ProModeler Servo: 420oz, billet case, o-ringed, $79

[mikemcE]

Originally Posted by jbeech

OK,let's talk about this, why on earth do you want to power the servo externally? The receiver will power the servo very nicely if you merely supply it with clean juice. Give it garbage (any BEC on the planet) and it's another story. I have 27 emails (and counting) with a fellow who wants to use stock type electronics despite my practically begging him to treat it like a nitro truck and isolate control-electronics from propulsion-electronics. How? Very, very simple. Use a 2S 1000 LiPo with dual leads. What does dual leads gain you? 10A into the receiver for starters! Best of all, that 10A is TOTALLY unaffected by anything the propulsion motor and electronics do. Think of it as a battery supplying pure analog juice versus synthetically derived digital juice (via FETs). Just like tube amps are better for mission critical stuff versus digital amps, analog juice from a battery is mo betta. Bottom line? There's just no need - in my opinion - to go outside the servo to do it. Please explain because maybe I'm having a stupid moment. Convince me!

I guess you didn’t read this.... clean juice.
John designs servos to mil spec, and supplies them. What’s your background?
Y’all call out John, I say bullshit.


Hang up and Drive

[snapon boy]

Originally Posted by mikemcE

I guess you didn’t read this.... clean juice.
John designs servos to mil spec, and supplies them. What’s your background?
Y’all call out John, I say bullshit.


Hang up and Drive

John provides us with quality and has improved his quality of products and services with minimal price increase.
Also the beer cover are sweet.

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[Discohair]

I got this battery charged and tested and the results were better than the smaller batteries but the BEC hooked to 3s propulsion Power still had higher stall voltage.




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[Discohair]

Originally Posted by mikemcE

I guess you didn’t read this.... clean juice.
John designs servos to mil spec, and supplies them. What’s your background?
Y’all call out John, I say bullshit.


Hang up and Drive

While he did mention noise (but no comparative oscilloscope data) early on, the subsequent arguments centered on voltage so that’s what I tested.

I’m a construction electrician with some experience in electronic controls and lightning and surge protection and that experience has taught me two things:

1. Even though I work with electricity every day I cannot even begin to understand the complexities of the subject and

B. Words without data are just noise.

I feel obligated to insert a caveat here just so nobody gets there feelers hurt.

I own 2 Promodeler servos and they are now my go to servos. My quarrel is not with quality or performance, my quarrel is with unhinged diatribes with no associated data, no matter the source.


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[mikemcE]

Originally Posted by Discohair

While he did mention noise (but no comparative oscilloscope data) early on, the subsequent arguments centered on voltage so that’s what I tested.

I’m a construction electrician with some experience in electronic controls and lightning and surge protection and that experience has taught me two things:

1. Even though I work with electricity every day I cannot even begin to understand the complexities of the subject and

B. Words without data are just noise.

I feel obligated to insert a caveat here just so nobody gets there feelers hurt.

I own 2 Promodeler servos and they are now my go to servos. My quarrel is not with quality or performance, my quarrel is with unhinged diatribes with no associated data, no matter the source.


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Fair enough.
John is light years beyond me, I run bec’s without problems.
John tells us the complete science.

I would bet he can provide you with gobs of facts.


Hang up and Drive

[Jim85IROC]

Originally Posted by mikemcE

I guess you didn’t read this.... clean juice.
John designs servos to mil spec, and supplies them. What’s your background?
Y’all call out John, I say bullshit.


Hang up and Drive

Mil Spec is a great buzzword that rarely means much in real world applications. Mil Spec components are built to a very specific standard... not necessarily a "high" standard, but definitely a specific standard. Mil Specs exist to ensure that the customer gets exactly what the customer expects. This is usually done so that the government can buy the component from anybody who meets the spec with confidence that it will work in their intended application. That doesn't necessarily mean that a mil-spec component fits YOUR needs best.

John wants his servos to get clean, consistent power. That's why he doesn't like BECs. BECs can be very noisy with a lot of high frequency junk, and sometimes that high frequency junk can cause problems with electric motors. Getting power from the same battery that also powers the rest of your truck can also cause voltage sag, but as Mike's tests showed, so can too small of a dedicated battery. In our applications, running a big enough dedicated battery to realize the benefits of reduced sag can be problematic, and not ideal for the purposes our vehicles are used for. If my servo was going into a UAV that absolutely must not experience failures, then I'd want it to have the cleanest power possible too, but when it's going into my toy truck, I have different priorities. My priorities don't allow for the added mass of a second huge battery. I'm willing to accept some of that high frequency noise from the BEC in exchange for more consistent torque output then I can get from a tiny battery and easier packaging/weight than what I can get with a big servo battery. UAV builders, maybe no so much.

