RE: [DOG mailing list] Magneto removal.
Dear, Rob, Ian, Ian and Nigel Thank you for a very precise and comprehensive description. In fact, it will be a big challenge for us ( like many other things about flying motor gliders ) If you were ever in Poland, come and visit us, we will make a barbecue, fly and talk about magnetos :-) Tomasz
RE: [DOG mailing list] Magneto removal.
Hi All. Attached will be of interest as removing the mag in a H36 is well challenging. This was available in the archives but I cant find them anymore “comment Pete”. It covers those pesky challenges of an H36. Supplement Ian’s abbreviated version with it and you should find it straight forward. Cheers. Nige. From: dog@lists.riverland.net.au On Behalf Of Ian WIlliams Sent: Tuesday, May 30, 2023 2:54 PM To: dog@lists.riverland.net.au Subject: RE: [DOG mailing list] Magneto removal. Hi TMG team, Rob I hope u don’t mind me responding as well. Here in NZ we have to have the mag bench checked every 2 years and I look after 2 coming up 3 Dimona’s and 2 Grob 109’s so do this job with monotonous regularity. My procedure is as follows. * Disconnect battery * Remove the right hand Carb (from the front) and disconnect the choke and throttle rods. * Disconnect and remove the starter and remove spark plugs * Turn the engine so cyl *1 (The front right hand side one) is top dead centre on its compression stroke (Finger over the spark plug hole) * Note the little mark on the prop flange … it is set to 25 degrees so wont line up with the case centre seam at TDC .. it is used for retiming the mag * Use a long allan key and undo the 2 clamps attaching the Mag … the Alternator bracket and probably the throttle bracket are also attached so note how they are connected. I keep the bottom alternator bolt tight so it doesn’t move slackening off the belt. * Pull out the mag and remove the rear cap with the 4 HT leads (3 screws) * Get the Mag serviced Back on * The Dimona Mag is Right hand. So get a pin (an unused pop rivet works well) Look at the back of the mag and u will see 2 holes. Use the one marked RH Put the pop rivet into it and slowly turn the input until the rivet shaft slips right in. The mag is direct drive but has a 2:1 reduction inside and the pin / hole is in the smaller gear so u may have to turn it twice to make the pin go fully in. * Now the tricky bit. I use a length of masking tape crossed over to secure the impulse in a fixed position but in such a way that once the flex coupling is almost in place the masking tape can be pulled out. THEN REMOVE THE POP RIVETthen reinstall the rear cap and the 3 screws .. note there is only one way it can go on. Taking care not to dislodge the masking tape. * Now Double check Cyl*1 is at TDC. Offer up the mag and the gasket as Rob has described. Be real careful here. You can see the coupling through the Alternator belt slot. With a torch. Once it looks as if it will slip in OK, remove the masking tape and reinstall the 2 mounting clamps but don’t tighten just yet. * Make up a small “buzzer”. I use a real cheap electric ceramic buzzer (about the size of your finger nail and a 1.5 volt AA battery) Write it up and use 2 flying leads with clips at the end. Check that when you join the clips together the buzzer makes a noise. Connect one clip to the “P” lead on the mag and the other to ground Now rotate the prop around the TDC point. You should hear a change of tone on the buzzer when the Mag points change state. It is not much of a tone change but is clearly heard * Now identify the mark on the prop flange and rotate the prop around it listening for the change of buzzer tone. Adjust the mag position so when rotating the prop in reverse (ie taking up any slack in the drive) the change of tone happens exactly when the flange mark is lined up with the split in the case halves. * Once you are happy tighten the 2 mag retaining clamp / bolts * Then slowly rotate the prop through all compressions and note the spark should correspond with that cylinder on its compression stroke The firing order is 1 3 2 4 ie 2 bangs on one side and 2 on the other. * Because of the impulse of course the firing spark is quite retarded when turning the prop manually and is roughly at TDC. This is a good way of confirming u have it correct. * Then put the leads back on the mag, reinstall the starter and Carb. And of course the plugs and battery * All should then make the usual noise . I hope this is of some help Best regards Ian Williams ZK-GCB PS… Is anybody else having big issues with Hoffmann propellors ?? From: dog@lists.riverland.net.au <mailto:dog@lists.riverland.net.au> mailto:dog@lists.riverland.net.au> > On Behalf Of Rob Thompson Sent: Tuesday, May 30, 2023 9:38 AM To: dog@lists.riverland.net.au <mailto:dog@lists.riverland.net.au> Subject: Re: [DOG mailing list] Magneto removal. 1 Line up the engine at the timing mark firing on #1 cylinder. 2 Remove the engine control rods and starter motor so you have room to get the magneto out and back in again. 3 Take the cap and harness off using a right angle screw driver. I replaced the slot hea
Re: [DOG mailing list] Magneto removal.
