Wildguzzi.com
General Category => General Discussion => Topic started by: ozarquebus on January 13, 2020, 03:12:18 PM
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Well, I thought I was ready and I read every post I could find on stator removal and decided to just make the pin that is inserted into the center shaft, then reinsert the allen head stator bolt to put pressure on the taper and rap it. It comes right off, right?
Well mine won't come off and I can't get the home made extractor pin out.
I think the steel of the pin may be too soft and it may be bent in there, but I hope not.
What next, now that I have screwed it up?
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If you can get the stator out eventually, the homemade pin should be accessible to come out. Not sure, my thoughts are very hack-ey at the moment to the point I don't even want to suggest anything, but.... Is the rotor toast and you are replacing it? If so, maybe you can gently tap in round and round and maybe it will break loose?
I broke the rotor bolt in mine one time, and the stress level hit the roof. It actually ended up coming out very easily in my case. Then I bought the removal tool :wink:
Hopefully someone has a better suggestion
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Lucky you.
I did something similar many years ago.
I made a custom puller for my slap hammer.
I'll send it to you.
You will need to pull the front wheel and fender so you have direct access.
I'll send a picture later. Hate working from a phone.
Patrick Hayes
Fremont CA
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I am a bit confused. Stator = stands still. Is the outside parts which is hold in position by 3 M5 screws. Easy to remove.
Rotor is the rotating inner part, which is removed by extracting it out using a HARDENED STEEL pin + the original bolt. Screw the bolt fully in and apply a hammer blow on the head(of the screw).
If you have used SOFT STEEL, then sorry for you. You might have big trouble to remove the soft steel part.
The gold long hardened special M8 screw fully left in the picture), is made by me for this work.
(https://i.ibb.co/vJXWHkT/Tools.jpg) (https://ibb.co/vJXWHkT)
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Ouch!
I think everyone has tried that approach, very few succeeded. If all mention of it could be erased from history, I'd do it.
The pin is now jammed in the end of the threaded crankshaft. Hope the threads are ok.
The rotor is held on mostly by the taper - it's a taper fit and requires a good blow usually to break loose, but a puller will do it too. That's what the proper tool is all about. But a regular gear puller at this point won't work since there's no way to push on the crankshaft end. The only solution now is the slide puller.
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For a removal pin, I cut down a 5mm Allen wrench. Plenty hard and most of us have more than we need.
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OK, here's the tool. An original rotor bolt welded to a threaded shaft that fits my slap hammer. Screw this into the rotor. Get the wheel and fender out of the way. Use the slap hammer to yank the rotor off the nose of the crankshaft. The residual piece inside the hollow crank will likely come out easily unless you have really done some bad damage.
(https://i.postimg.cc/T1pzys2w/MVC-187-L-zpsfbcb6bd5.jpg)
Now you know why the factory pin tool is made from a hardened shaft.
Give me a PM with your postal address so I can send it along. Find a slap hammer that fits the pulling thread.
Patrick Hayes
Fremont CA
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Yes its the rotor not the stator. The stator came off easy. The alternator is in good shape in general. Just taking it off to get at chain and damper. Everything from the fender to the exhausts and even the front engine mounting bolt all came apart easy.
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Have a big box with lots of padding ready to catch the rotor when it pops off. Even with the proper tool the rotor can fly and crash to the floor, so create a soft place to land. The rotor is rather heavy and a bit much to control at the end of the slide hammer, so don't expect to be able to keep it from crashing. It will.
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I sent this as a PM to the OP but then I thought there might be some others who are new to Guzzi and need to know how this alternator system is attached.
You made an extractor 'removal pin' of soft metal. What dimensions did you use for that tool? The length is critical. Here are the dimensions of my factory tool:
5.97mm or 0.235" diameter by 52.57 mm or 2.0695" length
Are you certain you know how the factory pin tool works?
Look at my photo above again. See the length or number of turns of thread on the business end? Important number of threads. I think about 10-12 turns.
For a NORMAL INSTALL of the rotor:
Look inside the rotor body itself and you will see it has about 8 turns of internal thread.
