Originally Posted by FX777

Looks like a great product. Curious about how many amps can be supplied to all of the servos at one time and to each servo individually, continuous and spike or peak load.

The servo bus power and ground is "stiched" 5oz copper (most circuit boards use 1oz or 1/2oz copper). This means that there are hundreds of vias (that bridge the top and the bottom layers together). A servo pin is technically only good for 5A continuous with 10A burst - we do pull more than that, and after hours of continuous use there can be micro-arcing that occurs. It really just starts breaking down the gold flashing that is inside of the servo connectors. I used 30 micron gold pins (instead of 15 micron or "flash") to help prevent this. So, the weak link is actually the servo pins/connectors, not the servo bus on the X24. Until manufacturers change their connector method, we will have to live with that.

Originally Posted by FX777

Also, is it compatible with all popular high torque and high voltage servo brands? It seams like the new Futaba 7018 may be having problems with the MKS and newer Hitec servos. There may be an issue with excess voltage being fed back to receiver when control surface load is released with some servos. Do you have any concerns with X 24 compatability?

The only issue I am aware of is with the newer Hitec servos, and apparently Hitec is correcting (or has corrected) the issue. It stems from the voltage of the motor actually feeding back into the battery and raising the battery voltage beyond the differential threshold that is used to clock in the PWM signal. For those of you who are thinking, "what the heck does that mean?" its simple really - the PWM (servo pulse) output voltage of all 2.4GHz receivers is 3.3v, with some early Futaba receivers being 2.7v. If the servo electronics are using the input voltage as a reference to the input signal, and if the input voltage difference is too great, the electronics won't see changes in the input signal. This is why some of the older analog servos (JR's retract servo in particular) do not work well (or at all) with modern receivers. The JR retract servo uses a fixed reference, and is expecting the input signal to be close to 5v. Nearly all of the old 72Mhz receivers output the receiver battery voltage for the signal voltage, which was typically around 5.5v. Fortunately, most servos use an extremely low fixed signal reference, and function all of the way down until the electronics themselves stop working.

[Some power expander type products increase the signal voltage to 5 volts. I didn't do that with this product because it requires at least one (but correctly two) voltage regulator to do that, and I absolutely hate voltage regulators because they can fail. It took theKM a bit of convincing to make me add the BEC for driving ignition systems]. NOTE! This has changed. The servo signals are now boosted to 5v! There are dual power regulators for the CPU, so if one fails the other still works. The input power bus has dual sets of redundant power FETS. You can operate at 50A on a single FET, but you have 4 total as backup (and for distributing the load). The battery inputs are simultaneous draining, so there is no magical switching between both power sources. I think that's a bit silly. Packs should be discharged equally. If one power source fails, the other still works though.

Can you just use Spektrum remotes with this without an actual RX?

Yes, it accepts up to 4 Spektrum satellite receivers (no main receiver is required). The Spektrum receiver ports are voltage controlled (from the dual regulator power source) so no adapter is required.

Can't wait!!! Might be a great upgrade for my big birds that are all currently running XPS X10+ Power Expanders! I love them as is, nearly exactly the same functionality as PowerBoxes without the bulk, weight and cost. I love their low latency, functionality, 80A+ current handling, tattle tale LED for lowest voltage sag, and best of all, I run them with dual diversity RX's via SBUS which it switches to the RX with the highest RSSI on my X8R RX's from my FrSky Taranis.

Looks to be a sweet product to test out!

hmm no signal line voltage boost..

When all the hoopla was going on about twitchy Hitec 79xx servo's, I had never ever had any issues since I pretty much standardized on Smart fly expanders which, as you know, boost the signal line voltage to 5v.

With servo extensions running 5 or 6 feet, even when using 20g extensions, there is some voltage drop when not using a signal line booster.

Have you tested the XPS24, feeding a hitec 7955 or 7950 with extensions that a typical 42% would use all the way to the stab servo's?

My compy uses seven 72" extensions to the 7950's that are in the tail section.
3 in a durrant drive for the rudder, and two each for the elevators.

