Quote Originally Posted by Trakyan View Post
You can actually use a solenoid relay, it uses what's sometimes called Bang-Bang control rather than a PID loop with PWM. It basically involves turning the heater fully on and switching it off as it approaches the target temperature, then switching it on as the temperature drops. It's a lot cruder and the temperature is less stable since the heater is either off or going full tilt, you can't turn it on just a little for fine adjustment. It is usable if you're on a tight budget like OP says they are, but they're also wanting to use profiled linear rails so that's sending some mixed messages.
Thanks, but i will probably just go with a mosfet because its more suited for the job. When i say I'm on a budget i just mean that I don't have an unlimited budget and if I wanted to spend a ton on a printer i would just buy one already made. I have several printers already so i don't want a cheap crappy printer that can just print. I want a really nice quality print and a large print volume and am willing to spend the money on things that make a difference like linear rails and maybe even genuine Hiwin or equivalent as I have heard they are worth the money. Its sometimes a challenge figuring out what will really be worth spending on but there are certain things I know will help. anything that makes it run smoother basically so belts, bearings, pulleys, stepper drivers, linkages etc will not be where i will look to save.

I just want to be smart about where i spend the money. A perfect example is the SKR board. It was like $30 CAD compared to a duet or others for $150-$300. I bought a clone E3D V6 but bought the genuine block sock and thermistor kit and hope to replace the heat break soon as well. I may stick to the 24V heatbed just to keep the costs down but may buy the 120v depending on how the budget is doing.

Power stuff I will stick to what is safe and made for the purpose. life span of electronics is related to proper power regulation as well as heat dissipation and duty load etc. I always use decent power supplies and components as it saves a lot of time and money in the long run.