I am looking for recommendations on Servo Motors for an automotive HVAC project. I have been using the small form factor 9g servos up to this point, but I am interested to know if there are more reliable types out there. There are some true automotive units, but to be honest, I can’t figure out which ones are true “standard” servos. Some are 90 degree only (all one way than all the other - not really servo), some are complicated auto algorithm units (I don’t begin to know how to program/control these), and some are, allegedly, true servo units that could be controlled by arduino. I am searching for the latter, but not having much luck without ordering a bunch of different ones to try them. And some are incredibly expensive.
So, my question is if anyone has any insight/experience in using these style servo motors and/or if someone has some alternatives that might be suitable in an HVAC (Evaporator/Blower box setup).
I've only used servos for hobby purposes but have only used top brand name servos like Futaba and Hitec, never had any problems with either. Yes, the good ones can be quite expensive but like most things you get what you pay for.
I would have a look at motors as fitted normally to such car heaters - they will work and fit and run from 12 or 5v . Better than making your own hardware . You should be able to interface to them . They maybe stepper motors or have some form of feedback and gear motors - research needed, google , buy used off eBay ?
Some cars use vacum actuators controlled by solenoid valves and the vents are usually open or shut , volume controlled by motor speed and manual dashboard flaps
I work on cars, trucks, heavy equipment for a living and my advice is to go to a salvage yard pull some out yourself then take them apart to see how they work.
Automotive parts follow specific standards because it's a harsh environment for electronics.
Servos for HVAC vary from simple motor/potentiometer combos
Rotary encoder / motor combos
Digi pot / motor combos
And then there's some with an internal microcontroller.
As previously mentioned some use vacuum, especially diesel engines because diesel engines don't create vacuum in the intake manifold.
Find yourself a 1996 to 2000s toyota and you've got yourself a simple reliable HVAC servo
Thanks folks. To answer some questions, I have looked at this a few times over the last couple of years. You are right, there is an endless number of options like I mention above. There are basic back and forth options, custom (to the OEM) options, and somewhere there are true, standard, servo options, but I’ve not been able to pin point which are true standard servo options.
I’ve been using the 9g type in my application and they work ok, but I can’t help but feel that there is a better, more reliable, option. I have had some failures on some types and others are DOA so my confidence is low. I have purchased about 10 different types and settled in on one that I feel is the best for my application. However, I’d like to find an automotive grade servo that was designed for this environment.
The reason I am reaching out to the community is to see if someone has more experience than I do and someone who may have used these options already. Yes, I can figure out, eventually, but as someone mentioned above, why reinvent the wheel. (conflicting advise - “don’t reinvent the wheel” vs “go figure it out and reinvent the wheel” )
So, I’ll ask again, if anyone has worked on projects using a standard, automotive grade, servo options, I would love to hear about it. All I need is some bread crumbs to the part number.
I’ve already bought several styles that were advertised as servo and none of them are standard. And yes, I’m an engineer and have taken all of them apart to see how they work. Again, I can keep looking, and will, but if anyone has invented this wheel already, I’d really appreciate any information that you could share.
If you're looking for a high quality standard servo with +-90º travel check the ones from ServoCity. They also have myriad mechanical assemblies and parts to design you own actuator to use with the servos that as an engineer, you may appreciate.
As far as off the shelf automotive industry parts are concerned it sounds like you have explored that avenue thoroughly and were not happy with the results.
Thanks. I looked at this site a couple of years ago. The problem was the cost. My application has 9 servos in it and the cost jumps a bit @$40/each. I am considering commercializing it at some point and was looking for a less expensive, yet reliable, option so I was still searching. That said, I’ll circle back and check this site again.
And, it’s not that I’m unhappy with what I’ve found. I just haven’t found what I’m looking for. I know it exists. I’ve seen images of the servos in application, but I can’t read the part number and I can’t ask the company who is using them as they would/could be a competitor if I choose to sell these units.
)