I’m currently working on a biped project which would be an improved version of the lynx brat (cross with a kind of lynx 209 biped torso ).
I begun one week ago, so I’ve not working on it more than 12 hours.
Here are my CAD drawing :
Yeah, I know, the brackets look really crude, but I’ve no CNC milling machine at home and my school is closed until the 15th september. So, maybe I will remachine some parts later.
My big question for now is : “Are the hs-422 powerful enough to support the biped during its transition on one leg while walking or should I buy at least 2 (or 4) more powerful servo for the ankle/bottom leg joints ?”
i think you have done well making your brackets. i think if you gave them a light sand down on the face and a few nice layers of spray paint they would look cool. i did once see someone spray their brackets black and then use a tint of orange to give then a rusted look.
those hs-422 wont cut it by a long way. i would think about starting with hs645mg’s.
take a look at zentas work here: viewtopic.php?f=7&t=6342
I was hoping not to have to buy hs645mg’s. They cost 4 times as much as 422 and have only 2 times more output torque.
Don’t you know any other cheaper servo brand ?
I found these with a rapid search on the web :
Servo HD-1501HB MG (17Kg/0.14Sec) for only 25 euro/st. (they are really powerful and fast for a standard servo, am I missing something ??? )
yes that’s one of the biggest problems with a robotics hobby. but you do get what you pay for with servos.
sorry to be there barer of bad news but the hs-422’s will collapse under the weight.
those 1501MG’s sound promising.
might have to get some too. nicely priced i think.
you might like to try looking on eBay for the 645’s. i think i have brought about 7 in total from there a few years ago and they are still working well. so i even got for £10 each.
There are some great servo package deals about so id keep looking if i was you.
Could be cool to have Lynxmotion brackets in other fancy colours than just black/metallic grey.
EDIT : Ok, just ordered a bunch of HD-1501 MG (from the review found on the net, they are a lot better than all the cheap scrap servo). They are full metal gearbox/ 2 ball-bearings.
cool. what a good idea. the test plate looks great, well done. you have inspired me to anodize some of my plates.
keep us posted on how you get on with the servos. im very interested in how they perform.
No, I’ve just used an old 12V DC supply, old electric motor brush as cathode, battery acid for electrolyt and printer cartridge ink.
But I’ve some difficulties to control the ink retainment at the final stage (must be because of the non homogeneous flame heating, I should try with a hot ink bath). So, some pieces are well-done, others are just slightly couloured.
EDIT : Ok found how to do it properly. I forgot to wash some pieces after the electrolyse and the remaining acid interfered with the ink. And I’ve also used a boiling ink bath.
Here is an example in pink :
Ok, I’m still experimenting to see what’s necessary to do in order to have this nice finish.
I’ve done a test with pale yellow and just bought a bottle of dark red ink. If it works, I will try with a servo bracket. Will post the results tomorrow .
Still waiting for my servos (currently out of stock), but I already got my µcontroller/servo controller board.
Also, I was wondering about which battery technology to use.
My first idea was to use traditionnal NiMh battery pack (in part because I was afraid of LiPo technology since a buddy set one of the school’s labs on fire ! ) but I just talked with R/C enthusiast about my dilemma.
They advised me to use the new LiFe technology, which would be saffer for robotics applications.
They are rated at 6.6 V (2s) and I was wondering if I had to use a regulator or if I could power up the servos directly ?
Does anyone here ever used one of them ?
Thanks,
PS : I changed my mind about the anodization process. I must find pure red dye because the reaction don’t want to work with mixed ink (I got only patch of colors from the two dye, not a uniform taint which should be the mix of the two’s).
So, I painted them with a nice metallic deep red (yeah, influence from Iron Man) :mrgreen:
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