bateman

Greetings everyone,

I have a query regarding countersinking the front and rear shock towers and upper deck on my on and off road cars. What are the benefits (or cons) of doing this as so far I have had different opinons ranging from 'it will secure the parts a little better' to 'it will weaken the parts'. I have noticed that certain pro drivers have their parts countersunk but others don't so I am not sure if it is worth me getting it done unless there are benefits (besides the fact that it looks alot cooler).
If anyone could offer some insight on this topic, it would be greatly appreciated.

Thankyou and take care.

bateman

Greetings everyone,

Does no one have any information regarding the above post? Any input would be muchly appreciated.

Thankyou and take care.

greencactus3

well iknow the underside of a chassis will definily be better off countersunk. other places, i dont care at all.

burbs

iTrader: (1)

it has nothing to do with performance.. the bottom of the chassis yes.. is so you have no drag.. anywhere eles on the car, it is the choice of the maker to do what they choose.. IT doesnt matter

sg1

iTrader: (79)

Hey bateman,
I think it does matter where you countersink at. Esp. if you do it yourself. You wont be able to put the countersink on the exact location needed, unless you have the print of the part and are using a mill. If the countersink location walks .010" you'll put a nice "tweek" in your chassis if you do a top brace. Same goes for a-arm mounts, shock mounts, etc. You need to do it correctly or you're causing a problem. Just my 2 cents...
Wayne

Speedo

No, it does matter, a lot. Countersinking does a whole lot to stop a car tweaking due to the part moving in relation to the screw. This is why most top decks are countersunk.

rovic

how does it stop tweek?

it really doest increase surface contact enough to make a differance.

correct me if im wrong, but tweek occurs when the chassie twists, under the screw. chassie doest move back and forth or side to side on the screw, the screw hole prevents that type of movement.

sg1

iTrader: (79)

I can see where the counter sinking the top deck or brace would help with the stiffness and help prevent movement in a hard crash, but I would rather have a button head there. Reason being, during the prototype work on the BMI 1/12 car Jason from BMI noticed there was a variation in the countersinks, heads, and concentricity of the 4-40 flat heads. We would put the main chassis brace on and the chassis and it would twist and be tweeked. There needs to be some room for the inconsistancy of the screws, standoffs and locations on the graphite. If everything in the world was 100% accurate It would be fine, but it's not, so room for error is needed. Maybe because of the smaller size standoffs and thinner graphite pieces for 1/12 it's more critical. But we did have a lot of problem trying to use flat heads there.
Wayne