[JatoTheRipper]

Originally Posted by Jim85IROC

Mil Spec is a great buzzword that rarely means much in real world applications. Mil Spec components are built to a very specific standard... not necessarily a "high" standard, but definitely a specific standard. Mil Specs exist to ensure that the customer gets exactly what the customer expects. This is usually done so that the government can buy the component from anybody who meets the spec with confidence that it will work in their intended application. That doesn't necessarily mean that a mil-spec component fits YOUR needs best.

100%! Mil-Spec is a minimum spec not something high end.

[jbeech]

Several of you have said that because I'm an airplane guy (true) . . .



That I don't grok crawlers (not exactly true) . . .


So please bear in mind how I may not be 'quite' off-the-deep-end as much some of you guys, nevertheless I'm still a modeler and thus, I do dabble with many other things . . . some of which have four wheels!

Meanwhile, Discohair, good test - well done! What you've shown us is the BEC will deliver higher voltage when the servo stalls, 7.5V vs 6.7V - no surprise because unloaded voltage is always higher than loaded voltage. The BEC started at 8.4V and dropped .9V to 7.5V while the battery began at 8.2V and dropped 1.5V to 6.7V (but nominal voltage of any LiPo is actually 7.4V not 8.2V you get without a load so the drop from 7.4V to 6.7V of 0.7V is similar to the voltage drop with the BEC - again, pretty much as expected because, basically, 'any' voltage source will depress under load.

So how about doing this next? Add something with which to measure current under that same load, please. This, because data is king. Note; most VOM will also measure DC current up to 10A so using one of these is plenty good enough for our purposes - and color me keenly interested in your results.

Meanwhile, more than one of you has observed crawlers are different and that I don't understand the issues you face because I live in a fixed wing world. Well as the photo above should show, that's actually not quite true - BUT - maybe you're right in a way. Anyway, believe me, this old dog is always willing to learn new tricks! So have I been wrong all along, e.g. with a crawler it doesn't matter? Especially if you're using a good aftermarket BEC? Maybe yes, maybe no. Anyway, yes it's true I am more fixed wing-centric in my approach. So I know how a BEC won't cut it when dealing with high current servos (especially when instead of one servo, a large model may have from 6-15 of the DS470 servos (and some UAS carry 24). And maybe I have failed to give adequate consideration of the fact a rig has just the 1 high current servo for steering so maybe it doesn't matter. Dunno but like I said, I'm keeping an open mind because quite frankly, there is a big difference between powering one servo and a dozen!

So let's see how well that aftermarket BEC does when you measure current, specifically the CCBEC 10 you're testing. By the way, I continue to maintain the BEC included with the stock ESC doesn't have the cojones to operate the servo (mine or anybody's making this kind of power). But, it's a fact most of you guys are in a different league than someone bashing in their back yard, breaking the servo, and coming to me for something better. E.g. you guys are more sophisticated in your approach and thus, more willing to try new things.

Bottom line, maybe it doesn't really matter for a rig equipped with a decent aftermarket BEC - let's see what Discohair comes up with in the way of result! Note, it would be nice to strap a WATT meter to the rig and see what the currents are under loads.

Finally, on another note, my TRX4 has one steering servo and three submicro servos (two lockers and a 2-speed). I've been working on a submicro servo to fit into this model (yes, complete with 13 o-rings and not just metal gears but steel gears like in a 470 or 630). Anyway, I'm thinking this may be a killer steering servo for any of the crop of 1/24th micro crawlers - or - a sweet addition to your TRX4 for the locker and diff. This is a photo of the prototype.

[WHITE-TRASH]

At least you're willing to give it a chance that a bec does in fact work in our world. I know in your world you're probably right about becs but this is a whole simpler animal.

Castle has another bec that is better than the typical 10 amp version. It's 14 amps max and 8 amps continuous in the voltage range I use rather than the 10 amp putting out 5 amps in that range. There is definitely a difference in power output at the servo in my experience.

