Mike:
yes I think you are probably right about the second magnet being used for detecting revs also probably to detect direction as well.

Extra_300_S:
I am going to modify mine for the time being because I think it will be some time before MVVS send out the replacements etc. [&o]

what I think we need to do is make a spanner of sorts to hold the drive washer (prop driver) which will need to be a piece of Ali/steel bar about 2 inch wide with a 1/2 inch slot cut in the end to fit around the shaft then say 3 or 4 holes to align up with the existing holes on drive washer. This will enable you to hold it tight and stop it turning whilst you have two 10mm nuts locked together on the shaft (don't forget they are 10mm fine thread), use another spanner to undo the shaft, but as mentioned by someone else here it will be tight and may need a little heat to release the threadlok if there is any. I am also assuming the shaft is on a normal right hand thread. Using heat on the shaft like this means you will have to be extremely careful not to over heat otherwise damage will occur to the bearing seal etc !!

Any better ideas welcome

regards Ian

OK you need to either to get a hub/sprocket/pully puller 2/3or 4 arm and use that, or ckeck to see if your prop bolt holes go all the way through the hub if they do get hold of at least two prefferably four bolts that are threaded full length and will go all the way through the hub and gently tighten them alternatly against the front bearing housing, if you can put something inbetween the bolt and the housing to stop any peening over of the bearing seating. Still do not know why you need to get it of though.

Mike

mike: it needs to come of so the second magnet can be repositioned to segments away from the first to give the 120 degree timing instead of 180 degree which is cause of this problem.

the drive washer will need heating to soften the glue which holds the magnet and then a new hole drilled in the correct place

Ian

mike have a look at the image I posted on the "new type ign modual" thread

this may make it a bit clearer

Ian

Concerning the spanner, we don't have to make one. I used the thinner prop I had, installed with six short (but long enough) bolts, tightened lightly. Then installed 2 M10X1 nuts locked together. Using a 17mm wrench on the inside nut and holding the prop (like a spanner), I've been able to unscrew the prop shaft which is normal RH threads. It was moderately tight but no trace of threadlocker. I will use a puller to remove the drive hub, the prop bolt holes don't go all the way through the hub. One of the six bolts is broken, I have to repair or replace the hub.

JF

Yup I now know why you need to get it off, but I am going to wait for the manufacturer to get it right or inform me of what is wrong, I am still not convinced that moving the magnet to 120deg will cure a non starting problem, most engines will run with the timming out they just run badly, until someone who knows tells me it needs to be moved mine is staying where it is. Think of your warranty.

Mike

mike

I knows what you mean about the warranty, I am waiting to see if extra 300_s get his running, I have been informed by Eftychios the distributor in cyprus that he has already done this Mod for one of his customers, who found my original post on this subject

Ian

Thats odd my bolt holes do go all the way through its the unthreded part of the bolt that stops the bolt from reaching the bearing housing, find some longer threded bolts if yours is the same.

EDIT
Just had a look at mine the holes go all the way through but I am not sure about the thread so it may be a no brainer.
Mike

Just a thought applying a big hot soldering iron to the magnet may get it off without dismantaling the prop driver.

Mike

I bet you we are all waiting for someone else to do this first.

Mike

Mike:

Just got my off - piece of cake, Made a spanner type bar from 3mm ali, 50mm wide with 11mm slot to clear prop shaft and drilled 4 holes to secure to drive washer with 16mm long cap hd screws, un-did shaft then carried undo-ing until drive washer poped of easy.

Just deciding whether to go ahead and move the magnet - large soldering might be a good Idea, should not need to much heat because the magnets are only about 3mm deep/long

mike

Eftychios (cyprusjets) the distributor in cyprus says he has

I think I will have a go cause I think we will have to wait quit a while before we get any answers from MVVS.

Somthing else that has just occured to me _ I wonder if the magnets have been put in with correct polarity ie north/south poles ? I know mine will only spark on one magnet at TDC Eftychios said they should be same way round

Going to check this now

Ian

Ian

Are you saying the prop driver is threaded to the shaft.