Look inside the nose of the crankshaft and you will see about 8 turns of internal thread.
Put the rotor onto the tapered crank.
Realize that you now have TWO sections of internal threading but they are not continuous. There is a significant blank, unthreaded internal space between the rotor's internal thread and the crank's internal thread. That blank space is longer than the threaded portion of the central bolt.
Insert the central bolt and it impacts the internal threads of the rotor.
Spin the bolt in until ALL of the bolt's threads pass through the rotor and they now reach into the above described empty space.
The bolt is now free to spin and free to move slightly fore and aft.
Push the bolt in further until it impacts the internal threads of the crank.
Turn until the head of the bolt sets in the recess at the front of the rotor and tighten appropriately.
For REMOVAL of the rotor:
Note the internal threading descriptions as above.
Insert a properly dimensioned factory extractor 'pin' tool or a suitably HARD substitute.
The extractor pin tool must be long enough that its outer tip is outboard of the crankshaft internal threads and thus prevents the central bolt from ever reaching into the crankshaft internal threads.
Insert the central bolt and turn it in until it abuts the end of the extractor pin tool.
Tighten substantially to set up an internal pushing force to force the rotor to 'pop' off the crankshaft. It is held only by taper friction, but that can be quite substantial.
Most have found that the rotor will not pop and thus a judicious hammer whack on the rotor body or central bolt may be the extra vibration needed to release the rotor.
The rotor will fall, so be prepared with a soft place to fall.
If your extractor pin was not sufficient length, that might allow the central bolt threads to reach in and grab the first few internal threads of the crankshaft. Doing so would create a crushing force against the extractor pin tool but never apply any outward force to release the rotor. Bad juju!
If your extractor pin was not HARD enough, it might bend or 'mushroom' inside the crank before providing enough force to pop the rotor off of the crank taper.
Someone makes and sells an extractor tool with bolt threads and the proper length extractor pin all in one piece. I don't recall who.
Rotor, bolt, and factory tool in one pic:
(https://i.postimg.cc/Zn9fb0pQ/rotorpintool.jpg)
Patrick Hayes
Fremont CA
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Someone makes and sells an extractor tool with bolt threads and the proper length extractor pin all in one piece. I don't recall who.
Here's one source:
https://www.euromotoelectrics.com/product-p/boalt-rotor642tool.htm
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Or you can make an extractor yourself. I got a bunch of grade 12 (forgot the exact grade) allen bolts from Fastenall and turned off the end threads. It was one of my first projects after getting a lathe. Without a lathe, careful use of a grinder could accomplish the same.
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Thanks Patrick, for the spec's on that pin! :thumb:
Paul B :boozing:
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Thanks for the info, everyone. I will supply update.
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Thanks for the info, everyone. I will supply update.
:popcorn:
You are the first guy to do this.. :evil: :smiley:
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For REMOVAL of the rotor:
Note the internal threading descriptions as above.
Insert a properly dimensioned factory extractor 'pin' tool or a suitably HARD substitute.
The extractor pin tool must be long enough that its outer tip is outboard of the crankshaft internal threads and thus prevents the central bolt from ever reaching into the crankshaft internal threads.
Insert the central bolt and turn it in until it abuts the end of the extractor pin tool.
Tighten substantially to set up an internal pushing force to force the rotor to 'pop' off the crankshaft. It is held only by taper friction, but that can be quite substantial.
Most have found that the rotor will not pop and thus a judicious hammer whack on the rotor body or central bolt may be the extra vibration needed to release the rotor.
The rotor will fall, so be prepared with a soft place to fall.
If your extractor pin was not sufficient length, that might allow the central bolt threads to reach in and grab the first few internal threads of the crankshaft. Doing so would create a crushing force against the extractor pin tool but never apply any outward force to release the rotor. Bad juju!
If your extractor pin was not HARD enough, it might bend or 'mushroom' inside the crank before providing enough force to pop the rotor off of the crank taper.
Patrick Hayes
Fremont CA
Have folks ever used some effective penetrating oil to help liberate the rotor from the taper? I would, however, worry about the chemical action on the insulation and shellac(?) coating on the windings...
