Some ideas/brainstorming for a 1/7 scale on road car build - Page 2 - RC-Monster Forums

lincpimp · 12.09.2010, 11:43 PM

Ok, I am not quite with it today.

For some reason I thought I could swap the steering bellcranks and put the servo on the other side...WRONG

So I got the motor out of the flux, set it up on the same side as the steering servo, and found some small pinions, 18/22, for the 2 speed adapter. It all fits, with room to slide the motor over for the smaller 16/20 gearing I need to order.

Also, the brake servo will fit behind the steering servo and in front of the centerfront bulkhead. So good to go. Battery fits a little better on the opposite side, and the MMM looks lost behind it. I do need to figure out some sort of tx/bec mount or box.

Only issue is that the rear brace off the rear diff bulk will need to be moved to clear the motor. Looks like I can swap in a longer turnbukle and run it slightly diagonally and mount it on the other side of the rear center driveshaft.

Forgot to take pics but will do that in the morning.

What's_nitro? · 12.09.2010, 11:45 PM

Quote:

Originally Posted by lincpimp

Ok, I am not quite with it today.

For some reason I thought I could swap the steering bellcranks and put the servo on the other side...WRONG

Manufacture a new steering link, perhaps?

lincpimp · 12.10.2010, 12:26 AM

Quote:

Originally Posted by What's_nitro?

Manufacture a new steering link, perhaps?

I would have to make an ackerman plate too, and the arc of the mount points of the bellcranks would be very weird if I swapped them. I will stick with putting the motor and both servos on one side, and the battery and esc on the other.

lincpimp · 12.10.2010, 10:45 AM

Here are some pics with my current configuration. Think this will be the final one, so I will get to making the motor mount plate.

Overdriven · 12.10.2010, 08:43 PM

Instead of using a longer turnbuckle for the rear chassis brace, how about moving it to the outside of the mount. I know the mounting screw won't be double shear then, but it is only for onroad. Although if you have a longer turnbuckle lying around... Looks nice though, never knew Hot Bodies made a 1/7, thanks for sharing.

JERRY2KONE · **Setup. -** 12.10.2010, 11:09 PM

Hey James. Your setup looks pretty clean to me and practical to. The only issue I see so far is the battery center diff gear spacing. I will assume that you plan on using a battery tray of some kind to keep them from coming into contact with each other. That could be one ugly incident. Looks good James.

Finnster · 12:36 AM

How radical are you thinking about getting? There seems to be quite a bit of real estate on that chassis. Any thoughts to maybe moving the center diff back a few inches and offset towards the batt side, that flips the motor around too, and you could bring it and the battery closer to the center line of the chassis?

There seems to be some space around the nitro motor mount holes where you could fit the CD in. Makes mounting the rear brace a bit trickier tho. F brace could move to other side of driveline, which is fine as the brake servo goes back w/ the CD, and there may be space in front of the motor. Just a wild thought. GLWTB.

lincpimp · 12.11.2010, 02:42 AM

Quote:

Originally Posted by Overdriven

Instead of using a longer turnbuckle for the rear chassis brace, how about moving it to the outside of the mount. I know the mounting screw won't be double shear then, but it is only for onroad. Although if you have a longer turnbuckle lying around... Looks nice though, never knew Hot Bodies made a 1/7, thanks for sharing.

I was thinking this, just use a longer screw and put a sapcer in the space that is left so I can run the screw thru both tabs. Might do this as it is easier than digging up another turnbuckle.

Quote:

Originally Posted by JERRY2KONE

Hey James. Your setup looks pretty clean to me and practical to. The only issue I see so far is the battery center diff gear spacing. I will assume that you plan on using a battery tray of some kind to keep them from coming into contact with each other. That could be one ugly incident. Looks good James.

Yep, will have a full height sides battery box with velcro straps, I aften put a piece of al on the outside of the box just in case the box breaks and gets too close to the spur.

Quote:

Originally Posted by Finnster

How radical are you thinking about getting? There seems to be quite a bit of real estate on that chassis. Any thoughts to maybe moving the center diff back a few inches and offset towards the batt side, that flips the motor around too, and you could bring it and the battery closer to the center line of the chassis?

