65 replies to this topic

[Duffy]

Oh, that's soo true of me, too--I was taught to be all anal about expressing the decimal points & all for clarity and accuracy blah blah blah, and after decades of working with unibrow slackjaws who mumble "one oh forty, duhhh" I still get a rash. It ain't easy bein' this prissy, trust me.

Duffy

[Prof. Fate]

Hi

Oh, you glory in tilting your nose up and going "well, 040...hmm might as well be wrong by a mile, you slacker".

If you check your prop shaft hole, or axle holes, you will commnly find a run out on the 0rder of 006 as well.

Fate

[Duffy]

I primly state: you have never seen my axle hole. I have my standards, y'know.

Now, seriously: I was asking whether the "48 pitch" designation was based on the pitch diameter rather than the OD, not really trying to be a pompous axle.


Now, not-so-seriously: yes yes yes, as we were saying in DC-65's motor thread a couple weeks ago, it's not slavish commitment to the number so much as the awareness that the number's there and what it means. In a mechanical system best considered as "a race to see which bit fails first," knowing what you can and can't stack up perfect and making decisions based on that knowledge is where the fun is. For some of us.

And completely not-seriously: the point of working on that level of knowing is, your knowledge informs the way you use what tools you have at hand; you get a sense of how & when to use care and preparation to get the best results you can. Both Pablo & I have publicly acknowledged the virtues of the Lost Cause paradigm "anything doable by a 12-year-old with his Dad's hand drill" and folks, it's a darn good paradigm. In my own current build, careful jigging, secure fixturing and alignment--



--resulted in surprisingly good results in boring out my chassis for bearings.



So, take that as a lesson. The System Works.

Duffy

[Pablo]

Not to mention the fact good friends always help those who help themselves

[Pablo]

18/45 is the best fit:



All four wheels will be set screw. BIG donuts :

[Horsepower]

18/45 is the best fit.
All four wheels will be set screw. BIG donuts.

That's pretty high with a 2.5 to one ratio but if it doesn't work out speed wise, I think you could go to a 16/48 set up for a 3 to 1. I suppose it's pretty close as it is.

[Pablo]

Gary, given the mount I have in front of me, this is going to have to work.
If it does not, I'll go to plan "B" Or "C"

I see some K & B gear combos on ebay that are approx. 2 to 1, so I think it will work.
Track test in 2 weeks......

[Hworth08]

If you're gonna build a Legend car you ought to see how it is to drive one. From the Nashville Fairgrounds quarter mile track. The line seems to be the same as 33 years ago.

[Pablo]

Steve, here is what I have so far, flag is a modified Jet with a big Classic weight.
Drop arm uses a hinge.

[Pablo]

Wheels are ready, .500 BWA inserts need to be painted.

[Silver Fox]

Looking good Pablo.
Thanks a bunch friend.

[Jairus]

OH MY! This is a GREAT picture!

[Pablo]

Jairus, if it turns out to be a POS, we'll just sell it to the Tramway at Palm Springs as a third backup device

Steve, I'll warn you right now, the rear width is gonna be 3.5" , impossible to get it any narrower than that without compromising things I don't want to. When you want to run this car, you may want to give the other drivers a heads up to go play somewheres else for a while You own the track, you can do that

Front and rear setscrew wheels are Okeefe/Electric Dreams/DC-65X Russkit replicas
Flag is a heavily modified Jet Flag. Weight is a genuine Classic. Gary Stelter supplied the K & B 18 T solder-on pinion.
The K & B Royal Bobcat 36d is brand new and bone stock

Next challenge : Pans.

[Hworth08]

Steve, I'll warn you right now, the rear width is gonna be 3.5" , impossible to get it any narrower than that without compromising things I don't want to.

An age old problem with sidewinders. The anglewinder Dynamic bracket would narrow the track but they didn't make one!

If you can find them, Russkit did make a narrow rear wheel. There is likely enough weight back there that front-width wheels will work, maybe better.

Everything's looking nice anyway. A Dynamic framed with 36D power was a lot of people's first "good" car!

[Pablo]

Thanks, Don

The monster is ready for a track test:

[Pete L.]

Really Cool !

