Member postings for Fulmen

I agree with Robert, you're at the limit of what you can measure with retail equipment. There are 4 measurements, so even 1% per measurement will get you a total of 4%. Getting it right to within 5% is pretty decent.

If you have a furnace I would give carburizing a try. All you need is a metal box with a removable lid, bbq charcoal and soda.

Fill the box with ground up charcoal mixed with 10-20% soda. Bury the parts completely, heat to 800-850C or so for a couple of hours, then quench and temper.

Based on this (engineersedge.com) you can expect the surface to be 10HRC harder than the core.

I tried a gluten free beer made from chestnuts once. Guess what it tasted like.

Beer.

If they can do that, then surely they can make edible food without gluten?

EN8 is in the bottom range of what is considered hardenable (I think that's a word even though the spellcheck flags it), don't think you can expect more than 1/4" depth even in water (Jominy test). But it should work on small parts.

First thing I would try is to reduce the tempering down to 300-350C. If that's not good enough I would start looking for a better steel. Carburizing isn't that hard, but you really need a furnace with some sort of temperature control.

My advice is: Don't. Shrink fits is hard on small parts, they loose heat too fast. Anything short of a sausage-in-a-hangar fit will surely bind halfway down the joint and seize permanently.

At least take the time to work out a reliable method in advance. As for the details, consult this page: https://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

It can be done with a 45° mill if you can tilt the head 45° in both X and Y.

Well done.

Neil has some good advice, printing is not like machining. Much of the strength is in the skin, it also affects filament use and printing time. And the material is directional like wood, so consider your printing orientation carefully.

Perhaps a more relevant comparison: 55J is the same as dropping the 19kg machine 3 inches.

My math says it's equivalent to dropping a 1kg weight from a height of 5,5m. Not sure if that helps.

No, he's right. An alternator produces alternating current, red/blue indicates direct current.

Could be motor oil pored in a random container. never know with second hand stuff.

I've been pondering that myself, but I'm not sure if it's the diameter (IIRC 0,01-0,02mm below a whole number for both the shaft and rollers) or the flat spots that cause it to seize up. I didn't take the new clutch apart to check the dimensions, figuring I was doomed to break something.

I think I can make new rollers, haven't measured the hardness but I'm sure I can find a suitable material. But I'm not so sure about regrinding the shaft. Best I can muster is a diy dremel toolpost grinder.

So the first order of business should be to reduce wear on the new one. Restoring the starter lockout seems like a sensible approach. I never liked the original solution (requiring the clutch to be engaged), but the bike has a lamp indicating neutral. Adding a relay to that might be a more elegant solution.

The "new" bendix clutch works, so old Maggie is back on the road yet again. But I always try to figure out why a part failed in the first place. In this case it might be as simple as 40years of wear, but there is another possibility.

Originally the starter was wired through the clutch handle, requiring the clutch to be engaged for starting. This was annoying as heck, in part due to the crappy switch they used so I quickly removed that. But that does result in the occasional "jump start" when I've left the bike in gear. It hasn't bothered me much really but it does put more strain on the starter...

I think you have good instincts, always assume the most beneficial interpretation.

I interpret "rounout" as TIR while "concentricity" is the axial displacement, but English isn't my first language so please don't take my word for it.

What do you mean by "old"? I could imagine a true Briton chewing on broken glass before using a metric thread to this very day Or have you guys conceded that fight yet? It's a very nice system once you get to know it.

Besides nobody uses anything other than metric coarse (M8x1,25) unless they really have to.

@Baz: You're right, I have been in the sun too long today. I started thinking in ratios, not difference for some reason.

What I don't understand is why they were running at atmospheric pressures. IIRC you can handle 2-3bar abs without decomp, and you have two hours for that if needed.

They do make the coolest toys ever.

This was a cowboy operator with no regard for safety. The founder was even quoted as saying that current regulations "needlessly prioritized passenger safety over commercial innovation"...

Yeah. Don't have much sympathy for rich tourists disturbing a grave site for fun.

Edit: Bill makes a valid point. But I still think there is a difference between remembering something like the Holocaust and respecting a grave site.

Also, people are drowning in the Mediterranean every day without anyone giving a hoot. But the moment a couple of rich a***oles go down the whole world holds it's breath. The only real sad part is that Musk wasn't on board.

Edited By Fulmen on 22/06/2023 19:38:53

Edited By JasonB on 23/06/2023 07:41:09