primary drive options from a tapered shaft

[albertaphil]

So I finally got an afternoon with my engine and Comet 94C primary, and here is what I now know:

1)my engine (a ruggerini md151) has a 1 1/8 dia. tapered, keyless crankshaft with a taper of 1/8" in 7/8" (I think...could be 1")
2)my comet pulley has a diameter of 30mm and a taper of 1mm in 10mm.
3)comet does not make a pulley with the dimensions of my crankshaft

I'm thinking that an adapter to mate my pulley to my crankshaft is out of the question (different sizes and tapers would take a magician to turn an adapter on a lathe). Comet makes a straight-bore pulley with a 1 1/8" bore. So I have some questions:

1) is there a way to adapt my tapered crankshaft to a straight-bore pulley?
2) is there a taper-lock setup for my tapered shaft?
3) what would you do?

I did want to go the CVT route, but that dream seems to be dimming. Which the most probable route as converting a 2 stroke transmission ala. mazdog, Sam Brumby and others. But that is only if I can come up with a primary to bolt onto this doggone crankshaft. Thanks, gents.

Phil

[coachgeo]

Dont know what your flywheel looks like. but suggestion to me today by member Locomotivebreath was to take a broken Harley Crankshaft, Fly wheel side. Machine down the crankshaft side and set it up to bolt to your engines flywheel. Im using an Ultima so this would work perfect for my needs. Check to see if a CVT exist that fits the Harley shaft.

Now Im sure Locomotivebreath ran a cvt on his Ruggerini so he may hop in here (or relay thru me) an answer for you. His net service is next to none at the moment.

[OilyPhil]

No idea of the sizes but I do remember a MZ ETZ250 had a clutch mounted on a taper on the end of the crank, maybe you could have your crank ground down to match the clutch?

Phil

[albertaphil]

Thanks, guys. Phil, your post made me think...the end of my crankshaft appears to be 1" diameter. I'm pretty sure comet made a 94C with a 1" straight bore. Would it be terrible of me have the end 1.5" of my crankshaft ground to a straight 1", or will it break off with the big pulley and belt pulling on it? The bolt hole in the middle is a 5/16, which would leave 11/32 of metal around the hole. Seems like that might be a little weak. Opinions, anyone? Thanks.

AlbertaPhil

[sbrumby]

Pretty sure the adapters are available from ruggerini/lombardini,http://www.slovatec.sk/deutsch/Ruggerini_Teilelisten.pdf
look at item chapter 7. The idea of machineing down the harley cranshaft and bolting it to your flywheel would be good if you only wanted to go backwards.

[Crazymanneil]

Phil,

Got a pic or diagram of the crank? That said it looks like others are familar with the engine. Hope you get sorted.

Neil

[albertaphil]

Thanks, everyone.

Sam, thanks for the link to the parts manual. On page 100 of the manual, item 20 (which is called a "plug" on the next page) looks like it could be an adapter to make the shaft a straight bore (of unknown size), although the name does not really suggest that. I'll follow that trail for a while. Incidentally, what bike did the 6 speed transmission in your VF come out of? What do you use for a primary drive? I guess your engine is turning the same direction as your wheels. In the event that I can't get this CVT to work, 6 speeds would be nice, but if I could have the engine running the opposite direction to the wheels and driving the primary from the right hand side of the bike the way mazdog did it on his CB350 ("Kaiser") I would be very happy. This would get my oil filter and filler out in the open, and allow my cooling air to blow backwards, instead of into the wind, although I guess you don't have any cooling issues.

Phil (just a little bit oily:-)

[albertaphil]

Sam,

No need to rehash your 6speed...I just found your explanation over in the gearbox section of Technical Talk ("2 stroke trans. idea" for those interested in checking it out). Pretty cool way of doing it I must say.

Philip

[Crazymanneil]

Phil,

Could you go at it from the opposite direction? Mount up the pulley in a lathe and cut the taper into it to match your crankshaft? You'd need a pulley with bore same as or less than the small end of the taper on the crank and enough meat that the big end would not be too thin after I guess.

N

[sbrumby]

On the name of the stub shafts, It would have been written in Italian then translated. Quite a lot of these stationary engines are used as generators. They are attached to the alternators with a long bolt that goes right through the alternator. Useually its the alternator that breaks. So its good to get the hole unit put an angle grinder though the alternator and retrieve the last 5" of shaft. this can then be lathed down to a useable size. On the point of the air blowing the wrong way they never get any more than warm not even on a hot day.

[coachgeo]

...The idea of machineing down the harley cranshaft and bolting it to your flywheel would be good if you only wanted to go backwards.

hmmmm... what rotation does these air cooled motors go?

Didn't Hieko's bike power the belt drive off the crank side to the Ulima six speed?

