Very curious, No where in my files have I been able to locate an inclusion reference to stm32f10x_it.c, and yet when I add one into my project directory, it becomes active, despite not causeing errors when previously absent. I booted up the SysTick interrupt, pus some simple code between the curlies { } after the SysTick handler label, and it works. I would prefer to know how it attaches to thby grael - RepRap Host
> Whoa, what happened? I'm trying to advance the > technology in use by Reprap, not make money off of > it. Why do you think I'm posting schematics, etc? > I'd say that the ideal result would be my designs > being adopted by RRRF. I don't think that's > particularly likely, but at least I can provide an > alternative build path. I'm not sure where Reprap design is at curby grael - Controllers
What's the heat disipation in the motors like with the voltage up that high ? I have provision in my circuit board to run to the L298 maximum, I'm still working on my wave forms at the moment though.by grael - Controllers
Larry, Great to see you have some progress too ! I see the protoboard is fairly bare bones, which is good, you don't have to deal with stuff going to connections you don't want in your application. Have a good long look at the I/O, a lot of it can be remapped, and you can even run timers as encoder counters. I spent a big part of my circuit board design on mapping pins. Somewhere, I saw somethiby grael - RepRap Host
Those who have been following this thread, may have noticed that I'm a C newbie. This weekend, I experienced some frustration with trying to modulate the drive power, and to change direction of the stepper motors while they were running (like a washing machine action). My software wasn't working as expected Finally, I tracked it down to having assumed that parameter n1 and parameter n2 and paraby grael - RepRap Host
It depends on hardware as well as software. If you use an add on module with step and direction inputs, then it probably only has a common enable input, in which case there's no way to apply PWM to the coils individually for proper microstepping. I think pretty much all the PCBs using the L297 logic chip to convert from direction+step to actual stepper enable signals are fixed to a maximum of 8by grael - General
I have a friend who set up an X-Y table using hex x-section steel. You can make interlocking parts quite easily with hex, without the need for special groove cutting, and you don't need any special tools other than drills, file, tap, hacksaw and a drill press. You can buy washers, nuts and screw thread, and bodgy a handle up out of something, and make your own X-Y table simply like this yourself.by grael - CNC Routers, Mills, and Hybrid RepRapping
most of the possible pump configurations have been invented and exploited already. A gear pump would be the most practical for generating the extrusion force, but it wouldn't have the bulk granule transport capacity unless either the gear pump was made way oversized, or the granules were caster sugar sized, instead of wheat sized. Gear pumps have huge ineffeciencies when pumping viscous fluidsby grael - Mechanics
I have the hardware on my board to pick that up, but it's a bit of a mission to do it this early on in the project. I have 0.1 Ʊ sense resistor on each stepper motor coil, and wired traces from these to my micro. There would be smoke if the resistors came unstuck ! I realised after I'd assembled the PCB that there is a potential for negative transients to drive the sense resistor negative withby grael - Mechanics
Pressure fits are an acceptable solution for backlash removal. Where a joint is meant to have movement or slide though, creating pressure through additional hardware as Annirak mentions, is sometimes needed. Less backlash usually means more driving power is required though. Ah! Now I see why Annirak needs the more powerful stepper motor drivers !by grael - Mechanics
Calibration of anything that moves in 3 axis of rotation, but that is intended to plot points in XYZ coordinates is going to be a nightmare. Possibly worth further investigayion by any budding techno art students interested in creating objects with mutant warp effects.by grael - Delta Machines
It may be that the rubber is detuning mechanical resonant effects quite seperately from any capacitive/inductive effects. In fact, I suspect the capacitances involved in the circuit are negligible, but there will be frequencies at which the motor body elements absorb large amounts of the active freqency, and mechanically resonate, with the effect that beat frequencies occur between the driven fby grael - Mechanics
Hurry up Zach ! I'll have my own spare boards and software ready to go soon too !by grael - Controllers
Thanks for approving my choice of generic chip type for my own board design ! ><by grael - Controllers
Hi Brendon, My real estate designated for steppers comes to about 4"x6", but that's with the L298s. and 4 axis. I used KiCad, which doesn't rubberband like Protel, so it's a lot more tiresome trying to compact things. I really like the look of the L6228Q by ST, I know you wanted to use L293 and separate boost stage on the same PCB but I still like my approach. If I need, I can configure my steby grael - Controllers
