What is the main difference between the price differences for servo's. I mean there are servo's for EUR 4,95 but there are also servo's for EUR 29,95. Is the difference the speed or the torque...or both?
Also what is the difference between these servo's. ie. what does the JR / FUT etc. mean? I'm planning on building a hexapod, and I will need quite a lot servo's for this. What are the best price / quality I can buy?
Yes. FUT being Futaba. This may also, then have a bearing (ha ha ha) on the connection.
My advice? For a hexapod? 18 (for 3 DOF per leg) or 12 (for 2 DOF per leg) of the $4.95 ones. They are typically used in R/C cars and will have a ton of torque for your application. I used them in my biped and the onlyone which wasn’t powerful enough was the one whose job it was to lift the 6-cell battery with a lever about 70mm long. I knew I’d need more for that job.
Do you have a link for Do you have a link for magical $4.95 servos? I’m assuming they are just like all the others (allow for 90 degrees to left and right or any stop in between) just less torque or speed.
Cheap Servos Here’s a set of 4 for $20 including (UK) postage. Please check his international shipping rules. He’s throwing in a battery box and a switch. I have used him before. No complaints. You have about 2 hours before I hit “BuyItNow.”
FUT/JR Not sure about the other one, but FUT is futaba and JR is JR. The “plugs” (which are ACTUALLY SOCKETS - don’t get me started) are both 3-pin SIL IDC 0.1in spaced sockets.
Yep, horns with the servos should work, and have a variety types. If you buy something called “servo savers” they usually have an adapter that can be changed for several types of servos.
I knew someone that built the Lynxmotion EH3 hexapod, which uses smaller than standard size servos. I think they are called micro rather than standard. I think he purchased Hitec HS-81s for it initually, which has a nylon gear train. These wound up stripping occasionally, and so several were replaced with HS-85MG metal gear servos. The standard size servos might have less chance ofgear stripping, but the metal gear option seems pretty good.
My favorite servos have been Cirrus CS-80s (discontinued), a GWS model, and Bluebird BMS-620MG ($20.95 high torque) that I’d intended for an arm or 2, still working through. I’ve got some other standards types, which $9-10 seems to be a good price for, though some can find them cheaper.
My experience is that the metal gear servos produce about 10 times more torque and are about 3 times the price of standard servos. Micro servos seem to produce about 0.75 the amoutn of torque as standard and are about the same price as standard.
Watch out for an interesting effect, though: standard servos can draw 350mA at stall.If you have 3 of them and your MCU supplied from the same 1A regulator and they all stall, your MCU will reset. This happened to me once. I spent WEEKS looking at my software, thinking it was crapped when it wasn’t.
Also, the metal gear / high torque servos draw even more current than the standard ones…