[Horsepower]

If only they were THAT sano back in 1965! Looks beautiful. As they say in the diet commercials "Where can I get a body like that?". That's the best lookin' coupe I've seen in a while, even with no paint on it!
OK, I went back to the first post and it says JK body. I missed that the first time. I'm not always at the top of my game.

[Gary Bluestone]

I primly state: you have never seen my axle hole. I have my standards, y'know.

Now, seriously: I was asking whether the "48 pitch" designation was based on the pitch diameter rather than the OD, not really trying to be a pompous axle.


Now, not-so-seriously: yes yes yes, as we were saying in DC-65's motor thread a couple weeks ago, it's not slavish commitment to the number so much as the awareness that the number's there and what it means. In a mechanical system best considered as "a race to see which bit fails first," knowing what you can and can't stack up perfect and making decisions based on that knowledge is where the fun is. For some of us.

And completely not-seriously: the point of working on that level of knowing is, your knowledge informs the way you use what tools you have at hand; you get a sense of how & when to use care and preparation to get the best results you can. Both Pablo & I have publicly acknowledged the virtues of the Lost Cause paradigm "anything doable by a 12-year-old with his Dad's hand drill" and folks, it's a darn good paradigm. In my own current build, careful jigging, secure fixturing and alignment--



--resulted in surprisingly good results in boring out my chassis for bearings.



So, take that as a lesson. The System Works.

Duffy

A gear's pitch refers to the size of its teeth: the larger the pitch number, the smaller the teeth. That seems backwards, but it makes sense when you consider how pitch is determined. Pitch refers to the number of teeth that can fit around a 1-inch diameter disc; for example, a tooth size that permits 48 teeth to encircle a 1-inch disc is said to be 48-pitch. To squeeze 64 teeth onto a 1-inch disc, the teeth must be smaller; that's why 64-pitch gear teeth are finer than 48-pitch. The pitch of the gears in your car has no effect on their ratio, but the higher pitch gears tend to have more contact and transmit power more smoothly.Of course you will need to match the pitch on both pinion and spur gear.

[Pablo]

Thanks Peter, Thanks Gary
Track test tomorrow night
Should be very interesting. Sounds real slow on the power supply, but the circumference of the rears should "get it on down the road"

Chad, get your airbrush ready !! Are you out there ?

[havlicek]

Dayum Pablo that's a cool car! That big old honkin' 36D looks cool with those gears and the body really seals the deal. I figure that the car will be still be only about 1/2 way through it revs at the end of the straight Too bad there's no such thing as "scale Bonneville salt flats" racing, although I did see something like that in England on YouTube. You just might have a contender! Neat car

-john

[Pablo]

Thanks John

Well, the first test was interesting. Good news/Bad news

Good news:
The motor/drivetrain/power/gears work perfect. The car is not a rocket, but it is very steady and runs smooth. It's fast enough to where it will get spooky if you over drive it "It is what it is" , nothing more. Nice and smooth.

Bad news:
The hinge is nice for a bumpy track, but it comes at a severe price: only one screw holds the tongue. One slight crash, and the entire front end is misaligned. So the car sits in front of me now, bent front end, bent front axle, bent pans.

So, I need to go to work

[Pablo]

Mission accomplished.
New 1/8 Kelly Racing front axle.
New full-length tongue.
Hinge is gone. Steve's tracks are smooth so I think it will be mucho better now.

The hardest part of this project was understanding that a stock 1960's 36D motor runs just fine in this configuration with a 2.5 to 1 gear ratio. It's not a G7 racecar, just a blast from the past. Once the decals and paint are applied, it will have personality

As soon as the wheel inserts dry, my job here is done I'm hoping Chad will take photos after he paints and decals it, and post here, or email to me and I will post them

[Duffy]

The hardest part of this project was understanding that a stock 1960's 36D motor runs just fine in this configuration with a 2.5 to 1 gear ratio. It's not a G7 racecar, just a blast from the past. Once the decals and paint are applied, it will have personality

This is a lesson I have to learn as well. I keep applying modern thinking to cars we didn't think about near as much!

Thanks for this build. There'll be a couple more Dynamic chasses showing up in these pages soon, hopefully with a minimum of Duffy-think in evidence.

Duffy

[Pablo]

Once I get my Mabuchiracha finalized, I'm done with aluminum for a while
I miss my minitorch

[Pablo]

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