CD's for the savage? - Page 4 - RC-Monster Forums

Nixpus · 03.24.2011, 04:43 AM

No no :)

The outrunner is a project on its own with direct to F/R diff connection. The battery placement will be identical for the two setups (CD+1717 & Huge ass outrunner).

The spec's are here: http://www.hobbyking.com/hobbyking/s...idProduct=2097

Gunning for 38mph @ 6 cells and 57mph @ 9 cells... according to the speed calc.

Regarding the battery placement Im not that concerned. I'll make sure the skid plate protrude a bit to each side under the battery. With that and a set of 40 series mashers on each side Id say they aren't that exposed. Once I blow a battery up I'll look into better protection ;)

Jahay · 03.24.2011, 09:11 AM

WOW 280kv! THAT IS LOOOOWWWW you could push a bloody 30lbs baja easily with that...

So these outrunners do not require a diff as the shafts from F&R diff go directly to the motor?

Nixpus · 03.24.2011, 09:25 AM

Yep thats the plan. There are a few of these outrunner direct to diff conversions around here if you want to read a bit about them :)

Im a little concerned about the start up of the truck... which is also why we picked a BIG motor with low KV and alot of poles.

Nixpus · 03.29.2011, 07:13 AM

CD & motor mount done. Nothing Fancy. Should be able to accept down to 10T pinions - might need to file down 3 of the ribs on the engine for that. Engine plate is 6mm. hope it will hold the 1717 alright... time will tell ;)

The circular hole in the motor plate is proff that we consider the environment and recycle as best we can :)

Jahay · 03.29.2011, 07:17 AM

Nice work on the mount!!! Clean job!!!

i have also been doing some gearing calculations... and it looks like i may need to run a 9-10t pinion!

I really dont like the idea of running something so small... it will wear quickly wont it? especially with the brushless power...

Nixpus · 03.29.2011, 07:38 AM

More or less ending up in a G-Maxx layout I think... Question is if I should keep the cut out and try to get the bats as close to the dogbone as possible or simply use the TVPs as sidewall in the battery "tray". Having the bats outside would leave plenty of room for the wires ;)

Cut out placement:

Bats outside TVPs:

Pretty low CoG:

Skidplate mounting to the front bulkhead. Using the 4 existing screws in that area. Just swapping them to slightly longer counter sunk screws. the rear will bolt with 4 screws into the CD mount (CD mount will bolt into TVPs with 8 screws)

Expecting to use 3mm alu for the skidplate and trim TVPs/skid as best I can to loose weight at a later time.

Nixpus · 03.29.2011, 07:45 AM

Brian G's speed calc gives me theese figures when I run 40 series mashers (6.6 inches) and add 0.25 of ballooning. They are belted... hope it will last ;)

Anyway, the speeds come out like this:
10T 44.22 mph
11T 48.64 mph
12T 53.06 mph
13T 57.48 mph
14T 61.90 mph

No clue on wear... but I my 13T pinion didn't wear too bad last season (Robinson racing). Have 9-10-11T Novak pinion in the mail :)

Jahay · 03.29.2011, 08:02 AM

hmmm i would look to gear 12t or so....according to those numbers...
Doubt you should have any probs with heat issues running such a bit motor and 6s.

I would personally like to have the batteries half inside the chassis... But it could make strapping them in a little awkward?

Bmr4life · 03.29.2011, 08:17 AM

That mount is great. I'll definitely be copying that for my Savage. I want to try using 3/8 lexan though since I have a lot of it laying around.

Nixpus · 03.29.2011, 08:51 AM

Looking forward to a lexan version Brm4life :)

Jahay, your right. Moving the bats too far out on the sides will mess up more than it will fix... I was hell bend on having the wires inside the TVPs but in reality it doesn't matter. Will flip the batteries 180° and push them as close to the center as possible. Strapping will be solved... somehow... ;)

Nixpus · 03.30.2011, 10:55 AM

Look what the new 3D printer coughed up with :)

Its nothing short of amazing that you can do prototyping this way!

thzero · 11:02 AM

nice!

I like the extended parts, help distribute the load on the XL axle. However there is still a problem with the XL (and X) axle with the pin being so close to the threads; with the bigger wheels I snapped a bunch of XL axles at where the threads meet the rest of the axle. If you are making parts, I'd really look to replacing the XL axle with a truggy style axle; or at very least look to putting another hole in the axle further up the axle and using a truggy hex adapter or truggy axle extender, sorta like what I did with the XL axles to mount the Baja 5B 24mm hex hubs.

Nixpus · 11:03 AM

Seems like we need to push the rear bearing a bit back - 1mm should do.

Might have to push the whole front a bit. That dogbone has a fair bit of play!

In the front we need to adjust the opposite way... fun :)

We also need to shave off a good bit of material... because as it is we have 2° steering throw in both directions... we need as much as the standard setup and then some!

This is where the pin hole should be positioned.

thzero · 03.30.2011, 11:07 AM

Something like the hex for the RC8T (http://www3.towerhobbies.com/cgi-bin...?&I=LXVKH7&P=Z) is what I was thinking of. If I could find someone that could drill a pin hole (perpendicular to the existing one) so that the end of the RC8T hex nut is within .5mm of the bearing, I would be happy.

Jahay · 03.30.2011, 11:08 AM

that is so impressive! Im loving these 3d printers!!!

How long and how much is it to print a single hub like that? Also how fragile are those 3d prints???

To get rid of the xl axle, why not make use of the savage 5t truggy style axle. And build this hub to that specification so the pin is in the perfect place?