crossmember update (more pics..)

[treed2@u.washington.edu (T. Reed)]

> > Yeah, they slip inside the hollow bar and then will be bolted securely to
> > it through a horizontal bolt going through both the bar and the solid
> > stub. The purpose is to provide a threaded hole in the end of the hollow
> > bar (because I don't have the equipment to weld a nut at the end), and to
> > allow for adjustment of the bar length to fit an individual chassis that
> > may have stretched or deformed over time.
>
> There may be no need to bolt this. The forces are up and down This item
> can't help the bumper mounting areas to stay the same distance apart. As
> long as the core support is still there this dimention will not change.

You're probably right. I think I will bolt it anyway though, just because
I'm planning on painting all the bare metal surfaces of the bar and
bolting the "stub" in place will keep it from rubbing its paint off in
the event that it does move for some reason. It's also just "cleaner" -
I mean, theoretically you could use a steel cable tied between the two
strut bearings instead of an upper stress bar.. the bar might be
"overkill" because of that- but its much cleaner.. sort of a weird analogy
but I think you see what I mean.

There's nothing wrong with a /little/ overengineering :) It's when things
get out of hand that there's a problem.

> > No, I don't have a welder so I have no plans to weld it.. nothing is
> > preventing anybody from acquiring one and welding it themselves, though.
>
> Fair enough

.. which I guess is another plus for offering unpainted bars (easier to
weld)

> That is because there is a steel bushing in the motor mount to prevent the
> bolt from crushing it. This is not the case with your hollow tube. Be
> careful with the amount of torque you apply here.

True. I actually considered putting a piece of solid bar inside the hollow
at the middle to prevent it from crushing.. but when I actually tried
torquing down these bolts I decided it was unnecessary - you'd really have
to be a gorilla to overtorque these. They immediately got very hard to
tighten further as soon as I hit that "point". Not saying that its not
possible with an impact wrench or breaker bar, but in the cramped space
under the car with a box wrench on one end and a ratchet on the other
you're not going to succeed at crushing the hollow bar without the intent
to do so (or complete ignorance of tightening torque..)

> > Welding is the traditional way of making "stress bars" or other
> > aftermarket braces. I think that a well designed bolt-together unit can be
> > an improvement on a welded one - it allows holes to be oversized and
> > individual parts to be shifted up, down, left or right to fit a particular
> > car. This is the same mechanism of adjustment the factory uses for the
> > front motor mount cup bracket. The holes in the bracket are twice the
> > diameter of the bolts. The holes that I've drilled are much closer to the
> > bolt size but still slightly oversize (you have to make sure the bolt will
> > still fit through the hole after painting too!)
>
> Your holes should be equally large to allow for adjustment of that mount as
> well.

Actually, because the middle plate is stationary after installed, they
need only be big enough to align the holes in the plate with the threaded
holes in the crossmember. The front mount itself adjusts completely
independently of the plate.

Still, I agree with your point here (the ability to align the front mount
-is- important)

> > With a welded bar you would need to remove the front bumper or try and
> > hold it up with your knees while the bumper bolts are out, and
> > simulaneously lower the bar to the ground without dropping it and
> > chipping the paint. I can imagine how much of a pain this would be because
> > its hard enough to install the brackets for the bolt-on bar individually!
>
> I believe you might have mis-understood me here. I was only advocating that
> the center vertical member to be welded. That would still retain the
> atributes that you have detailed here.

Ah, yes. Now I can see your point. My only rebuttal is that my
metalworking skills are not perfect.. its very possible that the whole
thing is slightly cockeyed. There are no straight lines to compare it to
under the car because the body itself is curved at the bottom of the
crossmember. Welding it takes out a small amount of adjustment for
manufacturing tolerances. Other than that, though.. I can see no problem
with it. (of course, I still don't have a welder! :)

> Welding just the one piece would not alter the shipping in any significant
> way.

Agree.

> > It is about 1mm less wide on either side than the front mount cup
> > bracket. It just came out that way, I didn't really plan it either way.
> > Doesn't seem like the extra 2mm would make any difference other than
> > increasing weight.
>
> It looked larger to me so of course I had to ask.

Yeah, sorry about the shoddy pictures. I -will- put up some better (and
higher res) ones when I get a chance to take better pictures.

> > If I make any more I will probably change the shape of the bracket to be
> > rounded there.
>
> Been there, done that, oops!

Now that I think of it, I could only round it in that spot on the
passenger side bracket. The driver side bracket has a cutout there to
allow the radiator to be removed and installed without having the remove
the bracket. The little plastic bulge where the radiator fan thermoswitch
sits was interfering with the bracket so I had to carve away a little meat
there.. see http://students.washington.edu/~treed2/xmember7.jpg

> > > What is the gauge of the vertical side members?
> >
> > They are roughly 3mm thick.
>
> Should be plenty.
>
> Over all you have put together a great piece. My observations are from the
> point of view of my being my #1 customer. I do weld so of course a welding
> solution would come to mind. There are welders in your area who would draw a
> bead or two where you specified. You would be surprised at how affordable it
> is too.

I guess I would - I tend to shy away from businesses in general because
in my experience it always seems like they're trying to screw you. I
haven't let anybody else work on my car since I bought the thing (with the
exception of the windshield replacement people, and they poked a hole in
my headliner with their pointy little seal tool.. bastards!) Whenever I
get a quote for something it is always ridiculous (even at junkyards.. the
local yard wanted $100 for a pair of taillights and wouldn't negotiate). I
pretty much just "don't bother" any more. I stick with the few parts
suppliers out there that are reasonable (parts4vws, mark@aab, local vw
shops, etc)

I should just save up for a welder and go to "welding camp" or something

:)

> Well done!

Thanks, now I just have to sit back and step on the gas to see if it makes
any difference.

-Toby

> Rick Alexander
>