Let's Make Robots!

Which stepper driver?

Morning all! I am currently resurrecting a previous project, and incorporating code I have developed and learnt about since last looking at it. I am currently using a v1 adafruit motor shield to drive two steppers. As the af shield uses a shift register to drive the pins I have to use the af motor shield library, and am stuck with their pin choices (basically). 

 

Can i PWM a solenoid?

My CNC router (2D) tool lift function is controlled by a solenoid, which lifts the tool when powered, and releases the tool when not.

I have recently started using these nice little 0.2 mm tungsten carbide bits, however while machining a piece of copper plate the other day, the dropping of the tool onto the work piece caused the very fine bit to snap off. I was able to re set the tool height and use the now slightly shorter and therefore wider (1mm) bit.

My question to you is: is it feasible to use PWM to soften the lowering of the tool?

Well this seems to be an opportunity to good to be missed! A friend of mine was throwing out (THROWING OUT!!) the aforementioned CNC router. Well he wasnt, his … Read more

Program freezing (or getting stuck?) when asked to calculate large numbers

Hi Guys! Ive done buckets of trouble shooting on this, and i THINK i have identified where the problem is, but i cannt work out how to correct it. In short i am programming my CNC router (converting GCode into CNC movements)

FrankenCNCRouter: Re use electronics, or replace?

Ive pulled the back off the FrankenCNCRouter, and quite surprised by what ive found!

As far as i can tell, the box on the bed is just motor drivers, My knowledge of electronics leaves a lot to be desired, but as far as i can see this is a line of beefy transistors?, a line of VERY beefy resistors mounted on the bed to disperse heat, and a few other odds and sods (regular reistors, diodes and a big cap)

The 6 white terminal pins to the centre go directly onto the stepper motors (which are 8 wires each, but two are doubled up on the pins, pressumably common coil connections?)

Electronics question: LEDs on a slightly unpredictable power supply

Hi guys, Way off topic, but you guys have been so helpful in the past, and i KNOW you know the answers, so one cant but ask!

We are doing a camper van conversion, and i have found some sweet "decking lights" for internal lighting.

They are sealed, "3LEDs and a resistor", units, designed to run at 12V (off a transformer, the junction box is a simple parrallel arrangement)

Problem is, the vehicle battery will produced between 11 and 14V depending on charge condition and if the alternator is running.

Monitors the weight of a pet, Logs data and provides visual feedback
So our (My girlfriends) cat has a hyperactive thyroid. The over abundance of thyroxin means she cant regulate her weight and without keeping it in check she will … Read more

Scavange/reverse-engineer ALL the things!

Im sure most of us recover parts from where they can be scavanged

I recently picked up a "broken" printer/scanner from work. Ive pulled out a whole stack of working DC motors with encoders, belts, pulleys, cogs and rubber wheels.

It also has a cool looking little strip light which must be the light source for the scanner. Its like a flourescent tube, but tiny and slightly flexible.

Cannibalizing a broken printer/scanner. Suggestions?!

My boss asked if i wanted a partially working printer scanner combo jobby today. Dont think he was expecting me to rip it apart for parts.

Ive only got SO far into pulling it to pieces, i will have to go and get a complete Torx driver set tommorow, ive gone as far as i can with >T15.

Anyone got any suggestions as to what i should do with this thing?!

Thoughts on reverse engineering a wind speed sensor

A friend of mine wants me to make him a weather monitoring station. Temperature and light leves are easy peasy, but ideally wind would be useful too (this thing is going to have a real life purpose!!)

i found this little fellah on fleabay

http://www.ebay.co.uk/itm/Wind-Speed-Sensor-For-Use-With-Wireless-Weather-Station-N25FR-/190973703805?pt=UK_Home_Garden_Weather_Stations&hash=item2c76eb767d