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Have folks ever used some effective penetrating oil to help liberate the rotor from the taper? I would, however, worry about the chemical action on the insulation and shellac(?) coating on the windings...
That wouldn't work. People just don't realize how strongly a precision taper holds. You could take the bolt out once the rotor is seated. :smiley:
It's the same way a drill chuck is held into the tapered shaft that is held by the taper of a drill press or lathe. It takes a sharp impact to break the taper loose.
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What Chuck says. I'll also add that when replacing the rotor, clean the surfaces very well - tapers need to be mated up with clean surfaces.
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i work on outboard motors quite a lot, mostly old ones. On most of them the flywheel has to be removed to get to the ignition system. The flywheel is held on to the crankshaft by the same method namely a taper. They can mostly be removed with some sort of a gear puller. Once it is good and tight the flywheel can usually be loosened with a rap on the screw of the puller.with a hammer. However some can be quite stubborn and the possibility of mushrooming the end of the crank with several smacks from the hammer is a good possibility. I have found as well as many other outboarders that the use of a impact gun on the puller screw will usually break the flywheel loose with a minimal amount of drama. It is of course important not to turn the power of the gun to its max. Just enough to put pressure on the screw. It is mainly the impacts of the gun that "rattle or shock" is what breaks the fit of the taper. I think it would work here too. Just go gently.
kk
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The older Vespa flywheel/rotor also mounts the same way, but also have a woodruff key. The woodruff key is to line up the flywheel up to keep the points lobe where it needs to be. At the time, we'd use small tire irons or big screwdrivers as levers, then hit the crank and the rotor would pop out. If the flywheels had broken fins, depending on the generation (some were heavy, some light) and say a few cooling fins were broken, then those flywheels would occasionally pop loose because of them being out of balance. Maybe the nut wasn't quite tight to specs, but either way, then it was all downhill from there in many cases. The loose flywheel then would shred the woodruff key which would scratch the tapered surfaces of the crank and flywheel, then it was harder and harder for them to stay on because of the damage. Of course, these problems were mostly on our souped up engines. Careful emery cloth work, then we'd get the tapers clean enough to get them stable again, not always. Sometimes we'd have to change the crank as it was softer than the flywheel cam part.
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The older Vespa flywheel/rotor also mounts the same way, but also have a woodruff key. The woodruff key is to line up the flywheel up to keep the points lobe where it needs to be. At the time, we'd use small tire irons or big screwdrivers as levers, then hit the crank and the rotor would pop out. If the flywheels had broken fins, depending on the generation (some were heavy, some light) and say a few cooling fins were broken, then those flywheels would occasionally pop loose because of them being out of balance. Maybe the nut wasn't quite tight to specs, but either way, then it was all downhill from there in many cases. The loose flywheel then would shred the woodruff key which would scratch the tapered surfaces of the crank and flywheel, then it was harder and harder for them to stay on because of the damage. Of course, these problems were mostly on our souped up engines. Careful emery cloth work, then we'd get the tapers clean enough to get them stable again, not always. Sometimes we'd have to change the crank as it was softer than the flywheel cam part.
Groover - that's cool! Your're a two stroke guy! I would love to have a classic Vespa... P150, P200? I think they are. Can't seem to rid myself of this love affair, 2 stroke spooge-smell and all! I like the 4 speed manual Vespa's...
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i work on outboard motors quite a lot, mostly old ones. On most of them the flywheel has to be removed to get to the ignition system. The flywheel is held on to the crankshaft by the same method namely a taper. They can mostly be removed with some sort of a gear puller. Once it is good and tight the flywheel can usually be loosened with a rap on the screw of the puller.with a hammer. However some can be quite stubborn and the possibility of mushrooming the end of the crank with several smacks from the hammer is a good possibility. I have found as well as many other outboarders that the use of a impact gun on the puller screw will usually break the flywheel loose with a minimal amount of drama. It is of course important not to turn the power of the gun to its max. Just enough to put pressure on the screw. It is mainly the impacts of the gun that "rattle or shock" is what breaks the fit of the taper. I think it would work here too. Just go gently.
kk
That IS a good idea... percuss the rotor off. As indicated, the torque setting would have to be low - that makes sense.