I still need to buy a 630 but I've been holding out for something bigger.

[durok]

Nice to hear you are working on a micro-servo, there is definitely a market for an upscale replacement for the Traxxas ones.

And great to have you continuing to discuss your products on the forum - things can get heated around here and I was hoping everyone would just keep an open mind...

[spoo76]

Ive been looking forward to a ProModeler sub micro! It would be a nice upgrade to the MG90's in the more demanding rigs some of us use. That looks even smaller and may be a perfect bolt in solution for the axial SCX24

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[mikemcE]

As I’ve been on the bandwagon here, my simple comment is that John designed and built the finest servos I own. I’m also glad to see his passion here with the facts. My 2 PM servos are still strong smooth and of course whisper quiet!


Hang up and Drive

[JatoTheRipper]

Originally Posted by mikemcE

As I’ve been on the bandwagon here, my simple comment is that John designed and built the finest servos I own. I’m also glad to see his passion here with the facts. My 2 PM servos are still strong smooth and of course whisper quiet!


Hang up and Drive

Have you tried all of the other top tier brands? Mine seems woefully overrated in terms of torque. It struggles to move 1.9 tires that are experiencing resistance.

[HumboldtEF]

Originally Posted by JatoTheRipper

Have you tried all of the other top tier brands? Mine seems woefully overrated in terms of torque. It struggles to move 1.9 tires that are experiencing resistance.

I have experienced this too on a 2.2 rig with the 470, seems like in a vacuum it makes all the torque but when faced with real rocks it seemed to throw in the towel like there's a safety or something telling the servo to go limp when it sees resistance.
I even went so far as to send it back as defective, John was kind enough to test it and it passed all of his tests. When I got it back I put it in a 1.9 rig and it does better there. I had also gifted a 470 to my brother who used it in a 2.2 rig, he also mentioned that it felt a bit weak.



I took a short video of my 470 running straight off of a 2S battery sitting at the bottom of a hill with no rocks in its way (on each side). There are points where the servo refuses to move at all and when it did move is was only a tiny bit of movement. As far as I could tell there some sort of safety built in that tells the servo to cut power when it sees resistance which is far from ideal. This kind of hits home with what John had been mentioning about "dont you want all the power all the time?", seems like even with the recommended setup you wont get "all the power" anyway.


https://youtu.be/h2WkfUNLOCQ


(Say the word John and I'll remove this link if you'd prefer (it an unlisted video BTW)

If the issue with going "soft" was solved and maybe a new version with either 3S capability or a direct connection for batteries (or BECs) was added I really think these servos could become the absolute best available. I would love to see that come to fruition!

[mikemcE]

Originally Posted by JatoTheRipper

Have you tried all of the other top tier brands? Mine seems woefully overrated in terms of torque. It struggles to move 1.9 tires that are experiencing resistance.

All ? No way

Savox 2290 beast, but in my 1.9 it’s not needed. Ive also had a few hitecs, and a wad of cheap JX, HD, Solar , and numerous cheapies from savox.
I’ve actually turned my 420 down to 6.5 v to slow it down a bit. Never any hesitation , it’s in my VS4. And my 470 is in my Bully2 MOA, never any binding or wait, smooth and crisp.

I did run it in my 2.2 Wraith at 11.5#
And it wasn’t strong enough. So I tried a couple of Holmes, ate gears and pins, needed the 2290 and no issues.

The PM was better than the Holmes with a bit less torque. But when you’re undersized, you will fail.


Hang up and Drive

[snapon boy]

I've not had any issues with the pm 420 in my wife 1.9 scx10 with dlux knuckles. My son has a 470 in his scx10. My 8x8 has a 630 and it's worth every penny! Thank you John for your time help and service.
Fish
AKA Snapon boy

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[JatoTheRipper]

Originally Posted by HumboldtEF

I have experienced this too on a 2.2 rig with the 470, seems like in a vacuum it makes all the torque but when faced with real rocks it seemed to throw in the towel like there's a safety or something telling the servo to go limp when it sees resistance.
I even went so far as to send it back as defective, John was kind enough to test it and it passed all of his tests. When I got it back I put it in a 1.9 rig and it does better there. I had also gifted a 470 to my brother who used it in a 2.2 rig, he also mentioned that it felt a bit weak.

