|
Post by oldtimeracer on Nov 6, 2008 16:02:04 GMT
Now we are mostly running brushless systems I wondered what people use to make sure they dont blow them up during the inevitable wet Sunday's we are going to have over the winter.
I have already suffered with speedo problems on a wet day and cannot afford the expense of replacing.
So what is the best way to waterproof the electrics or is there a waterproof speedo we should all be getting?
|
|
|
Post by lesbaldry on Nov 6, 2008 16:38:39 GMT
So what is the best way to waterproof the electrics or is there a waterproof speedo we should all be getting? I haven't seen or heard of any fully water proof speedos yet Ian? no doubt they are or will be out there soon,Todays BL speedos are a bit like going full circle back to the house brick sized first Fet speedos that used to pop if sneezed on "remember those little bute's?" If its "that wet" I doubt if any of us would run anyway,we never used too?..at the moment when its moist I just poke Blue tack in the appropriate holes with a layer of Gaffer tape if ness and keep fingers crossed! so far so good,it was pretty damp last Sunday.
|
|
|
Post by MonkeyNuts on Nov 6, 2008 17:00:12 GMT
I heard a couple of months back that Mtroniks are bringing a Brushless speedo out, dont know wether its waterproof, but it more than likely will be as its Mtroniks.
Liam
|
|
|
Post by oldtimeracer on Nov 6, 2008 17:09:18 GMT
They did or they have. They are showing in this months Racer mag. However, they are sensorless only. Not sure how that works to be honest or whether it's a good thing.
|
|
|
Post by yellowshark on Nov 7, 2008 7:27:26 GMT
I heard a couple of months back that Mtroniks are bringing a Brushless speedo out, dont know wether its waterproof, but it more than likely will be as its Mtroniks. Liam Yes they are. I thought we would be be running it at the Cotswolds but ultimately they were not ready. It is sensorless; if I have that the right way round, ie no cable, controlled by software.
|
|
|
Post by lesbaldry on Nov 7, 2008 7:57:39 GMT
I heard a couple of months back that Mtroniks are bringing a Brushless speedo out, dont know wether its waterproof, but it more than likely will be as its Mtroniks. Liam Yes they are. I thought we would be be running it at the Cotswolds but ultimately they were not ready. It is sensorless; if I have that the right way round, ie no cable, controlled by software. Now here's a topic worth looking into?.....What are the advantages/disadvantages for sensored/sensorless is in the wet ? As for performance from what I have heard is that sensored are smoother to drive and sesorless give better top end??
|
|
|
Post by Martin S on Nov 7, 2008 8:44:35 GMT
Yes they are. I thought we would be be running it at the Cotswolds but ultimately they were not ready. It is sensorless; if I have that the right way round, ie no cable, controlled by software. Now here's a topic worth looking into?.....What are the advantages/disadvantages for sensored/sensorless is in the wet ? As for performance from what I have heard is that sensored are smoother to drive and sesorless give better top end?? OK all you electronic wizzards. How does a sensorless set up not clogg on start up. Even those motors that say they can be run without the lead seam to clogg up off the line. Or have they got round it somehow.
|
|
|
Post by oldtimeracer on Nov 7, 2008 8:50:53 GMT
From what I have been reading the electronics in the latest versions of the sensor-less speedos is far superior to that of a few years ago. They used to suffer from cogging particularly off the line but were OK when up to speed. I am told this is no longer the case. Don't ask me how it all works but allegedly it does now. Might be worth a back to back test to see the difference.
Wonder if I can blag a set up from a manufacturer to try?
|
|
|
Post by Simon Crabb on Nov 7, 2008 9:05:14 GMT
I keep wondering where MRT are in the brushless world. We all loved their brushed stuff, but I guess the investment needed is pretty high and difficult for the small manufacturer. Hence they and others are late to the party.
And, what happened to the vogue of waterproof receivers? It's all gone backwards to go forwards!
For me though, i'm not interested in getting the car wet, rebuilds are tedious!
|
|
|
Post by oldtimeracer on Nov 7, 2008 9:14:34 GMT
Yes we know what a wimp you are Simon ;D Seriously though. While many of us will not race if it is "wet" many of us would want to race if it was just damp. Trouble with our track is that when it is damp, the grass is always wet! OK so if you do not go off it may be OK but for some of us that part is difficult Now I may be being stupid here as I really do not know this. Can you run any motor with a sensorless speedo or do you need a special one.
|
|
|
Post by Martin Young on Nov 7, 2008 9:22:41 GMT
As far as a conversation with MRT a few months ago they were developing a brushless speedo. How long that’s is going to take who knows! With regards to sensorless as stated above they are ‘apparently’ now more reliable and don’t suffer from cogging as much as the first generation. The only question I have is with high turn motors like the 17.5 and the 13.5, which even some sensored speedos struggle with how well will the sensorless work? The GTB I use at the moment has ‘cogged’ several times when the punch on the speedo is reduced, so will the sensorless speedo’s suffer from a similar fate on high turn motors??
|
|
|
Post by Simon Crabb on Nov 7, 2008 9:24:19 GMT
Yes damp is okay! Just makes you try real hard to keep it on the track!
