There is a 3 page article in this month's edition of Roadracing World Magazine, the best US print magazine covering everything from club racing to WSB and MotoGP action. The full name of the magazine is 'Roadracing World and Motorcycle Technology', making their coverage of my project even more appropriate.
I spent some time on the phone with writer Michael Gougis and then send him a load of images and web references. Out of that jumbled download he was able to craft a great summary of the project starting from my introduction to roadracing on a vintage RD350 air cooled 2 stroke through to blogging on the V4.
If you don't have a subscription you can check the magazine out at most motorcycle parts and accessory stores or you can go online and view this month's issue electronically on their website.
This week I will get some time and be able to machine the clutch cover and maybe a few other small parts so keep an eye out for an update.
Chris
Friday, August 19, 2011
Thursday, July 21, 2011
Some manual work for a change
What to do when it's baking out? I know, weld some parts! One of the myriad custom small parts for the bottom end of the engine is a double gear for the electric start system. Yup, when my rider has rare occurrence of hitting the pavement (of course due to some other rider's error) they'll be no yelling at recalcitrant marshals for assistance here. A press of the magic button and the bike will start right up and be back in the action.
Several of the electric starter components are sourced from various OEMs and this double gear is one of them. It needs to have an increased separation between the gear faces than the original part. To accomplish this I'll start with 2 complete gears, machine one face off of each, then weld a spacer in between with the appropriate jigging to keep both gears and bores properly aligned.
Original gear:
Machining large ring from one part:
Gears machined apart and spacer ring prior to welding:
Assembly pressed together:
and welded:
I used a Miller Syncrowave 250 TIG welder using stainless rod to join the gear pieces with a piece of 1018 steel. This should provide a weld that is not too hard and does not have too much alloying element diffusion. I took care to keep heat input to a minimum to avoid losing the hardness of the teeth and let the part cool very slowly to prevent cracking. The part looks good and both gear faces run true so I can take one more part off the to-do list.
I am waiting for some metric 5C collets to arrive then will finish the oil pump shafting and some other various simple round parts like front suspension arm inner races and rear swingarm link and pivot races.
Chris
Several of the electric starter components are sourced from various OEMs and this double gear is one of them. It needs to have an increased separation between the gear faces than the original part. To accomplish this I'll start with 2 complete gears, machine one face off of each, then weld a spacer in between with the appropriate jigging to keep both gears and bores properly aligned.
Original gear:
Machining large ring from one part:
Gears machined apart and spacer ring prior to welding:
Assembly pressed together:
and welded:
I used a Miller Syncrowave 250 TIG welder using stainless rod to join the gear pieces with a piece of 1018 steel. This should provide a weld that is not too hard and does not have too much alloying element diffusion. I took care to keep heat input to a minimum to avoid losing the hardness of the teeth and let the part cool very slowly to prevent cracking. The part looks good and both gear faces run true so I can take one more part off the to-do list.
I am waiting for some metric 5C collets to arrive then will finish the oil pump shafting and some other various simple round parts like front suspension arm inner races and rear swingarm link and pivot races.
Chris
Saturday, July 16, 2011
Back to our scheduled programming
After the hustle of the past few days it was nice to get a quiet day at the shop. I was able to successfully assemble and test the complete transmission and shifter assembly. After doing a couple of simple manual 2nd operations on the part (deburring, threaded cross oil hole passage) I pressed the bearings in and assembled and carefully checked the drum and shifter fork alignments to assure smooth shifting performance.
Pressing the bearings in with a medium sized C-frame press.
Bearings in and parts ready to go.
Shift drum detent spring and stop in place.
Shift drum bolted in.
Shift forks and rods.
Primary and output shafts, assembly is now complete.
Another view.
Transmission, meet girdle. Girdle, say hello to transmission.
Very nice. Fit was perfect and this is one more assembly towards a running engine. It felt good to make some progress in the past weeks and I hope to continue the run of productivity!
Next update will document the machining, testing, and assembly of the various shafts, gears, and gerotor for the oil pump system. Once this is done I can test the setup and verify that the pressure and volume delivery characteristics of the pump meet my design specifications.
Keep an eye out for another update soon.
Chris
Very nice. Fit was perfect and this is one more assembly towards a running engine. It felt good to make some progress in the past weeks and I hope to continue the run of productivity!
Next update will document the machining, testing, and assembly of the various shafts, gears, and gerotor for the oil pump system. Once this is done I can test the setup and verify that the pressure and volume delivery characteristics of the pump meet my design specifications.
