RE: xyz cdi
[quote]ORIGINAL: RC Extreme power I have been converting and selling gas engines for close to eight years and the method I posted is about as accurate as you can get, If dead center of the lose play with the piston on top of compression stroke is not top dead center then what is it. Milton Words removed by moderator [/quote] TDC is when the piston stops moving up, or the moment the dial gauge stops moving. During the rotation where the dial gauge does not move the crank has passed tdc and big/little end play is being taken up. The above can be demonstated with a simple cardboard cutout. Engines with lots of big/little end play will have a larger degree of rotation where the guage does not move. Dave
Posted on: 8/8/2009 5:23 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8999292

RE: xyz cdi
[quote]ORIGINAL: JIMARRINGTON I went back and reset the timing using the method you guys described.  I had it set around 15 degrees BTC when I started.  When I set it at 28 degrees BTC, it was right where I had started.  And at WOT it randomly missfire.  I moved it back to about 20 degrees and it smoothed out and ran normally.  Any explanations? Jim [/quote] Is it missing or detonating
Posted on: 8/8/2009 5:13 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8999286

RE: diy cdi
I will dedicate this post to the cdi here: http://www.modelbouw.gompy.net/newcdi/newcdi.htm With all respect to the designer I feel it necessary to outline some errors I found with this project. I have built and tested this cdi. Built as outlined it "will not work". I downloaded all related info for this maybe 8 weeks ago, since then at least one change has been made. The two biggest errors are the wiring connection for both the sensor and led strobe as shown on the component layout. With these wired as per the diagrams I received the cdi will not work in any mode, test or normal. Pictures below show sensor connections that have been corrected by designer in last month or so. + to - P to + - to P LEDs are polarised and must be orientated correctly. Have a look at both the pcb and component layout. Component layout shows to wire led incorrectly. It puts the kathode or - on the positive 5 volt rail. Corrections to parts list to follow. It appears the "last update" on this site is a calender and changes every day. So it might be that nothing on the page is actualy being updated as you would expect. Dave
Posted on: 8/7/2009 9:19 PM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8998657

RE: New CDI - opensource project JMJ and Bigboat
Just in case John was wondering, I thanked bigboat for posting the cdi in an email around the time I started building it. Have a nice day
Posted on: 8/6/2009 11:06 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8994292

RE: New CDI - opensource project JMJ and Bigboat
[quote]ORIGINAL: jpanhalt [quote]Original:boating around Unziping to folder and opening with programming software sounds easier and should work??? [/quote] Just how do you have any idea what is easier for me to do to get a quick look at a hex file? Did you know that I keep MPLab and other important... two of the hex digits and leave the rest untouched. [quote]Original:boating around edit: I hope
Posted on: 8/6/2009 11:04 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8994279

diy cdi
This thread is for all things related to diy cdi conversions. Circuits, ignition curves 2 and 4 stroke, pictures, links etc. In the not to distant future I will post some info on an online diy cdi I have just made. I believe it will be very helpful to those considering building it. I'm also working on a cdi unit with a mate. Early stages yet, will post something when/if its up and working. I will keep this first post updated with any and all important info. Such as links, circuits, errors and the like. A few pics of ryobi conversion. Stock, 6600rpm static with 16 x 10 prop. Dave
Posted on: 8/6/2009 11:03 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8994417

RE: diy cdi
Ignition curves. 2 vs 4 stroke. The most perplexing questionfor many people is why a 2 stroke has an ignition advance curve totally the reverse of a 4 stroke. A typical 4 stroke will start with about 10 degrees of advance at idle and finish with around 32 @ peak torque rpm, extending to perhaps 37 @ peak hp rpm. However the advance curve shown below is what will be found in many 2 stroke engines
Posted on: 8/6/2009 11:00 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8994689

RE: New CDI - opensource project JMJ and Bigboat
tm curve http://www.pvl-zuendungen.de/en/fb_tm.htm
Posted on: 8/6/2009 3:00 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8994148

RE: New CDI - opensource project JMJ and Bigboat
roughly drawn curves
Posted on: 8/6/2009 1:15 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8994043