I believe any motor can run sensorless.
|
|
|
Post by Martin Young on Nov 7, 2008 9:28:14 GMT
Now I may be being stupid here as I really do not know this. Can you run any motor with a sensorless speedo or do you need a special one. I would love to know the answer to this too. Some motors state both sensored and sensorless but others state they are for use on only one type. Why would a sensored motor not work if used on a sensorless speedo??? Anyone know
|
|
|
Post by lesbaldry on Nov 7, 2008 9:28:27 GMT
Now I may be being stupid here as I really do not know this. Can you run any motor with a sensorless speedo or do you need a special one. ...Your not the only one..no Idear Ian,but I think some speedos cater for both! As for the "off roading " wet grass,I've had some silly off's into the wet stuff but as I said ,so far so good ,..gaffer tape shield with Blue Tack
|
|
|
Post by TryHard on Nov 7, 2008 9:59:31 GMT
Obviously, a sensorless only motor does away with the sensor board and connections... so can only be used on a sensorless speedo. However, the reason some sensored work and some don't is simple to do with quality of windings etc. A friend of mine was using a sensorless Tekin R1 with two types of modified motor. One was a GM Evo, the other an Orion Vortex. The orion would cog like anything, the GM was fine....
IMO, sensorless still isn't suited to our racing application... simply as starting from a standstill is a critical part of our racing. With higher wind motors, cogging becomes a much bigger issue as well. If sensorless was the future, why would companies like Tekin etc all be developing sensored versions of their speedo's for use with higher wind motors? For a brushless motor, without the speedo instantaniouls knowning where the rotor is (i.e. by a sensor), it will always need to test the rotor position, hence the cogging. It's something you can reduce, but never escape from completely with a sensorless motor.
That's not to say sensorless doesn't have an application... I think it's spot on for use further up the rev range, so the SpeedPassion GT really appeals (use both types throughout the rev range, sensored down low, sensorless up top).
Regards Ed
|
|
|
Post by mattsedgley on Nov 7, 2008 11:03:14 GMT
**instant expert time coming up**
From what i understand (waits for a dig about only been racing 5 minutes)
Sensorless systems work by powering two coils at the same time to move the rotor into a known position (like a stepper motor) once the rotor is in the known position the coils can then be energised in sequence to allow the motor to move, Instead of having a sensor lead - the sensorless system works by measuring back EMF (current travelling in the wrong direction - towards the speedo from the motor) it all depends on what speed the motor electronics are running at, for example - an acorn PC compared to a shiny new Mac trying to search the internet.. one will do it quicker and fall over less...
cogging could be a result of the speedo not moving the rotor to the correct position.. or a delayed start to the sequence (which could be caused by the motor not creating enough EMF or other electrical interference confusing the signals returned to the speedo)
just my thoughts... dont shoot me down - please..
|
|
|
Post by oldtimeracer on Nov 7, 2008 13:25:53 GMT
"Sensorless has, in the past been accused of not being as smooth or not as responsive to throttle commands, this is now an opinion of the past! The Mtroniks Genesis range of Brushless Speed Controls has a perfected and proven start up and smooth throttle control, which is now no different to that which you would expect form a Brushed Speed Control.
With the Mtroniks Genesis Brushless Speed Controls you get the feel of a Brushed Speed Control with all the advantages of Sensorless Brushless Control! Greater run times, greater efficiency, very little maintenance and since they are sensorless they will replace an existing Brushed Speed Control install one for one without the need for all the sensor wires!!"
Taken from the MTroniks web site. Do we believe it? I guess if they say so then it must be true.
|
|
|
Post by lesbaldry on Nov 7, 2008 13:58:22 GMT
A little while ago my car suffered what I can only describe as a stutter,the same symptoms to cogging but normally half way round a bend on medium throttle,not from a standing start where would imagine gogging to show.
In my ignorance to what I thought was cogging I changed Motor "dirty/faulty sensors?" then speedo "faulty?" even the RX "interferance?"...wrong!! it ended up been a servo.
Worth remembering.
|
|
|
Post by TryHard on Nov 7, 2008 13:59:38 GMT
" Sensorless has, in the past been accused of not being as smooth or not as responsive to throttle commands, this is now an opinion of the past! The Mtroniks Genesis range of Brushless Speed Controls has a perfected and proven start up and smooth throttle control, which is now no different to that which you would expect form a Brushed Speed Control.