Keep an eye out for another update soon.
Chris
5 min of fame
The post couple of days here at the shop have been a bit different. Through AHRMA racer Kenny Cumming's contacts we've had the film crew from Velocity (formerly Discovery HD Theater) filming footage for a couple of episodes. Kenny was behind the development of my vintage fork upgrade kit and is a consistent winner with multiple AHRMA championships on his trick Seeley Norton.
One episode will be based on trying to do the ton on a new Royal Enfield at Beaver Run racetrack near Pittsburgh, PA. We helped out sort the suspension a bit for high speed operation and tried to remove all the excess equipment on the bike. I would have preferred to do a more comprehensive performance build but time limitations and available parts were extremely limited. I think at least now it won't throw the rider off!
The second episode focuses on the bike space a few friends and I share and will have break outs with each of us individually and I get to talk about my project more directly. It was fun and although there were no shouting matches or fistfights it should be worth watching. I'll make a new post when they finalize a broadcast date.
Chris
One episode will be based on trying to do the ton on a new Royal Enfield at Beaver Run racetrack near Pittsburgh, PA. We helped out sort the suspension a bit for high speed operation and tried to remove all the excess equipment on the bike. I would have preferred to do a more comprehensive performance build but time limitations and available parts were extremely limited. I think at least now it won't throw the rider off!
The second episode focuses on the bike space a few friends and I share and will have break outs with each of us individually and I get to talk about my project more directly. It was fun and although there were no shouting matches or fistfights it should be worth watching. I'll make a new post when they finalize a broadcast date.
Chris
Friday, July 15, 2011
And Back to the Mill
Just got some more time on the mill to finish out the cassette transmission plates. The last post on these ended with the first operation complete. The next steps are to machine a fixture plate and then run the 2nd operation which includes boring the bearing seats to final size with a +.0002/-0 tolerance. That's pretty tight, about 10% of the thickness of a human hair.
Here's the fixture plate, a piece of MIC-6 cast aluminum ground tooling plate with dowel and mounting holes:
Here's the part after finishing the profiles and roughing the bearing bores:
Now I'm finish machining the bearing bores with the custom boring bars ordered from Microbore:
The reason I am using such a long tool for this operation is that the same bore sizes need to be machined deep inside the lower crankcase girdle casting. By dialing in the size with these shallow parts I can use the same tool later on when line boring the block and be sure the bearings have a consistent fit. The primary and output shaft and shift drum bearings were all single point bored to size with these long tools.
Tomorrow I'll do a test fitting of the gears, shift drum and forks, the shifter pawl assembly and try to stuff it all into the crankcase girdle casting. Look for another post soon as the bottom end starts to take shape.
Chris
Here's the fixture plate, a piece of MIC-6 cast aluminum ground tooling plate with dowel and mounting holes:
Here's the part after finishing the profiles and roughing the bearing bores:
Now I'm finish machining the bearing bores with the custom boring bars ordered from Microbore:
The reason I am using such a long tool for this operation is that the same bore sizes need to be machined deep inside the lower crankcase girdle casting. By dialing in the size with these shallow parts I can use the same tool later on when line boring the block and be sure the bearings have a consistent fit. The primary and output shaft and shift drum bearings were all single point bored to size with these long tools.
Tomorrow I'll do a test fitting of the gears, shift drum and forks, the shifter pawl assembly and try to stuff it all into the crankcase girdle casting. Look for another post soon as the bottom end starts to take shape.
Chris
Friday, June 17, 2011
When the mill is busy....
Switch to the lathe. Got a bit of time in to make some parts for the front end, specifically the steering stem. Although my bike does not have forks, it does have a steering stem, one that moves with suspension travel but does not pivot with steering. The design is a throwback to my original Mk1 chassis that used a combination of tapered roller and deep groove ball bearings instead of spherical rod ends at the upright pivot. Sorry for the vintage shot but those were the early days of digital.....
Those were the early days (2001) of nearly zero rake and an air cooled Rotax single. In case anyone was wondering, do not use Daytona as a maiden voyage for a race bike, frame still warm from welding. We both survived but it was a lesson learned!
I've almost come full circle, having experimented with various bearing configurations in the quest to maximize feel and minimize friction and hysteresis in a compact package. This is an area in front end design where just equaling the feel and feedback quality of telescopic forks will be a very good result. With a linkage and multiple pivots there are many more areas where the vibrational energy that is feedback can be lost. Careful detail design can minimize this loss and is a necessity for high performance race applications but the solutions are not always obvious. For a while I was using high quality Aurora spherical rod ends that gave me easy adjustability but lacked in extended lifespan and were relatively expensive. The bearings in the current version are different styles from what was originally used and should be an improvement in feel and packaging.
