Page 2 of 4

Re: Build Thread for all

PostPosted: Mon Nov 27, 2017 2:35 pm
by Duke7777
I first built an inline chassis with the body mounted on some light side pans. It ran OK, but after experiencing the power of these motors at 10v I decided to try something lighter. I still need to add paint and wheel inserts, but so far the car weighs 58 g and runs well with just a couple of grams of weight added up front.

Image
Image

Re: Build Thread for all

PostPosted: Mon Nov 27, 2017 5:26 pm
by Lou E
Anglewinder, I like it!!! Chassis looks awesome, nice work.

Re: Build Thread for all

PostPosted: Mon Nov 27, 2017 5:58 pm
by VTECFOUR
Aaah, that's what I was hearing about from TF1250, fellow GVSCC member and SPR 2018 participant.

You probably won't be much over 60 grams, light compared to mine at 76 grams.

Looking forward to seeing it tested on Luf's Big Targa track.

Dan

Re: Build Thread for all

PostPosted: Mon Nov 27, 2017 8:25 pm
by brainslot
Wow...many impressive creative builds going on here. I am going the CAD and 3D printing route. Designed a pod with an 1/8" thick rubber pad that connects the pod to chassis. Thinking that this might give a nice dampening and suspension to the set up. Patent not pending yet. I have been using SolidWorks for years and sent the files in last Friday to Shapeways, maybe see them the end of this week. I did CAD up and machine my own wheel inserts in black ABS.
brainslot

Image

Image

Image

Re: Build Thread for all

PostPosted: Mon Nov 27, 2017 8:37 pm
by Lou E
Boy oh boy, I need to step up my game!!!!

That looks awesome, can’t wait to see pictures of it once you get into back from shapeways. Are you using bearings or bushings for the axles?

Re: Build Thread for all

PostPosted: Mon Nov 27, 2017 9:08 pm
by brainslot
Thanks....I am using bearings....thus the larger size axle holes. Made the front mount area a 'slot' so I could adjust the front axle height.

Re: Build Thread for all

PostPosted: Tue Nov 28, 2017 9:50 am
by chrisguyw
[quote="brainslot"] I am going the CAD and 3D printing route.

Image


Hi Brainslot, Nicely done !!. Did you consider using only one pod mounting post on the front and back of the pod, while adding screws/posts to the 2 side mounted pod lugs.
This would control lateral and fore/aft movement just as well , but, would provide a more precise and smoother torsional rotation.

Cheers
Chris Walker

Re: Build Thread for all

PostPosted: Tue Nov 28, 2017 10:14 am
by brainslot
Just kind of flying by the 'seat of my pants' here as far as being able to figure out how the rubber dampening will work. I have some options for a higher durometer rubber to try. These cars all so small and light.....I don't know if it matters too much. I want to try this with a Sideways Group 5 car to really see if it is beneficial.

Brian

Re: Build Thread for all

PostPosted: Tue Nov 28, 2017 11:27 am
by chrisguyw
brainslot wrote:Just kind of flying by the 'seat of my pants' here as far as being able to figure out how the rubber dampening will work. I have some options for a higher durometer rubber to try. These cars all so small and light.....I don't know if it matters too much. I want to try this with a Sideways Group 5 car to really see if it is beneficial.

Brian


Hi Brian, You will find the rubber dampening works well.....while the reduction in vibration certainly helps, it it the ability of the pod to "flex" torsionally, not flop, that really makes a difference.
A pod that just bounces around is somewhat like driving a 1:1 car with bad shocks (I am sure you have seen cars with their wheels bouncing around, driving down the highway).......if you can't control the movement of the wheels, and keep the tires in contact with the road, consistent handling and traction are just pipe dreams.
By controlling pod flex (not flop) the tires are where the should be.........you have no doubt seen many racers now using tape across their pods to do just this......eliminate the "slop" and introduce controlled flex.
Additionally, torsional flex (the right amount varies with tire grip, motor, track grip/design), allows the outside rear tire to load progressively in a turn, adding grip.

All cars, light or heavy, fast or slow, will benefit from the correct amount of torsional flex.

Below are a few cars that I have built using urethane washers between the bottom of the pod lugs and the chassis plate.........some have done very well in various proxies.

Cheers
Chris Walker



This car was built for last years Ford/Ferrari wars proxy...a bit difficult to see the washers, but, they are there........the car finished a very close second in the proxy, despite missing one of the rounds.

Image


This was the winning chassis from the TLOR proxy a couple of years back


Image

A customer car built 6/7 years ago....it did very well in its European club series.


Image


Washers above and below the pod lugs.....chassis originally built 5/6 years ago, and has been entered in the Group 5 proxy.

Image

This is a Thunderslot with a hard chassis/pod,.....it is difficult to see but there are 30thou. urethane washers on all pod lugs, and also on the body post mounts

Image

Re: Build Thread for all

PostPosted: Tue Nov 28, 2017 11:40 am
by brainslot
You really have done some great development using rubber to dampen movement and the brass work is wonderful. I have always thought that the loose screwed pods with tape can be hard to get right and screws... even with the threads removed can get hung up.
In my case the rubber bridges a gap at the front and back of the pod that is 3.6mm+ wide. The rubber is clamped down tight at either end to the pod and chassis. All theoretical to me.
Brian

Re: Build Thread for all

PostPosted: Tue Nov 28, 2017 1:05 pm
by JT Previa
As one of the organizers of this proxy, t’s really gratifying to see such quality and creative chassis solutions from both the hand craftmanship and the computer printing. I’m sure Dan agrees. Fantastic work - and engineering discussion- all around.

Add me to the vibration absorption advocates. I’ve used simple felt to cushion and limit loose body motion. Felt has a “longer travel than most foams at 1/32 scale, but can flatten out over time.

JT

Re: Build Thread for all

PostPosted: Fri Dec 01, 2017 9:36 am
by chrisguyw
I still have a few minor cosmetic bits to finish off, but, the car is essentially finished.

This pic. was taken outside on a dingy day, and the main colour (Tamiya Champagne Gold) looks a lot less brown than it does in the photo.

I have never run a Tuna16K motor, so it is hard to tell if this is a good one, but, the car runs very well.

Cheers
Chris Walker

Image

Image

Re: Build Thread for all

PostPosted: Fri Dec 01, 2017 11:59 am
by glasshorsevh
chrisguyw wrote:I have never run a Tuna16K motor, so it is hard to tell if this is a good one, but, the car runs very well.


Chris,

I sure hope that thing doesn’t run as good as it looks.....!

Val

Re: Build Thread for all

PostPosted: Sun Dec 03, 2017 3:03 am
by DRW21
Very tidy work as usual. Well done Chris.

Re: Build Thread for all

PostPosted: Tue Dec 05, 2017 2:54 am
by DRW21
Here's my entry, yet to fit body and get it looking complete.

All brass chassis, way too much traction for my liking but too late to start again. Still a fun build and pleased to be on the grid.

Image

Image

Image