31 Jan 2010

Where did January go? A lot more got done on vacation… not that I’m complaining.

The good news is that one push-rod setup is done. Turns out that the next shorter shock size could have been used. As it is, the setup has more droop than it needs, meaning the springs will rattle loose under full extension. Not really worth the money to correct at this point. The plans will use shorter shocks unless the extra travel’s needed for softer springs… doubtful.

Again checked the wheel motion versus shock motion and it’s still as close to 1:1 as can be measured. Right now most of the bolts are either the wrong length, aren’t AN bolts, and don’t have bushings holding the rod ends in the brackets. Needless to say, they rattles a bit.

Updating the drawings goes on; parts are changing faster than the drawing modifications are happening – the consequences of the first article. It only hurts once; after it’s in the computer and in the book, then I’ll relax a little. That’s not too hard with a dog who, exactly like a 5-yr old kid, comes in every five minutes wanting to play. We both get in trouble running around the house…

24 Jan 2010

Cleaning up the chassis table does wonders for a positive mental attitude.

One rocker arm is done thought the support are not – what’s shown here is not the real deal! Not much else to show other than this because of how much time goes into designing bits. Once it’s complete and the first item produced, building more goes much faster. These use spherical bearings instead of rollers. Yes, it can be built in many different ways using many types of bearings/bushings, but the approach worked well for Kimini, so it’s used again here.

Received the Grizzly metal-cutting blades… they’re a massive 1″ wide blade and too course a tooth pitch; it’s all they had. Better blades have been ordered from elsewhere, as the 1″ wide blades are no good for going round corners. (Great for small lumbermill, though!)

Like I mentioned on the forum, I admit I’m a little down about having to cut out pre-existing tubes, tubes that were “done.” Mentally it’s a drag because it’s more that double the work, kind of like sliding down a hillside aways and having to claw myself back up. However, the silly issue pales in comparison with having your entire city collapse in an earthquake.

17 Jan 2010

Spent the day figuring out the push-rod suspension, this time in metal. A few tubes have to be cut and a few more added, but it’ll be okay.

However, the day wasn’t very productive because sometimes I get “out of phase” with the project. When that happens, not much gets done, concentration isn’t there, dumb things happen and mistakes are made. Today’s big indication of that was smashing my finger good. Hurts like hell and it’s no fun typing. We’ll see if I lose the nail. Anyhow, when things like this happen it’s time to clean up and get out before something worse happens. No point tempting fate when there’s a bandsaw nearby!

10 Jan 2010

Since the hoist was on-hand to set the bandsaw on its stand, it was used to pull the engine. The chassis is complete enough that it can come off the table. Unfortunately, dismantling the table leaves the tubing (stored on a hanging rack below the table) with no home; guess it’ll go in the rafters. The table is a beast, 2 x 6 lumber, two MDF surfaces, glued and screwed together, probably around 300 lbs. There’s no way it’s coming apart nicely – might need the chainsaw.

Anyhow, the chassis will sit on sawhorses, making access much easier, though things such as tipping the chassis over to get at the bottom become a bit dicey. How to proceed is a bit unclear:

1. Finish the chassis, cut and drill the panels, then finish the electrical, dash, brakes, clutch, reinstall the drivetrain, then drive down the road and back. Then, completely disassemble it for paint, repeating assembly once it’s back.

Or:

2. Finish the chassis, cut and drill the panels, and go straight to paint. When it comes back, <em>then</em> finish the electrical, dash, brakes, clutch, reinstall the drivetrain, get it tuned, and be done.

At the moment, the second approach seems more efficient because the engine, wiring, brake, and clutch system are installed only once. With Kimini, the first approach was used, ensuring that every bracket and hole was in place. The second approach is faster and can be just as good, but there’s a chance of missing a hole or bracket, meaning the painted chassis would have to be drilled or welded.

Then there’s the fuel map. Disassembling the engine today revealed evidence that it’s running very rich, the exhaust system contained a <em>lot</em> of raw fuel. Too much fuel washes oil off the cylinder walls, causing trouble with the rings. It seems wise to have the engine tuned before driving it, though this alone doesn’t decide which approach to use. Still, at the moment, #2 is looking faster.

In other news, I asked my brother if he was ever going to finish painting his Stalker. He said that at the moment there’s no point. His rear fenders are badly sand-blasted by grit kicked up by the front tires. Maybe I’ll use the side vents as shields.

9 Jan 2010

Mocked-up one push-rod front suspension with wood. One “feature” is that a portion of the rocker-arms will stick through the hood. Is it worth compromising the geometry (100% motion ratio) to force it below the hood? I’m thinking not, leaving it as-is. The mock-up confirms that the front shocks will be shorter than the rears.

Making the wood mockup required cutting up wood fairly accurately, and the new saw worked great. Metal is cut at around 200 feet/minute (fpm), where it runs eerily silent, while wood needs around 2800-3000 fpm. That’s when an oscillation was noticed when passing through 1800 fpm or so, like the wheels are out of balance. Visually they run true, so who knows. While it doesn’t really affect me for how I use the saw, it shouldn’t be doing that. If I had to cut at that speed it wouldn’t be unacceptable. We’ll see what Grizzly says.

Forum membership continues to grow so it looks like it’ll stick around. I tend to make daily posts in there as it’s more convenient than here.

8 Jan 2010

The Grizzly bandsaw arrived so the day was spent cleaning off the goo they put on exposed metal, then assembled it. I give them high marks for quick shipping and for how it’s put together, and 9/10 on their manual. It’s clear and well-written, walking through assembly and setup though there’s a few logical-flow problems. For example, the blade is carefully setup, yet later if it needs adjustment, it undoes all the work done earlier. Eh, I’m happy with it; the variable speed is sweet. Still waiting for the metal blades, coming from a different warehouse so for now it’s still a wood-cutting saw.

4 Jan 2010

The spherical bearings showed up – sort of. It’s a sore point with me, how companies take your money, say the stuff’s on the way, and it isn’t until you receive some of it that you discover part of it’s back-ordered. Specifically, it says, “Shipping direct from the manufacturer.” Okay, so now the book will recommend buying directly from the manufacturer instead of this business that wasn’t up front about being out of stock – what goes around comes around.

Over on the Locost forum, someone complained about my advice that reaming critical holes. He said it isn’t necessary, that drilling with a Unibit-type drill is sufficient. As proof, he showed pictures of the hole  – wow, a picture, I’m convinced. I guess if it’s pretty, it must be good, right?

Curious, I drilled three holes in some scrap material with the drill press, starting with 1/8″ pilots, then 3/8″, then 31/64″. The first hole was finish-drilled to 1/2″ with a drill bit; the second finished with a Unibit, and the third with a reamer, then all were measured with digital calipers.

I was impressed how close the 1/2″ drill bit was, 0.502″. The reamed hole was – not unexpectedly – 0.5005″, but the big surprise was the hole Unibit hole… 0.508″ – yes, you read that right. Perhaps if the Unibit was brand-new it would have been closer – perhaps not. Maybe my drill press is worn, but since the reamed hole was accurate, and the drill and Unibit were not, that’s proof enough for me. So the next time says something’s “fine” because of appearance, be sure to do your own research.

Anyway… the good news is that the bandsaw’s been ordered, from Grizzly 🙂