Back to today's part, the steering stem. It serves to connect both suspension a-arms and provides a pivot axis for the wheel/legs/upright assembly. It has 2 bearing journals that define the steering axis, a jam nut thread, and 2 cross holes once for each a-arm.
Herre's the bare part:
The first step is to turn the main part geometry from bar stock on the CNC lathe.
Close the door, press the button and...
Open the door and presto, a part:
To assist in getting the bike dialed in I had to make several different versions of the stem. Think of them as different triple clamps and you won't be far off. In combination with other interchangeable parts they allow near independent adjustment of several important chassis parameters.
Here's the 3 different part geometries with the steering bearings that will be used.
These parts will now need to go into a 4th axis mill setup where I will add the flats and cross holes, finishing them.
That's all for now.
Those were the early days (2001) of nearly zero rake and an air cooled Rotax single. In case anyone was wondering, do not use Daytona as a maiden voyage for a race bike, frame still warm from welding. We both survived but it was a lesson learned!
I've almost come full circle, having experimented with various bearing configurations in the quest to maximize feel and minimize friction and hysteresis in a compact package. This is an area in front end design where just equaling the feel and feedback quality of telescopic forks will be a very good result. With a linkage and multiple pivots there are many more areas where the vibrational energy that is feedback can be lost. Careful detail design can minimize this loss and is a necessity for high performance race applications but the solutions are not always obvious. For a while I was using high quality Aurora spherical rod ends that gave me easy adjustability but lacked in extended lifespan and were relatively expensive. The bearings in the current version are different styles from what was originally used and should be an improvement in feel and packaging.
Back to today's part, the steering stem. It serves to connect both suspension a-arms and provides a pivot axis for the wheel/legs/upright assembly. It has 2 bearing journals that define the steering axis, a jam nut thread, and 2 cross holes once for each a-arm.
Herre's the bare part:
The first step is to turn the main part geometry from bar stock on the CNC lathe.
Close the door, press the button and...
Open the door and presto, a part:
To assist in getting the bike dialed in I had to make several different versions of the stem. Think of them as different triple clamps and you won't be far off. In combination with other interchangeable parts they allow near independent adjustment of several important chassis parameters.
Here's the 3 different part geometries with the steering bearings that will be used.
These parts will now need to go into a 4th axis mill setup where I will add the flats and cross holes, finishing them.
That's all for now.
Saturday, May 21, 2011
Finally another update
Sorry for the extended interval since the last update. I've been trying to get as much paid work as possible while it is available, the life of an independent is feast or famine, and there hasn't been much feasting lately!
Anyway I was able to get some extra time and sanity and made some progress on the transmission cassette cover. These parts are made from a billet of 7075-T651 aluminum. They hold the two transmission shafts, the shifter drum, 2 shift forks and shafts, and the selector mechanism. The transmission design allows the entire assembly to be pulled from the clutch side of the engine without having to do any other engine disassembly, making for easy ratio changes. As we are using Kawasaki transmission parts there are several available ratios from the race kit.
Here's the 2 blocks of 7075 waiting for machining:
No fixture needed for this first operation, just a wide open vice:
This side of the part was pretty straightforward, no special machining operations needed. The next side will bore the bearing pockets using some of the custom boring heads I had made. After about 15min of machining you end up with 1/2 a part and a lot of chips:
Now insert the 2nd billet and repeat:
I'll be machining the other side sometime in the next few days so an update should not be an extended wait. I hope to be able to put a big push in the coming month and get this baby running ASAP.
That's all for now.
Chris
Anyway I was able to get some extra time and sanity and made some progress on the transmission cassette cover. These parts are made from a billet of 7075-T651 aluminum. They hold the two transmission shafts, the shifter drum, 2 shift forks and shafts, and the selector mechanism. The transmission design allows the entire assembly to be pulled from the clutch side of the engine without having to do any other engine disassembly, making for easy ratio changes. As we are using Kawasaki transmission parts there are several available ratios from the race kit.
Here's the 2 blocks of 7075 waiting for machining:
No fixture needed for this first operation, just a wide open vice:
This side of the part was pretty straightforward, no special machining operations needed. The next side will bore the bearing pockets using some of the custom boring heads I had made. After about 15min of machining you end up with 1/2 a part and a lot of chips:
Now insert the 2nd billet and repeat:
That's all for now.
Chris
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