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Yes, currently still have a P125x (177cc now), and a P200e both 4 speed. Growing up I went though at least half dozen 50 Specials, which at the time could be take up 130cc max, but now they have a gazillion kits types, some 180cc, and some extreme kits at 250cc. Best two stroke smelling oil I think, Motul 710 2T :wink:
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Quite a while ago I bent a soft extractor piece inside my rotor. A tip was to screw in a grease nipple and pump the rotor off. It worked so it did.
Cheers
Min
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Novel idea. Do you have a picture of the fitting? Seems to me that the threading of the rotor would tend to leak grease... but if pump-in rate is higher it will deliver net pressure. Still, no "shock" to break-loose the purchase the rotor has on the nose of the crank. Further to this... when people use the factory-provided pin - do they use the hammer to tap right on the head of the original screw, or use a piece of hardwood as a buffer, or tap laterally on the rotor? Seems to me that only a slide hammer that grabs under the screw head (yet still leaves adequate threading into the rotor) would actually rap the rotor in the correct direction... ????
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Seems to me that only a slide hammer that grabs under the screw head (yet still leaves adequate threading into the rotor) would actually rap the rotor in the correct direction... ????
I don't think direction is important. You already have outward removal force set up. The hammer rap is merely to set up a vibration effect which helps to release the taper grip.
Patrick Hayes
Fremont CA
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The shock of hitting the bolt head with a hammer breaks it loose.
In my manual for my BMW, it calls for the service tool or a suitable substitute (I think it gave the dimension of the tool/rod) and to use the pinch bolt from the rear axle. Tighten it up holding the rotor by hand and rap the head of the bolt with a hammer.
I have done this on the BMW, yes it does just pop right off.
Tom
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Here you are from my special tools tin.......
8mm x 1.25 grease nipple.
Wind it in , pump it up, off it comes.
Hopefully.
(https://i.postimg.cc/pryjHTSx/20200117-092951.jpg) (https://postimg.cc/RJ5h1M9b)
(https://i.postimg.cc/YSfYNTgc/20200117-093043.jpg) (https://postimg.cc/yJxDsQvn)
Cheers
Min
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^^^^ Nice.. :thumb: I've removed blind bearings by making a punch that's a slip fit in the bore, putting grease in it, and smacking it with a copper hammer.
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hydraulics.. who would've thunk - great tip!
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I've removed caliper pistons with grease, but never would have thought of it for the rotor. Thanks for that trick!
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^^^^ Nice.. :thumb: I've removed blind bearings by making a punch that's a slip fit in the bore, putting grease in it, and smacking it with a copper hammer.
That is one way to remove the blind bearing in the front of a Mercury Outboard Quicksilver racing gear case.
kk
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I have been trying to find a 8mm x 1.25 grease zerk with a longer threaded shank like this one that theoneandonlymin showed. All I can find have the short 1/2" shank.
Anyone know of a source?
(https://i.ibb.co/vxbqkJJ/20200117-092951.jpg) (https://ibb.co/vxbqkJJ)
That looks like a brake bleeder screw in the photo.
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Sorry folks, my mistake.
It is a bleed nipple and I've made an international fool of myself so I have.
Cheers
Min
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You are in the right place, I use this forum to make an international fool of myself on a regular basis
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Hey that is great news. I have been tying to do the pump-off of my rotor with the M8 1.25 grease zerk and having a heck of time getting in on there. Also was looking in vain for an extended M8 grease zerk to no avail.
So, the brake bleeder is m8 x 1.25 thread also?
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At the risk of fully revealing my mechanical ineptness, I still haven't got my rotor off. I have used the pehayes extraction bolt as a center pull type of extraction method and am able to put sufficient pressure on the rotor to significantly flex the 1/4 in steel cross bar of the improvised puller. I think I am exerting a sufficient amount of force for the rotor to come off, but no amount of 'heavy tapping' on the rotor bolt will free it. Front wheel is off and I can get a pretty good swing at it.
