Search found 70 matches

by Jeff Piazza
Tue Feb 03, 2009 11:48 am
Forum: Car & Semi-Truck Photos
Topic: 2009 Parent/Sibling car Speed Racer - Mach 5
Replies: 17
Views: 45986

Re: 2009 Parent/Sibling car Speed Racer - Mach 5

Absolutely awesome!

It looks like you made your own windshield. If so, can you say a few words on how you accomplished that?
by Jeff Piazza
Fri Jan 30, 2009 7:29 am
Forum: Car & Semi-Truck Construction
Topic: Making a Friction Test Ring
Replies: 13
Views: 5158

Re: Making a Friction Test Ring

I've had only limited time to pursue this further during the week, but it looks like the balancing issues are greater than I thought. The whole assembly shows fairly extreme "chatter" beyond a relatively low speed. I tried doing a static balance by identifying the heavy side and attempting to estima...
by Jeff Piazza
Mon Jan 26, 2009 10:42 am
Forum: Car & Semi-Truck Construction
Topic: Making a Friction Test Ring
Replies: 13
Views: 5158

Re: Making a Friction Test Ring

Yes, balance is definitely a concern -- there's a clear heavy point at present. Lead flashing seems not to be of uniform thickness, although I can't tell how much that's due to handling after it leaves the store. I may look at melting lead if there's a "v2.0". I'm pretty ambivalent about the whole m...
by Jeff Piazza
Mon Jan 26, 2009 7:34 am
Forum: Car & Semi-Truck Construction
Topic: Making a Friction Test Ring
Replies: 13
Views: 5158

Making a Friction Test Ring

A recent derbytalk.com thread ( http://www.derbytalk.com/viewtopic.php?t=4420 ) inspired me to try building Stan Pope's spin testing rig described at http://www.stanpope.net/pwafm.htm . I found building the rig to be a project in itself, and wanted to share the details of the experience here. The go...
by Jeff Piazza
Wed Jan 07, 2009 9:39 am
Forum: Car & Semi-Truck Construction
Topic: Painting stripes/pinstriping
Replies: 10
Views: 7001

Re: Painting stripes/pinstriping

We've had decent results painting the main body color first, masking with masking tape, and then spraying the stripe color over. The resulting edge was quite good, with only small defects that were noticeable only under close inspection. An alternative we've used for the pinstripe effect you're desc...
by Jeff Piazza
Tue Jan 06, 2009 9:32 pm
Forum: Car & Semi-Truck Construction
Topic: Tape on Pro Body Tool to add wheel tilt
Replies: 5
Views: 2249

Re: Tape on Pro Body Tool to add wheel tilt

You may have been looking for this: http://derbytalk.com/viewtopic.php?p=32018#32018, which shows the technique of using a drill bit to tilt the pro body tool by a known amount, for a specific cant.
by Jeff Piazza
Wed Dec 17, 2008 4:31 pm
Forum: Car & Semi-Truck Construction
Topic: Pro Body Tool
Replies: 4
Views: 1878

Re: Pro Body Tool

We're obliged to use the slots, but can fill them. We use five-minute epoxy, which works well, with these two caveats: 1. It's necessary to clamp wax paper on both sides of the block, otherwise the epoxy will flow out the sides of the slot, just where it's most needed. 2. The packaging on five-minut...
by Jeff Piazza
Thu Jul 24, 2008 10:03 am
Forum: Car & Semi-Truck Construction
Topic: Brad Point Drill Bit...she's too fat for me
Replies: 12
Views: 6612

Re: Brad Point Drill Bit...she's too fat for me

I can confirm that a #44 brad point bit (from Fuller) drills holes that are significantly looser than those drilled with a conventional HSS bit. I drilled axle holes using each bit in a drill press, and then again using each bit in pin vise with a Pro Body Tool. Both brad point holes were looser tha...
by Jeff Piazza
Mon Jun 02, 2008 10:06 am
Forum: Construction Workshops
Topic: Post your jigs and other time saving devices (some pics)
Replies: 16
Views: 28379

Re: Post your jigs and other time saving devices (some pics)

Here's a pretty cool belt sander stand from Instructables: http://www.instructables.com/id/Belt-Sander-Stand/.

I recently built a stand based on this, but I haven't tried it at a workshop yet.

/JEP
by Jeff Piazza
Wed Apr 23, 2008 5:28 am
Forum: Car & Semi-Truck Construction
Topic: Q-tip shaft diameters
Replies: 31
Views: 17122

Q-tip shaft diameters

For the last two seasons, we've been using Q-tip shafts (that is, with the little cotton balls cut off) for polishing wheel bores (in the style of Doc Jobe, http://www.pinewoodderbyphysics.com/pdf%20files/Lecture%2017.pdf ) and for burnishing graphite into the bore. This year, my wife bought a new p...