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Re: thermistor calibration - 8 months ago

just found out that a lot of 'cheap' PT100 are probably not platinium more likely those are nickel those can probably still be used as some form of PTC thermistor but that the coefficients and graphs are different, some are probably an attempt to replace the platinum PT100, not likely to be the same thing

by ag123 - General

Re: thermistor calibration - 8 months ago

@VDX thanks much for your response, I'd think PT100 is probably a good idea for a reference at least. A difficulty I still confront is that it isn't easy to find a suitable liquid to do high temperature calibration from 100-250 deg C. from room temperature to boiling is 'relatively easy' to do in a lab

by ag123 - General

thermistor calibration - 8 months ago

ok I understand that this topic is as ancient as 3d printing itself, in fact a thread surfaced years back Now here is the motivations: If you simply go to the "online flea markets" e.g. a simple search for a thermistor returns all of them claiming '3950' thermistors with *no specs* no doubt they are cheap, but my own experience suggest that I've once got a (hotend) thermistor that measures 50

by ag123 - General

'RAMPS' board for stm32 'development boards' - 2 years ago

Something got my attention about '3d printing boards'. I've always wanted a Ramps board that can cater to stm32 and other ARM based 3.3v 'development boards'. I did not find it earlier until ... I stumbled into this board it is the 'M5' extension board and not the GTR-V1 board that I'm interested in The good thing about that 'M5' board is that the microcontroller is not on the board. So

by ag123 - Controllers

Re: We need a different sort of 'RAMPS' boards ! - 3 years ago

hi m10cube, thanks for the quick response well, not necessarily 'all sorts of io', mainly the 'most common' 3d printing drivers parts. the core driving chain mainly. things like (TFT/OLED) lcd goes direct and independently to the mcu board, so do sd card etc. Those don't make sense to be on this '3d printing (motor/mosfet) driver sub-system' board, as it'd just add more wires other 'accessories'

by ag123 - RAMPS Electronics

Re: We need a different sort of 'RAMPS' boards ! - 3 years ago

thanks m10 cube is a nice concept! A thing here is that 'ramps' style electronics is a little more specialized. It creates a stereotype / model of the 'driver' stages of a 'cartesian' (actually delta and maybe more printers runs on it too ) 3d printer driver stages. the common components these days are: - stepper drivers X, Y, Z, extruder (maybe at least 2), that 'spare' extruder controller can

by ag123 - RAMPS Electronics

Re: We need a different sort of 'RAMPS' boards ! - 3 years ago

It isn't too much about 'form factor' of RAMPS, the mega pins are pretty 'useless' to most other boards as they won't fit. In terms of size it is 'about right', but I'd think putting more stuff e.g. onboard dc-dc buck converter would result in a larger board. in terms of 'dupont' connectors, I'd think there are many better ones out there. I'd guess even JST connectors are likely slightly better

by ag123 - RAMPS Electronics

We need a different sort of 'RAMPS' boards ! - 3 years ago

This forum seemed somewhat deserted. But I'm posting this here as it seemed relevant still and I'm hoping to get some mindshare about this: These days there are large number of 32 bit 'development boards' e.g. mostly ARM based STM32 and various NXP and some from Atmel. TI, and not to miss out Raspberry Pico etc. You could find examples of stm32 boards here You can find various of these boards

by ag123 - RAMPS Electronics

Re: Compiling Marlin 3d printer firmware with stm32duino core using a makefile - 3 years ago

I've created an instructables with more (complete) information for some reason it keeps giving a 404 error if not logged in. try logging in to instructables if you are getting that error.

by ag123 - Firmware - Marlin

Compiling Marlin 3d printer firmware with stm32duino core using a makefile - 3 years ago

