Cutting the DFW notch?

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Vitamin K
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Re: Cutting the DFW notch?

Post by Vitamin K »

Hyperfocus wrote:
Vitamin K wrote: Wed Mar 06, 2024 3:49 pm I wouldn't worry too much about it. I just eyeball it. After all, the angle of the wheel is controlled by the angle of the axle hole, which is already bored and unaffected by shaving the body.

Now, I do sometimes wonder if it might be worth attempting to angle the side of the body for the DFW to match the camber of the axle, but I've never really tried that.
Right, you'd have drilled the axle hole already. Ignore my comment haha. I was thinking of if you were drilling the axle holes after the cut. :paperbag:
No worries. Sometimes it can be a bit hard to visualize when all we have is text.

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whodathunkit
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Re: Cutting the DFW notch?

Post by whodathunkit »

Vitamin K wrote: Wed Mar 06, 2024 1:33 pm I feel like I'm getting a little bit confused between narrowing (or shaving) the DFW side of the car, and cutting a clearance notch to keep the wheel from potentially rubbing. While we haven't bothered with a clearance notch in quite some time, we do still sometimes narrow the front end of the car. I'm not sure whether narrowing is required when you have a lot of positive camber (because positive camber will move the edge of the wheel inwards on its own).

I still kind of tend to want to bring the DFW side in a 1/16", though I haven't really done extensive comparison testing to see if it makes much of a difference. I guess I just feel better about the car when we do.
By cutting the notch 1/16 for the FDW this more the likely center's the rears to the rail.
Lightning Boy would always say.. this makes it easier to stage the car consistently as most stagers will center the car on the rail with the back wheels.
I once asked if 2 strips down the back of the car would let stages know where to stage the back of the car to the rail.

And i know what your saying about lots of positive camber and how it moves wheel rim edge inwards on its own.. with out narrowing the front.
The draw back to this is now the wheel also rides on the outer tread bumps to the tracks running surface. ( if using stock BSA wheels!)
I know a lot of league racers will use lathe turned wheels and save off the tread bumps for the DFW wheel only.
What type of automobile can be spelled the same forwards & backwards?
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Vitamin K
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Re: Cutting the DFW notch?

Post by Vitamin K »

whodathunkit wrote: Thu Mar 07, 2024 6:55 pm
Vitamin K wrote: Wed Mar 06, 2024 1:33 pm I feel like I'm getting a little bit confused between narrowing (or shaving) the DFW side of the car, and cutting a clearance notch to keep the wheel from potentially rubbing. While we haven't bothered with a clearance notch in quite some time, we do still sometimes narrow the front end of the car. I'm not sure whether narrowing is required when you have a lot of positive camber (because positive camber will move the edge of the wheel inwards on its own).

I still kind of tend to want to bring the DFW side in a 1/16", though I haven't really done extensive comparison testing to see if it makes much of a difference. I guess I just feel better about the car when we do.
By cutting the notch 1/16 for the FDW this more the likely center's the rears to the rail.
Lightning Boy would always say.. this makes it easier to stage the car consistently as most stagers will center the car on the rail with the back wheels.
I once asked if 2 strips down the back of the car would let stages know where to stage the back of the car to the rail.

And i know what your saying about lots of positive camber and how it moves wheel rim edge inwards on its own.. with out narrowing the front.
The draw back to this is now the wheel also rides on the outer tread bumps to the tracks running surface. ( if using stock BSA wheels!)
I know a lot of league racers will use lathe turned wheels and save off the tread bumps for the DFW wheel only.
We run Max-V wheels for our race, so the tread bumps aren't an issue.

I do remember one racer (5kids maybe?) saying that if you heard the sound of the tread bumps on the track, then you were doing it right, heh.
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whodathunkit
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Re: Cutting the DFW notch?

Post by whodathunkit »

Vitamin K wrote: Thu Mar 07, 2024 7:00 pm We run Max-V wheels for our race, so the tread bumps aren't an issue.
I do remember one racer (5kids maybe?) saying that if you heard the sound of the tread bumps on the track, then you were doing it right, heh.
You lucky Dog.. on the Max-V wheels. 8)

And yeah that sounds like something 5kids would say.
What type of automobile can be spelled the same forwards & backwards?
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Re: Post-Race Feedback, please!

