tag:blogger.com,1999:blog-59218315100471792292012-02-14T20:12:53.654-08:00Mechanical engineering, bicycles, and Etc. Not necessarily chronological, USE LABELS TO JUMP TO CATEGORIES.John Schmidthttp://www.blogger.com/profile/12334758662673021859noreply@blogger.comBlogger271100tag:blogger.com,1999:blog-5921831510047179229.post-77163228482375159762010-08-09T10:46:00.000-07:002010-08-09T10:59:55.386-07:00

Went to the goat rocks wilderness area this past weekend. Very nice! The sign posted on the trailhead said it was by far one of the most popular backpack areas (I had last been there 10 years ago... ) and they weren't kidding. the parking was full and we passed or saw perhaps 60 plus hikers on Saturday... But it's a big area and we found a nice place to camp and it still felt nice and private,

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-55838303589765142402010-07-01T09:36:00.000-07:002011-04-11T10:25:14.295-07:00

In past posts I have written considerable amount about bicycle wheels. I am a proponent of high spoke tensions and do believe if you build the wheel correctly (stress relieve etc) the spokes should never break.So imagine my surprise when I had two broken spokes on the drive side of tandem wheel (36 spoke 30mm deep rim). Did I put too much tension into the spokes? The answer is evidently yes, for

johnnoreply@blogger.com2tag:blogger.com,1999:blog-5921831510047179229.post-24041104424528686042010-02-17T08:06:00.000-08:002010-02-17T08:19:35.526-08:00

With the new digital TV, occasionally OPB runs shows from Oregon state university. Flipping through the channels on a Saturday evening a couple weeks ago, this lecture was on. Very good, I couldn't help but sit and listen to it. Very well spoken. Discusses farming, seeds, etc. Not to be missed !! 44 minutes. I found the video online also, it is here.:http://oregonstate.edu/media/xqltlClick the

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-84109550410414718552010-01-26T11:07:00.000-08:002010-02-08T12:53:03.111-08:00

heard this on NPR the other day. Looks like a good book to pick up read. Bomb Power: The Modern Presidency and the National Security State (Hardcover)http://www.npr.org/templates/story/story.php?storyId=122946351The comment on that page by john hamilton is right up the alley with what james kunstler writes in "the long emergency": "...The future does not bode well for the kind of system we have

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-28559161785043015452010-01-05T20:03:00.000-08:002010-01-07T19:40:59.323-08:00

Just got done reading "The Long Emergency". Very well written and thought out. Learned a lot ! We might have to go back to horsepower. No not that horsepower, like a real Horse, with four legs, Power.Started reading "How to talk so kids will listen & listen so kids will talk". Wow a very practical useful book. Not just for people who have young children. Published in 1980 ! Where have i

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-22342264224216706572009-11-17T09:23:00.000-08:002010-01-07T19:41:07.856-08:00

Been pretty busy the last month or so. First went up to Edmonton for a week of work at Sulzer service center. Nice service center, nice people. It was cold (below freezing) and yes snowed as well. Very car-centric. Would have been nearly impossible to go for a walk. Went to the huge indoor mall in edmonton. The indoor roller coaster was quite impressive! But the mall itself.. I don't know...

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-1077190814131360652009-10-09T13:52:00.000-07:002009-10-11T17:41:20.530-07:00

Recently picked up a cannondale racing frame and fork off of ebay for $230. It is light, by far the lightest bike i have ever owned. It is fairly stiff also. It had some issues: slight misalignment issues, wore-out dropouts, a bunch of corrision spots under the paint. But, for the most part a well made frame that rides nice and is fun to ride, and will make an excellent racing bike..It came

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-88197915946484023322009-10-09T13:44:00.000-07:002009-10-11T17:42:09.792-07:00

Here's what i was up to in September. Takes way too much time! Looks really nice now with paint on it though !This side was really bad, and the paint was really thick and cracked, so I took it all off. I have two huge garbage bags full of paint scraping just from this side of the house and only about 2/3rds up. Some of the siding needed repair also...The rest of the house will get a normal

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-24601541984890208862009-10-08T23:02:00.000-07:002009-10-11T17:42:51.216-07:00

Fixing a rear dropout does not require replacement. This method is quick, and precise and strong. Timewise, shouldn't take more then 15 minutes to 30 minutes. This one took a little longer because i also drilled out the helicoil thread repair and brazed in a proper 10x1mm "sleeve" made from a nut. Here is a pic after i straightened it best i could. I considered welding the crack as is, but i

