147LikesNew Sanwa MT-44 4-channel 2.4GHz radio system
05-24-2017, 04:29 PM
#391
Ok, this probably end this tread as it seems almost every time I ask a question the tread ends! Maybe my questions not worth answering, or too dumb or nobody knows. LOL
Anyway here it is:
Is there a steering wheel adapter that works with the 44.
Anyway here it is:
Is there a steering wheel adapter that works with the 44.
05-27-2017, 03:35 AM
#396
I have some updates as promised...
Unfortunately I wasn't able to race on Friday, but I did get about 2 hours of solid practice in, which is probably longer run-time than if I'd been racing, so it's still an interesting touch point.
The battery (3 x 750mAh AAA Panasonic Eneloops) voltage dropped from 4.2v to 3.8v during the course of the run, but didn't go below that. 3.8v is actually still higher than the nominal 3 x 1.2v of 3 x NiMH, and if I remember correctly, the discharge curve of NiMH should be reasonably flat. The battery gauge on the MT-44 currently indicates about 75% remaining. If that is true, then you'd get about 8 hours out of AAAs, and probably double that out of the optional LiPo. It's too early to say if that's accurate or not, and I'll try and post back as I learn more.
I also got a chance to take some additional PPM / Response measurements of M12S and MT-4S, and here are the results (original results also shown again for completeness; new data in bold):
This data shows that the MT-4S is identical to the M12S in terms of latency. This is interesting, because the MT-4S was billed as being 'As fast as the M12', and the M12S as being '20% faster than the M12'. Perhaps there is some un-known latency in the processing before transmission, but I'd be surprised...
Also interesting is that the MT-44 is slower in FH3 Normal mode, not that this is particularly important; I'm not sure why you'd use that mode.
One other thing I noticed when playing with the MT-4S and M12S, was that the spring tension, for the steering in particular, was much lighter on the M12S and MT-44 than the MT-4S and MT-S. Of course this is adjustable on all of these radios, but it seems that if you attempt to make the MT-S and MT-4S as low tension as the M12S and MT-44, they won't center correctly; something is different about the action of the MT-44 and M12S, and in a good way.
Unfortunately I wasn't able to race on Friday, but I did get about 2 hours of solid practice in, which is probably longer run-time than if I'd been racing, so it's still an interesting touch point.
The battery (3 x 750mAh AAA Panasonic Eneloops) voltage dropped from 4.2v to 3.8v during the course of the run, but didn't go below that. 3.8v is actually still higher than the nominal 3 x 1.2v of 3 x NiMH, and if I remember correctly, the discharge curve of NiMH should be reasonably flat. The battery gauge on the MT-44 currently indicates about 75% remaining. If that is true, then you'd get about 8 hours out of AAAs, and probably double that out of the optional LiPo. It's too early to say if that's accurate or not, and I'll try and post back as I learn more.
I also got a chance to take some additional PPM / Response measurements of M12S and MT-4S, and here are the results (original results also shown again for completeness; new data in bold):
- Sanwa MX-V: 63Hz / 15.9ms
- Sanwa MT-4 (Normal Mode): 90Hz / 11.1ms
- Sanwa MT-4 (SHR Mode): 192Hz / 5.2ms
- Sanwa MT-4 (SSR Mode - Narrow Pulse): 191Hz / 5.2ms
- Sanwa MT-4S (FH4T Normal Mode): 93Hz / 10.8ms
- Sanwa MT-4S (FH4T SHR Mode): 383Hz / 2.6ms
- Sanwa MT-4S (FH4T SSR Mode - Narrow Pulse): 383Hz / 2.6ms
- Sanwa MT-4S (FH3 Normal Mode): 110Hz / 9.1ms
- Sanwa MT-4S (FH3 SHR Mode): 332Hz / 3.0ms
- Sanwa MT-S (FH4T Normal Mode): 95Hz / 10.5ms
- Sanwa MT-S (FH4T SHR Mode): 384Hz / 2.6ms
- Sanwa MT-S (FH4T SSR Mode - Narrow Pulse): 191Hz / 5.2ms
- Sanwa MT-S (FH3 Normal Mode): 83Hz / 12.0ms
- Sanwa MT-S (FH3 SHR Mode): 332Hz / 3.0ms
- Sanwa MT-44 (FH4T Normal Mode): 95Hz / 10.5ms
- Sanwa MT-44 (FH4T SHR Mode): 383Hz / 2.6ms
- Sanwa MT-44 (FH4T SSR Mode - Narrow Pulse): 383Hz / 2.6ms
- Sanwa MT-44 (FH3 Normal Mode): 83Hz / 12.0ms
- Sanwa MT-44 (FH3 SHR Mode): 332Hz / 3.0ms
- Sanwa M12S (FH4T Normal Mode): 95Hz / 10.5ms
- Sanwa M12S (FH4T SHR Mode): 383Hz / 2.6ms
- Sanwa M12S (FH4T SSR Mode - Narrow Pulse): 383Hz / 2.6ms
- Sanwa M12S (FH3 Normal Mode): 110Hz / 9.1ms
- Sanwa M12S (FH3 SHR Mode): 332Hz / 3.0ms
This data shows that the MT-4S is identical to the M12S in terms of latency. This is interesting, because the MT-4S was billed as being 'As fast as the M12', and the M12S as being '20% faster than the M12'. Perhaps there is some un-known latency in the processing before transmission, but I'd be surprised...