This is a build log rather than a 'how to' post. I managed to compile Marlin Firmware 2.0 with STM32duino core and got it running on STM32 F4VET6 black board (this isn't quite a '3d printer board' more than it is a 'development board', takes some imagination add 'ramps' board to get it to work) using a unix/linux makefile. This makefile is maintained in this gist Accordingly the recommended m

by ag123 - Firmware - Marlin

Re: How to modify a standard RAMPS 1.4 to work with Arduino Due? - 3 years ago

this topic while is as old as it was, it is as relevant as ever, ramps 1.4 is nearly the 'stereotype' of a '3d printer board' - all the drivers that is, the mcu is a separate affair. these days there is ramps 1.6 (and 1.6+) basically an 'evolution' from the same 1.4 design with an additional heatsink on the mosfets RAMPS 1.6 microcontroller board? STM32F407VET6 black - 168 mhz ARM cortex-m

by ag123 - RAMPS Electronics

Re: Z Axis Design Help - 3 years ago

i'm late on this topic but that i watched this video rack and pinon with worm gear i think this is a feasible design, what looks interesting is this can be wholly 3d printed

by ag123 - CoreXY Machines

Re: MK3 Alu-Heatbed how to print with a hole in center. - 3 years ago

this reply is late kind of, but accordingly the center hole is intended for a thermistor ! so i'd guess if 'all else fails' one can perhaps get a thermistor to fill that hole (and maybe measure temperature?) ;/ i think as it is about 3mm, chances are that prints should bridge across it, but it is a heated bed so problem remains but i had to say it is a lousy design, that hole creates a whole lo

by ag123 - General Mendel Topics

3d print and cnc mill hybrid object design - 5 years ago

hi all, in my various web searches, searches on youtube etc, i stumbled into many different ideas and actual hybrid 3d print and cnc hybrid makes. but one of those things i'm curious about is has anyone literally used both 3d fdm printing and cnc milling to product an object or part? they can even be on 2 different machines i.e. a 3d printer and separately a cnc (end) milling machine. i got curio

by ag123 - CNC Routers, Mills, and Hybrid RepRapping

Re: using non-idler pulleys as idlers directly on the shaft - no bearings - 6 years ago

hi all, thanks much for the responses i decided to buy a few pieces of the (crappy) idler pulleys and a bunch of small ball bearings i checked prices, the prices of gt2 idler pulleys : small ball bearings can be as much as 10:1 i.e. a single piece of idler pulley buys 10 pieces of ball bearings. and it is likely those ball bearings perform better than the idler pulleys i think the ball bear

by ag123 - Mechanics

using non-idler pulleys as idlers directly on the shaft - no bearings - 6 years ago

i'm searching for parts on ebay/amazon/aliexpress for gt2 pulleys and as it turns out gt2 idler pulleys are expensive often double and more the prices of the pulleys that is directly coupled to the motors can you share your thoughts about using non-idler pulleys directly on metal shafts without the bearings as idlers? would that work after all? i'm thinking one way to reduce the friction is per

by ag123 - Mechanics

Re: thermistor - 6 years ago

thanks for the reply! i decided to do a thought experiment, i take one of those specs for MF58 100k ohm (25 deg C) beta: 3950 then i take the formulae from i got: and the list of points that made up the chart T R Deg C Ohms 15 158,446.1 25 100,000.0 35 65,027.6 45 43,446.1 55 29,749.7 65 20,832.8 75 14,890.3 85 10,844.5 95 8,035.2 105 6,048.9 115 4,620.7 125 3,577.8 135 2,805.3 145 2,225.3

by ag123 - General

thermistor - 6 years ago

i've been searching up (cheap) thermistors on ebay/aliexpress etc, for the cheap ones a lot of very similar ads for mf52 and mf58 etc the notable ones are mf52 types these apparently have a max temperature of some 120 deg c hence these are out then the other very common ones commonly labelled mf58 so called 'glass encapsulated' ones which could stand temperatures up to some 200-300 deg C (the

by ag123 - General

Re: Questions on driving DC motors with Arduino using PWM - 7 years ago

i'm bouncing this very old thread as my questions seemed relevant: recently i'm thinking about using L293D h-bridge with current sensing for stepper driving the specs for L293, L293D are here http://www.ti.com/lit/ds/symlink/l293.pdf and the pinouts are as follows 1 1,2EN | VCC1 16 2 1A | 4A 15 3 1Y | 4Y 14 4 GND | GND 13 5 GND | GND 12 6 2Y | 3Y 11 7 2A | 3A 1

by ag123 - Controllers