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-13216958176991863202009-08-17T23:33:00.000-07:002009-08-18T14:12:18.612-07:00

Bought an old burley tandem for $400. ~15 yrs old ? but lightly used and sensibly made (i like the internal shifter cables..). Fairly heavy, but sturdy.I added my new tandem wheels (the original tandem wheel had a bent axle even from light use). I re-machined the front bottom bracket eccentric to take a 110 mm spindle rather than the bowlegged length of 126 mm. Added V-brakes which of course are

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-62920876768272610872009-08-04T09:33:00.000-07:002009-10-09T14:12:51.267-07:00

Been making some nice garage shelves. The secret to making them fast and accurate is to Dado cut (shelve slots) the fours corner posts all together. In this particular case i had a 2x8 that I slotted, then i ripped into 4 pieces. With subsequent bracing makes for a lightweight and strong shelves. Finally got the metal shaper body hauled away to Metro Metals. 740 lbs. Using a pry bar, 4x4's and

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-2237120842345721382009-07-11T16:44:00.000-07:002009-07-15T14:04:58.056-07:00

If the little bearing on end of the pedal fails the pedal body can come off the spindle. The rest of the ride will be one-legged (if your lucky, if un-lucky a bad crash and ambulance ride) . Now i have had this happen to me, but not with an eggbeater, and I was lucky and didn't crash. To help prevent this from happening an extra bearing can be added. In addition to another bearing (686 sealed,

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-49954228309312861032009-07-11T16:39:00.000-07:002009-07-15T16:36:36.593-07:00

Been taking steel to Metro Metals. They have a pretty nice and fast process and helpful and friendly people. Weigh on the way in, dump steel, weigh on the way out, they print a check a give to you. This was $50 worth of steel,(I added a couple more items, and had 700 lbs of steel !) Disassembling the metal shaper, still need to get the body hauled. Maybe next weekend if my little truck can handle

johnnoreply@blogger.com2tag:blogger.com,1999:blog-5921831510047179229.post-40835968419622248342009-07-11T16:16:00.000-07:002011-04-11T10:25:41.811-07:00

Some pictures of working on tandem wheel.Here are the spokes, the nipples, the washers, nut driver. The nut driver bit had to make myself, with a file, brazing and then turning on the lathe. It is square to fit over the end of the nipples. The nipples took a long time to prep. I had to lathe-turn each one to get rid of the slot and to put a slight curve to them. Here is a picture of the

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-76236966576293887272009-07-11T16:04:00.000-07:002010-03-30T13:28:56.583-07:00

From previous post , the tensile strength and cross section areas are233 ksi (2.34 mm) 0.0066658 in*in240 ksi (2.0 mm) 0.0048695 in*in245 ksi (1.8 mm) 0.0039443 in*inThen it follows that:The ultimate tensile load of 2.34mm spoke is 1553 lbfThe ultimate tensile load of 2.0 mm spoke is 1169 lbfThe ultimate tensile load of 1.8 mm spoke is 966 lbfThe spoke is predicted to break in tension at those

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-923972156836817012009-07-11T16:02:00.000-07:002010-07-01T09:54:17.871-07:00

How many revolutions should a wheel last (need for fatique calcs)? Infinite is great of course, but what is reasonable? 10-20 years ? Rim-braked rims wear thin of course, so... For now I will go with15 years. Say 25 miles per day. 9125 mile per year. 210 cm (0.00130488 mile) circumference wheel (700x23c). 9125 miles/0.001305 miles per revolution = 6,992,882 revs per year or ~ 7 million wheel

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-38770158625400084892009-06-27T22:48:00.000-07:002009-06-30T21:02:46.796-07:00

Since I am too cheap to buy an expensive tandem hub (at least for the cheap tandem I am working on), i modified a track hub. Dual threaded for freewheel and drum brake. The Miche hub worked nicely for several reasons. 1. More threads, more nicely done, than other track hubs. As many threads as on a normal hub. I don't want to "strip" the threads with the extra power of a tandem.2. 12x28

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-70615894701930926622009-06-26T08:21:00.000-07:002009-06-30T21:03:27.086-07:00

Been in Allentown PA for interaction / training with the Pro Pump Services guys. Been here nearly two weeks. Visited two Powerplants, a foundry, and our Sulzer service center. Here we are at Cogentrix plant in Northampton that burns waste coal (basically coal that was "dumped" and is sitting in piles around Pennsylvania).Here we are measuring vibration on a booster pump (a small pump, yes

