Rallymech Wrote:
-------------------------------------------------------
> Kevin,
>
> I drive by that place all the time and wonder if
> it would be realistic to have some custome gears
> made. Let us know what they say.
>
> Robert.
I went by today to talk to them.
So, while I'm there talking to the sales guy, occasionally a production guy would walk through, and sales guy would show the pinion to production guy and say "do you want to make this?" and production guy would shudder, shake his head, and quickly walk away.

Here's the deal: They don't have machinery to cut racks. They can do it manually, but so can I with a horizontal mill and the right cutter (we have the mill here at work). The pinion is cut, hardened, and ground, in addition to ground seal and bearing surfaces, dowel pin holes, notches, and that hardened piece that's pressed in the end. With all the handling and different operations, they figure about $2000 per piece, or $4000 for a rack and pinion gear set.

At TGW, we tried to figure out the pitch, noticing that it was ZF, we assumed it would be metric. It's somewhere between 2 and 2.5 Module. Well, just now, I measured it, counted teeth, and found that it's 12 Pitch. Good.

This isn't over. I knew TGW was going to be a high price. But now I have more info to work with, so I can come up with design contraints, and some drawings, and maybe look at different materials to eliminate the hardening and grinding operations.

---

Monika Hawkinson
Seattle, WA

Sofa King Wrote:
-------------------------------------------------------
> With all the handling and different operations,
> they figure about $2000 per piece, or $4000 for a
> rack and pinion gear set.

Kevin call these guys: http://www.gerhardtgear.com/

-Tim

Today I thought about starting up my car.

http://www.mavalgear.com/ ??? not really following what is going on though

---

-KTurner
Stomp down on the exhilarator and hold on to the wheel.

Today i mailled in my ecutek dash display to see if they can fix it??
The midle of the board is all burned : /
The thing was still able to remember: its name, the custom welcom intro, and the time...so there is hope LOL

Tomorow, im starting the final prep for the Lanark rally...so lots of small things to do in the next 6 weeks or so : )


Cheers!

Alain

Kevin I have another PRV bellhousing we could throw in the mix.

---

JohnLane

Overkill is consistently more fun

Kevin for which rack?

The latest TRW rack is the most reliable and plentiful.

I'd really like to have 2.0 to 2.5 turns lock to lock.



Sofa King Wrote:
-------------------------------------------------------
> For other ppl's cars:
> Sent an email to the engineering department at The
> Gear Works (they're about two blocks from my work)
> asking about making new rack and pinion gears.
>
>
>
> Kevin Hawkinson
> Seattle, WA
> 83 Volvo 240 Gp5 (in progress)
> 34-ish

---

JohnLane

Overkill is consistently more fun

Alan certain of the Brits referred to these 'fuses' as 'Connectors;' as in practice the wire would burn to a crisp right up to the connector and continue onto the point where the smoke started to leak out of the circuit until the comsumer of smoke ceased operation.



tipo158 Wrote:
-------------------------------------------------------
> > I have been going through the wiring schematic,
> figuring out what I can take out, what needs to be
> made more robust or rewired, etc.
>
> One advantage of building a car from the 70s is
> that the entire schematic fits on a single page.
>
> The disadvantage is that the entire harness only
> has 6 fuses (including three 50A fuses). The
> works cars had 12 fuses.
>
> alan
>
>

---

JohnLane

Overkill is consistently more fun

Why do you call them Chapman struts? You got something against Mr. McPhearson? Or are you special?

I'm assuming it's chapman after colin chapman from lotus? Yea?

---

Michael LeCompte

ZF rack, because that's what Fidel sent to JV.

[notepad]
I don't know actual rack travel, and don't have the complete housing.
The rack bar has 28 teeth, at 12 pitch (just over 7"
The pinion has 7 teeth.
So, keeping in mind that the HOUSING limits travel, not the rack bar:
28 teeth / 7 teeth per turn = 4 turns (it's actually somewhat less)

If we say:
28 teeth / 8 teeth per turn = 3.5 turns
But that's pretty weak sauce.