[albertaphil]

Looking at the crankshaft, it is rotating counter-clockwise. That is, when the crank is on the left side of the bike, it is rotating the same direction as the wheels in forward travel.

Philip

[sbrumby]

Coach the reason I said "backwards" is the flywheel side is not the drive side,although some engines allow both sides to be used mostly flywheel side is only recomended up to a third of power of engine.

[jeremy]

I'm going through this same situation with my Hatz 1B30 and a Comet 500; the Hatz I bought was built by factory to bolt up to a generator as Sam has said, and so it has a taper with no keyway. It has a section of 28mm, steps to 7/8" then tapers and threaded hole etc. I purchased a 1" bore driver then bought a spare 3/4" bore spindle new, before the Co. went poof. I will either bore the smaller spindle out to match the shaft, or have my machinist cut a bushing from 7/8" up to 1"and loctite it to the shaft. Either way, we expect to set the motor on the table of his Bridgeport mill and cut a couple of woodruff key seats in line into the shaft/sleeve to make for a keyway, if not being able to cut a continuous one at that time. Then I'll still have the end-bolt to make it come together and stay there. We also have considered the idea of making a split "collet" to go over the taper and grip the bore/shaft as the end bolt is tightened, but this clearly presents the problem of making the thing hard to get apart once it's cinched up. It's real positive, though.

While on this subject, I'll add my standard warning: if you see an un-keyed, tapered shaft on your engine, beware: you most likely have an engine which has been set up at the factory for "static-speed" operation through particular governing, and will not perform satisfactorily under the use we have planned for it. You will no doubt become well acquainted with the process of remodeling the governor to make your power plant into a variable-speed unit, including sourcing the little bits that make the difference and learning how to get it apart, them in, and then it back together again. Maybe you've already discovered this...I was naive when I started. But I saved a thousand dollars...I think.

[Sphere]

I bought a keyless engine off ebay from the UK, but when we opened her up it read 3600 rpm on the sprocket. Don't think it's all bad. Or maybe I was just lucky. Or maybe it doesn't go over 2000 rpm when it fires. Anyway, I'll let you know.

[jeremy]

Update on my solution: I have had my machinist produce a "split collett" with matching taper in the bore to enter the outer side of the (CVT hub in my case) drive. It has a center bolt and an outer flange so it can be removed, either with a bearing puller or three small bolts run in through threaded holes, pushing on the drive hub. He also bushed-up the skinny part of the shaft from 7/8" to 1", then mounted the engine on his mill and sliced a woodruff-key seat through the bushing and into the shaft, so I have officially jumped one pesky hurdle... Now for the governor and then frame revisions.

[albertaphil]

Update on my solution:

I went through Martin Sprockets' catalog, which has thousands of types of sprockets of all sizes and attachments. Not seeing anything that had my particular dimensions, I emailed the address on their website and within a couple of hours had a response from someone. Several emails and a phone call later, and Martin will be machining a bushing to fit my crankshaft, and sending a #40 double sprocket to fit the bushing. Next step is getting a 48 tooth #40 double machined out to be just a ring with an ID of 5 1/2" to bolt onto (or weld onto) the piece of pipe I will be using to extend my clutch out far enough from the transmission case to line up with my crankshaft sprocket. Interestingly, the Martin guy told me that they can only sell me these parts for testing purposes as they do not make a sprocket that can handle 16hp at 3600rpm. Seriously, even a #50 double sprocket is only good for 14hp at 3600rpm officially. A #40 double is good for 10hp, and a #50 single is good for 6hp. Go figure. Countless Harleys are running around with a #50 double primary. I was originally thinking a #50 single as my primary since my wheel drive chain is a #50 single running out in the water and dirt, albeit at 2400 rpm instead of 3600rpm.

Jeremy, my Ruggerini is set up for variable speed operation so I don't have to worry. What did you have to do with your Hatz?

Phil

[Sphere]

For ignorant people (like me) the explanation of what #40 and #50 actually means (ANSI standard), taken from http://www.gizmology.net/sprockets.htm. Please excuse the layout, I don't really know how to brush it up on phpbb.



Chain Dimensions

Chain types are identified by number; ie. a number 40 chain. The rightmost digit is 0 for chain of the standard dimensions; 1 for lightweight chain; and 5 for rollerless bushing chain. The digits to the left indicate the pitch of the chain in eighths of an inch. For example, a number 40 chain would have a pitch of four-eighths of an inch, or 1/2", and would be of the standard dimensions in width, roller diameter, etc.

