Archive for March, 2009

30
Mar

Playing with countering direct sun

   Posted by: Mark    in Our children

Last week I played a bit with trying to balance direct-sun with the AlienBee. I had tried this weeks ago with the Vivitar 285HV, but couldn’t get it to put out enough light to get the effect I wanted. I put the B400 on top of a light stand, added my 54″ umbrella, and grabbed Lindsey for the first round of test shots. I was shooting directly into the sun, so my aperture was up over 20. I had the umbrella set up for shoot-through, and put it about three feet from Lindsey as I framed her against the sun. I adjusted a few things, and then shot a series with Isaiah, too. The B400 was great for this, and the 16-35 2.8 (thank you, Dad, for the loaner!!!!) allows awesome perspectives.

Some things I learned, most of which probably seem obvious:

  • Direct sun, even when the subject doesn’t have the sun directly in their eyes, will cause squinting if there’s too much reflecting around them. Shade may often be better to avoid this.
  • Use a sandbag on the lightstand!
  • (For the results I wanted) be sure the aperture is open enough to expose the ground/grass under by about 2 stops. Much more than that and it gets too dark.
  • Be wary of focus issues when pointed directly into the sun. My Canon 40D choked a bit, though this is not unexpected.

090325_0173

090325_0150

090325_0153

2
Mar

Building an MG-TC pedal car: Part 4

   Posted by: Mark    in Pedal car

Refer to the Introduction for links to all of the posts in this project.

This post is focused on the steering and drive components of the pedal car. These two areas have been the source of 95% of the problems, stalls, and headache for me. Admittedly, the primary reason for this trouble is my decision to use bicycle wheels instead of the plan’s plywood wheels. But no matter what I do, I can’t convince myself to eliminate the wire wheels. So I’m stuck with trying to come up with efficient ways to make it all work.

One of the commenters on the Introduction post indicated that he had built one of these years ago and used go-kart parts for the steering, which resulted in me searching for some parts I could use. I did find some web sites with decent prices, and am now waiting for a couple of sets of ball joints and tie rods, $20 with shipping. I may also break down and buy a cheap MIG welder for a few things (I’ve been wanting one anyway), but haven’t decided on that yet.

It seems I am now regularly finding ways to improve on this whole project. Bearings are so cheap that using pipe fittings and brass bushings seems silly. Kingpin assemblies are relatively inexpensive and much more clean than what the plans call for (though I am still a bit impressed with that whole assembly, made with pipe fittings). Chain drive doesn’t look all that difficult, especially with the decision to use bicycle wheels anyway, and the possibility of having a welder (though this raises some issues such as braking and coasting, but I’m planning to put together a summary at the end of all of this to address some of these things).

This post will be updated after the tie-rods and joints arrive.

*** UPDATE 3/5/09 ***

The ball joints are here, but only one tie-rod made it. They apparently only had one in stock, but the other should be coming (soon?). I expect to get a bit done this weekend, and look forward to posting some pictures!

*** UPDATE 6/8/09 ***

Hot dog! All the steering came together tonight, praise the Lord! I have a few bolts to replace since I got the wrong size, but I figured out how to make a pittman arm without any welding! Man, I’m so excited to get over this hurdle. I’ll post pics as soon asĀ  I have the correct bolts (tomorrow?). I still need to attach the steering wheel, but that’s the easy part.

Tags: ,