Chuck

We had company this weekend, but got out there and hit it this afternoon. Found some bearing bronze bushings, I'd already made one for the lever pivot, forgot to take a picture. Made the cam. 2017-11-25_04-52-34 by Charles Stottlemyer, on Flickr 2017-11-25_04-52-52 by Charles Stottlemyer, on Flickr Trial fit up and everything works. Even a blind hog finds an acorn now and then. 2017-11-25_04-52-09 by Charles Stottlemyer, on Flickr Made a coupler out of some ever present Delrin.. no picture again.. and hooked it up. Here are the springs to test. The Guzzi spring is in the center, .080" springs at the bottom, .071 springs at the top. Various amounts of preload. 2017-11-25_05-45-36 by Charles Stottlemyer, on Flickr Merrily clacking away, shifting 8600 times per hour. 2017-11-25_04-51-30 by Charles Stottlemyer, on Flickr Liberally squirted a mix of STP and 15-15 syn on moving stuff. I hope this isn't just a test of my low speed motor or gearbox. It was getting pretty warm after a half hour, so put a box fan on high pointed at the whole works, and now just have to be patient. Any takers on how long the Guzzi spring will go?

I get it. I'm not interested in a one day "National" in a bar in a big city.

What else needs to be said? Works for me, too. b

I doubt it will need stress relief. Most springs aren't. We'll find out after a few 10s of thousands shifts., *assuming* the gearbox of my little low speed motor holds up.

Austin is finishing up his little production job, so I'll have access to the mill over the holidays. I did learn a little more this morning. A lot of spring pressure is not a good thing. It tends to over shift, and neutral is hard to find. Too little spring pressure is not a good thing, either. It makes shifting up a function of the adjustment of the eccentric. The sacked spring I took out of the Mighty Scura has *no* pressure at the end of the up shift. Just for grins, I made an .080" spring with 2 1/2 active coils. I didn't think it would work, but it at least fits *this* particular shifter gizmo (technical term) and shifts beautifully, too. Should have plenty of travel, but I haven't run that through the spring calculator yet. I'll be back. Edit: Oh, yeah. Maximum safe travel is 56 degrees. (!) I'll look into it a little farther. 2017-11-22_11-33-07 by Charles Stottlemyer, on Flickr

It's not complicated to my eyes, and we need to test several spring versions.

I'm planning on using the bending fixture with a 15mm post and the cam driven by my low speed motor somehow. "Some sort of lever" also TBD in the picture of the cad drawing will pivot on the pin. The drawing shows the spring relaxed and at 39 degrees torsion. No Guzzi parts (except the spring) will be harmed in this exercise..

Same as one weekend in the Santa Monica Mountains, right? Seriously, that's a whole lot of shifting. Hopefully the rest of the pre-selector is up for the abuse - but I don't mind if you kill it. I'll just have a spare tranny with a dead pre-selector. All in the name of science. Oh, don't worry. I'll just be simulating what the preselector does. About the only wear yours is getting is taking it apart, trying a different spring, etc. I'm getting really good at that.

I've really not been slackin on this job.. busy. Experimented with a different way of holding the wire. Used the other end of the bending tool lever. Made several springs using this guide in the tool post. It's faster, but maybe not as repeatable. 2017-11-21_06-24-16 by Charles Stottlemyer, on Flickr Supervised Austin making steel mill oiler nozzles.. 2017-11-21_06-24-35 by Charles Stottlemyer, on Flickr I think he's a keeper, btw.. Rewired the motor.. I'ma believer in using what you brung.. I'll be able to use it as a hanger door thingy after this project. 2017-11-21_06-27-20 by Charles Stottlemyer, on Flickr Did *some* testing on various springs with my new scientific fish scale.. 2017-11-21_06-37-03 by Charles Stottlemyer, on Flickr Started on the design for the cam on the spring abuser ™. 2017-11-21_06-28-33 by Charles Stottlemyer, on Flickr Let's see now, 46 rpm X 3 = 138 X 60=8280 shifts per hour. That's 198720 shifts per 24 hours. I'll also make a couple of .080 springs with 2 1/2 active coils. My guess is they'll bind up, though. Still have to make all this stuff and get it working reliably, of course.. but i think we're on the right track. Shouldn't be much longer.

Yeah, the Grease O is basically a modernized Centauro IHMO.

Yeah. Give me a machine that is alive. I actually have to *know* how to make it work. It seems to appreciate it, and I have fun doing it. What's not to like about that? The Kid's very early 1100 Spot is very much that way. Of course, he gets it. His shiny modern Grease O sits.

Nope.

Thanks for that!

I've never ridden the ST3, but understand they're the best of the lot. Good score, Scud..

Here's my antique electrocutioner's special low speed electric motor that a guy gave me (Guzzi content) many years ago. Since it's reversible, I've planned on using it to open my manual hanger door.. but have never got a round toit. I gingerly plugged it in and tripped the switch. 46 rpm. That'll work. This will give me an excuse to rewire this sucker. 2017-11-19_11-42-20 by Charles Stottlemyer, on Flickr

I had a shift return spring break in the Mighty Scura.. Maybe it was an anomaly? The Mighty Scura *has* been shifted a lot. Pete had MPH go through the bike, and a new pawl spring was installed at that time. I've put 17000 miles (roughly) on it since. *Most* of that time has been spent in the Santa Monica and other mountains, and when not there, on the 5, 10, 405 etc. getting there, and shifting a lot. We have to simulate enough shifts per minute to test these things in a reasonable amount of time.. I ain't gettin any younger.. Let's see, now.. 1 shift per second would be 60 per minute times 60 would be 3600 per hour. I wonder if that would over heat the spring and temper it? It will lose it's ju ju at 300 degrees F, according to my supplier. We may have to use spray mist coolant or something..