The roller diameter is "nearest binary fraction" (32nd of an inch) to 5/8ths of the pitch; pin diameter is half of roller diameter. The width of the chain, for "standard" (0 series) chain, is the nearest binary fraction to 5/8ths of the pitch; for narrow chains (1 series) width is 41% of the pitch. Sprocket thickness is approximately 85-90% of the roller width.

Plate thickness is 1/8th of the pitch, except "extra-heavy" chain, which is designated by the suffix H, and is 1/32" thicker.

ANSI Standard Chain Dimensions

Chain No. Pitch Roller Diameter Roller Width Sprocket thickness Working Load
25 1/4" 0.130" 1/8" 0.110" 140 lbs
35 3/8" 0.200" 3/16" 0.168" 480 lbs
40 1/2" 5/16" 5/16" 0.284" 810 lbs
41 1/2" 0.306" 1/4" 0.227" 500 lbs
50 5/8" 0.400" 3/8" 0.343" 1400 lbs
60 3/4" 15/32" 1/2" 0.459" 1950 lbs
80 1" 5/8" 5/8" 0.575" 3300 lbs

Bicycle and Motorcycle Chain Dimensions

Chain No. Pitch Roller Diameter Roller Width Sprocket thickness
Bicycle, with Derailleur 1/2" 5/16" 1/8" 0.110"
Bicycle, without Derailleur 1/2" 5/16" 3/32" 0.084"
420 1/2" 5/16" 1/4" 0.227"
425 1/2" 5/16" 5/16" 0.284"
428 1/2" 0.335" 5/16" 0.284"
520 5/8" 0.400" 1/4" 0.227"
525 5/8" 0.400" 5/16" 0.284"
530 5/8" 0.400" 3/8" 0.343"
630 3/4" 15/32" 3/8" 0.343"

[jeremy]

Phil, that chain page is great--thanks for the reference. In the chain realm, I have cut down a standard #50 sprocket to 520 thickness for my jackshaft output-side, in order to run a motorcycle chain to my new aluminum rear sprocket--instead of industrial-width chain which will run but would be sloppy side-to-side.

As for the Hatz, I haven't cracked the outer case yet to get at the governor,that's next. As described somewhere here, I endured a struggle just arranging for it. The Mfg'er's service and supply structure is not designed for tinkerers like me; it took perseverance and too much time to suss-out what I'd need and where/how to get it. After ordering the factory shop manual and making numerous calls all over the US, I was able to find an engineer at the distributor's office who admitted that I could do it, and one savvy parts-guy somewhere else who was decent enough to look up and order the little bits needed to modify for variable speed. I think the parts were eight bucks!

[albertaphil]

Jeremy, thanks for the kudos, but it was actually sphere who posted the chain info. jdaftra, also on this forum has run into the same issue with a lombardini that you had with your hatz. I hope he can get some satisfaction the way you have. It's hard to get an answer, at least one that is not in Italian or German:-)

[jeremy]

Wups! So it was... must have been late when I replied. Best to you both then-- J.

[mark_in_manchester]

Three points caught my interest in the above thread:
1) there seemed to be some uncertainty whether keyless, tapered cranks are reliable for automotive use.
2) there was a lack of confidence that adapters could be made to lock onto them, for use with plain-bore sprockets (chain or belt).
3) someone mentioned MZ250s.

East German MZ TS and ETZ250 and variants (1974-about 2000) use a tapered keyless crank onto which the clutch fits. Power is about 21hp and peak revs are 6000. Put on correctly, they don't come off - in fact they can be a bugger to remove. 'Correctly' means warming the clutch to about 100°C and doing up tight onto the cold taper (cranks are normally threaded into their end, for this purpose), then leaving to cool with the tensioning bolt done up. Everything needs to be _really clean_. Some people use thread lock / magic goo, but I have not found it necessary. If you put it together cold and oily, eventually the clutch (soft) tends to spin on the crank (hard). If you stop quick you'll just have a buggered clutch centre. More delay, and the crank will have 'picked up' too, hard though it is. If both clutch taper bore and crank taper are in any way 'picked-up', you'll have a sod of a job trying to get a nice reliable fit - in fact in the MZ world, it is not unknown to weld the clutch on at this point (since clutch centre and crank are buggered anyway...one might even change main bearings and seals first!).

So, adapters - well, I made one to re-use a picked-up MZ clutch - I bored the clutch taper out plain, shrank a piece of mild steel bar into it (and put a couple of weld blobs on for good measure), then bored it out taper on my knackered old lathe. The only way I could get the set-over right on the top slide was to put a good clutch up in the chuck, mount a DTI (clock gauge) with a sideways 'finger' on the top slide, and mess about with the top slide angle until I could wind it down the taper without the clock changing its reading. Then swap clock for boring tool and proceed with caution! This worked fine, and I am not much of a turner.

So - it's all possible, even at home.

M.