I recommend printing this out link with the aircraft's papetwork https://www.kitplanes.com/magneto-timing/ Ian s is very good I recently saw aero VW (actually RAAus) with backup electronic ignition the little tit on top of car plug unscrewed itself and lead was hanging down. This guy does a lot of flying. So do up tit real tight. Ian McPhee 0428847642 On Tue, 30 May 2023, 3:57 pm Rob Thompson, wrote: > Good work Ian Great explanation! > regards > Rob > > Rob Thompson > 0429 493 828 > > > > On Tue, May 30, 2023 at 3:24 PM Ian WIlliams wrote: > >> Hi TMG team, >> >> Rob I hope u don’t mind me responding as well. Here in NZ we have to have >> the mag bench checked every 2 years and I look after 2 coming up 3 Dimona’s >> and 2 Grob 109’s so do this job with monotonous regularity. >> >> My procedure is as follows. >> >>- Disconnect battery >>- Remove the right hand Carb (from the front) and disconnect the >>choke and throttle rods. >>- Disconnect and remove the starter and remove spark plugs >>- Turn the engine so cyl *1 (The front right hand side one) is top >>dead centre on its compression stroke (Finger over the spark plug hole) >>- Note the little mark on the prop flange … it is set to 25 degrees >>so wont line up with the case centre seam at TDC .. it is used for >> retiming >>the mag >>- Use a long allan key and undo the 2 clamps attaching the Mag … the >>Alternator bracket and probably the throttle bracket are also attached so >>note how they are connected. I keep the bottom alternator bolt tight so >> it >>doesn’t move slackening off the belt. >>- Pull out the mag and remove the rear cap with the 4 HT leads (3 >>screws) >>- Get the Mag serviced >> >> Back on >> >>- The Dimona Mag is Right hand. So get a pin (an unused pop rivet >>works well) Look at the back of the mag and u will see 2 holes. Use the >>one marked RH Put the pop rivet into it and slowly turn the input until >>the rivet shaft slips right in. The mag is direct drive but has a 2:1 >>reduction inside and the pin / hole is in the smaller gear so u may have >> to >>turn it twice to make the pin go fully in. >>- Now the tricky bit. I use a length of masking tape crossed over to >>secure the impulse in a fixed position but in such a way that once the >> flex >>coupling is almost in place the masking tape can be pulled out. THEN >>REMOVE THE POP RIVETthen reinstall the rear cap and the 3 screws >>.. note there is only one way it can go on. Taking care not to dislodge >>the masking tape. >>- Now Double check Cyl*1 is at TDC. Offer up the mag and the gasket >>as Rob has described. Be real careful here. You can see the coupling >>through the Alternator belt slot. With a torch. Once it looks as if it >> will >>slip in OK, remove the masking tape and reinstall the 2 mounting clamps >> but >>don’t tighten just yet. >>- Make up a small “buzzer”. I use a real cheap electric ceramic >>buzzer (about the size of your finger nail and a 1.5 volt AA battery) >>Write it up and use 2 flying leads with clips at the end. Check that >> when >>you join the clips together the buzzer makes a noise. Connect one clip to >>the “P” lead on the mag and the other to ground Now rotate the prop around >>the TDC point. You should hear a change of tone on the buzzer when the Mag >>points change state. It is not much of a tone change but is clearly heard >>- Now identify the mark on the prop flange and rotate the prop around >>it listening for the change of buzzer tone. Adjust the mag position so >>when rotating the prop in reverse (ie taking up any slack in the drive) >> the >>change of tone happens exactly when the flange mark is lined up with the >>split in the case halves. >>- Once you are happy tighten the 2 mag retaining clamp / bolts >>- Then slowly rotate the prop through all compressions and note the >>spark should correspond with that cylinder on its compression stroke The >>firing order is 1 3 2 4 ie 2 bangs on one side and 2 on the other. >>- Because of the impulse of course the firing spark is quite retarded >>when turning the prop manually and is roughly at TDC. This is a good >> way >>of confirming u have it correct. >>- Then put the leads back on the mag, reinstall the starter and Carb. >>And of course the plugs and batte
Re: [DOG mailing list] Magneto removal.
