Tuesday, July 22, 2008

Doing Sketchup of the Adapter

I took a few hours last night to learn more about Google Sketchup. It's quite a powerful tool for visualization, but I realize now that, unless you buy the expensive "Pro" edition, don't bother trying to export any valuable information from it.

I took the adapter plate into a precision measurement shop to get all the hole locations for the Civic transmission bell housing. Here is the picture on the measurement table at the shop.

The spacer ring behind the adapter plate is much simpler. I simply took measurements with a caliper and a steel ruler to generate the above.

Some numbers:

  • Overall spacer diameter: 9.25" (not critical)
  • Internal hole diameter: 4" (not critical)
  • Total thickness: 2 3/8"
  • Outer diameter of raised ring: 8.5"
  • Inner diameter of raised ring: 6" (not critical)
  • Thickness of raised ring: 3/16" (not critical if over 3/16")
  • The recessed holes are 3/8" holes that hold bolts for the Warp9/ADC9" motor face
  • The sinks for the recessed holes are 19/32" diameter and .7" deep (approximate)
  • The threaded holes have 1/2"-13 threads and are 1.4" deep
  • The threaded holes have centers on a 7.25" diameter circle
  • The depression inside the raised ring is 5/16" deep

Here is a partial drawing of the adapter hub for the motor shaft into the rear of the flywheel. I didn't draw the taper-lock on the bottom end due to its complexity. There's actually a depression in the center of the hub above but, due to limitations in Sketchup, I wasn't able to delete all the facets correctly, so it looks like a circle drawn on the top.

Some numbers:

  • The six outer holes have 12mm threads and are 25mm deep
  • The outer holes are evenly spaced at 60 degrees and have centers on a 63mm diameter circle
  • The outer diameter of the hub is 80mm
  • The top part of the hub is 33.5mm thick
  • The overall height of the hub is 59mm thick
  • The bottom end of the hub is 2.25" in diameter
  • The depression in the top for the pilot bearing is 33mm in diameter and 2.5mm deep
  • The holes for the bolts to pull in the taper lock are evenly spaced with centers on a 33mm circle.
  • The central hole through the hub is 19mm in diameter

Here is a hacked drawing of the adapter plate. All the hole locations are correct because I typed them in from the precision measurement shop. The outline is just a quick hand drawing. Note that it doesn't have the cutout in the lower left corner for the CV joint shaft.

Here are the numbers for the hole locations I got from the CMM shop. I had a royal pain of a time getting a table into this blog, so you'll just have to click on this photo instead.

DISCLAIMER: With the exception of the precision hole measurements, all numbers are subject to my human error with a steel ruler and digital calipers. I do NOT recommend using these numbers to fabricate your own hub or adapter plate since there are probably slight errors in the numbers.

LICENSE RELEASE: This adapter plate and hub are proprietary designs from Electro Automotive and are not licensed under the TAPR Open Hardware License for this project. I'm including dimensions here as an academic exercise.


Perry Harrington said...

Tim, purchasing an adapter plate designed by Electro Automotive, then copying that design and re-licensing it under a license they themselves didn't agree to, violates the terms of the license, since it wasn't your design or information to license.

Electro Automotive has significant resources invested in each adapter design. Their design is proprietary and purchasing an adapter doesn't give you rights to the design, only a finished article.

You had a spare Civic transmission, why didn't you make all of the measurements off that yourself?

TimK said...

Hi Perry,

I completely agree that it's wrong to purchase Electro Auto's adapter and copy it for reproduction. I'm not attempting to relicense it, although having the TAPR Open Hardware License at the top of the blog might imply it. That's something I'll have to figure out. Perhaps I can add a note to this blog entry and note that the adapter plate is copyright Electro Automotive.
The reason I got the hole locations off the adapter plate instead of the transmission was sheer laziness. The transmission is dirty, heavy and awkward. The adapter plate is clean, light and easily transportable.
The intent was to get the hole locations in case someone else wanted to design and create their own adapter plate, not using the remaining ElectroAuto design.
Thanks for the heads up.
Cheers, Tim