I took a short video of my 470 running straight off of a 2S battery sitting at the bottom of a hill with no rocks in its way (on each side). There are points where the servo refuses to move at all and when it did move is was only a tiny bit of movement. As far as I could tell there some sort of safety built in that tells the servo to cut power when it sees resistance which is far from ideal. This kind of hits home with what John had been mentioning about "dont you want all the power all the time?", seems like even with the recommended setup you wont get "all the power" anyway.

(Say the word John and I'll remove this link if you'd prefer (it an unlisted video BTW)

If the issue with going "soft" was solved and maybe a new version with either 3S capability or a direct connection for batteries (or BECs) was added I really think these servos could become the absolute best available. I would love to see that come to fruition!

Thank you for sharing the video. I'm glad to hear I'm not alone or I would have thought I had a bad servo.

I'd urge you to make that video public so people researching these servos can get as much real feedback as possible.

Originally Posted by mikemcE

All ? No way

Savox 2290 beast, but in my 1.9 it’s not needed. Ive also had a few hitecs, and a wad of cheap JX, HD, Solar , and numerous cheapies from savox.
I’ve actually turned my 420 down to 6.5 v to slow it down a bit. Never any hesitation , it’s in my VS4. And my 470 is in my Bully2 MOA, never any binding or wait, smooth and crisp.

I did run it in my 2.2 Wraith at 11.5#
And it wasn’t strong enough. So I tried a couple of Holmes, ate gears and pins, needed the 2290 and no issues.

The PM was better than the Holmes with a bit less torque. But when you’re undersized, you will fail.

Hang up and Drive

Well you've tried most of the big name brands.

I wonder if ProModeler's tolerances vary more than the big names. I say that because there seems to be two extremes. There are people like me that don't have a powerful 470 and then others can't say enough good about them.

[mikemcE]

I have no way of knowing that, my 470 is different than the 420. I can see it’s faster, as specs show. The Holmes 500 had no more power, but did tear the teeth off, that’s the big PM difference much beefier gears .


Hang up and Drive

[HumboldtEF]

The gears are definitely amazing no denying that, I just wish the servos had the performance to match.

Originally Posted by JatoTheRipper

Thank you for sharing the video. I'm glad to hear I'm not alone or I would have thought I had a bad servo.

I'd urge you to make that video public so people researching these servos can get as much real feedback as possible.




Snip

I wonder if ProModeler's tolerances vary more than the big names. I say that because there seems to be two extremes. There are people like me that don't have a powerful 470 and then others can't say enough good about them.

I'm not sure I want to make that video public, I dont know if I really feel comfortable doing that. I only made that to show John.



Funny you mention the tolerances, when I was having issues with the weak servo in the video I also had another 470 purchased at the same time also in a 2.2 rig (Gmade Gom) and it was a fair bit better so I decided not to send that one in. Its also what made me think it was defective since the other performed better.
Everybody has different standards too so that could account for some folks being more than happy and others wanting a bit more.

[Jim85IROC]

Originally Posted by HumboldtEF

I have experienced this too on a 2.2 rig with the 470, seems like in a vacuum it makes all the torque but when faced with real rocks it seemed to throw in the towel like there's a safety or something telling the servo to go limp when it sees resistance.
I even went so far as to send it back as defective, John was kind enough to test it and it passed all of his tests. When I got it back I put it in a 1.9 rig and it does better there. I had also gifted a 470 to my brother who used it in a 2.2 rig, he also mentioned that it felt a bit weak.



I took a short video of my 470 running straight off of a 2S battery sitting at the bottom of a hill with no rocks in its way (on each side). There are points where the servo refuses to move at all and when it did move is was only a tiny bit of movement. As far as I could tell there some sort of safety built in that tells the servo to cut power when it sees resistance which is far from ideal. This kind of hits home with what John had been mentioning about "dont you want all the power all the time?", seems like even with the recommended setup you wont get "all the power" anyway.


https://youtu.be/h2WkfUNLOCQ


(Say the word John and I'll remove this link if you'd prefer (it an unlisted video BTW)

If the issue with going "soft" was solved and maybe a new version with either 3S capability or a direct connection for batteries (or BECs) was added I really think these servos could become the absolute best available. I would love to see that come to fruition!

I've had the same type of experience with the 470 in my Bomber. It seems to stall in situations that my cheap 20kg servos don't. Other times, it's got all the power in the world.