To refresh everyones' memory on this belabored thread, I have jammed a too-soft, home-made extraction pin in the cam shaft/rotor center hole and cannot get it our or use the standard method of rotor removal.
At this point I wonder how many turns of the screw are in the rotor and at what point does the screw engage the inner cam threads? I may be pulling on the whole cam instead of just the rotor, but am afraid of backing it off to just a couple of threads since I could possibly tear them out. I have tried a slap hammer, but the coupler was off center with too much flex. I am still in the process of making another fitting on that, but must re-borrow the slap hammer in the midst of social isolation.
Additionally, in reference to the grease zerk pump off method, the grease zerk shank is so short and the recess in the rotor so deep and narrow, I am unsure of tighenting that down in there with a ground-down diameter socket will not produce another dilemma as well as being unsure if the pump off method is going to work, anyway. Does anyone know from what vehicle the brake bleeder valve pictured in earlier post that is 8mm x 1.25 came?
I am almost to the point of cutting the rotor off with a dye grinder.
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Yes , as far as I can remember I bought it from a VW restoration shop.
Cheers
Min
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crickets...ohh thats not good...maybe walk away for awhile
Speaking of embarrassing yourself internationally.. :grin:
I went one step worse and broke a tap in there...
But, who knew? Mcmaster-Carr had....drum roll...Tap Extractors for broken taps...received it the next day and rescued my a$$
Now, freaky ending if your still listening...about 3 years later I responded to a guzzi ad for a v700...great bike I bought it rode swapped it to jason speaker....but
We picked it up from the manufacturer of TAP EXTRACTORS (yes we supply mcmaster carr) from a tiny drill size to foot wide oil pipe tap extractors...beauti ful polished from age machine shop built by his grandfather...
What a world
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at this point id think about making or finding a drill bushing and drilling it out with a left handed bit, maybe 1/8" or so. drilling a correct center will help you. breaking off the drill bit will not. tricky to get it on center with a hopefully soft rod wadded up in there. go slow and clear chips more often than you think you need to. normally there are threads, then no threads then threads again but I don't know their length . after you get a hole hopefully on center , go bigger gradually until the piece will come out. the threads are harder than what you are drilling so that helps. I'm grateful I'm not doing that today but maybe you'll have good luck with it. keep the bit lubricated and clear chips with compressed air.
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I wish you the best of luck in getting it out. On a more general basis I wonder if the hydraulic means of extracting a rotor (on a bike that is not in this predictament) is actually the best/safest method; with the next safest the use of Rolf's hardened one-piece tool? The idea of using a separate rotor extraction tool, albeit hard enough to not bend... nevertheless goes a slight amount cock-eyed... whereas Rolf's tool does not misalign with the rotor threads.
Comments?
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I had the same issue on my SP a few years back; the removal tool pin that came with the bike's tool kit bent in the nose of the crankshaft, and the rotor would not budge. I actually rode the bike without the rotor bolt for months hoping that the centrifugal force would spin the dam rotor off..... But no, no joy with that, either; the rotor stayed on hopelessly stuck.
In the end, penetrating oil behind the rotor and tapping around its edge with a plastic mallet finally let it go. The bent soft pin will protrude from the crank nose about 1/4", enough to grip it with vise grips and yank it out.
But, otherwise, at this point, you may need a 3 jaw puller and a length of a hard steel round shank that will fit in the rotor hole on which the center of the jaw puller can pry against. You should be able to rent one for free at any auto parts store.
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But, who knew? Mcmaster-Carr had....drum roll...Tap Extractors for broken taps...received it the next day and rescued my a$$
You are a lucky man, Chuck. :grin: Tap extractors are my "tool to break as a last resort before going to a carbide end mill or EDM." :smiley: :smiley:
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Don't know if this will help... The blade flange on old Lawn-Boy mowers fits onto a taper. No amount of pulling will separate them from the crankshaft (without destroying the flange). What works there is to loosen the nut holding the flange and blade to the crank, locking the crank from turning and then hitting the blade (still attached to the flange) one way or the other (clockwise or counter-clockwise).