Put the lever over the long pin and make the first bend. 2017-11-18_03-49-10 by Charles Stottlemyer, on Flickr That goes in the hole and is clamped by the screw with the wrench in it. 2017-11-18_03-53-19 by Charles Stottlemyer, on Flickr Oh, BTW, the lathe is unplugged from the power source during this operation. Leaving a chuck key, etc. in the chuck is verboten. Lining up the groove in the brass piece 2017-11-18_03-53-36 by Charles Stottlemyer, on Flickr and sliding the plastic on top. The groove is .005" shallow at the end, so clamp pressure is controlled by the front set screw. 2017-11-18_03-53-53 by Charles Stottlemyer, on Flickr Using the chuck wrench as a lever, the chuck is rotated. 2017-11-18_04-05-32 by Charles Stottlemyer, on Flickr The spring has to be over bent. You can see the two dashes on the back of the chuck that I decided was correct. It springs back about 90 degrees. 2017-11-18_04-06-00 by Charles Stottlemyer, on Flickr Here's the new spring on the bending fixture. As predicted by the Machinerys handbook, the ID is perfect. All that is left is to put the lever over the tall pin and bend the 45 degree angle. 2017-11-18_04-07-52 by Charles Stottlemyer, on Flickr Here's the first complete spring. The extra length will be cut off with the fiber wheel. We *know* the Guzzi spring at the bottom breaks, so the new one has a little more active coil. 2017-11-18_04-08-03 by Charles Stottlemyer, on Flickr Ok, let's try our other design with the .071 music wire.. 2017-11-18_04-08-25 by Charles Stottlemyer, on Flickr Using the spring calculator posted previously in this thread, this spring has considerably more "safe travel," and shouldn't break in service. To do it properly, I'll have to turn down the mandrel. The ID of the lighter wire is .030" or so bigger, but tried it anyway. Here it is installed. You can see the extra turn of wire here.. 2017-11-18_04-08-38 by Charles Stottlemyer, on Flickr It works so well if I were just making one for my bike, I'd bolt this preselector on and go with it. However, I'm fully aware that if you have spent some time and/or money on a project, your opinion may very well be colored. Time for testing. The new scientific "fish scale" will be here early next week, and I'll be doodling on some kind of cam arrangement that mimics the spring travel several times per revolution of my low speed motor. Stay tuned.

As promised, how to make a spring. At the end of Friday's installment, our hero was making the mandrel for the spring to sit on the bending fixture. As he was finishing it.. the cutting tool dug in at the end of the cut and made a crow digger. (technical term) Spent some time adjusting the gibs of the cross slide and saddle, and turned another. Center drill.. 2017-11-18_03-48-17 by Charles Stottlemyer, on Flickr and drill for a 1/4"bolt. If you drill 1/64" undersize first, the finish drill will be pretty close to on size. Plenty close enough for this work. 2017-11-18_03-48-27 by Charles Stottlemyer, on Flickr All that is left is to use a parting tool to cut it off, and face off that side. 2017-11-18_03-48-42 by Charles Stottlemyer, on Flickr Now we can bolt it to the fixture and make springs. Some die blue on the fixture, and a Guzzi spring gives the angle of the bend, 45 degrees, and I scribed a line at 90 degrees to eyeball the bend on the short arm. 2017-11-18_03-48-57 by Charles Stottlemyer, on Flickr The boss is calling me to breakfast, back later. Don't touch that dial!

Jim said.. If you look at the picture on page 7 of the preselector shaft, you'll see (barely) how the end of the spring rides up in the radius at the end of travel. I made the short leg a little longer to avoid that. You could go in with a die grinder and move that radius back a little. While you are there,radius and polish the edge. The reason it is breaking in the coil is simply over travel of the spring. A less than optimum design.

Flickr is down right now, so can't show any pictures. I mentioned to Lucky Phil about the radius the end of the spring rides up on, and made the new spring a little longer so it wouldn't do that. Radiusing the edge and polishing it would help, too. I made a for real .080 dia. spring today.. and an .071 dia. spring with 2.45 active coils. I would need to make a smaller mandrel to get the ID of the spring the same as the .080 spring.. it's .040" bigger. Figured I'd try it any way, and the preselector has never shifted better. We're still very early into this thing, but I'm cautiously optimistic. It shifts up or down as fast as I can move it.

Oh, no problem. I already have the red suspenders for being the oldest at the Ohio rally. Dang! This scale is 9 bux!! Why am I here in the house instead of out in the shop making springs? I don't want to walk out there in the rain and lightning.

Ordered this morning. Starting to get some *real* money tied up in this project..

Scud say Agreed. It is a *very* competent Sport tourer, basically a sport bike with bags. At that time, I couldn't handle the riding position. I thought I was in pretty good shape for a guy my age, but a personal trainer thought differently. He told me he'd get me back on sport bikes, all I had to do was strengthen my core and thighs. After nearly killing me for a while, I found out he was right, but by that time the Duck was gone. I can still ride the Monza ok, and it's pretty dedicated, too. "It's more fun to ride a slow bike fast than a fast bike slow.."

once I rode a Centauro, I went with Guzzi. I understand the ST3 is the best of the lot. Oh, BTW Scud.. back in the day, I made a billet setup to put conventional bars on the ST2-3-4 bikes, so if you want to put apes on it, I'm your man. You did that Chuck? Sweet! Due to Ducati being Ducati lots of parts from many other bikes work on it. I put conventional bars on mine by simply replacing the top triple with one from a monster. Fun times. Yeah, of course this is ancient history, but it had the flying D logo on it. I *may* have a picture somewhere in the archives.

The Kid called me last night and said he and Nora are in. Add a 1100 Spot to the mix.