T3 tube-through-tube joints - history
T3 tube-through-tube joints - history
(OP)
Can anyone direct me to historical design references to what Ford (F-150 frame) and John Deere now refer to as "T3" or "tube through-tube" joints? The joints are generally at 90 degrees (or possibly from 75 to 105 degrees) and are not telescoping joints.
Based on a photo, Alex Moulton (suspension designer of the early Austin-Mini) appears to have used a round horizontal tube (quill) which fully pierced the seat tube of the 1960's Moulton bicycle.
It appears that "round tube through tube" joints have been around for sometime, but none of my associates are familiar with the history of the practice. Does anyone know the historically correct terminology for this type of joint connection?
Thanks-
Gordo35
Based on a photo, Alex Moulton (suspension designer of the early Austin-Mini) appears to have used a round horizontal tube (quill) which fully pierced the seat tube of the 1960's Moulton bicycle.
It appears that "round tube through tube" joints have been around for sometime, but none of my associates are familiar with the history of the practice. Does anyone know the historically correct terminology for this type of joint connection?
Thanks-
Gordo35





RE: T3 tube-through-tube joints - history
RE: T3 tube-through-tube joints - history
Ford describes T3 joints as: "... tube-through-tube frame design, where the cross members pass through the section of the frame-rails, creating an inherently stronger joint. These joints are then completely welded around the perimeter for a fully boxed seam.".
Ford F-150 (and Explorer) frame-rails are now a full rectangular box section, rather than the former "C" channels. Holes are cut in both the inner and outer sides of the rectangular box sections, in order that the cross members can be welded to both the inner and outer sides of the box section. Alex Moulton used essentially the same technique with round tubes.
Thanks-
Gordo35
RE: T3 tube-through-tube joints - history
If the efficency of a nasty old box to box butt joint is 50-60%, a tube through box joint can have an efficiency of around 90-95%
Exactly how that efficiency is defined depends on your goals and geometry.
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: T3 tube-through-tube joints - history
Thanks regarding the 1955 Thunderbird tube-through-tube information!
I purchased my first auto in 1969, a turquoise 1955 Thunderbird! I regret having agreed to sell it by phone, while I was stationed in Germany. Although, my wife (of 34 years) has told me her roommates advised her to date me because of the '55 Thunderbird.
What experience have you had with the '55 Thunderbird?
Thanks-
Gordo35
RE: T3 tube-through-tube joints - history
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: T3 tube-through-tube joints - history
Have seen quite a few of your replies lately on various subjects and to various folks - appreciate your style, helpfullness and apparently wide knowledge plus common sense.
May have some questions myself some day.
Paul