RE: New CDI - opensource project JMJ and Bigboat
I have a number of books here on 2 stroke theory written by respected people in the know. I could go on and explain but suggest you use your favourite search engine and all your questions will be answered. In short a 2 stroke is very inefficient at low speed, but of course there is more to it. Edit: you will aslo find some 2 stroke curves if you look. I know what causes detonation, for the record I'm using highest octane available 98 and 30:1 oil.
Posted on: 8/6/2009 12:45 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8993952

RE: New CDI - opensource project JMJ and Bigboat
Finaly sorted out enough of the bugs to get a motor running. Got the help of someone more experienced in electronics. He checked my original work very closely. My work is good, I had done everything according to the instructions, which was my biggest problem. Call it what you want, but for those that have built projects like this I'm sure you will all appreciate the "help". Detonation. The advance curve for a 2 stroke is opposite to that of a 4 stroke. A 4 stroke will advance as rpm rise, a 2 stroke retards as rpm rise. The graph below shows a typical curve for both. At max rpm my Ryobi starts detonating at 22 degrees. If I ran the curves descibed here it would have blown up in minutes. Coil. Forget making an ignition coil. I couldn't find a pocket bike with cdi coil they all seem to be magneto ignition. The pitbikes and larger quads have cdi and use a coil identical to my XR600 coil. It is small and light and $15AUD, and works.
Posted on: 8/5/2009 9:26 PM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8993439

RE: New CDI - opensource project JMJ and Bigboat
LOL Another ERROR Hall effect in pins as marked on component layout are all wrong. Been down this road before, had I have known LOL Dave edit: I hope people have been reading what bigboat has been saying. I have asked several questions, some a number of times and he doesn't answer them. He says he can't see anything wrong, I am still finding errors. Well under the circumstances, I am sorry but I will not take all the blame.
Posted on: 7/1/2009 11:11 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8897599

RE: New CDI - opensource project JMJ and Bigboat
Well I'm still sitting here wondering which parts are correct. What polarity of led strobe pins is correct? What other errors I may have missed. I have made the thing as best I can according to your instructions. Time to shelve it and move on. Have a nice day. Dave
Posted on: 6/30/2009 11:42 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8894583

RE: New CDI - opensource project JMJ and Bigboat
I post errors when I see them, makes it easier for others. People on this forum not very helpful. Dave
Posted on: 6/30/2009 11:09 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8894501

RE: New CDI - opensource project JMJ and Bigboat
Why does John show different hex???? Dave
Posted on: 6/30/2009 11:07 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8894496

RE: New CDI - opensource project JMJ and Bigboat
I see video of model, no proof of working cdi?????????? Dave
Posted on: 6/30/2009 11:05 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8894493

RE: New CDI - opensource project JMJ and Bigboat
Unziping to folder and opening with programming software sounds easier and should work??? First time I programmed pic about 7 years ago I had an issue. I was viewing japanese web page using bablefish, when the hex file was downloading the file would be corrupted. You had to enter page without translater and download for it to work. dave
Posted on: 6/30/2009 8:12 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8894082

RE: New CDI - opensource project JMJ and Bigboat
I haven't read that anyone else has noticed the errors, particularly the strobe polarity. makes me wonder how many people have successfuly "completed" this project. I wonder if old cdi might be a better bet?? Dave
Posted on: 6/30/2009 7:01 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8893982

RE: New CDI - opensource project JMJ and Bigboat
C5 and C7 do need to be on list as schematic shows polarised and parts list says non polarised???? First line of your hex differs slightly to mine, why??? Hope you have written it correctly. I have connected led strobe as I see it should be. I now have some action. Led (quite dim) flashes slowly with no jumpers, and I get a steady light with pin 8 jumped. Nothing with pin 9 jumped. But as I said, its not bright. No spark???? Dave
Posted on: 6/30/2009 6:57 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8893977

RE: New CDI - opensource project JMJ and Bigboat
Would I be correct in saying the led strobe polarities as marked on component layout are wrong. There are 3 pins, center pin marked as + goes to transistor. Two outside pins marked as - are on 5volt rail???? Led gets power from battery and transistor grounds it. Dave I have a cro
Posted on: 6/30/2009 5:20 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8893885

