Any recommendations for car design? Help appreciated...

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davet
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Re: Any recommendations for car design? Help appreciated...

Post by davet » Wed Mar 15, 2017 2:35 pm

Ignacious wrote:Davet- 8 degrees on the DFW? Most recommendations I've seen is 1.5 and some 2? What is the benefit of such an extreme bend? And isn't that ridiculously hard to get the drift tuned in properly? We went with 2 degrees on the DFW this year just because our bender was incremented that way and it was insane trying to guestimate 1.5. There was a noticeable difference in tuning difficulty.
Copied from earlier post:

-- One regular winner at league races says he does like VK mentioned and goes as steep as he can and still get the axle through the wheel without damaging the bore. He and I have had our disagreements but he is regularly at the top of the rankings

-- I remember hearing the points VK just made but also heard you can run less steer with the steeper angle. We didn't have a way to test any different angles, just went with what the pros recommended.

--Also, I believe that with the steeper angle, the very bottom front edge of the wheel makes contact with the seams rather than higher up on the front of the wheel. This should mean less disruption to the car at the seams, especially if you hit a bad seam.

--A steeper bend also means less of the inner hub face is contacting the body all the way down the track.

--I'm not sure if 1.5 degrees of bend would even overcome the axle to bore clearance to lift the outer tread off the track. I've bent rears at 2 degrees and couldn't even tell that the outside edge of the tread was off the table.

Tuning the steer (drift) is a delicate action. It sometimes feels like you didn't even twist the nail.



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Re: Any recommendations for car design? Help appreciated...

Post by Vitamin K » Wed Mar 15, 2017 2:43 pm

davet wrote:
Ignacious wrote:Davet- 8 degrees on the DFW? Most recommendations I've seen is 1.5 and some 2? What is the benefit of such an extreme bend? And isn't that ridiculously hard to get the drift tuned in properly? We went with 2 degrees on the DFW this year just because our bender was incremented that way and it was insane trying to guestimate 1.5. There was a noticeable difference in tuning difficulty.
Tuning the steer (drift) is a delicate action. It sometimes feels like you didn't even twist the nail.
Or, you can drill the hole at a 7-9 degrees positive camber and then use a slightly bent axle (2-3 degrees) for tuning. This gives you the (IMO) advantageously large amount of positive camber, while allowing for precision adjustments to the steer.



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Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Wed Mar 15, 2017 2:54 pm

Since my son and I are having to do a four wheel rail rider what would the negative impacts be if the DFW were at an 8 degrees slight toe in positive camber and the NDFW was set at 7.5 degrees negative camber very slight toe out. We have found in limited testing that the if the DFW and NDFW are more than 3/4 degree different we can not get all four wheels to touch. Sporty noted very small bends on his examples with several council wins and in attempting to reach him I have not received a response. Thanks for anyone's insight.

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Re: Any recommendations for car design? Help appreciated...

Post by davet » Wed Mar 15, 2017 2:56 pm

Drill the NDFW lower or at a cant



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Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Wed Mar 15, 2017 8:53 pm

OK. We will look at that option. Thanks.

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Re: Any recommendations for car design? Help appreciated...

Post by davet » Wed Mar 15, 2017 10:10 pm

OR, glue toothpick in your existing DFW hole then redrill higher when cured. This is better anyways as the car will sit more level instead of front high.



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Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Fri Mar 17, 2017 9:13 pm

Curious.. Does anyone have a calculation of how much wheel height increases for each degree of angle of axle bend assuming negative camber. Just looking that if we were to put a 3 or 8 degree bend on a wheel and the wheel across I want very little if any camber what height difference could I drill the hole and still keep 4 wheels on the ground. Should be able to calc using triangle angles, base lengths, sine/cosine but did not know if someone had already created. Thanks for any response.

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Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Sat Mar 18, 2017 10:39 pm

OK.. We are progressing... I know someone mentioned adding pledge to the axles while adding graphite... Do you simply apply pledge, dip axles in graphite then install wheel and axle or different... My son was asking so thought we would reach out to verify.

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Re: Any recommendations for car design? Help appreciated...

Post by Speedster » Sun Mar 19, 2017 4:16 am

This is my technique.
Spray pledge into a dish. Apply the pledge with a Q-tip on the nail where the wheel will ride. Let it dry and buff it gently with a strip of clean handkerchief. Cut a piece of wood 3/8" wide and 7" long. (you probably have a piece of wood left when you cut out your car). Cut a notch in one end and screw the other end on a base to hold it upright. I cover the notch with a piece of clean handkerchief. Put some graphite in the notch. Install the nail into a Pin Vice, place the area where the wheel will ride into the graphite and turn the nail around and around gently and slowly. You are finished. The graphite will probably not be visible on the nail but a film is there.