Let's do it different:
28 teeth / 2.5 turns = 11.2 teeth per turn
but we must use integers:
28 teeth / 11 teeth per turn = 2.545 turns

Ok, let's see what an 11 tooth pinion looks like:
pitch diameter = 11/12 = .917
addendum = 1/12 = .0833
OD = PD + 2*A = .917 + .1667 = 1.084

But that's not quite right because a 7 tooth pinion is supposed to be:
pd = 7/12 = .583
a = .0833
OD = .583 + .1667 = .75
and the pinion I have is measuring .923 (it's the spiral!)

So I'd guess that a real 11T pinion is going to be more like 1.257" OD.
However, the seal diameter is 1.023, and the housing ID is about 1.125"
Based on the same numbers:
12T = 1.340" and 2.33 turns
11T = 1.257" and 2.54 turns
10T = 1.173" and 2.8 turns
9T = 1.090" and 3.11 turns
8T = 1.006" and 3.5 turns

Theoretically, we can get a bigger seal and open up the housing, but that adds $$$.
[/notepad]

EDIT: I'll entertain thoughts of a different rack if somebody puts a mostly disassembled one in my hands.


JohnLane Wrote:
-------------------------------------------------------
> Kevin for which rack?
>
> The latest TRW rack is the most reliable and
> plentiful.
>
> I'd really like to have 2.0 to 2.5 turns lock to
> lock.
>
>
>
> Sofa King Wrote:
> --------------------------------------------------
> -----
> > For other ppl's cars:
> > Sent an email to the engineering department
> at The
> > Gear Works (they're about two blocks from my
> work)
> > asking about making new rack and pinion
> gears.
> >
> >
> >
> > Kevin Hawkinson
> > Seattle, WA
> > 83 Volvo 240 Gp5 (in progress)
> > 34-ish
>
>
>
>
> JohnLane
>
> Overkill is consistently more fun

---

Monika Hawkinson
Seattle, WA



Edited 1 time(s). Last edit at 03/26/2009 10:45PM by Sofa King.

Why not a steering quickener instead? Cheap, proven, and available.

>
> EDIT: I'll entertain thoughts of a different rack
> if somebody puts a mostly disassembled one in my
> hands.


Does it need to be in good shape? I think I still have the one that was on my 242 when I bought it.

---

Francois

Francois Wrote:
-------------------------------------------------------
> >
> > EDIT: I'll entertain thoughts of a different
> rack
> > if somebody puts a mostly disassembled one in
> my
> > hands.
>
>
> Does it need to be in good shape? I think I still
> have the one that was on my 242 when I bought it.
>
> Francois
Nope. Half-dead (or mostly-dead) is perfectly acceptable!

---

Monika Hawkinson
Seattle, WA

Last night we were able to finish painting the cage.

tonights plans are to weld the roof back on, bolt up everything on the firewall and lay in the wiring harnesses.

---

the woods are lovely, dark and deep. and still hours to go before i sleep.
www.brokenmotorsports.com

Continued my reworking of the wiring schematic. Identifying subsections to put on their own fuse. Adding support for rally bits (co-driver light, computer, driving lights) into the schematic. Calculating the draw on each subsection to determine what amp fuse to use. Thinking through harness routing after adding the roll cage and removing the carpeting.

Talking to the guy making the header, trying to figure out if he found the payment info that I sent him.

Looking at Halda Twinmasters on eBay. More than I paid for the car. Then again, the cage is gonna be more than I paid for the car. The suspension is gonna be more than I paid for the car (found out that the work cars used Escort Mk II adapted into the stock strut/stub axle assembly). The rear diff is gonna be almost as much as I paid for the car. This is the depressing part of building a rally car based on an inexpensive car!

alan