I am modding the tail lift on my truck to carry a lightweight race car. I
need to make a frame, the side arms will be 65 x 25 mm steel plate, the
cross pieces 65 mm hollow box, about 16 gauge. I have a 220 amp TIG and a
150 amp MIG, I am better with the MIG as the TIG is a new acquisition,
which is the better to use? The other snag with the TIG is I only have thin
filler rods, and a torch which only takes 3/32 tungstens. Thanks for any
advice!

Chris wrote:
I am modding the tail lift on my truck to carry a lightweight race car. I
need to make a frame, the side arms will be 65 x 25 mm steel plate, the
cross pieces 65 mm hollow box, about 16 gauge. I have a 220 amp TIG and a
150 amp MIG, I am better with the MIG as the TIG is a new acquisition,
which is the better to use? The other snag with the TIG is I only have thin
filler rods, and a torch which only takes 3/32 tungstens. Thanks for any
advice!

Chris
I can't help you, but I'm sure curious about your project. Are you
going to haul a formula car in a pickup using a modified "Tommy Lift" to
load it?

Rex B

side arms are 65mm x25 mm PLATE?? As in SOLID cross section?

Chris wrote:
I am modding the tail lift on my truck to carry a lightweight race car. I
need to make a frame, the side arms will be 65 x 25 mm steel plate, the
cross pieces 65 mm hollow box, about 16 gauge. I have a 220 amp TIG and a
150 amp MIG, I am better with the MIG as the TIG is a new acquisition,
which is the better to use? The other snag with the TIG is I only have thin
filler rods, and a torch which only takes 3/32 tungstens. Thanks for any
advice!

"RoyJ" wrote in message
k.net...
side arms are 65mm x25 mm PLATE?? As in SOLID cross section?

Chris wrote:
I am modding the tail lift on my truck to carry a lightweight race car. I
need to make a frame, the side arms will be 65 x 25 mm steel plate, the
cross pieces 65 mm hollow box, about 16 gauge. I have a 220 amp TIG and a
150 amp MIG, I am better with the MIG as the TIG is a new acquisition,
which is the better to use? The other snag with the TIG is I only have
thin
filler rods, and a torch which only takes 3/32 tungstens. Thanks for any
advice!

What a tank!!!

xman

On Thu, 12 Jan 2006 16:06:07 -0600, Rex B wrote:

Chris wrote:
I am modding the tail lift on my truck to carry a lightweight race car. I
need to make a frame, the side arms will be 65 x 25 mm steel plate, the
cross pieces 65 mm hollow box, about 16 gauge. I have a 220 amp TIG and a
150 amp MIG, I am better with the MIG as the TIG is a new acquisition,
which is the better to use? The other snag with the TIG is I only have thin
filler rods, and a torch which only takes 3/32 tungstens. Thanks for any
advice!

Chris
I can't help you, but I'm sure curious about your project. Are you
going to haul a formula car in a pickup using a modified "Tommy Lift" to
load it?

Rex B

It's a 7.5 tonne Mercedes box with a existing tailift, modded quite
`orribly to extend it. I am starting afresh, and the 65 x 25 material is to
make much longer one piece hinge arms that will fit in the extrusions that
form the sides of the alloy platform.

On Fri, 13 Jan 2006 01:47:08 GMT, RoyJ wrote:

side arms are 65mm x25 mm PLATE?? As in SOLID cross section?

Correct, they'll form one piece hing arms, the existing ones are this
section, the platform will be 8 feet long with a fold out extension to go
to 12 feet.

A solid form has a very low strength to mass ratio compared to tube or
other structural shapes. Not to mention HEAVY!!

All my charts are in English units so I'll have to change systems (sorry
about that!)

Your proposed arm is about 1"x 2.55" which has a section modulus of
1.083 in^3 and weighs 8.56 pounds per foot. In the states we would
normally choose a suitable rectangular tube. For example, 2"x4" x.120 is
readily avilable, weighs 4.7 pounds per foot and has a section modulus
of .958 in^3 (The most exact match is either .134 or .148" wall , not
commonly available)

This sheds around 40% of the weight, is much easier to fabircate, is
much easier to aquire. Bumping up the wall thickness gives you a linear
increase in strength, increasing the long dimension is a squared function.

You may have other reasons to use the solid but rectangular tube is nice
stuff.

cheers.




Chris wrote:
On Fri, 13 Jan 2006 01:47:08 GMT, RoyJ wrote:


side arms are 65mm x25 mm PLATE?? As in SOLID cross section?


Correct, they'll form one piece hing arms, the existing ones are this
section, the platform will be 8 feet long with a fold out extension to go
to 12 feet.