Youtube hearted comments of crazypj (@1crazypj).

  1. I can't believe I feel like you left us in suspense on a machining channel ! 🤣
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  2. .................and you wonder why 'Made in America' costs so much?
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  3. I've been 'playing' with engines about 50 years and this is the best video explanation I've seen. Any time I learn something new is always good. I had never heard of semi solid casting before although I had an idea of high pressure die cast parts due to various places my father worked. I thank you and wish I was in a better position so I could send some cash your way
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  4. That was the simplest and best explanation I have ever seen on con-rod angularity and piston speed. (and I've seen and read a lot over last ~50 years) It's something I've been aware of but probably too much math in previous explanations? Primary and secondary forces and balance shafts, about the same as I knew from 1970's but the first part was absolutely brilliant
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  5. That was a really good history lesson. Thanks.
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  6. Very simple, Nicola Tesla wanted to do it 120 years ago but Westinghouse couldn't put a meter on it to charge people 😁
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  7. Honda used dual balancers on 1978 CB250 and CB400 twin and continued until the 1985 CB450 twin, they ran at crank speed though In 1969, BSA/Triumph were building inline 3 with a 120 degree 'twisted' crank so technology has been available a long time and obviously wouldn't cost any more to twist 75 degrees than 90 degrees More than 20 years ago, I read the article about Phil Irvin's Triumph. Back then, re-phased Yamaha XS 650's were being built and in vogue. As the crank is splined in the middle, moving 3 splines gave an 83 degree offset, far cheaper than the custom made main-shaft to get a 270 degree twin and more or less half way between the two. Yamaha actually built XS650 as a 270 twin for racing How can so many people still get the concept so totally wrong? There is NOTHING about balance and everything about acceleration as reasoning for it in the original article, exactly as you describe around 17 minutes Reduction in mass and lighter flywheel, one piston at maximum acceleration while the other at top of stroke. In practice, lighter flywheels give better lap times The Triumph crank was around 200mm diameter with main flywheel 60mm wide and a bore spacing around 90mm, so, quite heavy. The reduction in vibration was a secondary factor and not the primary reason for 75 degree crank The article is available online, I may even have a copy of it somewhere. BTW, Didn't KTM say they used a narrow angle to make motor shorter to have shorter wheelbase?
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  8. I think it's really impressive that you can put out so many incredibly interesting video's so often without a full production team. I've been a subscriber since you had less and could respond to individual replies, with over 992K subscribers and the video's you put out, I would be surprised you can reply to any comments. The engines behind you make a great display. I stopped watching Scotty Kilmer video's, sometimes his opinions are just wrong and based on his biases. Trail riding video's on your CRF isn't a problem for me, do what you like doing or you will get burned out, personally I haven't posted a video for 6~7 years and last motorcycle video was 2011. A channel just for motorcycle riding you do would be of great interest to me as it is something I have a ton of experience with (riding since 1968) I can fully understand a paid subscription but personally, I can't afford Patreon so I wouldn't be watching it though. (getting old suck but still beats the alternative 😁) Edit, my avatar is me racing Enduro in 1980
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  9. This was such a good video I watched it again
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  10. First time I've seen ceramic tips used on manual machine since late 1970's. Ceramics didn't 'work' on cast iron, cut too interrupted but were great on steel. Ceramic tip made real quick work of the chrome/hardened layer. Using carbide tools was a real pain (particularly brazed carbide) Probably made several 'miles' of piston rods for various machines. Kinda miss having a large rigid lathe to work with
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  11. Without the gantry crane you would need to be an Olympic weightlifter! That was some heavy chunks of steel. The inner radius tool must be pretty stout to make a cut that wide without chatter Surprised just how good the finish was with a parting /grooving tool, polishing looked like it didn't take too long?
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  12. That looked damn scary even at 70 rpm, big chunks of steel spinning around! Is it probable the dumper was so overloaded the bore has 'stretched' in the direction of force applied while braking ? (although that would probably show up as 'egg shaped'?) That could account for surfaces that didn't have any wear being so out of round
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  13. I guess it's designed to be used until something wears out then scrapped as repair is going to be somewhere between difficult and impossible 'on site' ?
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  14. Just like workers everywhere 110~150+ years ago. How do you think 'giants of Industry' made their millions?
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  15. I really thought they un-machined area's were going to get a shot of Cat yellow 😁
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  16.  @d4a  Thanks for reply. I've said it before but I'll say it again, I have no idea how you find out this stuff but I'm glad you do.
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  17. I was wondering why they would cut up a pipe then flatten it in the first place as they were forming it into channel? A flat sheet would have been a better starting point if channel the size they actually needed wasn't available? (it probably is direct from steel works?) Maybe they can get boatloads of pipe free from somewhere?
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  18.  @makingmistakeswithgreg  That was a very interesting write up. About 45 years ago, I welded up rear mudguard mount on my brothers Honda S90. I was doing some form of rod melting a few days a week so 'in practice' (plus my eyesight and hearing were a LOT better) It was probably around 0.020" thick and I remember 1/16" rod with a cheap buzz box on minimum setting, probably 20A (I didn't know what I didn't know so just did it) Few years later, I learned to use Oxy/DA gas weld but was still self taught so picked up the usual bad habits. Anyway, I now have an older Craftsman AC buzz box with DC terminals. (what I could afford at the time) Only have 7018 and 6013 rods, (welding suppliers in Central Florida seem to charge a massive premium for anything else) Pretty lousy at welding as I may not switch it on for months or years at a time and I know you can easily get out of practice . I'm finding 1/8" rods are heating up too fast and getting red hot, even on relatively low AC amp settings. (60-90 amps) Is it arc length too short or do I have a fundamental misunderstanding of settings? (would I be better off using DC?) I haven't checked yet but have you done a very basic set up for those of us without a Miller or Lincoln? (I see you have a cheap vs expensive but it looks like a newer inverter welder?) Thanks for the video's, I don't learn too well without seeing whats happening
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  19. Interesting explanation. You did miss out the 'nails scraping down blackboard' I'm probably not the only one who remembers people almost being sick when it happened 😁
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  20. That's the worst one I've seen and I thought I had seen some pretty destroyed parts. It's the cheapest way to lock piston and is really piss poor method. Never had issues with cast iron wear rings, they work real well, as long as the fit is checked properly and adjusted (seems not many fitters know what to do and just take stuff out of box then bolt things together?) Tank return side filters were around in the 1990's, at least on majority of larger stuff I worked on. It really helps when you have had to make and repair things, you get a much better understanding of how they work and what can go wrong (often better than the person who designed it)
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