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Re: RE: Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Mon Mar 20, 2017 4:29 pm

Speedster wrote:This is my technique.
Spray pledge into a dish. Apply the pledge with a Q-tip on the nail where the wheel will ride. Let it dry and buff it gently with a strip of clean handkerchief. Cut a piece of wood 3/8" wide and 7" long. (you probably have a piece of wood left when you cut out your car). Cut a notch in one end and screw the other end on a base to hold it upright. I cover the notch with a piece of clean handkerchief. Put some graphite in the notch. Install the nail into a Pin Vice, place the area where the wheel will ride into the graphite and turn the nail around and around gently and slowly. You are finished. The graphite will probably not be visible on the nail but a film is there.
Got it... Thanks as always Speedster... Next on the question list... What to treat the body/axle/wheel hub area with? Do you use CA glue and lightly sand with 320 grit or no sanding followed by graphite? Hard clear nail polish (sand or not) followed by graphite? Nothing at all l, sand very smooth and treat Pinewood with graphite? I noted in the past in using nothing at all and applying graphite seems to do ok but I noticed in inspecting prior cars that the body get indentions from the wheel hub rub.. If it is that soft to get an indention it seems it may have more friction... Love all your thoughts as always.

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Re: Any recommendations for car design? Help appreciated...

Post by davet » Mon Mar 20, 2017 6:29 pm

When we ran graphite we would put an old wheel on an axle and install in the car with a big wheel gap. We would then put graphite around the axle on the body and push the wheel up against the body with pretty good pressure. We would reapply graphite several times and keep doing this.

The wheel hub would compress the wood and force that graphite into the wood. It would get so hard that I couldn't make a mark with a fingernail. You can do it as long as you want as as hard as you can to get a rock hard area for the wheel to rub.



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Re: Any recommendations for car design? Help appreciated...

Post by derbypain » Mon Mar 20, 2017 6:33 pm

Davet thanks for the feedback.... OK we can make that work definitely as an option and it makes sense. We are required to use graphite so goes along with our needs. Thanks.

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Re: Any recommendations for car design? Help appreciated...

Post by whodathunkit » Mon Mar 20, 2017 7:03 pm

You could coat that area in both ways.. by means of a hard shell nail polish or CA glue.
Some builders let it dry and sand it smooth then coat with graphite.. and then some rub graphite into the glue or polish while its some what tacky also.
If Your car is set up as a rail rider with canted back axles and the wheels drive out to the axle heads is this treatment needed for the back wheels?
for the DFW id say yes because that wheel hub will rub on the car body .
However every little bit you can do in those areas help and you never know when something might happen and when they might rub at some point.

The Sally Hanson.. advanced hard as nails brand polish in a clear is about the hardest hard shell nail polish that I can think of in the nail polish lines.
I'm not sure how hard the ca glues will get when its cured out .. if it's better then a hard shell nail polish or not!

And then Some builders just don't paint that area but rub graphite into the wood .. and then some will paint & shoot a clear lacquer in those areas as well when dry rub graphite in .
For the oil lubes what ever you can do to harden those's areas up with out a graphite rub and oil mix gumming things up your better off.

As far as davet's way like he said.. old wheels are best used .. do not use your good wheels there is to much of a chance to miss up the wheels.


What type of automobile can be spelled the same forwards & backwards?

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Re: Any recommendations for car design? Help appreciated...

Post by whodathunkit » Mon Mar 20, 2017 7:54 pm

derbypain wrote:Curious.. Does anyone have a calculation of how much wheel height increases for each degree of angle of axle bend assuming negative camber. Just looking that if we were to put a 3 or 8 degree bend on a wheel and the wheel across I want very little if any camber what height difference could I drill the hole and still keep 4 wheels on the ground. Should be able to calc using triangle angles, base lengths, sine/cosine but did not know if someone had already created. Thanks for any response.

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What type of automobile can be spelled the same forwards & backwards?

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Re: Any recommendations for car design? Help appreciated...

Post by davet » Mon Mar 20, 2017 8:08 pm

I forgot to add, when pushing wheel against body keep twisting the wheel back and forth.



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