FW: Uprights

[Teritius D. Fortune]

From: Teritius D. Fortune [mailto:teri...@yahoo.com]
Sent: Thursday, March 23, 2006 11:34 PM
To: Open-Source-Sport...@googlegroups.com
Subject: Uprights

Hello all,

Last time I spoke (wrote) I mentioned an upright that would cost us less
than $200 per corner. This e-mail is in furtherance of that description.

This is the upright I'm using on my Levensfere project; it's made from 1/4"
steel plate and pre-cut into the appropriate shape. Of course, since
Levensfere is a little heavier than the car we're designing here, the
material wouldn't have to be 1/4" thick. The components are purchased and
welded by the purchaser/builder or they could be done by a third party. I
know a fabricator who would give us a good price if we gave him the
business. Anyway, the materials for each upright would cost less than $100
and we are looking at $40/hour to weld them. This would take less than one
hour to weld, so we're looking at $140 for a finished upright.

If someone has designed the geometry already, I'd be more than happy to
design the components of the uprights and submit them for the group's
approval.

Also, I have seen that we are getting together a parts list or, as we called
it at Elan, a BOM (bill of materials). If there's interest, I don't mind
submitting for group use the vehicle parts list template used for every car
I've designed and we could customize it together.

Let me know what the group wants to do.

Teritius D. Fortune
900 Legacy Park Drive #915
Lawrenceville, GA 30043
Tel: (678) 368-4542
Fax: (678) 407-2345

[Daniel Heineck]

After much waffling about welded vs. alum uprights I chose alum
uprights as a better solution for our use. No doubt I can make a
stiffer steel upright, but manufacturability is questionable. Sure you
have an individual that can make a batch right now, but what about in a
few years? Alum uprights would be much much easier to go to a properly
equipped shop with than sheet steel.

Cheers,

Daniel

[Teritius D. Fortune]

Daniel - Maybe I've missed something in the postings but you've lost me on the manufacturability issues; are  you suggesting cast aluminum uprights?  If we're considering welded aluminum, I'm sure you understand that welding steel is much easier than welding aluminum.  I would have larger concerns about having a shop weld aluminum than welding steel.

 

I'm glad you've brought up this issue because we, as a group, will need to address a few pertinent questions sometime within the near future.  How are going to go about paying for the tooling needed to build this car?  My purpose in suggesting what essentially becomes a flat-pack upright was that the tooling costs are isolated to the individual.  If we are going with sandcast or diecast aluminum uprights, then we have to pay for the molds and the final machining of the finished components.  I'm flexible, though; let me know what the group thinks.

[Daniel Heineck]

Mr. Fortune,

I was more implying machining from al billet to be honest. Cast is IMO
out of the question, as I agree with you that sheet steel uprights are
much more doable than a cast part. Also, I don't like the idea of a
welded alum upright, as heat treatment becomes very difficult.

Manufacturability in general is an issue that will rear its ugly head
very soon. All the fixures and molds will either need to be self built
or contracted. I haven't breached that process at all, as I'm still
much more working on determining how to implement the vision of the
car.

Cheers,
Daniel

[Teritius D. Fortune]

Daniel,

I tend to come off a little strongly when I communicate, please don't let it
put you off as I was only trying to make a point. It's the project manager
coming out of me.

As for the Mr. Fortune part, well, I'm too young to be a 'mister'. Call me
Teritius (tair - ah - tis).

Machining an upright from billet sounds like a good idea but it would take
forever to CNC it, so there would be a corresponding increase in cost. On
the other hand, a 2" x 4" x 10" (estimated size of upright) block of billet
aluminum would weigh around eight pounds before machining and we could buy
those all day long for under $40. That's less expensive than the solution I
proposed and the two would weigh about the same, so let's put our heads
together and see if we can come up with a solution for this.

Manufacturability specifically is my forte so I don't mind pricing and
sourcing, then bringing quotes back to the group. Otherwise, we can take a
poll now and everyone could chip in, letting us know what skills they have.
This way, we could reduce the tooling costs by having everyone in the group
produce the tooling in their garages.

As far as your other e-mail, that's no problem with optimizing rack
position. Typically, I go for 100% Ackerman as a start then I try to
eliminate bump steer. I'll give it a go as soon as you send me those
numbers.

Kind regards,
Teritius

Mr. Fortune,

Cheers,
Daniel

--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.1.385 / Virus Database: 268.3.1/292 - Release Date: 3/24/2006

[Daniel Heineck]

Tertius,

I typically err on the side of being cautius with age, so I figure it's
more polite to address someone formally and be corrected than the other
way around. Manufacturability is the least of my know how, so I will
certainly learn plenty from your experiences.

Steering optimization for me has been to first remove bump, then work
ackerman. The current theory is to make the upright with a bolt on
steering arm, which should provide variable ackerman percentages. In
my opinion, I wouldn't be surprised if we stay very close to 100%, with
a course dominated by higher radius corners using more anti and a
smaller radius course using more ackerman. But we can discuss this as
we look at the curves.

Daniel

[Teritius D. Fortune]

Daniel,

The more I think about it, the more I think you have the better solution for
the uprights. They are more durable, cost less, and though they would take
more machining, I think the overall product would be less expensive.

I've let Allan Staniforth submit a photo to best describe how I usually go
about eliminating bump steer. It'll be an iterative process in eliminating
bump steer and obtaining the Ackerman we're looking for.

As an aside, I've also noticed on Sports Racer net that Fast Forward
provides uprights at around $200 each. I don't know if we've ever
considered these, but we just might be re-inventing the wheel. Just wanted
to throw it out there so that everyone knows about it.

Regards,
Teritius

-----Original Message-----
From: Open-Source-Sport...@googlegroups.com
[mailto:Open-Source-Sport...@googlegroups.com]On Behalf
Of Daniel Heineck
Sent: Monday, March 27, 2006 7:13 PM
To: Open Source Sports Racer Initiative
Subject: Re: FW: Uprights

Tertius,

Daniel

--

No virus found in this incoming message.
Checked by AVG Free Edition.

Version: 7.1.385 / Virus Database: 268.3.2/293 - Release Date: 3/26/2006

[Dave Craddock]

Teritious/Daniel;I think Daniel has been on the right track on this subject
and cnc machined uprights can not only be made strong but manufacturing is
actually less expensive in the long run if the quantity is there ,my guess
would be if one was talking about sets of ten or twenty (depending on
whether the upright was front/rear or universal) the price would be fair
optimizing setup and material costs.The Fast Forward uprights the
inexpensive ones I don't believe will work on a modern car design where the
uprights are out of the airstream and lend them selves readily to
push/pullrod suspension systems,they are however very good quality with many
users out there,thats my two cents on the subject.
Dave Craddock