If you don't mind destroying the rotor, the same could be done on a Guzzi, might work, I've never needed to find out if it does or not. Lock the crank from turning, use a chisel or punch against something on the outer circumference of the rotor, whack it with a big hammer.
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It’s not time to drill until the rotor is off. If you use a puller that the legs rest on the case be careful to not crack the case. If there is some of the pin out the snout, your a lucky man!
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normally there are threads, then no threads then threads again but I don't know their length
OK, let us discuss the internal design here for clarification.
The removable rotor has a set of internal threads. Normally, those rotor threads are not in use and don't do anything.
The nose of the crankshaft has more internal threads. These crank threads are used to pull and hold the rotor in tight against the crank nose taper.
The rotor can fit onto the crank taper in any rotary position. There is no keyway or process by which to precisely align the outer rotor threads and the inner crank threads. Unless you were VERY lucky, it would be impossible to thread in very long bolt to engage both the rotor threading and the crank threading at the same time. The slightest amount of rotation of the rotor on the crank nose would make the two sets of threads "out of timing" and the long bolt would never work. And if you did happen to get the threadings aligned, that would prevent the bolt from pulling the rotor inward differentially so as to engage the crank taper.
The original Guzzi bolt has a long narrow shank with a set of wider or larger threads at the business end. How long is that set of threads on the factory bolt? I don't know. Someone with a bolt handy can measure.
So, there is an open, unthreaded space between the end of the rotor's threads and the beginning of the crank's threads. How long is that open space? I don't know. Easy enough to measure and extrapolate if someone else has one apart. Most importantly, the length of the unthreaded empty space MUST BE longer or deeper than the length of threading on the factory bolt. You can feel this when installing original parts. The factory bolt threads into the rotor. It turns and turns until suddenly it goes through ALL of the rotor threads and pops free internally. Now, push it in freely in the open space until it bumps up against the crank nose. Begin turning again and those same bolt threads will now engage the crank threads and turn in until the bolt seats home.
Unless you are not using a factory original bolt, it is NOT POSSIBLE to engage both the rotor threads AND the crank threads at the very same time. The empty space between is longer than the length of threading on the bolt.
The idea behind the factory hardened pin tool is to take up all of this free, unthreaded internal space. The factory bolt threads into the rotor but it abuts the extractor tool before it can pass into the unthreaded space. Pressure on the bolt now forces the rotor off of the crank taper. (We hope!)
So, take the tool I sent you. Count how many turns of threading are on the end of that tool (which was made from a bent factory bolt). Install the tool and turn it to engage rotor threads. Count the number of tool rotations to match the number of thread crown count. If it has ten thread crowns and you turn it in ten times you will have 100% of possible thread engagement contact. Use the slap hammer and be bold.
I know the tool is bent or curved and that accounts for some slight 'shock absorbing' effect. I know you currently have it set up with a rigged up 'puller'. I would discourage the puller idea. The removal from a taper is more dependent on SHOCK or IMPACT value than it is on raw FORCE value.
You have my sympathies. I would have thought it would be free by now. OK to destroy the tool if necessary. You could make another. Just understand the relationship between the length of bolt threading and the length of internal rotor threading. Make a bigger, harder, stouter tool but just match the threaded end length.
Charlie may have hit on a good shock idea (pun intended). You seem to be prepared to destroy the rotor anyway. How about huge Vice Grips on the rotor solid body. VERY tight. Then beat on the Vice Grips with a stout hammer in a rotational rather than linear fashion. The crank, pistons, flywheel will all provide an inertial resistance. Maybe you can create enough rotation force to break the taper grip. You could also 'lock' the flywheel with a stout screwdriver through the bell housing inspection hole.
I would resist the idea to try and CUT the rotor off. IIRC, the back end of the rotor fits into a sealed hole in the timing chest. Not exactly sure where you will cut off the rotor without damage to the crank nose. You may end up with some portion still stuck on the crank. Then you'd have to remove the timing chest cover to get at the remainder for further cutting. UGH!