Post by Loud2ns »

FatSebastian wrote:I am curious how others cut the notch / recess / inset into the body to accommodate the offset of the dominant front wheel (DFW).

In our racing heydays we pretty much just shaved off the entire body by ~1/16" from the front until just past the back of the wheel (here's a body so cut from Vitamin K). We did it this way because it was fast and easy to do on the available equipment (bandsaw with fence). For a more symmetrical front, I think we also tried using a Forstner bit to get a wheel-shaped recess into the block, although the point of the bit will wallow out the opening of the DFW axle hole a little.

But I have seen some precisely carved out wheel notches on some bodies. Some notches go the span of the wheel; others only notch out the wood at the hub and tread areas (so three small notches in a plank).

What techniques and tools are being leveraged to make precise (and cosmetically appealing) notches that don't just start shaving from the front of the car? Combed cut-outs? Sanding sticks? Chisels, files, or rasps? Router? :polling: For example, Doc Jobe used a hacksaw and a jeweler's screwdriver as a "chisel" to make his wheel notches.
We used to use files to take off the body material by the dfw. Now we mark it, and it gets hit on the belt sander. The side of the car is angled slightly from the nose to the front of the rear weight pocket.

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Re: Cutting the DFW notch?

Post by FatSebastian »

Vitamin K wrote: Wed Mar 06, 2024 4:03 pmMy little 1x30 HF belt sander makes it pretty easy...
FatSebastian wrote:I don't have one of those myself, but I thought that this subject could be a good application for one. If only it was a 1.18+ x 30 belt sander!
Hah. It is a good little tool.
Harbor Freight was running a 15%-off coupon for Easter weekend for a one regularly-priced item, so I used it to pick up a 1 in. x 30 in. Belt Sander.

I think this tool it will come in handy, and appreciate the suggestions. Typical of many HF tools, it had some QC issues out of the box that needed to be addressed. The biggest issue was that the aluminum table was noticeably bent, after which the application of some super-human thumb pressure made it "less noticeably" bent (usable).

BTW, what belt grit(s) do you find most useful with this little belt sanders for derby-car construction purposes? It came with one 80-grit belt...
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Re: Cutting the DFW notch?

Post by Vitamin K »


FatSebastian wrote:
Vitamin K wrote: Wed Mar 06, 2024 4:03 pm
BTW, what belt grit(s) do you find most useful with this little belt sanders for derby-car construction purposes? It came with one 80-grit belt...
I think I have 150 grit in there right now, which is good for shaping small bits of wood.

Much finer grits, btw, are great for sharpening metal tools (with the right jigs for angles) and coarser grits of the right medium can be used for quick-and-dirty metal shaping.
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Re: Cutting the DFW notch?

Post by whodathunkit »

60,80,100,120,150,180,240,320,400, for woods.. for metals much finer grits.
What type of automobile can be spelled the same forwards & backwards?
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Re: Cutting the DFW notch?

Post by FatSebastian »

whodathunkit wrote: Tue Apr 02, 2024 10:32 am60,80,100,120,150,180,240,320,400, for woods..
:lol: So pretty much anything over 40 up to 400…

:thinking: Let me restate… if I were to buy one grit size especially for grinding out the DFW notch with this little sander, what might you recommend? (It needs to be effective, but not too aggressive, as it is only 1/16”.)

Similarly, If I were to buy one all-purpose grit for generic shaping and woodworking (say, for communal use at a derby build clinic or workshop), what might you recommend?
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Vitamin K
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Re: Cutting the DFW notch?

Post by Vitamin K »

FatSebastian wrote:
whodathunkit wrote: Tue Apr 02, 2024 10:32 am60,80,100,120,150,180,240,320,400, for woods..
Image So pretty much anything over 40 up to 400…

:thinking: Let me restate… if I were to buy one grit size especially for grinding out the DFW notch with this little sander, what might you recommend? (It needs to be effective, but not too aggressive, as it is only 1/16”.)

Similarly, If I were to buy one all-purpose grit for generic shaping and woodworking (say, for communal use at a derby build clinic or workshop), what might you recommend?
I would say 150.
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