Good work Ian Great explanation! regards Rob Rob Thompson 0429 493 828 On Tue, May 30, 2023 at 3:24 PM Ian WIlliams wrote: > Hi TMG team, > > Rob I hope u don’t mind me responding as well. Here in NZ we have to have > the mag bench checked every 2 years and I look after 2 coming up 3 Dimona’s > and 2 Grob 109’s so do this job with monotonous regularity. > > My procedure is as follows. > >- Disconnect battery >- Remove the right hand Carb (from the front) and disconnect the choke >and throttle rods. >- Disconnect and remove the starter and remove spark plugs >- Turn the engine so cyl *1 (The front right hand side one) is top >dead centre on its compression stroke (Finger over the spark plug hole) >- Note the little mark on the prop flange … it is set to 25 degrees so >wont line up with the case centre seam at TDC .. it is used for retiming >the mag >- Use a long allan key and undo the 2 clamps attaching the Mag … the >Alternator bracket and probably the throttle bracket are also attached so >note how they are connected. I keep the bottom alternator bolt tight so it >doesn’t move slackening off the belt. >- Pull out the mag and remove the rear cap with the 4 HT leads (3 >screws) >- Get the Mag serviced > > Back on > >- The Dimona Mag is Right hand. So get a pin (an unused pop rivet >works well) Look at the back of the mag and u will see 2 holes. Use the >one marked RH Put the pop rivet into it and slowly turn the input until >the rivet shaft slips right in. The mag is direct drive but has a 2:1 >reduction inside and the pin / hole is in the smaller gear so u may have to >turn it twice to make the pin go fully in. >- Now the tricky bit. I use a length of masking tape crossed over to >secure the impulse in a fixed position but in such a way that once the flex >coupling is almost in place the masking tape can be pulled out. THEN >REMOVE THE POP RIVETthen reinstall the rear cap and the 3 screws >.. note there is only one way it can go on. Taking care not to dislodge >the masking tape. >- Now Double check Cyl*1 is at TDC. Offer up the mag and the gasket >as Rob has described. Be real careful here. You can see the coupling >through the Alternator belt slot. With a torch. Once it looks as if it will >slip in OK, remove the masking tape and reinstall the 2 mounting clamps but >don’t tighten just yet. >- Make up a small “buzzer”. I use a real cheap electric ceramic >buzzer (about the size of your finger nail and a 1.5 volt AA battery) >Write it up and use 2 flying leads with clips at the end. Check that when >you join the clips together the buzzer makes a noise. Connect one clip to >the “P” lead on the mag and the other to ground Now rotate the prop around >the TDC point. You should hear a change of tone on the buzzer when the Mag >points change state. It is not much of a tone change but is clearly heard >- Now identify the mark on the prop flange and rotate the prop around >it listening for the change of buzzer tone. Adjust the mag position so >when rotating the prop in reverse (ie taking up any slack in the drive) the >change of tone happens exactly when the flange mark is lined up with the >split in the case halves. >- Once you are happy tighten the 2 mag retaining clamp / bolts >- Then slowly rotate the prop through all compressions and note the >spark should correspond with that cylinder on its compression stroke The >firing order is 1 3 2 4 ie 2 bangs on one side and 2 on the other. >- Because of the impulse of course the firing spark is quite retarded >when turning the prop manually and is roughly at TDC. This is a good way >of confirming u have it correct. >- Then put the leads back on the mag, reinstall the starter and Carb. >And of course the plugs and battery >- All should then make the usual noise . > > I hope this is of some help > > > > Best regards > > > > Ian Williams > > ZK-GCB > > > > > > PS… Is anybody else having big issues with Hoffmann propellors ?? > > > > *From:* dog@lists.riverland.net.au *On > Behalf Of *Rob Thompson > *Sent:* Tuesday, May 30, 2023 9:38 AM > *To:* dog@lists.riverland.net.au > *Subject:* Re: [DOG mailing list] Magneto removal. > > > > 1 Line up the engine at the timing mark firing on #1 cylinder. > > > > 2 Remove the engine control rods and starter motor so you have room to get > the magneto out and back in again. > > > > 3 Take the cap and harness off using a right angle screw driver. I > replaced th
RE: [DOG mailing list] Magneto removal.