Originally Posted by Eganwp

Can't wait!!! Might be a great upgrade for my big birds that are all currently running XPS X10+ Power Expanders! I love them as is, nearly exactly the same functionality as PowerBoxes without the bulk, weight and cost. I love their low latency, functionality, 80A+ current handling, tattle tale LED for lowest voltage sag, and best of all, I run them with dual diversity RX's via SBUS which it switches to the RX with the highest RSSI on my X8R RX's from my FrSky Taranis.

Looks to be a sweet product to test out!

I'm sitting here thinking about binding 4 X8Rs to the Taranis just because it can be done lol

Haha exactly!!! I mean heck, I have several extra X8R's lying around anyway, and they're cheap in comparison to others!

Originally Posted by Eganwp

Haha exactly!!! I mean heck, I have several extra X8R's lying around anyway, and they're cheap in comparison to others!

FrSky also have the XSR on the way. It works just like the spektrum satellites for just signal through sbus, 4 XSR and an X24 would be perfect for giant scale.

Ya I saw that as well! They look pretty sweet. I'm excited to try the XSR's on my FPV stuff because the diversity for better polarization positioning with them will be insane!

Originally Posted by Cryhavoc38

hmm no signal line voltage boost..

When all the hoopla was going on about twitchy Hitec 79xx servo's, I had never ever had any issues since I pretty much standardized on Smart fly expanders which, as you know, boost the signal line voltage to 5v.

With servo extensions running 5 or 6 feet, even when using 20g extensions, there is some voltage drop when not using a signal line booster.

Have you tested the XPS24, feeding a hitec 7955 or 7950 with extensions that a typical 42% would use all the way to the stab servo's?

My compy uses seven 72" extensions to the 7950's that are in the tail section.
3 in a durrant drive for the rudder, and two each for the elevators.

For a test, I ran 100 feet of extensions and that worked fine. I then used a 1000' spool of telephone wire (32 gauge). There were no signal issues, but the current was very much limited, which you would expect with such small gauge wire. The signal current requirement is less than 1mA (typically about 300uA). There is very little drop in voltage even at a hundred feet with this amount of current required.

If the servo twitches plugged directly into your receiver, it would do the same with the X24. The problem apparently only occurred with the older 795x series when using a 8.4v input and a 3.3v signal line. A partially discharged Lipo or LiFe didn't exhibit the issue. My 7955's don't have this issue, and they are more than a year old, so I am not sure when this issue was corrected.

Originally Posted by Eganwp

Ya I saw that as well! They look pretty sweet. I'm excited to try the XSR's on my FPV stuff because the diversity for better polarization positioning with them will be insane!

for Taranis, best link upgrade is to stick an XPS taranis module in the back... same price rx's as FrSky, made locally, higher quality, lifetime warranty. just say'n

XSR is an XPS RFU wannabe

Originally Posted by XPS

For a test, I ran 100 feet of extensions and that worked fine. I then used a 1000' spool of telephone wire (32 gauge). There were no signal issues, but the current was very much limited, which you would expect with such small gauge wire. The signal current requirement is less than 1mA (typically about 300uA). There is very little drop in voltage even at a hundred feet with this amount of current required.

If the servo twitches plugged directly into your receiver, it would do the same with the X24. The problem apparently only occurred with the older 795x series when using a 8.4v input and a 3.3v signal line. A partially discharged Lipo or LiFe didn't exhibit the issue. My 7955's don't have this issue, and they are more than a year old, so I am not sure when this issue was corrected.

thanks for the detailed info.

The 7950's in mine are approx 5 years old so they are definitely the older G2 circuitry. It also has 6 7955's, 3 in each aileron and they are of the same age.

I run Duralite Li Ions so it may not exhibit the same twitchy behavior sans the smart fly's but I've not tested it out to be honest.

Cool product!

Originally Posted by Eganwp

Can't wait!!! Might be a great upgrade for my big birds that are all currently running XPS X10+ Power Expanders! I love them as is, nearly exactly the same functionality as PowerBoxes without the bulk, weight and cost.<snip>

I was reading this and thinking the same thing. I have a couple X10's and like them a lot.

On top of the technical upgrades, the X24 seems to be a much better form factor with respect to the plug locations. The one thing that bugs me on the X10 is the connection directions, with the SBUS being perpendicular to the servo plugs. It does not lend itself to simple or clean installs IMO.

How about X24 working with the Hitec Aurora 9 or 9X?