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-83433055446904781992009-06-05T22:55:00.000-07:002009-06-27T23:31:25.573-07:00

With the new digital TV, I was able to watch the Giro. I noticed slideouts occurring on corners with dry pavement. Watching the riders go down, it was apparent what went wrong: Not enough weight on the front wheel.If you watch carefully, just prior to the front wheel slipping, the rider's weight is back on the saddle. One can find all kinds of information on how to corner, the majority of

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-39733182938137927052009-05-23T22:53:00.000-07:002009-07-11T17:07:40.986-07:00

Ever wonder what is up with the large pulleys recently showing up on the inexpensive shimano derailluers? Decent engineering. Fairly common knowledge since the 18th century days of mechanical clock making*, to minimize friction loss, the ratio of axle diameter to wheel diameter should be minimized. ( e.g. the axle/bearing diameter as small as possible, the wheel/pulley as big as possilble).

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-52959255596502810522009-05-11T23:14:00.000-07:002009-06-05T23:59:27.729-07:00

The pedal to crank joint is a pretty poor design.  Obviously thought up before bolt joints/preload was understood, nonetheless it is functional.  For example, a 9/16" bolt can easily be preloaded to around 5 tons of force! Which one should not do or you will deform your crank threads (or maybe even make a miniature slinky).  So the 9/16"  axle size is obviously chosen for stiffness.   Yet if not

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-41590847123575720962009-03-24T21:24:00.000-07:002010-03-30T08:49:55.668-07:00

Spoke Material and PropertiesFrom spoke manufacturer's websites:Dt spokes: 18/10 stainlessWheelsmith: 304 stainless *Sapim spokes: 18/8 stainless. Strength = 1080(157 ksi)-1180 mpa (basic spoke, middle section) , Strength=1350 mpa (196 ksi) (normal double butted spoke, 2/1.8) "Strength" unfortunately don't know if this is Tensile or Yield Strength. *(304 ss is 18-20 Cr and 8-10 Ni, so basically

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-28367776364449472612009-03-21T22:53:00.000-07:002011-04-11T13:42:53.921-07:00

A few projects I have worked on in the last couple months:  After quite a few other methods tried, by far the easiest and fastest way to take a old steerer tube out of a fork crown. Use bimetal hole saws.  Started with a 7/8 " ended with a 1".  Took only a few minutes. Now it is ready for a new steerer tube. There is a story of welders needed up high on a water tower.  The job was advertised as

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-39236191924425907302009-03-07T11:50:00.000-08:002009-07-11T15:43:46.719-07:00

I've built spoked wheels since 1989. A lot of engineering mechanics and design concepts are nicely illustrated with a bicycle wheel. The concepts are not necessarily complicated but can still be hard to grasp. Even with engineering degrees (although I understood the physics behind the wheel) I did not really start to "know" spoked wheel until i sat down and starting doing calculations and

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-88666181233350878302009-02-24T14:00:00.000-08:002009-06-05T23:59:58.398-07:00

Have you ever wondered about  quick-release clamp force? (that which holds your wheel in the frame) ?   Way back, this came up in a forum, and it was mentioned that Bicycling Magazine actually tested/measured it! (imagine the time wasted!) At the time,  I commented that, that was pretty silly because it is easily calculated. Which I didn't bother to do until now and yes it is easy calculation!   

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-88522426341486043422009-02-24T13:06:00.000-08:002009-02-26T17:15:19.830-08:00

Bought an old craftsman saw for $75.  My initial interest was because it has its own vacuum with overhead and cabinet suction.   But also I know see this is a very solid saw that will be worth future updating.  Had a lot of rust but cleaned up nicely.   One of my first improvements:  I didn't like the tilt screw, basically a ball running on stamped sheet metal...  a lot of friction.  So I updated

johnnoreply@blogger.com0tag:blogger.com,1999:blog-5921831510047179229.post-5950750244924210152009-02-20T03:14:00.000-08:002010-10-07T13:51:38.290-07:00

In general this applies to Single Speed or Fixed Gear bicycles with a horizontal slot dropout but could also apply to Tandems or to any bicycle where you want to insure a secure wheel. How to insure your rear wheel doesn't slip (with subsequent chain throw).Although this is common sense, most of the hub manufacturers don't have it figured out (using small diamter serrated locknuts means you

johnnoreply@blogger.com0