Your lucky ! I didn't like the products I saw on here, so I had to design and make my own circuit board. Design started in January, Bare boards received and one assembled in April, only now starting to get steppers doing the basics ! Grahamby grael - General
grumpy mike, re the temperature profile, a small domestic is actually brilliant for the job, as they are designed for a much higher thermal inertia load, i.e. toast, potatoes, roast meat etc. All these contain water, which has a very high specific heat capacity, higher by volume than PCB components. My advice is to buy a cheap meter with thermocouple, and insert this in the oven with the populatby grael - Reprappers
I think the high pressure nozzles are too small, but if there is a pressure regulator after the supply, then they may be big enough. Another option that might be a lot more practical, is many motorcycle engines are fittes with "jets", that are available in a number of sizes, to control the fuel flow. Not sure if they go down to the 0.5mm size, but they do have a range around 1mm and under in diaby grael - Reprappers
Sometimes it's productive to leave a problem for a day or two, and come back to it fresher. I had another crack at PWM last night, on the steppers instead of my piezo this time. I set only half the stepper motors to PWM (GPIO_Full_Remap_TIM3) etc, and after some messing around, I got some motion on a stepper again (jerky this time), and then sped up the timer to smooth the control. Tonight'sby grael - RepRap Host
I've looked at the beagle board, It could actually do quite well as a low cost, low power server, but intel have stepped up their game with the atom processor, which is big for the embedded market, on higher spec functionality. The beagle board is ARM based, and a fast one at that, but what concerns me, is the life cycle of the chip. I could see it being used in at least one big application, butby grael - Controllers
Larry, some simple checks to do: The dimple IS the mark that looks like an ejector pin, that's pin one, and it's the wrong way around compared to an atmel chip, from the writing. Check your power consumption on the 3.3 volts to the STM32, if it's more than 20mA or so, with an unprogrammed chip, then you have misconnections (see above) The gnd and power pins need to all be connected to the righby grael - Controllers
The big challenge with a box design is access. You might consider removable panels with wingnuts to secure, and a basic box framework, strengthened by the attached panels.by grael - Reprappers
You might try allowing cookies for their website, that's been my problem on some web sites. I generally dissalow, and only create exceptions when I have to.by grael - General
The cardboard circuitboards look quite inspiring for cash short developers.by grael - General
I think gen 3 PCBs by Zach are optimised for SMD assembly. If you don't want to deal with customs, to the extent that you would prefer to do your own boards, then you might want to go back a generation or two... reduced performance though. I'm working on a new board too, but my softwares not at the functional stage yet. Nothing wrong with getting a makerbot kit, it only takes unavailability ofby grael - Controllers
The Fallen: The high integration keeps costs down, as it reduces interconnections and component counts. annodomini2: "structures" have an equivalent in visual basic that I've used before, definitely useful. I've use the AVRs quite a bit, both AVRs and PICs easily do table jumps too, similiar to a select case statement in VB, or switch case in C. Now I have some working code, my main challenby grael - Controllers
I'm stuck at the moment, The libraries and the chip documents don't quite seem to match, so I'm waiting on a reply from STM. Either I've overlooked something obvious, or there's a lot more work involved in using the libraries than one would expect, in which case it's almost worth discarding some and starting afresh. STM make their chips with extraordinarily flexible I/O though, so it's a lot ofby grael - RepRap Host
Is there a sigma curve die off in store for our machines too ? And a technicality, If I create a machine that is substantially engineered and designed personally, is it a reprap machine, or are only Zach's PCB driven machines repraps ?by grael - General
nophead Wrote: > Wave isn't often used. Torque is highest in full > step as there is always two coils on. Half step > gives better resolution. > > There are some interesting alternative half step > schemes here: > > /halfstep.htm Interesting, It looks like a very simple way to achieve constant current (total) drive, and therefore considerably smooth the drive. I wonby grael - Mechanics
If your XYZ axis are really rigid, then you could use a repetitive pin punch setup, with a die for the punch bit mounted under the material you are moving.by grael - Mechanics