|
|
Post by Professor Moriarty on Oct 7, 2017 21:43:30 GMT -5
So the the 1 1/2" x 1/2" x 1/4" blocks are $6.25 but shipping is another $6 FedEx from China. 1.5 is too long. Wouldn't shipping depend on volume? Why would it be per piece? I think DHL is the way to go. Micro...why do you say it is too long? telling you Chuy... tapered rear is the next big thing... one triangle is isosceles in my drawing... the other one is a right angle... so you can stack the right angled ones to make up a full back row... if you are feeling timid that is... another great shape is this one... .25”x.25”x .185” this will allow for new possibilities... we are stuck with cubes right now. Either 3/16 or 1/4.... |
|
|
|
Post by Professor Moriarty on Oct 7, 2017 21:45:49 GMT -5
The price increases due to taxes that must be paid to China...
|
|
|
|
Post by micro on Oct 7, 2017 22:07:56 GMT -5
1.5 is too long. Wouldn't shipping depend on volume? Why would it be per piece? I think DHL is the way to go. Micro...why do you say it is too long? telling you Chuy... tapered rear is the next big thing... one triangle is isosceles in my drawing... the other one is a right angle... so you can stack the right angled ones to make up a full back row... if you are feeling timid that is... another great shape is this one... .25”x.25”x .185” this will allow for new possibilities... we are stuck with cubes right now. Either 3/16 or 1/4.... Never mind. Having brain fade. Just a back piece I would go for 1.75 |
|
|
|
Tungsten
Oct 7, 2017 22:18:25 GMT -5
via mobile
Post by Chuy on Oct 7, 2017 22:18:25 GMT -5
I also asked for the tapered piece but they haven't responded yet. I am assuming a similar price because most of the cost is probably machining. I have it out to about 6 manufacturers right now. As the quotes roll in, I'll keep everyone informed. I specified mill finish with +/- 0.01" tolerances
|
|
|
|
Post by Bracket Also on Oct 7, 2017 22:31:16 GMT -5
1.5 is too long. Wouldn't shipping depend on volume? Why would it be per piece? I think DHL is the way to go. Micro...why do you say it is too long? telling you Chuy... tapered rear is the next big thing... one triangle is isosceles in my drawing... the other one is a right angle... so you can stack the right angled ones to make up a full back row... if you are feeling timid that is... another great shape is this one... .25”x.25”x .185” this will allow for new possibilities... we are stuck with cubes right now. Either 3/16 or 1/4.... Not in my opinion. The drag from the wheels has to be greater than the drag from the back edge of the body and I wouldn't want to give up the PE for a tiny or non-existent aero improvement. You could always go back and cut vortex generators into a square back. |
|
|
|
Post by Professor Moriarty on Oct 7, 2017 22:41:46 GMT -5
Pffft!
You can make up for the PE with side weights to get more weight behind the rear axles...
The turbulent wake from the body creates a good deal of drag...
The turbulent wake from the rear wheels is the next obstacle...but for now... I think the tapered rear will streamline things considerably.
|
|
|
|
Tungsten
Oct 7, 2017 22:50:59 GMT -5
via mobile
Post by Chuy on Oct 7, 2017 22:50:59 GMT -5
Next quote, $1.8/ounce. Minimum order, 100 oz, $43 shipping. $2.2/oz total
|
|
|
|
Tungsten
Oct 7, 2017 22:52:25 GMT -5
via mobile
Post by Chuy on Oct 7, 2017 22:52:25 GMT -5
80% drag is from the wheels
|
|
|
|
Post by Professor Moriarty on Oct 7, 2017 23:43:37 GMT -5
These are very low prices...
Sure ... so that means that we can trim almost 20% of the drag by having a tapered rear.
I have been thinking more about something extreme...
Sorta like the Down4Derby car that Mr. D mentioned in another thread...
Except...
Instead of stopping the body just behind the front axles like D4D...
Allowing the body to continue to the rear but only 1/16” thick...
This would allow the builder to keep the rear holes stable by connecting them with structure...
And make up some of the weight needed back there with 1/16” plates.
|
|
|
|
Tungsten
Oct 8, 2017 8:07:19 GMT -5
via mobile
Post by Bracket Also on Oct 8, 2017 8:07:19 GMT -5
Pffft! You can make up for the PE with side weights to get more weight behind the rear axles... The turbulent wake from the body creates a good deal of drag... The turbulent wake from the rear wheels is the next obstacle...but for now... I think the tapered rear will streamline things considerably. But side weights invoke a handling suck and you're not going to "remove 20% of the drag" by tapering the rear. The body will still have some drag no matter the shape. |
|
|
|
Tungsten
Oct 8, 2017 8:15:55 GMT -5
via mobile
Post by Bracket Also on Oct 8, 2017 8:15:55 GMT -5
We can buy aluminum tube in streamlined shapes, I would look into something like that to bridge between the rear wheels before I'd build a 1/16" thick car? Either that or machine solid tungsten or steel into an aero shape with square ends where it attaches to the legs of the body. You could drill axle holes into the square ends and the alignment should hold true.
|
|
|
|
Tungsten
Oct 8, 2017 8:22:57 GMT -5
via mobile
Post by Chuy on Oct 8, 2017 8:22:57 GMT -5
So, the "extreme" case of this is the two wheeler. I would also disagree with side weights causing handling issues. My two wheeler ran true and 100% of the weight was on the side
|
|
|
|
Post by Professor Moriarty on Oct 8, 2017 9:03:18 GMT -5
Hear hear Chuy!
The two fellas that observed some sway at the bottom of the hill (and attributed this to the side weights) did not drill their cars with the clear drill jig.
With proper weight distribution and a good drill job... I contend that there will be no sway.
|
|
|
|
Post by Professor Moriarty on Oct 8, 2017 9:10:18 GMT -5
I figure that I can build the car similar to the D4D style and use a snap off tungsten plate to bridge the span between the axle holes.
The holes will have a minimal depth to them... say 3/8”
Printed steel for a rear spoiler is another option but I would rather avoid cutting the air twice.
I think that D4D ganged up some side weights to bring the car up to weight...
In doing this the weights stick out of the wheel void too much in my opinion...
I found it funny that he split the rears to gain some aero but almost everything else he did with those cars was horrible for aero.
|
|
|
|
Post by Bracket Also on Oct 8, 2017 9:20:14 GMT -5
So, the "extreme" case of this is the two wheeler. I would also disagree with side weights causing handling issues. My two wheeler ran true and 100% of the weight was on the side Chuy, on a car with a 1.75" wide body the side weights are MUCH farther apart than they would be on your skinny two wheel car, right? It's the distance apart that causes the issue not the fact that they are on the side. |
|
