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5 axis CNC machines have 3 translational and 2 rotational axes.
I am looking for an open source project which i will create kinematic tree in it.
I know some opensource projects but they are too complex.
Thanks; I've actually communicated with that guy a bit - his site is a good resource.
Misc / hobbyist for hire?
« Last post by dmehling on January 30, 2015, 05:44:53 PM »
I am a disabled person and I need to build a very simple device with a microcontroller and a single micro servo.  Basically a simplified version of the $50 robot.  However, I really do not know of anyone who can assist me with this project.  So I'm just asking how to go about finding a trustworthy person who can easily build that robot for me, with a couple of slight modifications.   
Electronics / Re: Electric bicycle
« Last post by newbie_teach on January 30, 2015, 12:22:25 PM »
So yeah, i'll order those motors first and then get back(maybe for help regarding mounting), and further discussions on batteries and esc
P.S. :- Any other motor's link will also be fine :) (in the same price range though)
Electronics / Re: Electric bicycle
« Last post by Schlayer on January 30, 2015, 12:06:03 PM »
   I would have to say its probably better to get the $30 motor with pre-mounted gearbox and other mounting hardware included. This will intimately save you a lot of headaches and time, already having a mounting solution and a properly sized sprocket and such. I would not recommend running two different types of batteries together in the same circuit as this leads to difficulties determining when your batteries are discharged, plus its generally just a hassle. To need to run multiple packs in parallel you need balancing circuitry that I personally don't know how to assemble, though I'm sure you can find it online easily. You can easily do any ESC controlling through an Arduino using a PWM output pin and the servo controller libraries built into Arduino's coding system, thus you should't need to worry about converting any values besides finding the max and min value for the ESC to accept. You will be entering values between -180 and 180 as if sending angles to the servo and these will be translated to the same signals an ESC needs to determine which direction to go in and how fast to run the motor. Go to adafruit's website; they have an in-depth tutorial on the subject I've used myself. Also google how to use this for an ESC since there is usually another 'arming' step that differs depending on your speed controller model. This will help you with any battery related questions, but keep in mind with a 24V motor you need a 24V supply, not 12V. If you used four 6V lithium cells of 10Ah in series you would get the necessary 24V, but I think you need all those packs to be capable of discharging at a rate of 25A. or you will definitely wreck your batteries. Lithium batteries and I have not had a great pastime... Suffice it to say you should exercise extreme caution with rechargeable lithium battery cells. Make sure you have data sheets for every pack and triple check you are using them within those specifications.
Also, never leave Lithium batteries unattended while charging! My brother set fire to his carpet when his charger malfunctioned causing a LiFePo4 battery to overcharge and explode.
Electronics / Re: Electric bicycle
« Last post by newbie_teach on January 30, 2015, 10:48:09 AM »
Electronics the esc will probably be scratch built, arduino hooked up to the throttle and map the ADC value and converting them to pwm range and given to the driver circuit(probably power transistors).
I have 2 options now, scratch build this thing,i can get a motor nearby for less than 10$(pretty sure) and then gear it down to a ratio close to 10 (9 teeth on the motor shaft and 90 teeth on the other side of the 90 teeth sprocket's axle  a 10 teeth sprocket and that goes to the rear cassette of gears).
or else simply buy this online motor and directly mount it on my bicycle and no problems from mechanics point of view.
What will be better,saving money and undertaking a heavy task of mechanics also not having access to much tools(i can find machinist's though), or just buy a ready motor and eliminate all this?
And another question,
If we have 2 batteries, say 1st battery is a SLA battery-6V,10AH
2nd battery is a li-ion battery,6V,10AH, we connect them in series. What will be the final output? 12V right?
in another situation say we have both li-on batteries and one of them is 6V,10AH and other one is 6V ,15Ah, we connect them is series what will be the final voltage and current specs?
Does connecting 2 different types of batteries(li-ion with SLA) cause problems?
Electronics / Re: Electric bicycle
« Last post by Schlayer on January 30, 2015, 10:34:53 AM »
    Also, I may need to take back what I said about needing to replace your peal power system entirely; look at some actual E-bikes and you'll see none of them rely solely on electric power. This is pretty much the cheapest E-bike on the market. It runs - that's about it. You should probably end up spending a little bit more than this E-bike's price on your own bike, since you found an incredibly cheap motor. You will want to source a speed controller that can handle your needs, then spend basically all of the remainder of your budget on a battery that's as large as you can get in terms of Amp-hours, since that translates directly to your 'range' or how far you can go before the battery dies and you're back to pedal power. Speaking of, we may as well take this opportunity to talk about batteries.
    The reason you shouldn't use a battery as cheap as the one on this $500 E-bike is because Lead Acid batteries (this is explained in the article I linked you to) are really awful when you need to use them for frequent discharging and recharging by more than 30% or so; they require replacing much sooner than any other battery. You can damage them by discharging too much similarly to Lithium batteries. Plus, whereas NiMH batteries have 1/4th the energy density of LiFePO4 but are also about a third the price, Lead Acid batteries have half the energy density of NiMH. Buying them also is hit or miss, as you might find a 13Ah NiMH like this: which is safe to discharge at a rate of 25 amps, which you need. 13Ah is fair, though $300+ seems expensive, though you will actually need to pay this much for cells that have the discharge rate you need and the added capacity is a bonus. 
   That battery seems absurdly expensive when you at first glance see this: This is a sub-$40 lead acid which you could use two of in series ($80) to supply 24V, and they each have 20Ah! almost double that of the NiMH! Except that they can't even remotely supply the continuous current you need. The clearly erroneous listing of a 300A max discharge rate should make you very suspicious. Looking at the data sheet we can confirm that the battery may discharge at a rate of 300 amps; for 5 whole seconds. There is a chart in the data sheet which shows that this battery cannot supply anywhere near 350W of power for your motor over a time period of more than 15 minutes. It would likely do terrible damage to the battery to even put this level of strain on it, even split between two batteries in series. Basically, do not use this battery.
   If you want to get a bit cheaper this could work: This comes with a charger and has 10Ah for a total of around $250, which is decently priced. I would still recommend you go bigger if you can however. Let me know if that all made sense or if you need any more help dealing with purely electronics.
Software / Re: $50 Code
« Last post by mklrobo on January 30, 2015, 09:24:51 AM »
 :) Hello!
At first glance a the code, the command, rprintfProgStr(XXXX) acquires a value in
Rom, not the ram, assuming a value was stored there.
Command char_attribute_(XXX) - puts a value to store hex conversion in Ram.
Command rprintfProgStr( XXx) on the last page prints a string from Ram.
From the errors at the bottom of the page, the debugger can not "pick up"
where the command is. Usually, a header file is responsible for this definition.
If those commands can not be recognized, then any commands for char_attribute(XXX)
can not run.
Since this is a C program, I would try to locate the header file responsible for calling these commands.
Header files are always at the top of the program. and direct any commands to a library for
running the program. Once the program is compiled, an executable is formed which can run by
itself, without any libraries. This is just a thought, at first glance. :D
Electronics / Re: Electric bicycle
« Last post by Schlayer on January 30, 2015, 09:17:47 AM »
will this motor do?

Yes, that looks like its simply a cheaper listing for a motor identical to the one I linked you. 1016Z3 model with the same gearing ratio of 9.78 and the same 9 tooth 410 chain sprocket :) Keep in mind however, you might have to spend quite a lot of money on a battery for these 24V motors.
Electronics / Re: Electric bicycle
« Last post by Schlayer on January 30, 2015, 09:07:10 AM »
I second that  ;D
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