With the Mtroniks Genesis Brushless Speed Controls you get the feel of a Brushed Speed Control with all the advantages of Sensorless Brushless Control! Greater run times, greater efficiency, very little maintenance and since they are sensorless they will replace an existing Brushed Speed Control install one for one without the need for all the sensor wires!!" Taken from the MTroniks web site. Do we believe it? I guess if they say so then it must be true. Pinch of salt Ian At the end of the day, they are not going to say it's poo are they, good lesson in marketing speak, particularly this bit... and since they are sensorless they will replace an existing Brushed Speed Control install one for one without the need for all the sensor wires!!Completely forgetting to mention the third motor wire that is required, and a sensor wire isn't exactly huge... Cynical, moi... never ;D
|
|
|
Post by yellowshark on Nov 7, 2008 14:01:37 GMT
To avoid any confusion, the Mtroniks Genisis is not the ESC we are all waiting for. It is an older model and you will see it is somewhat on the large side.
|
|
|
Post by oldtimeracer on Nov 7, 2008 14:19:07 GMT
OK I have spoken at some length to M Troniks. Yes the speedos on their website are the old ones. New ones will be listed shortly.
They say the lower the wind the better the sensorless speed controls are so a hot 3.5 will be fine. They have not tested any of the new versions of their speed controls on brushless motors with winds as high as 17.5 so I am going to send them my spare motor for them to test. If succesful they will send me a speedo to try under race conditions.
Could be very interesting and if it works would be a good way to go during the winter.
Watch this space.
|
|
|
Post by Simon Crabb on Nov 7, 2008 14:38:32 GMT
The sensor leads do seem to be rather fragile, always the wrong length, and often a source of issues, if they disappear (and work as well without) , I won't miss them!
But, do I want 'the feel of brushed'? I rather prefer the feel of a brushless setup! Perhaps I've not experienced the joy of high-end brushed technology?
I'm alarmed that they've not tested a whole range of winds Ian! I would have expected that to be part of their R&D!
|
|
|
Post by oldtimeracer on Nov 7, 2008 15:25:40 GMT
I was also more than little surprised Simon. I would have thought you tested everything. Mind you they did sound surprised we were running anything that low.
Is this just another case of manufacturers working to fulfill the high end modified racers and not worried about the much larger club level stock market I wonder.
Seems a bit short sighted but then as we know we (SHMCC) seem to be in a minority when running 17.5 in the UK.
Mtroniks cannot be worried about the USA market. Then I suppose the USA market is pretty poor as regards sales of waterproof speedos as they do not race when its wet. So I have heard anyway.
|
|
|
Post by Simon Crabb on Nov 7, 2008 16:17:25 GMT
It's strange, all the cars and equipment are essentially built for team drivers to win Worlds / Euros / Nationals / Regionals. Then it filters down to club level via results, word of mouth and marketing.
I suppose it's an unusual circumstance that something that works with mod might not work with stock!
Regards 17.5 use, I noticed some talk on RaceChat of WLRC considering them too.
|
|
|
Post by oldtimeracer on Nov 7, 2008 16:35:26 GMT
Oh well that is good news. The more people who use them the better. Have written an article for Racer mag extolling the virtues of the class and how well it has been taken up at Bashley. Might create a bit more interest.
On the brushless motor/sensor less speedo thing. I have e mailed all the brushless motor manufacturers I can think of to ask if all their brushless motors are suitable and will perform the same if used with sensor-less speedos. Be interesting (at least to me) to see what their response will be.
|
|
|
Post by oldtimeracer on Nov 7, 2008 17:08:17 GMT
Well I have had a reply from LRP. They say all their motors will work OK with sensor-less speed controls.
So now you know.
|
|
|
Post by oldtimeracer on Nov 8, 2008 9:15:48 GMT
Lovely! This is the response from Novak.
"This is more of a question for the Sensorless ESC manufacture then us. The motor doesn’t determine if the ESC will work or not, the ESC’s available motor types does. I’m sure they’ll be able to tell you right away if their ESC will run a Novak Motor"
Draw your own conclusions from that.
|
|
|
Post by yellowshark on Nov 8, 2008 10:14:24 GMT
I guess that makes sense Ian. Having read up on this a few months back the sensorless esc works on the back current (forgotten the technical term ) in the powerlines. I guess all motor configurations create this current - whether they are variable or not I know not.
|
|
|
Post by mattsedgley on Nov 8, 2008 11:47:28 GMT
Back EMF pete - electro magnetic force "Back-EMF is the electric potential difference that opposes the current that induces it. " www.physics247.com/physics-help/back-emf.shtmlstudents find the best websites at times edit - motive - magnetic - watching murder she wrote! it's all about the motive!
|
|
|
Post by keitheroonie on Nov 8, 2008 11:57:37 GMT
I guess that makes sense Ian. Having read up on this a few months back the sensorless esc works on the back current (forgotten the technical term ) in the powerlines. I guess all motor configurations create this current - whether they are variable or not I know not. Yes indeed Pete they are variable, it depends on how fast the motor is spinning, basicaly whenever you pass a magnet through or past a coil, a current is produced. the sensorless brushless ESC will power two coils simultainiously (star winding) which moves the rotor past the unpowered coil, this send a voltage back to the ESC from the unpowered coil which lets it know which position the rotor is in.
|
|