Hi TMG team, Rob I hope u don’t mind me responding as well. Here in NZ we have to have the mag bench checked every 2 years and I look after 2 coming up 3 Dimona’s and 2 Grob 109’s so do this job with monotonous regularity. My procedure is as follows. * Disconnect battery * Remove the right hand Carb (from the front) and disconnect the choke and throttle rods. * Disconnect and remove the starter and remove spark plugs * Turn the engine so cyl *1 (The front right hand side one) is top dead centre on its compression stroke (Finger over the spark plug hole) * Note the little mark on the prop flange … it is set to 25 degrees so wont line up with the case centre seam at TDC .. it is used for retiming the mag * Use a long allan key and undo the 2 clamps attaching the Mag … the Alternator bracket and probably the throttle bracket are also attached so note how they are connected. I keep the bottom alternator bolt tight so it doesn’t move slackening off the belt. * Pull out the mag and remove the rear cap with the 4 HT leads (3 screws) * Get the Mag serviced Back on * The Dimona Mag is Right hand. So get a pin (an unused pop rivet works well) Look at the back of the mag and u will see 2 holes. Use the one marked RH Put the pop rivet into it and slowly turn the input until the rivet shaft slips right in. The mag is direct drive but has a 2:1 reduction inside and the pin / hole is in the smaller gear so u may have to turn it twice to make the pin go fully in. * Now the tricky bit. I use a length of masking tape crossed over to secure the impulse in a fixed position but in such a way that once the flex coupling is almost in place the masking tape can be pulled out. THEN REMOVE THE POP RIVETthen reinstall the rear cap and the 3 screws .. note there is only one way it can go on. Taking care not to dislodge the masking tape. * Now Double check Cyl*1 is at TDC. Offer up the mag and the gasket as Rob has described. Be real careful here. You can see the coupling through the Alternator belt slot. With a torch. Once it looks as if it will slip in OK, remove the masking tape and reinstall the 2 mounting clamps but don’t tighten just yet. * Make up a small “buzzer”. I use a real cheap electric ceramic buzzer (about the size of your finger nail and a 1.5 volt AA battery) Write it up and use 2 flying leads with clips at the end. Check that when you join the clips together the buzzer makes a noise. Connect one clip to the “P” lead on the mag and the other to ground Now rotate the prop around the TDC point. You should hear a change of tone on the buzzer when the Mag points change state. It is not much of a tone change but is clearly heard * Now identify the mark on the prop flange and rotate the prop around it listening for the change of buzzer tone. Adjust the mag position so when rotating the prop in reverse (ie taking up any slack in the drive) the change of tone happens exactly when the flange mark is lined up with the split in the case halves. * Once you are happy tighten the 2 mag retaining clamp / bolts * Then slowly rotate the prop through all compressions and note the spark should correspond with that cylinder on its compression stroke The firing order is 1 3 2 4 ie 2 bangs on one side and 2 on the other. * Because of the impulse of course the firing spark is quite retarded when turning the prop manually and is roughly at TDC. This is a good way of confirming u have it correct. * Then put the leads back on the mag, reinstall the starter and Carb. And of course the plugs and battery * All should then make the usual noise . I hope this is of some help Best regards Ian Williams ZK-GCB PS… Is anybody else having big issues with Hoffmann propellors ?? From: dog@lists.riverland.net.au On Behalf Of Rob Thompson Sent: Tuesday, May 30, 2023 9:38 AM To: dog@lists.riverland.net.au Subject: Re: [DOG mailing list] Magneto removal. 1 Line up the engine at the timing mark firing on #1 cylinder. 2 Remove the engine control rods and starter motor so you have room to get the magneto out and back in again. 3 Take the cap and harness off using a right angle screw driver. I replaced the slot head screws with Alan screws to make the job easier to refit the cap. 3 Loosen the magneto bolts with a long Alan key. I welded a long Alan key to a 1/4 inch socket and then used a small ratchet spanner in behind the magneto. 5 Follow the magneto install instructions in the manual. It is important to get the gasket measurement right or the magneto may FAIL. You can do a trial fit with plasticine or Blu Tac which compresses against the flywheel and then measure that you have the right clearance. regards Rob Rob Thompson 0429 493 828 On Tue, May 30, 2023 at 6:22 AM Tomasz Dzikuć mailto:x...@op.pl
Re: [DOG mailing list] Magneto removal.
1 Line up the engine at the timing mark firing on #1 cylinder. 2 Remove the engine control rods and starter motor so you have room to get the magneto out and back in again. 3 Take the cap and harness off using a right angle screw driver. I replaced the slot head screws with Alan screws to make the job easier to refit the cap. 3 Loosen the magneto bolts with a long Alan key. I welded a long Alan key to a 1/4 inch socket and then used a small ratchet spanner in behind the magneto. 5 Follow the magneto install instructions in the manual. *It is important to get the gasket measurement right or the magneto may FAIL.* You can do a trial fit with plasticine or Blu Tac which compresses against the flywheel and then measure that you have the right clearance. regards Rob Rob Thompson 0429 493 828 On Tue, May 30, 2023 at 6:22 AM Tomasz Dzikuć wrote: > Dear Dimona users. > > > > The date of inspection of our magneto is approaching. > > > > The information I found on this list shows that the removal of the magneto > can be done without disassembling the entire engine. > > > > Unfortunately, we don't know how to do that. > > > > Does anyone have any short instructions on how to do this or just can > write some tips here. > > > > Thank you in advance and best regards from Poland. > > > > Tomasz Dzikuc > > > > TMG Team > > AZL Zielona Gora >
[DOG mailing list] Magneto removal.
Dear Dimona users. The date of inspection of our magneto is approaching. The information I found on this list shows that the removal of the magneto can be done without disassembling the entire engine. Unfortunately, we don't know how to do that. Does anyone have any short instructions on how to do this or just can write some tips here. Thank you in advance and best regards from Poland. Tomasz Dzikuc TMG Team AZL Zielona Gora