Keep us posted. We're all rooting for you over the rotor.
Patrick Hayes
Fremont CA
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Thank you for that concise description of the thread situation, pehayes.
Armed with the knowledge that I am not engaging the cam threads, I feel emboldened.
When I get the slap hammer back with the new in line fitting fabricated to hold your extraction bolt, things are bound to give. If not, I'll try to twist the rotor off and replace it.
On my previous puller described I was using hardwood blocks against the case to prevent damage there, at least.
Sorry for being such a pathetic cry-baby, but at least I walked away several times, as suggested here, without resorting to dynamite and the mine hole in the back yard.
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If you go the "rotate to break it loose" routine, consider a BIG F***ING pipe wrench. A strap wrench might be worth considering - that's something you could even make yourself.
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This is a big block motor. The rotor is on the nose of the crankshaft, not on the camshaft.
A strap wrench is not likely to work. Rubber or leather strap will absorb and attenuate the shock we are trying to transmit into the metals. There is a chain version, but even that has flexibility that might reduce shock. The pipe wrench is a good rotation idea.
Patrick Hayes
Fremont CA
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Personally, if I didn't *care* about the rotor and all else has failed, I'd just take a big copper hammer and rap it sideways a few times. It definitely takes *shock* to break a holding taper. It's the same thing that keeps a drill chuck on it's arbor and that arbor in the drill's spindle. Pulling on a holding taper is pretty futile.
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Eureka! The rotor is finally off. Using the pictured high tech tools, I beat on the rotor with hammer and a brass drift pin against the steel lobes of the rotor with rotational force with bike in gear. Also attached was the makeshift 'puller' improvised from a lawn mower blade, two hardwood blocks and Patrick's double-ender bolt pulling adapter. With tension applied, I hammered until the rotor made a full revolution taking up slack in the engine and drive train. As I was about to give up, I gave it one more might whack and " Kabong" the rotor and all the pulling contraption leapt off joyfully onto the wooden floor of the shed. the happy hooting and hollering was audible for a block by all the whole neighborhood sheltered in place.
Visible in the picture is yet another home made bent extraction pin. I will say what everyone else has said that I failed to heed: either buy the cheap tool from Harpers or MG cycle or if you make it your self, make double sure it is hard tool steel and of the exact correct length and diameter.
Removal of my rotor by striking it on its steel lobes has marred the surface of them, but appear to still be straight and the commutator is undamaged and it still has correct electrical continuity, so I guess I will re use it unless someone knows why I shouldn't.
(https://i.ibb.co/6HH3P71/DSC-0041.jpg) (https://ibb.co/6HH3P71)
(https://i.ibb.co/d7G7t1H/DSC-0043.jpg) (https://ibb.co/d7G7t1H)
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Sometimes "a bigger hammer" is the only solution. :smiley: Congrats..
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Glad you succeeded!
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For a removal pin, I cut down a 5mm Allen wrench. Plenty hard and most of us have more than we need.
Did the same. Just gotta make sure its a good quality steel.
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The actual method I used was due to my prior screw-up using a bad home made pin.
This guy in the video link below did it with a hardened bolt with the lower threads ground off.
Once you have seen how things are actually put together it becomes clearer.
The key for me was understanding there is a gap between the threads of the rotor and the threads on the crank and that you cannot really accidentally thread both with a single continuously threaded bolt.
I kind of like that idea better than inserting a pin that could get stuck, since the bolt still will be sticking out during use.
https://www.youtube.com/watch?v=9gvGtpn-GYM
Advice above from Patrick and Chuck above helped me a lot.
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I sure like the idea of Rolf Halvorsen's tool (extreme LHS in photo) for this job. The notion of having a separate push-rod (which can go cock-eyed) after potentially mushrooming - gives me the heebie-jeebies. One-piece makes more sense to me. Also, prevents you from having to whack the head of the original Allen head capscrew.
One side of me would prefer a hex bolt... to Rolf's Allen-head... but I would NOT want to experiment / deviate away from a known working arrangement, that is to the say, the proven metallurgy / yield strength of Rolf's special tool. Maybe put a piece of flatbar up against the Allen head, then whack on the piece of flatbar instead?
