crawler settings. then i switched to the reverse type "with reverse" and 0% drag brake and the torque limit test ran normally.
Note that firmware 1.28 detected a reasonnable kv value for my motor (7582 kv/low timing for a "7700kv" brushless motor),

Suggestion:
it would be also nice for future firmwares/programs to keep the result of the motor torque/kv test displayed in the window of the torque limit setting. I would also suggest if possible to have the option to manually enter the KV value of the motor for a given known motor timing so that people that know the result of the test would not need to physically run the test again and again when needed. (why not as a "pro mode" activated when a box is ticked ? or with a choice of motors commercially available with pre-entered caracteristics?)

how to open a locker without the key?

Somebody lost the last key of the locker of his bike, so the only solution: brute force of science.



we dumped the 15€ dead locker into liquid N2 ...

the funny thing is i did not expect it to break where it broke, i was hitting what i though was more fragile: the cable connection, but nonononono i broke the hook fixation!

reading comments online, i realised that this type of locker can be cracked with a pen, or twisting it until it breaks. it seems "D" locks are more difficult to crack.

To follow in our next science test...

Monday, August 23, 2010

method for data preparation: running MONSA (Hamburg ATSAS) on SANS and SAXS data

i finally managed to start MONSA with the SAXS data from ESRF ID14EH3
here is how to proceed to prepare the data .dat files:
-1- subtraction of baseline with correction in excel /cut noisy area ( >3.4 nm^-1), normalise max. intensity to 1.
-2- create a .dat file with 2 columns with saxs data (>1300 points)
-3- run GNOM (hamburg ATSAS program package)
-4- edit the .out in excel to keep only the 2 first columns of data. (1300 points shrink to 447 points that monsa can digest)
-5- make it a .dat file. (ascii tabulated separated .txt to rename .dat)

if you use the .dat file from step 2, you will soon have the error that the "Abscissa is out of range" after starting the run. This medhod prevents it from happening.

Sunday, August 22, 2010

lac de Pierre-châtel (Laffrey)

nice day :)
i swam the yellow line (see picture) both ways or 2x0.50km=1km without touching the floor waaaw
nice cause there is no need to to backwards every 10 sec like in a swimming pool


Saturday, August 21, 2010

the worse bike pedal removal ever!

You can nowadays find lots of replacement pieces in the stores, most of which are good quality, but sometimes you buy rubbish without knowing, even when you pay the price.... an example: bike pedals for mountain bikes. life expectancy for daily with a man: 1.5 year. not more. people will say that i am raugh... but maybe not that much knowing that the original pedals of the new bike held 15 years. it was in metal, not plastic.



this pedal was very stuck on the bike shaft that i broke a few spanners getting it out. I really though i would never get it out after breaking 2 spanners. Then i had the clever idea (what else could it be?) to dig the metal around the edges to free the tension of the metal. It worked! ouf but the last 2 spanners broke under the power of my legs as i was already able to unscrew, it was so rusty. i had to finish with an ajustable spanner (not shown).


spanner 's cost of the operation: 2.4+3€ (new platic pedals = 4 euros)

I shall remember to always apply grease on those screws in the future, it avoids lots of trouble some years later.

Tuesday, August 17, 2010

réparation des charbons du ventilateur d'habitacle de citroen xantia (pulseur d'air)

J'ai découvert pourquoi malgré le fait qu il reste de la substance aux charbons du ventilateur valéo de ma citroen xantia, le ventilateur avait un fonctionnement erratique, parfois refusant de démarrer/ventiler ou en faisant un bruit curieux et ce surtout lors de conditions climatique particulièrement humides:
- Le cordon en cuivre tressé du charbon poussé par le ressort dans le couloir de coulissement est simplement arrivé en butée du trou de passage. en passant le fil tressé dans le ressort, il est encore possible d'éviter de remplacer les charbons mais je doute que ça fonctionne très longtemps. Autant remplacer les charbons directement. J'ai utilisé des charbons d'alternateur retaillé ( ca prend 3 min max. sur une lime)

http://www.serial-kombi.com/-charbons-d-alternateur-la-paire-N33878.html
j 'ai payé 12 euros pour 4 charbons ( accolés 2 a 2 dans le montage final) dont 6 euros de frais de port au lieu de 100-250 euros pour un nouveau ventilateur :)



et c'est reparti pour un moment, mais pas trop car les collecteurs en cuivre du moteur sont fort usés déjà et le ventilateur ne fera plus 255000km à nouveau!

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-Pour déposer le ventilo:
  • (1) Démonter le soufflet d'étanchéité du connecteur
  • (2) Pousser le caoutchouc vers l'axe central en tirant légèrement sur cet axe vers le haut, le faire pour les trois caoutchoucs en fait ce sont eux qui tiennent coincés tout l'intérieur du ventilateur avec le fond.
  • (3) Pour les charbons il y a juste le petit clips et le ressort à sortir
(http://blog.passion-tarn-et-garonne.info/index.php/post/2008/12/20/Pulseur-d-aire-xantia-qui-me-joue-des-tours)

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Réparation des faux contacts de la lampe d'habitacle de Citroën Xantia:
Les lampes d'intérieur de la voiture s'allumaient de manière erratique depuis quelque temps et j'avais pensé que le problème était dû à de l'oxydation sur les contacts des lampes. en regardant un tout petit peu plus près j'ai remarqué que le plastique du support du socle de la lampe avait un tout petit peu fondu et par conséquent la force exercée sur les contacts pouvait varier énormément. Cela est donc la cause des faux contacts.
Il suffit de percer plusieurs trous dans la carcasse du support de la lampe et d'y insérer un fil ainsi qu'une visse pour le fixer. (voir figure ci-dessous)

il suffit de tordre le fil de fer avec une pince pour le tendre et ainsi favoriser le contact électrique.
:)