Chuck

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.

I was just taking a trip down memory lane.. btw, when I stopped in the Duck dealer to get Ohlins fork seals and oil this spring, there was a Rosso sitting in the parking lot. I thought, "Oh, Conners must be here." Went over and looked, and it wasn't Rosie. Pristine, low mileage. When I asked about why it was there, the manager just said some guy dropped it off for service. (!)

It should be ok on your Coppa, but the shaft was 1mm oversized on the earlier bikes. This would cause coil binding when the ID of the torsion spring became smaller as the legs rotated. In this thread, we've discovered that the Guzzi design puts the spring into over travel. That is what we are trying to cure.. either by a different torsion spring or a coil spring. To be determined..

Well, it's not like Scud is running out of LeMans any time soon. My last Duck was an ST2, and 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.

The Ohlins are a hand job, too.

My pleasure, Docc.. I like making stuff. It's what I do..

Alrighty, proof of concept worked out, now it's time to make a spring. We need a bending jig, though.. so draw it on the cad 2017-11-17_05-16-13 by Charles Stottlemyer, on Flickr The green represents the spring, the blue some dowels, and the brown will be the lever that bends the wire. The numbers on the right are code to drive the cnc. Found a piece of aluminum in my good junk pile, and drilled and reamed the three holes for pins and tapped the bigger one for a bolt to hold a mandrel that just fits the ID of the spring. 2017-11-17_05-16-01 by Charles Stottlemyer, on Flickr I was a mold maker in a previous lifetime, and this is a hardened ejector pin.. used to eject parts off of a mold. IMG_20171117_163040512 by Charles Stottlemyer, on Flickr My aluminum piece is 1/2 inch thick, so cut 2 pins 3/4" long, and one 1" long with a fiber wheel in a die grinder. 2017-11-17_05-15-38 by Charles Stottlemyer, on Flickr Put the pins in the plate, and we're about done. The lever that will bend the spring is also shown. Forgot to take a picture while making it. It'll be turned over and pivot on the long pin on the right to bend the wire. IMG_20171117_170230229 by Charles Stottlemyer, on Flickr All that's left is to turn the mandrel, so chucked up a piece of mild steel I found in the good junk box.. and.. Tweeeet. Quitting whistle. It's beer o'clock. 2017-11-17_05-15-15 by Charles Stottlemyer, on Flickr More tomorrow, with any luck at all..

That would be no. I'm doing good just remembering to shoot an occasional still with my cell fone. Takes two hands to do this stuff.. Dark is much faster.

The Kid.. being an aircraft mechanic thought he'd like to know what the oil temp was, so he called MG cycle. Gordon said, " I'll sell you one, but you won't like what you see. Then, what are you going to do about it?" That Gordon is a salesman, now.. The Kid decided he was probably right.

Wanderer Maybe the valves got stuck in the guides. You have to pull the heads to check... Uhh, it's a little late, but no you don't.

Thanks. I'll show how to make a spring when I get the tooling finished. Scud said.. I'll also try the .071" dia. spring at 890 and 895 degrees. The brass piece has a groove for that wire on the other side. I'm doing a little thinking about how to make a test fixture as we type. I have a low speed electric motor..

^^^^I'm making the short leg of the spring a little longer (about .050") so it doesn't ride up quite so far in that radius, too.

Ahh, Dang! Caught me.. I screwed up a $10000 taillight reflex pin bundle when I was an apprentice *many* years ago, and don't do math in my head. Period. If I write it down, I'll see the error.. even (or maybe especially) simple stuff.

I wonder if drugs were involved?