(https://i.ibb.co/vqB5J9f/Rolf-Halvorsen-s-Tools.jpg) (https://ibb.co/vqB5J9f)
(https://i.ibb.co/DKYwTc7/Rolf-Halvorsen-s-Rotor-Removal-Tool.jpg) (https://ibb.co/DKYwTc7)
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You are over thinking it. Just put some pressure on the bolt, give it a whack with your copper hammer.. you *do* have one, right? and be prepared to catch it before it rolls off on the floor. :grin:
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Not sure if I have a copper hammer. Probably have a bronze one though in Dad's stash of tools I inheritted...
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I sure like the idea of Rolf Halvorsen's tool (extreme LHS in photo) for this job.
I have it along with a few more of Rolf's tools, all of them work a treat.
Like a lot of things in life you get what you pay for
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Now that the rotor is off on my G5, I have been thinking through the failed previous attempts.
List of fails:
1. getting the bad pin stuck inside, FAIL
2. Using a large slap hammer with claw gripping the extraction bolt on the rotor FAIL
3. then using the improvised lawn-mower-blade inside puller. FAIL
I had managed to apply so much pulling tension against the rotor that the lawn mower blade was flexing at about 15 degrees. Hammered on the double nutted head of the pehayes extraction 'bolt' so much that 'had to change out the nuts, they were so beat up. 'thought for sure it would have come off then. Plenty of room to swing with a cat wif front wheel & fender off. I must admit, 'had no brass hammer and was using a short 2lb iron hand-sledge.
I really thought that would have done it and was assuming at that point the rotor must be corroded onto the shaft.
SUCCESS: as described in earlier post, after getting off by beating it rotationally with puller, the shaft was inspected for corrosion: NONE.
It slick and shiny as new.
So lessons learned
1. Use good tool to start
2. Only moderate pulling force is needed if shock is effectively delivered.
3. An improvised INside puller of large mass largely damps the shock from the hammer
4. The taper fit is indeed very strong
5. There is a noticeable gap between the inside threads of the rotor and the inside threads of the crank shaft and it is unlikely to thread them both accidentally with an extraction bolt.
5. Though I would not normally recommend it, the steel lobes of the rotor are strong enough to carefully beat on some and rotor may survive if windings are not damaged and commutator area is protected.
thanks to especially to pehayes, cdn850, & chuckindiana
So i was wondering, is the brass hammer used to protect the bolt or does it deliver a more effective shock?
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This may be frond upon in some places , before we stopped making copper pennies ( here in the great white north ) I took a
piece of thick walled steel tubing and proceeded to fill it with pennies , and then put my acetylene torch to it and continued to
add pennies until it was full , they melted into a lovely copper block that I attached a handle to , cheap and the best use of
pennies ever :laugh:, Peter
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So i was wondering, is the brass hammer used to protect the bolt or does it deliver a more effective shock?
"copper" hammer. It won't mar steel, it won't chip and send some projectile directly toward your eyeball. It's easy on punches, chisels, you name it. Get yourself one. You'll be glad you did. :smiley:
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Replacement of timing chain and damper continues at glacial pace in Missouri 'swampland'.
Now that I respect the threat of screwing up with the wrong tool, some may be glad to hear that in the removal of the front crank nut, I spared no expense. Using the correct spanner socket from MG Cycle and the electric 1/2 impact wrench from Harbor Fright, I put the G5 in gear and took all the slack out of the motor and drive train and froze the back wheel in place with a board through the cast wheel spokes. I carefully gave 'er heck and the nut came off in a couple of milleseconds. Also if turning the motor by the rotor bolt rotor off, put a thick spacer on it first to keep from bottoming the bolt out and squishing the first couple of threads on the rotor bolt, like I did. So I went out to the OTHER shed and tried to take the rotor cover off the front of the Convert engine, but only let the bolts soak since they would not loosen. If I could only find my tap and die set...Might have to order a new rotor bolt.