Also interesting is that the MT-44 is slower in FH3 Normal mode, not that this is particularly important; I'm not sure why you'd use that mode.
One other thing I noticed when playing with the MT-4S and M12S, was that the spring tension, for the steering in particular, was much lighter on the M12S and MT-44 than the MT-4S and MT-S. Of course this is adjustable on all of these radios, but it seems that if you attempt to make the MT-S and MT-4S as low tension as the M12S and MT-44, they won't center correctly; something is different about the action of the MT-44 and M12S, and in a good way.
05-27-2017, 04:08 AM
#397
Nezil - what programing box are you using to perform the latency test?
05-30-2017, 07:39 AM
#400
05-30-2017, 09:56 AM
#405
Tech Apprentice
iTrader: (2)
Sorry, I didn't check RCTech over the weekend, and just noticed this question.
Yes, I used a SkyRC progbox for my tests. This gives you a readout of the pulse rate, which when inverted (1 / Pulse Rate) gives you the duration between pulses. The way a servo works, is to read the width of the pulse, and use this to determine position. The faster the pulses come, the lower the response time.
What this testing is not able to do, is to account for any latency in the transmitter in converting the analog inputs from the wheel and trigger, into digital signals. This should be very very fast these days however, and I don't think this is likely to factor into the overall latency in any meaningful way.
I tested a Spectrum DX4C at my local track, and got a response time of 11.1ms. @Billdelong and @SBD also did some tests in the past of other radios, the results of these are:
All of this additional data is not mine, so I can't give full information on the testing done, but my understanding is that they used the same approach that I did, using the SkyRC Progbox.
Yes, I used a SkyRC progbox for my tests. This gives you a readout of the pulse rate, which when inverted (1 / Pulse Rate) gives you the duration between pulses. The way a servo works, is to read the width of the pulse, and use this to determine position. The faster the pulses come, the lower the response time.
What this testing is not able to do, is to account for any latency in the transmitter in converting the analog inputs from the wheel and trigger, into digital signals. This should be very very fast these days however, and I don't think this is likely to factor into the overall latency in any meaningful way.
I tested a Spectrum DX4C at my local track, and got a response time of 11.1ms. @Billdelong and @SBD also did some tests in the past of other radios, the results of these are:
- Graupner X-8N (24ms Mode): 441Hz / 2.3ms (Might be an error)
- Graupner X-8N (12ms Mode): 82Hz / 12.2ms
- Graupner X-8N (6ms Mode): 165Hz / 6.1ms
- Graupner X-8N (3ms Mode - Narrow Pulse): 331Hz / 3ms
- Graupner X-8N (1.5ms Mode - Narrow Pulse): 663ms / 1.5ms
- BER TRC1: 49Hz / 20.4ms
- AuStar AX5: 49Hz / 20.4ms
- Spectrum DX2E: 181Hz / 5.5ms
- Turnigy 3XS: 62Hz / 16.1ms
All of this additional data is not mine, so I can't give full information on the testing done, but my understanding is that they used the same approach that I did, using the SkyRC Progbox.