Graupner x=8n
#17
My futaba has to be rebooted as well, but a re bind is necessary when I change the response time. I don't mean to be argumentative, I'm seriously interested in this radio and am looking to help work out the problems.
#19
Tech Regular
Joined: Nov 2014
Posts: 378
An interesting feature is that in x-8n you can set latency independently for each channel. I have tested it - I have set the four channels to different latency and it works flawlesly. This allows to match the capabilities of the equipment connected to given chanel. From what I have seen in Sanwa manuals, and I may be wrong as I have no MT-4s nor M12 to experiment, when you change the latency in Sanwas (Normal/SHR/SSR) you change it for all channels. This means that the best achievable speed is limited by the weakest connected equipment - so if you have SSR servo but your ESC is not compatible with SSR, the overall speed must be match to the ESC capabilities.. Upon second look in the Sanwas manual this is not true. For m4s the channels are individually set to appropriate mode (Norma, SHR, SSR).
Last edited by sbd; 11-27-2014 at 05:02 AM. Reason: Corected information
#20
Tech Regular
Joined: Nov 2014
Posts: 378
@ sbd... thanks for posting your test results between the RC3S vs MX-V vs X-8N
I'm curious for you to explain how you measured those test values? I'd like to conduct the same experiments myself to include testing on several other brands of radios too. It would be really nice to have an apples to apples comparison for ALL brands of radios.
I'm curious for you to explain how you measured those test values? I'd like to conduct the same experiments myself to include testing on several other brands of radios too. It would be really nice to have an apples to apples comparison for ALL brands of radios.
I have seen your video about the Bluetooth functionality of the SkyRC Toro 120 ESC. I assume you have the SkyRC multifuntional Progbox too.
This programmer is able to monitor PPM signals when you plug it to a receiver channel. It even seems to have build in BEC so not needed to power the receiver with additional source. Plug the battery balance connector to the card, chose from the card menu the PPM monitor option, plug the servo wire from the card to the receiver and you get the information about the PPM signal on the progbox screen.
Then you move the controller sticks/wheel/trigger to the end positions and you see what it reads.
Now when testing the Mx-V, RC3S, and x-8n I used the steering channel and repeated the max min mid positions several times. The absolute uS values are not so important as they depend on the transmitter trimmer setting, D/R etc. Same for the middle point value. The middle point value actually provides the information if the signal is standard 1000 uS to 2000 us signal midpoint cca 1500 us or narrowband midpoint 760 uS (faster) or in the case of x-8n 300 uS.
What is interesting to note is the repeat-ability of the signal values when you have max, min, mid controller positions. This is where in my measurement the x-8n excelled. I got always the same value. For the mx-v and the RC3S there where small deviations see the middle point in the table - mx-v been better than the rc3s in this regard. This actually gives good sense how well the overall process chain, form the potentiometer to the output of the receiver, works. The lower the deviations the better the quality of parts and transfer process is.
The frequency values on the progbox screen is the important part for the best achievable latency for the channel. The frame rate is the limiting factor for latency. It is in Hz but it is readily recalculated to mS (1/Hz*1000). This provides the min theoretical latency.
Could you please share what you have measured?
#21
Joined: Mar 2011
Posts: 6,410
From: Austin,TX
@sbd, thanks for sharing your testing method, that's very convincing to me to be a legitimate method for getting decent metrics to compare various radios.
I don't actually have the SkyRC ProgBox, I got the BlueTooth Module instead and I'm not so sure it will work with any random radio. I'll go ahead and place an order for the ProgBox and follow-up with my test results later to help expand my list of differences that I've been maintaining.
Much appreciated!
I don't actually have the SkyRC ProgBox, I got the BlueTooth Module instead and I'm not so sure it will work with any random radio. I'll go ahead and place an order for the ProgBox and follow-up with my test results later to help expand my list of differences that I've been maintaining.
Much appreciated!
#24
Tech Initiate
iTrader: (3)
Joined: Feb 2010
Posts: 40
From: Torrance Ca
I just got a 8N and I like it. However i'm having an issue with a Gr4 rx. I installed it in my buggy and get a total signal loss every once in a while when moving the steering servo. I can see this reported on the telemetry display. My servo is a fairly cheep turnigy digital. Could this servo be causing the problem?



3Likes