There seems to be some space around the nitro motor mount holes where you could fit the CD in. Makes mounting the rear brace a bit trickier tho. F brace could move to other side of driveline, which is fine as the brake servo goes back w/ the CD, and there may be space in front of the motor. Just a wild thought. GLWTB.

If I was going to make another chassis I would do just about what you have said. I would have the center drive at the back, and use a long center dogbone to get power up to the front diff. The motor would sit in the middle, pinion facing rearwards, and possibly offset the center drive so the battery could move in closer to the centerline. Even balance side to side would be nice, and I would like the ft to rear balance to be about 1/3 of the way from the front of the chassis, for more forward bite under acceleration.

Might do this at some point, but sticking to the center drives and stock chassis on this one. I do plan to make the motor plate big enough to go under the center drive and act as a brace. Something similar to the xray truggy chassis brace Mike makes.

lincpimp · 12.31.2010, 10:01 PM

Ok, little update here. Had some time so I figured out the brake servo mount, and would have cut it to length but the "tires" on my bandsaw have dry rotted, so I had to order new ones.

So I removed the center drive and the other parts and found a nice piece of al, 2/10ths of an inch thick, to use as a combined brace, motor mount etc. Motor will mount to this piece from the underside, as will the brake servo mount and the rear of the battery tray. Will thread holes in it so it can be held to the chassis from the underside thru the stock chassis holes.

Plus the front and rear chassis braces will mount thru it, and it will stiffen the center of the chassis, and help keep the gears mesh correctly. The gear mesh will be set with the center drive and the motor mounted to the plate off the vehicle and then the whole assy will be mounted in. I could cut some "windows" in the stock chassis, kinda like a nitro chassis, just depends.

Heres a couple of pics, had more but the stupid "smart phone" did not save them correctly...

Semi Pro · 12.31.2010, 10:07 PM

im looking forward to seeing how this turns out

lincpimp · 01.01.2011, 04:31 AM

Quote:

Originally Posted by Semi Pro

im looking forward to seeing how this turns out

Me too, should be decent.

Big House · 01.02.2011, 12:10 AM

Due to the length of your project, I would suggest you find a way to fab up a top plate that connects the front and rear of the chassis to cut out flex. I don't think the front and rear braces, in my opinion are not enough to keep the chassis from flexing.

lincpimp · 01.02.2011, 04:37 PM

Quote:

Originally Posted by Big House

Due to the length of your project, I would suggest you find a way to fab up a top plate that connects the front and rear of the chassis to cut out flex. I don't think the front and rear braces, in my opinion are not enough to keep the chassis from flexing.

The sides of the chassis are bent up and that helps with the flex. The motor mount plate will act as a chassis stiffener, effectively doubling the chassis thickness in the middle. I do not think I will have any problems. I have made top plates before, but that was a flat chassis vehicle that did have flex issues.

simplechamp · 02:53 AM

Kind of like a 1/10 4WD TC right Big House?

Kind of unrelated, but my truggy has a carbon-fiber "spine" so to speak as Big House described, and it has done a great job reducing flex (especially since it's the 6061 RTR chassis, not 7075 Pro). Diggity Designs makes a similar item for the Caster buggy:

http://diggitydesigns.com/D3_Caster_EX_UpperDeck.html

I spoke to Damon about using setups like this, and he said with the reduced chassis flex you will have to change the suspension setup a little, but overall it will be more consistent. You still need to have a little flex, but shock oil and springs are more predictable than a flexing chassis, and they should be doing the bulk of the suspension "work". And especially with a TC I think a stiffer chassis is the way to go, since the surface is smooth and high traction.

lincpimp · 01.05.2011, 11:14 PM

Did some work tonight on the center chassis plate. Looks like it will work fine.

Need to order gears from Mike, might as well do that tonight too! Once they come in I can finalize the motor clamps locations and do a few test runs. Also need to make a battery tray, but that covers the construction aspects of this project...