RE: New CDI - opensource project JMJ and Bigboat
Just going in circles now. Still nothing. Picprog4u sayes its programming with no errors. Pic is getting 5V. Programmed in and out of circuit. I have programmed many pics of various type and some avr, this is not new to me. First line of program starts as follows: 0000 298B 3FFF 3FFF 3FFF 30EE 1303......does this look correct? ?????????? Can't see there is anything else I can do. Dave
Posted on: 6/30/2009 4:52 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8893868

RE: New CDI - opensource project JMJ and Bigboat
No go. I've double, triple checked my work, can't see anything wrong. Tried the jumpers in all possible configerations. I sometimes get a nice spark when power is applied to circuit, but thats it. I suspect the schematic is correct but to be sure see the following mistakes, which is correct? ............. Parts list.................... shcematic C5..........0.1uF..........................100n C2..........100uF.........................47uF C6..........100n...........................470n C4..........470n...........................100n C7.........100n............................0.1uF R3..........1K..............................150 ohm Should the LED strobe light up in test mode? It doesn't. Thanks Dave
Posted on: 6/29/2009 9:03 PM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8892486

RE: New CDI - opensource project JMJ and Bigboat
A couple more questions concerning making an ignition coil and I should be done. From what I read a ferrite core will work? Can be bought at Dick Smiths and can be found in am radios. Supply is 6 volt, what voltage does transformer see? The diode will drop it 0.6 volt I think. What voltage should ignition coil see? 200 volt? What voltage should spark plug see? 20,000 volt? If I can get an answer to these questions I can make better coil. I will be able to better determine winding ratios. I will document the making of coil as I go and post results. Here is link to making coil, may help. http://members.misty.com/don/trigcoil.html
Posted on: 6/28/2009 5:03 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8887484

RE: New CDI - opensource project JMJ and Bigboat
Thanks I guess for a given amount of turns thinner wire has higher resistance and thinner wire can handle less current. Maintain turn ratio. Dave
Posted on: 6/26/2009 10:12 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8882573

RE: New CDI - opensource project JMJ and Bigboat
Hi Futterama, No I didn't remove walls. Not sure it will make enough difference, I think I wouldn't get much more than 200 on. Dave
Posted on: 6/26/2009 6:55 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8882227

RE: New CDI - opensource project JMJ and Bigboat
Re winding transformer. I bought a ccfl inverter. They did not have 100mm so got the 300mm inverter. Went to wind 400t of 0.25mm wire on and there is no way it was ever going to fit. Having read in post 42 that 0.15mm wire "have to work" I used that and it just fit on former. Now I am about to assemble board I read in post 105 that " 0.13 wire may not get power to load cap". Not much difference between 0.13 and 0.15mm? Bit worried now. Sould I have used 0.25 and reduced the number of turns? If so to what? Also, is there better instructions on making a coil, eg wire size number of turns etc. TIA Dave
Posted on: 6/26/2009 5:09 AM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8882171

RE: New CDI - opensource project JMJ and Bigboat
No one has the time to send pcb layout???????????? Must say, not a very helpful bunch of people on these forums, but thats typical of people today. With a little help, not from here, I have managed to do pcb. Have a nice day. Dave edit: forgot to mention error in parts list supplied for this project. C5 and C7 are wrong.
Posted on: 6/23/2009 8:38 PM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8875349

RE: New CDI - opensource project JMJ and Bigboat
I give up
Posted on: 6/22/2009 7:44 PM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8872433

RE: New CDI - opensource project JMJ and Bigboat
I will try and make myself clearer. I used layout 1:1,5 You will see if you print this out it is very pale and has white streaks. No good for toner transfer method (any method for that matter) I have downloaded Layo1 program but can't get pcb layout up in program. Not sure that if I do it will be any better. Dave edit: to date I have used ms word to resize and print supplied pcb layouts
Posted on: 6/22/2009 7:31 PM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8872378

RE: New CDI - opensource project JMJ and Bigboat
Not happening. Is there someone out there who understands my problem and who can send me a copy of pcb layout.
Posted on: 6/22/2009 7:00 PM by Author "boating around" in the forum "Engine Conversions"
http://www.rcuniverse.com/forum/fb.asp?m=8872310