Fender Notch's.

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whodathunkit
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Fender Notch's.

Post by whodathunkit » Mon Jan 25, 2016 6:53 pm

Tried looking this one up in the search!

Thought i'd start a topic about notches for the fenders..
How wide and deep should the notch be cut to clear the rails if your looking to make your own.

Should they be notched 1/8" to 1/4" away from the car body to clear the rail like to here some thoughts on this.


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

iflytii
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Re: Fender Notch's.

Post by iflytii » Wed Jan 27, 2016 2:28 pm

We haven't run ours yet so I'm interested in this too! We notched them about 1/8 flush out from the bottom,and then tapered them the rest of the way. Just using the ol' calibrated eye ball it looks like the first thing that will touch will be the wheel, but as stated this has not been on a track yet to verify.



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Re: Fender Notch's.

Post by whodathunkit » Wed Jan 27, 2016 7:33 pm

Thanks iflytii it's good to see someone else from Oklahoma here on Derby Talk!

Here are my thoughts..
The new wheel weights have a notch that is cut 1/8'' by 1/4'' deep in a tungsten round or u shape
the 1/8' inch notched side turn inward to the car body for clearing the rail.

Okay:
If you were to drill your back at axles at 3* & install wheels and set your hub to body gap up at 0.35 .889 mm for each side.
The distance between the wheels should be around 1 15/16" on the bottom side from tread edge to tread edge.

With the fenders notched at 1/8'' away from the car body your distance would 2'' across between notches
Is 1/32" on each side away from the wheel treads enough or should the wheel to body gap be set tighter?

Note:
if you were to pull the gap tools out of your wheels you would have a little bit more wiggle room to move into the 2''
distance across from tread to tread. (due to bore and axle slop.)

I like your idea of giving the wheels a little more wiggle room by tapering the fenders bottoms so it wont rub the rail.


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

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Re: Fender Notch's.

Post by iflytii » Sat Jan 30, 2016 9:24 am

We ran our cars at the test night last night and didn't have any issues with the fenders rubbing. Here is a photo of the under side:

Image

Probably could have just gotten away with either notching or tapering but we were playing it safe. On a side note I ended up hogging out the rest of the spaces between the holes on the lower car and it still weighed more than the upper. :/ Final weighing allowed me to put quite a bit more weight in the back of Lucas' (upper car) and the result was pretty obvious - his car is faster.



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Re: Fender Notch's.

Post by whodathunkit » Sat Jan 30, 2016 11:00 am

Nice looking car shapes are they the under sides to your cool looking Batmobile cars?

It is crazy how 2 cars can be built alike is size and shape and one will be heavier then the next
Due to the density of the wood from wood grain patterns to sap and moisture content etc.

What i'm wondering about with just notching the fenders:
Is how much of the lower part of the fender should be covering the wheel tread .. like the top side of the fender is.
And if there is any but little speed to be gained...
by also deflecting some of that air flow away from the wheel tread bottom side.

I've been watching some of the league racing videos.. with the cars that are running with the wind deflectors in the rear wheels cavities to block off the air flow from entering the cavities.


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

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Re: Fender Notch's.

Post by whodathunkit » Sun Feb 07, 2016 5:26 pm

I used to make the notches in fenders with the table saw.
However I was always taking a chance with the 3/8 thick wood falling down into the throat plate.
As the table saw I have has no close fit throat plates or dado blades attachments offered for it.
Image

Well I set out to find a better and safe way of making notches before cutting the fenders out.
I had this Ryobi plunge router that was a Christmas gift that was just setting in the shop
and not getting used much if any at all.
I thought spending $60.00 for a router table would be better then cutting fingers on the table saw.

Image
Image
Image


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Re: Fender Notch's.

Post by davet » Thu Feb 18, 2016 8:15 am

Our fenders are made from balsa. We cut the basic triangle shape (slightly larger than we want for final size) with Exacto knife then place a strip of 80 grit sandpaper around an old wheel and fasten with doublestick tape. We put the wheel on an arbor and use the wheel to sand the arc into the fender. We then place fender on the car where we want it and draw a line along the back where it meets the bottom of the car body. We then use a simple file to file the bottom portion so it's just a hair further out from the body than the wheel is when it's against the head. We then lay sandpaper on the table and just start running the face of the fender on it to make the taper and final finish touches. Each fender takes about 10 minutes. Much easier than when we used pine.



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Fender Notch's.

Post by whodathunkit » Thu Feb 18, 2016 12:20 pm

Not every child likes the look of fenders on there car.

Some that do just stay flush with the bottom of the car.

But here lately it seems like the kids like the looks of the arrow type fenders.
Or those that close up the openings around the wheels and run closer to the track.

Most all the photos of car or truck builds
I have been sharing have been of adult builds.
There is no way I would let a child use the table saw or a router table to make the notches for fenders on there own.





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Last edited by whodathunkit on Thu Feb 18, 2016 9:07 pm, edited 1 time in total.


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

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Re: Fender Notch's.

Post by gpraceman » Thu Feb 18, 2016 12:43 pm

whodathunkit wrote:I used to make the notches in fenders with the table saw.
However I was always taking a chance with the 3/8 thick wood falling down into the throat plate.
As the table saw I have has no close fit throat plates or dado blades attachments offered for it.
You might want to see if you can find a "zero clearance" insert for your saw.

You can also make one for your saw. See http://www.rockler.com/how-to/zero-clea ... w-inserts/


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Re: Fender Notch's.

Post by whodathunkit » Thu Feb 18, 2016 9:05 pm

Thank's for the Table saw insert info Randy!

I'm going to look in to getting this for my saw as well
now that I have a router table set up for shaping the insert.


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Re: Fender Notch's.

Post by Scrollsawer » Fri Feb 19, 2016 6:19 am

With balsa, you could rig up a sanding block with coarse grit sandpaper (e.g., 80 grit) glued onto a wood block template/fence, and make quick work of sanding your notches down without having to use any power tools. I've clamped custom sanding blocks into my woodworking vise, and had the boys rub the car body part (in this example, a fender) back and forth against a 90 degree corner of the vise-secured sanding block. Should take no more than 2-3 minutes per fender to sand off that much material.

You just need to put some thought into cutting your sanding block shape so that the boys achieve the desired result. You could even mark the block with a stopping marker to indicate when to stop rubbing the balsa back and forth.

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Re: Fender Notch's.

Post by whodathunkit » Fri Feb 19, 2016 7:44 am

Scrollsawer,
Could I get you to post a photo or to
On the topic.

Balsa is a very soft wood!
Could your idea work on the harder woods like basswood and pine.
I'v been thinking that tapering the under side of the fenders could also be done on a drill press with a drum sander.


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