Search found 70 matches

by Jeff Piazza
Thu Jan 14, 2010 9:19 am
Forum: Construction Workshops
Topic: 2 Hour Workshop
Replies: 5
Views: 7011

Re: 2 Hour Workshop

In our pack, I run two separate events: a "hints and tips" night with a presentation and demonstrations on physics and practicalities, and then a fully separate workshop on a Saturday morning. I think a workshop is not a great venue for presenting, both because the room is laid out for a different p...
by Jeff Piazza
Thu Jan 14, 2010 8:06 am
Forum: Car & Semi-Truck Construction
Topic: Bore Ream Guide
Replies: 23
Views: 9071

Re: Bore Ream Guide

Here is the Bore Ream Guide. What you can't see in the pic is that the 5/8" Dia steel cylinder is really two cylinders glued together with super glue. The interior of the guide is 3/8" for most of the length but 0.098" for about 1/8" at each end. The reason for the large diameter interior is that I...
by Jeff Piazza
Sun Aug 02, 2009 6:05 am
Forum: Other Vendors
Topic: Carson Optical digital microscope on sale
Replies: 1
Views: 2454

Carson Optical digital microscope on sale

Just came across this today, buy.com has the Carson Optical MM-740 zPix 200 digital microscope on sale for $50. http://www.buy.com/prod/carson-optical-mm-740-zpix-200-zoom-digital-microscope/q/loc/17250/209118860.html I don't have any experience with this particular model, but I have found a digital...
by Jeff Piazza
Sat Apr 11, 2009 7:23 am
Forum: General Car/Truck Racer Topics
Topic: Camber Analysis Help Needed:
Replies: 13
Views: 4598

Re: Camber Analysis Help Needed:

I think I must be missing something in the question. Suppose rear axles cambered negative (axle heads away from the track) about 3 degrees. Further, suppose that the rear axles are aligned so that the wheels roll straight when the car is on the flat. I think that this means that a plane through the ...
by Jeff Piazza
Tue Apr 07, 2009 1:56 pm
Forum: Car & Semi-Truck Construction
Topic: Axle Angle
Replies: 5
Views: 3048

Re: Axle Angle

If the axle's orientation is such that it's 0.001 inches closer to a reference plane at the nail head than where it meets the body, and those two points are 0.5 inches apart (as measured along the axle), then the axle angle is arcsin(0.001/0.5) = 0.11 degrees or so. I think the challenge would be to...
by Jeff Piazza
Tue Apr 07, 2009 7:10 am
Forum: Car & Semi-Truck Construction
Topic: Alignment mysteries
Replies: 9
Views: 3776

Re: Alignment mysteries

I actually did have an "aha" moment last year about camber and toe canceling each other out in one direction and combining in the other, but somehow blocked it out this year in thinking about the question. Thanks to Stan's reminder, we found that the right rear wheel was, indeed, down and back. It a...
by Jeff Piazza
Mon Mar 30, 2009 10:24 am
Forum: Car & Semi-Truck Construction
Topic: Alignment mysteries
Replies: 9
Views: 3776

Alignment mysteries

Oldest son and I are working on alignment for this year's car. The car was a disappointing 6th in the pack race, but we're hoping to help him defend his district championship (for rank) from last year. On Saturday we had gotten to a point where the rear wheels stayed where they were placed (in or ou...
by Jeff Piazza
Sat Mar 28, 2009 9:06 am
Forum: Car & Semi-Truck Construction
Topic: Wheel bore photos
Replies: 9
Views: 5064

Wheel bore photos

The discussion in this thread http://derbytalk.com/viewtopic.php?t=4815 got me curious, so I tried capturing some pictures of wheel bores before and after prep. I'm not very expert at this, but I thought the results were interesting enough to share. Here are some 60x images of a "fresh out of the bo...
by Jeff Piazza
Sat Mar 21, 2009 7:03 pm
Forum: Other Vendors
Topic: How to sharpen a Pro Wheel Shaver XT II?
Replies: 12
Views: 9226

Re: How to sharpen a Pro Wheel Shaver XT II?

Wow. I just tried the "index finger and thumb" method reported by quadad. My sharpening "stone" is 600 grit sandpaper glued to a piece of glass, and I use baby oil (=mineral oil) as a lubricant. A visible change in the blade took just a few minutes. The difference in the experience of using the tool...
by Jeff Piazza
Wed Mar 18, 2009 9:02 pm
Forum: Planning, Preps & Running the Race
Topic: Capturing car photos at check-in
Replies: 4
Views: 3660

Re: Capturing car photos at check-in

Our process this year was stickers on both top and bottom, the latter mainly to help identify the car in case the top sticker were to fall off. None did, but we'd have just affixed a new top sticker if one had. I tried to arrange the process so that the car got a tag, then photographed, then sticker...
by Jeff Piazza
Mon Mar 16, 2009 9:39 am
Forum: Planning, Preps & Running the Race
Topic: Capturing car photos at check-in
Replies: 4
Views: 3660

Capturing car photos at check-in

We just had our pack race on Saturday. One new thing we tried this year was having a photo stand and getting pictures of each of the cars as they checked in. Two desk lamps, a tripod, and an ordinary digital camera yielded good results. We had pre-printed tags with the boys' names, rank, and car num...
by Jeff Piazza
Sun Mar 15, 2009 12:09 pm
Forum: Other Vendors
Topic: How to sharpen a Pro Wheel Shaver XT II?
Replies: 12
Views: 9226

Re: How to sharpen a Pro Wheel Shaver XT II?

I have the sharpening jig shown in the picture, but the shaver blade is much too short for the jig to match the existing bevel.
by Jeff Piazza
Mon Mar 09, 2009 9:00 am
Forum: Other Vendors
Topic: How to sharpen a Pro Wheel Shaver XT II?
Replies: 12
Views: 9226

How to sharpen a Pro Wheel Shaver XT II?

I suspect the blade in my shaver is dull. I've never sharpened it before, and I don't really know how to go about it. It looks to me like the blade actually has three faces, as there's a thin "top" that connects the flat back to the beveled front. The "top" appears to be intentional, and not merely ...
by Jeff Piazza
Fri Feb 13, 2009 6:49 am
Forum: Car & Semi-Truck Construction
Topic: Q-tip shaft diameters
Replies: 31
Views: 17122

Re: Q-tip shaft diameters

Here's an update, most of a year later: I replaced the box of oversized Q-tips in the master bathroom, since it had minimal utility for PWD. As I mentioned in another post, I found enough well-sized Q-tips in an old-style box to get us through last season. Over the summer, I found a nearly-full box ...
by Jeff Piazza
Tue Feb 10, 2009 10:43 am
Forum: Car & Semi-Truck Construction
Topic: Do you glue your axles?
Replies: 28
Views: 17458

Re: Do you glue your axles?

Sounds silly but could you epoxy the slot. let it harden then drill the holes? We did this successfully last year, using a Pro Body Tool to drill. One word of caution: after 24 hours, our five-minute epoxy had a taffy-like consistency in the middle, that grabbed the bit more securely than the drill...