Haddi Taha

Thats what I will be doing too, I want to get 2 spec-r tb03 diffs, use very thick oil in the front and medium thick in the rear. Should give a spool effect minus the gear wear

proanti1

My Feedback: (2)

Well you cant let it leak out into the diff case, because then it will be worthless... and you will just have a ring and pinion trying to move 10,000 weight oil around. The whole purpose is to keep it inside the carrier with the spider gears. The newer ones are sealed with a blue o-ring, I just put 5000 in mine a few days ago, maybe you should at least update to the newer style.

depro

I'm using an older tmaxx diff which I already had and a newer one I bought off ebay (trying to keep costs down). The silicon doesn't leak into the ring and pinion area. It leaks out when the output shafts spin to give differential action and gets all over the car and creates an ugly mess. Thus far in my offroad vehicle the o-rings have kept all the silicon in and my diff action still feels just as good. I put some of the associated grease for the ring and pinion gear, and I used some epic oil for all my bearings. The result was a drive train that was unbelievably free and smooth

dragnse7en

It's log, log, log - beautiful - made of wood. It's log, log, log, beautiful - deadly and good.

Lah Lah it's Log, Log <log.

girbilix. I pooped a log down the flusher!!!!!

depro

Is that a new way of asking for updates?

depro

I managed to get a few pieces cut out this weekend. Each piece takes at least 45 minutes from drawing it on the plastic, to final shape. First I cut them out with my jigsaw, and then use my drill press with a router bit to shave all the edges to their final shape and make the sides perfectly perpendicular and smooth. Then I use another router bit in my drill press to get the nice curved edges on the plastic. My fingers are so sore right now from constantly working with these little plastic pieces. Thus far I've been lucky and haven't gotten bitten by the router bits yet, although there have been some close calls. Also to get symmetrical pieces I cut them out separately first, then screw them together and use my router bit to shave them down until they are identical.

dragnse7en

Looking good! It reminds me of very early Team Associated.

Haddi Taha

are you spraying the nylon another colour or leaving it white?

depro

I'll be dying the nylon black like the offroad truck I posted on this thread. It'll look pretty sweet. I'm really beginning to wonder what will break if I end up hitting a wall or something with this thing.

warnos16v

Awsome project dude.. hats off to you.

Haddi Taha

If your worried of breakages, make a front bumber that will protect the front wheels and front suspension parts of damage in a crash, A foam urethane bumper will absorb the impact. Metal bumbers aren't goiod, they will bend in a crash and try to bend your chassis. The Foam bumper works with you body shell in hands, the bumper will support your shells shape in a crash and your shell protects your car from every angle

djyjrlz

i think the tyres on a kyosho drx squeal quite well 

Haddi Taha

any updates

depro

I've got the main bulkheads attached to the chassis now and tomorrow I'll begin working on the upper deck and bracing. Even with a centerpunch and a drill press its difficult to get all the holes exactly where they need to be. It was also super tricky trying to get all the steering components stuffed in there on Autocad. Yes it'll have a front bumper, but I'm still curious what will break in a collision

web-head91

i've been following you project and i gotta say i'm impressed
well don't forget to check all chassis that are avialabe in the market, you might some few good ideas from them.
you can also take a certain concept and try to improove it
as for what part would crash. i think we need to run a crash test XD
plastic may resist for a while but it might crack with time, so you've got to think of something that absorbs the schock of the impact.
good luck with your project

dragnse7en

Typically, anything that has a sharp bend will break first. Look for those, and look for breaks close to the bend.

What version of AutoCAD are you running? I use that and Solidworks and MDT6 and Inventor. I like 3D CAD over 2D any day.

The chassis is looking good with the bulkheads. Beefy!!!

dragnse7en

Here's a 3D model I did for freelance telecommute work for Guilles in Paris, France. The owner of the company (Guilles) made resin prototypes with a 3D laser printer that cures the resin, and works almost the same way as a mutli-axis machine. It's a 1/35th scale Uniroyal military tire, used on France's wheeled armored VAB.

Off topic, sorry, but I do CAD too!!! I emailed him a special export file format that his 3D resin printer can accept.

depro

When its done I'm gonna take it to an onroad track I found nearby, and see if I can keep it in the lanes. I've never raced or even driven on a track before so that might be the ultimate bunch of crash tests. I had a really weird dream last night about changing the hinge pin attachment points into ball cups so in the event of a crash they would just pop off and leave everything undamaged. What do you all think?

As for Autocad its the 2009 version and I really never spent the time to learn how to make 3d objects. I'm sure a few afternoons of youtube tutorials would help, but until then I'll stick to 2d. If I had access to a cnc milling machine then I'd definitely start drawing in 3d.

Here's a quick drawing of the ball cup idea. The ball post would be screwed into the end of the nylon hinge pin holder, and the cup would be screwed onto the end of the hinge pin.

dragnse7en

I'd suggest reversing that design, and use a ball joint as the pivot end on the hinge pin, and the ball cup as part of the suspension holder. If the ball stud is installed squarely, then it will center the axis of the hinge pin every time it moves.

depro

Yeah I think that's a better idea. I'm just going to keep things as they are right now, and see what breaks before trying to improve anything. I was also thinking about making my hinge pins super brittle so they would simply snap in the event of a hard crash.

On the plus side I finally got the ackerman right on autocad so now I can start cutting out steering components.

dragnse7en

That sounds expensive - buying some sort of plastic stock tube that will shatter under a pre-determined weight. . . Carbon fiber tubes are both super expensive and are only rated according to their chord length - (chord length per ft, for example).

Good luck with that tho Keep it simple hoss!!! Come ON!

In true engineering, it's not what you can add, but what you can take away from the equation to make the whole solution work - Socrates

I think you'll want my help in the future.

Okay; on-road, 190mm chassis. okay.

Wheelbase shall equal 239mm.

CG shall be no taller than 5mm from the bottom of the lower main deck plane.

Weight shall be no lighter than 1400 grams.

Belt or Prop - driven propulsion is only allowed. (Chain, belt pulley, toothless belts, direct gear - gearbox or pulley transfer driven, prop (shaft) driven, via transfer case or otherwise; prop - to - belt transfer allowed, as long as there is a sole, one and only transfer system. Only a one style drive system is allowed to drive a different style on a single primary system.

Two - speed automatic and manual transmissions are welcome, but after the prime setup is met, the weight of current 2 speed trannys are inefficient, to date.

depro

You're definitely an engineer. Engineers always make things more complicated and expensive than they need to be. I do like the idea of using a nylon or hdpe rod instead of steel hinge pin though. I might just use that as the designated breaking point. You gotta remember this is an rc car and not a high profile project that requires exact specs. From my perspective I simply need a rod that doesn't break under normal use, but will snap during a heavy collision.

The width of my car is currently adjustable between 190 and 200mm. The roar wheelbase requirement is between 250 and 270mm and I'm currently at 254mm but adjustable to around 265mm. I'm not sure where my CG is at, but all the components are as low as possible. And it'll be single speed and shaft driven. So far the weight adds up to around 3lbs, and my 3 cell lipo isn't roar legal but there are plenty of 2 cell packs of similar weight that will fit.

dragnse7en

Yeah, I guess you can smell an engineer from a mile away when they smell

dragnse7en

Oh - I do my best NOT to make it expensive. Realistic, and BOSS - yes. Unrealistic and ridicuolous, NO. Point Blank Mang!!!!

depro

Eek I was just making a general statement about engineers and their projects. But hey, who can blame them. I'm sure if my project was government funded it would cost at least 10 grand ya know