Bryan Kast's Build

Follow progress of your fellow builders. Pictures encouraged!
Langan
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Re: Bryan Kast's Build

Postby Langan » 15 Jan 2015, 16:42

Sure like that hub. Where do I get one?

bgkast
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Re: Bryan Kast's Build

Postby bgkast » 15 Jan 2015, 17:08

Jegs.

They have a 5-hole grant version for $65: http://www.jegs.com/i/JEGS-Performance- ... tId=758026


And a 3-hole version for $60: http://www.jegs.com/i/JEGS-Performance- ... tId=758026

If I had ordered the 3 hole my horn would have fit and I would have saved $5. :(

bgkast
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Re: Bryan Kast's Build

Postby bgkast » 16 Jan 2015, 10:29

Pedal mount is finished. It seems to be plenty stiff, and is fairly light (and looks cool :mrgreen:).

Image

More steering parts arrived yesterday: the upper bearing, lower bearing and a shaft collar.

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Unfortunately despite the lower bearing package being marked 3/4 the bearing is actually a 7/8 bearing. A call to the vender this morning has the right one on the way, and they told me to keep the wrong one. Excellent customer service by Chrico vw and buggy parts. Anybody need a 7/8 bearing?

With the pedals mounted I started playing with steering wheel placement. I really need to mount the seat before I finalize the location, but for my initial tests it looks like the dash bar is right where I want the steering wheel to be. So far this is the best placement compromise without conflicting with anything. I'm debating keeping the extended shaft as a accident deterrent. :P

Image

WickedOne
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Re: Bryan Kast's Build

Postby WickedOne » 16 Jan 2015, 13:44

It would also be handy to scratch or pick your nose when you had both hands occupied.

bgkast
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Re: Bryan Kast's Build

Postby bgkast » 23 Jan 2015, 17:28

It takes a surprising amount of time to get the ergonomics of the cockpit sorted out. Over the past several days I have tried several positions for the steering wheel and seat. After much testing I found a comfortable fore/aft location and angle for the seat. I tried setting the seat both 1.5 and .75 inches off the floor and came up with the same location and angle, so it must be right. :P I am going with the lower position to give myself some additional head and helmet room. At the higher position my helmet would just hit the 1" SCCA required roll cage padding. Also for street driving without a helmet the more space between my skull and steel tubes the better!

I also found two comfortable positions for the steering wheel/shaft.

High (over the dash bar):

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And low (under the dash bar):

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I prefer the high location, because it gives more of a Z shape to the steering shaft to aid in safety. In the low position the shaft basically runs straight to the spline on the rack, and I'm concerned that in an accident it would act as a spear pointing directly at my face.

I liberated the steering shaft and spline from the Neon's steering column. It just happens to be 0.75" ID, and the narrow part by the spine is 0.75 OD.
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Last night I mocked up the "high" steering position in metal and found that the upper U-joint will conflict with the brake master cylinder.

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In the photo the bolt/nut on the joint is hitting the fitting on the back of the cylinder, and the lower part of the shaft still needs to come up a bit to point in the correct direction, further increasing the conflict. I may need to go with the "low" steering shaft location. With the low configuration the angles are such that I could get away with only using one U-joint at the steering rack, but I think that using a single U-joint is a no-no due to the non-constant rotation that a U-joint transmits. Can anybody confirm or deny this?

Midlana1
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Re: Bryan Kast's Build

Postby Midlana1 » 23 Jan 2015, 17:44

How about lengthening the lower section several inches and reducing the upward slope just a bit? That would move the U-joint back away from the master cylinder.

bgkast
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Re: Bryan Kast's Build

Postby bgkast » 26 Jan 2015, 13:45

More mock-up....I'm itching to get back to actually building something.

I figured out what it would take to get the upper steering position to work. The advantages to this position are slightly better leg clearance, probably better crash safety and more clearance where the steering shaft passes between the pedals. Disadvantages are still-tight clearance with the brake master cylinders/brake lines, harder to build, and the top of the steering wheel is higher than the cowl which might look weird.

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Basically the back edge of the u-joint has to be over the dash bar. If I go this way the chrome bushing in the photo will be replaced with a flanged bushing inserted into a piece of tube that serves as a steering column. The steering column tube will be welded (or bolted?) to the dash tube and will have another similar bushing right behind the steering wheel.

I also did a more detailed mock-up of the lower position.

Image

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This would be easier to build, but there isn't much Z shape to the steering shafts, and there isn't room for the collapsible accordion in the intermediate shaft. It also gives less (but still adquate) clearance between the bottom of the wheel and my legs, and the shaft and my feet by the pedals.

I'm going to make the seat mounts and mull it over. Any input is appreciated.

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Re: Bryan Kast's Build

Postby Midlana1 » 26 Jan 2015, 15:29

Safety-wise I do like the pronouced Z-shaped one. Can you cheat and have the shafts go to either side of the master cylinders?

bgkast
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Re: Bryan Kast's Build

Postby bgkast » 27 Jan 2015, 11:02

I can't cheat it without making the steering wheel uncomfortably off-center or angled towards the outside of the car.

I lied about building something and did......more steering mockup. This time a detailed mockup of the upper position.

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It clears, but just barely!

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I have about 1/8" clearance between the 3/4" steering shaft and the corner of the master cylinder. These master cylinders are no-longer made (you can still get rebuild kits), so I checked similar designs from Wilwood and Tilton, and they seem to be shorter so it doesn't look like I am designing myself into a corner. Now that I know that both positions will work, and be comfortable to use I need to think about things like cowl clearance and space for gauges... :roll:

Midlana1
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Re: Bryan Kast's Build

Postby Midlana1 » 27 Jan 2015, 13:13

Don't be unhappy about the time spent mocking up steering, pedals, and seat, because every time you drive the car you'll be reminded how perfect - or poor - the placement is.

1/8" clearance is fine since you confirmed it with a physical mockup. Does the final layout result in a definite Z shape of the shaftts?


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