Author Topic: Throttle linkage  (Read 11391 times)

Offline Bernd

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Throttle linkage
« on: August 22, 2008, 03:35:21 PM »
I was asked to stretch a throttle linkage from 6" to 17". Below is a pic of the 6" linkage.



First I cut the linkage in half. I then drilled a #38 hole and tapped 5-40 threads. This picture shows the right part finished.



Now I need to stretch this out to 17". Here's the machine I used. It's my Sherline lathe and I'm about to cut a length of rod to the proper size.



I held the rod in my right hand as I cut it off. Worked great. As long as your cut off tool is on center this will work fine.

Next I drilled and tapped the long rod 5-40 and made up a couple of threaded rods from brass to screw the two pieces together.



The parts were then cleaned of all oil and screwed together. Then they were silver soldered together. And here is the end result. A throttle linkage with a distance of 17" between the center of the heim joint.



Some may ask why I did it this way. Well the original rod with the threads on it is stainless steel. Also I don't have a die of the size needed and the part was needed right away. The best thing to do in a case like this is to use what you have available to you. So I cut the rod in half added some threaded rod to hold the parts together for silver soldering. The rod in between the joints is just plain old steel. It was a fast fix.

Bernd
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Offline Brass_Machine

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Re: Throttle linkage
« Reply #1 on: August 22, 2008, 05:55:45 PM »
Not too bad! That was a good quick fix.

Eric
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Offline Bernd

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Re: Throttle linkage
« Reply #2 on: August 22, 2008, 08:37:26 PM »
More to come as I build the rest of the throttle mechinism (SP? :-\) from carb to foot pedal.  8)

Regards,
Bernd
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Offline Rog02

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Re: Throttle linkage
« Reply #3 on: August 24, 2008, 02:03:03 PM »
I doubt if that would make it through tech inspection at any track we frequent. 

The proper way to do that is to extend the length using a piece of DOM tubing for the extension piece as tubing has a much higher bending moment for the same given weight as the solid rod.  The tubing would be cross drilled (I would probably use a 3/16") and button hole welded as well as welded about the end (I would TIG it but, O/A would be acceptable as long as it is a fusion weld). 

Quote
Some may ask why I did it this way. Well the original rod with the threads on it is stainless steel. Also I don't have a die of the size needed and the part was needed right away. The best thing to do in a case like this is to use what you have available to you. So I cut the rod in half added some threaded rod to hold the parts together for silver soldering. The rod in between the joints is just plain old steel. It was a fast fix.

Hate to be such a Hard A%% about this, but having lost a couple of acquaintances to stuck throttles, this is one of those areas that requires much attention and forethought.  Compared to the cost of repairing a wrecked race car, tools are cheap.  Compared to the cost of a funeral, tools are a bargain!

As a fabricator, before I start any job I require the client to supply me with a RULE BOOK for the sanctioning body and the contact information for that organization's technical director.  I will call the tech guy with any questions the rule book does not spell out in detail, before I start the job.  I also make it a habit of trying to get the tech people out to the shop to inspect the work before dragging it out to the track if at all possible. 

As a fabricator, I take great pride in doing things right the first time around.  Race day is not the time, nor is a race track, the place to be working on race cars!  Safety begins in the shop! 

While working on my Senior Parachute Rigger ticket I was presented with a little plaque that has been duplicated and hangs in place prominent so I see every morning.  The plaque simply reads "May the cost of my mistake, not be another person's life."
Roger
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Offline Bernd

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Re: Throttle linkage
« Reply #4 on: August 24, 2008, 03:04:03 PM »
Well Rog02 if you saw what some of these guys do and their welds and are racing you'd probably be committted to the loony bin. What I've done is a 1000% better than what some of these guys use and they are going down the quarter mile at well over 100mph.

I did a linkage for a guy that has a 1/4 mile gasser. Aluminum bar was used for the throttle linkage to 2 quad barrel carbs. I saw what can be bought because that is what he had on the car to begin with.

The linkage I show in the pics is for a "street rod". The guy had originally built his own. I wish I would have had pic of it. It would have never passed your tech inspection. Also the linkage only pulls, it does not push.

Quote
Hate to be such a Hard A%% about this, but having lost a couple of acquaintances to stuck throttles...

I'm not familar with drag racing rules or what is required in a drag car, but I would think that you would be required to have a master shut off for the ignition if that happened. I do know that a master switch to the battery is required on the back of a drag car to kill electrical power.

The technique I show is just giving an idea of how easy it is to lengthen or shorten something that has disssimular end pieces on it. I'm not advocating that anybody use this method for their own car.

No problem being a hard a$$. At least you told how it should be done the proper way. Thanks.

Bernd
« Last Edit: August 24, 2008, 03:06:45 PM by Bernd »
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Offline Brass_Machine

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Re: Throttle linkage
« Reply #5 on: August 24, 2008, 07:55:17 PM »
Learn something new everyday.

I wouldn't call it being a hardass when you educate someone on something that otherwise could be dangerous.


While working on my Senior Parachute Rigger ticket I was presented with a little plaque that has been duplicated and hangs in place prominent so I see every morning.  The plaque simply reads "May the cost of my mistake, not be another person's life."

Rog... were you a PR in the military?

Eric
Science is fun.

We're all mad here. I'm mad. You're mad.