Mike

Mike:
No its on a taper with key, to pull it off the shaft has a ridge on it which when you carry on undoing the shaft will push against the underside of the make shift spanner which acts like a puller

Ian

Ian

What a neat solution good man, are you going to move the magnet, from what I gather from Eftychios mail the magnets should be on either side of the logo, is that how you see it or am I barking up the wrong tree.

Mike

just checked polarity of magnets they are at the moment opposite poles - so we need to confirm what cyprusjets says, he says they both need to be the same way but should they be both with north pole facing out or the south facing out, it is possible the Hall effect tranistor/sensor may be bi-polar ?

mike

I understood from cyprusjets that the one next to the logo which is actually @ TDC and already makes the plug spark stays where it is and the other one needs to be moved to 2 segments in front of the first one 120 deg advanced but I am not 100% at the moment - looking into this now

Ian

Ian

Giving that some thought, would the ignition know what magnet to fire on if they were both the same pole? If they were the same you could get 240deg timming, so it may be that the ingnition module requires a north south signal to operate in the correct sequence/timming and to differentiate direction and revs, I understand that this new module will stop the motor if it starts up backwards, the only way it could know is if it gets the signal in reverse. Prepared to be shot down in flames I am typing this as it occures to me.

Mike

mike

what you say does make sense

Iam wondering why mine fires at TDC because normally the timing is retarded to make it easer to start but not sure if only done by software in ECU or wether its the magnet positions or wether it see a north pole first then a south and decides where the piston is, maybe like you say the magnets do need to go either side of the logo and when first flicked ignores the first and fire on the second untill running which to me means the first magnet at TDC at the moment could have be wrong polarisation as well ?????

Ian

Ian

Oh isn't this fun, have you noticed how quite Pre has been on this, I don't think he knows either. Perhaps an e-mail to Cyprus may sort it out. I think we may wait a long time for MVVS to respond.

BTW what were you going to put the Pro in, I bought mine for a QQ 85" Yak but had second thoughts about the amount of power (too much), I am waiting for the 45 to arrive at JE and use that instead, putting ISO mounts on as well as I do not like excesive noise.

Mike

mike

just had an idea[sm=idea.gif]

what I could do is drill new holes on every segment and try all possibilities ie position/polarity at the field (mine is already installed in model not easy to run in the street to many Kids around)

Ian

mike

YES I did notice, I have even put a query on his own forum but have not seen any answer yet.

Mine is in an old 90 inch Diabolo I built from a Pilot kit about 17 yrs ago, upto now I was using a OS BGX1 which was good for general aero's and does fly well, did weigh about 17lbs now about 1 1/2 lbs more but with the reports have seen etc I should get something like 2.25:1 power to weight ratio, maybe over the top but I want to start doing good 3D with this to be different and make my local club member look gobsmacked smoke as well in future[8D]

But will have to wait and see, so fustrating I ordered this engine quite a few weeks ago and now I can't wait

Ian

Ian

The Yak with the 45 in should come out to just over 15lb, Angus Balfor is using the 58Pro in one and his comes in at 16lb 7oz and said it is a demon, mind you I am not in the same class as a member of the British F3A team. I have had the 45 on back order for over a month now just as well I went fishing to fill in the time.

Her in doors who must be obeyed has indicated its time to put my toys away, signing off will check again tomorrow morning speak to you then.

Mike

Mike
check with supplier again if on back order because I got mine 2 weeks ago which was back ordered and JE had just got a big order delevered then did you order yours from JE ?

I don't have the wife problem I divorced mine years ago !!!!

Ian

Eftychios

Can you confirm new position of each magnet in relation to the "Pro Sport" logo on the drive washer for 120 degrees.

Is one fitted either side of the logo 120 deg apart or Is both fitted before as shown on the picture I attached to a message in the "New type Ign Modual" thread Post #9

Also are they definetly both polarised same way ?