Do I need a bec to run a 1/10 servo?

[Sabunimwil]

Edit: I found a bunch of threads that had bec's buried in them. It looks like some folks with lipo don't need it and some run one regardless. I have a cc bec sitting in a drawer so I might as well use it.

I know this may have been answered elsewhere but I couldn't find it. I built a custom servo tray and now I have a high torque 1/10 servo on my mrc. I'm not having brown outs yet while running a 2s lipo with the stock electronics. I'm wondering if I'm just lucky and it hasn't happened yet. My question after all that is, should I be running a bec with the 1/10 servo? I'm going to be upgrading to a brushless motor and esc soon. Yay.

 

[HumboldtEF]

Its not based on being 1/10 scale so much as it has to do with amp draw. The real metric is how many amps the servo is asking vs how many can the ESC provide.
I tried to look up the stock ESC but cant find any specs listed, I guess you'll be swapping ESC's to go brushless soon enough anyway.

You say its not browning out now but after you install your new motor you might check for that again. Its possible the new motor may draw enough to cause it.

 

[Sabunimwil]

Its not based on being 1/10 scale so much as it has to do with amp draw. The real metric is how many amps the servo is asking vs how many can the ESC provide.
I tried to look up the stock ESC but cant find any specs listed, I guess you'll be swapping ESC's to go brushless soon enough anyway.

You say its not browning out now but after you install your new motor you might check for that again. Its possible the new motor may draw enough to cause it.

That's why I figure I'll just install it any way. I have it, might as well use it. I'm ordering this 4500kv motor and esc tomorrow:
https://www.ebay.com/itm/RACERSTAR-...-/282281613610?_trksid=p2349624.m46890.l49292

 

[Sabunimwil]

Which would do better in this mrc, a 4500kv or 4000kv motor? I'm still learning about them. Both are 35amp.

Here's the 4000kv one:
https://www.ebay.com/itm/1-18-BRUSH...-/283896192002?_trksid=p2349624.m46890.l49292

 

[QuesoDelDiablo]

Yowza, those are both extremely high Kv. In my rigs (trail truck/crawlers scx style rigs) I won't run anything higher than 3000, I try to stick to the 1400-2700 range. I don't exactly how that reflects through an MRC as I've never owned one but it's just something for you to consider.

I suppose one advantage of high kv is that your gear your pinion & spur waaaaay down which probably helps to reduce the cogging in an unsensored system.

Also, be careful with using esc's that aren't crawler specific, a lot of them don't have a drag brake and that's a non-negotiable must-have for me.

As far as the bec and whether or not to run, it's already been touched on but I'll try and explain a little further for you.

The need for a bec has very little (nothing?) to do with what type of batteries you use, it's purely related to the amount Amperage your servo wants and what your ESC can provide. Most ESC's are rated at 1-3Amps and many servos will draw up to 5Amps or more. If you're not getting brown outs right now, that's great, it pretty much indicates that your servo/esc are working well together. A bec will almost always provide increased performance because it has more Amps available but quite often you don't see the benefit's until you're trying to do stuff that's hard on the system - like wiggling the tires L-R to try get out of a tight crack.

 

[HumboldtEF]

Yeah that KV is way higher than I would consider for a crawler. I stick to 1800 -3000 KV for a crawler.

If you want an easer time browsing for crawler specific parts try RPP or Amain.

I wonder if the HH revolver 380 would be a good fit for the MRC?

 

[Sabunimwil]

I ended up buying a 3000kv motor with a 35amp esc that's programmable. Finding a 380/370 motor for crawling is tough. It's slim pickings. I got it for under $50 so if it doesn't work well I'm not out much.
I appreciate everyone's opinions and knowledge.
I have a losi nightcrawler that I've added a bunch to but parts are readily available for it. Not so much for the mrc.

 

[Robotboy]

Yeah that KV is way higher than I would consider for a crawler. I stick to 1800 -3000 KV for a crawler.
I wonder if the HH revolver 380 would be a good fit for the MRC?

I put the HH Revolver in mine and it's great. Running with the SW Micro, it's
smooth with more than enough power & torque.

 

[HumboldtEF]

I put the HH Revolver in mine and it's great. Running with the SW Micro, it's
smooth with more than enough power & torque.

Is it the normal revolver or the 380?


That little 380 has a lot of potential, I'd love to play around with one.

 

[Robotboy]

Is it the normal revolver or the 380?
That little 380 has a lot of potential, I'd love to play around with one.

The 380, 2600kv. "thumbsup"