FWD/FF Buggy

[Burty248]

Is the chassis only capable of shorty lipos?
Are you aware of ROAR rule 8.2.3 about shorty lipos in electric cars? i don't thinks it a BRCA or any European rule.

Here's a link: http://www.roarracing.com/?p=1438

Sounds a bit of a stupid rule if you ask me.

[Origineelreclamebord]

It is yes, and I'm aware of that rule... I wouldn't be too surprised though if they have another rule at the ROAR stating that they don't accept front wheel driven cars at all...

Whatever the case is, rules may be open to change, and if that's not the case it might be possible to bypass them... but if it's only the shorty that is a problem, it's easy making a saddle-compatible version I know it's not everyone's cup of tea though to use shorty packs - definetely something to consider, and probably therefor something to work on later on anyway.

[mattr]

Try 410 shafts, sure they come in a 70 ish mm size

[mattr]

Originally Posted by mattr

Try 410 shafts, sure they come in a 70 ish mm size

scrub that, all the C-C lengths are over 70 or under 65.

[Tomboo_91]

Originally Posted by Origineelreclamebord

There is only one BIG problem I have to overcome. The length of the DEX210 driveshaft is too short (it's 65, and needs to be more like 69-70mm). The first choice would be using as many existing parts as possible - especially of the machined type like driveshafts - so does anyone have suggestions for this?

Mr. Dremel (Janus) made some custom length drive shafts a few years ago. He cuts them and glue them together by using a small tube.

[johnnygibbon]

awsome work and durango parts to
[ want this car even more now )
the tube extension method on drive shafts works ive seen our race controller do it on woodys car and it worked great
keep up the good work and put me down for a conversion kit
deposit ready any time hahahah

[Origineelreclamebord]

Thanks for the comments guys

Originally Posted by Tomboo_91

Mr. Dremel (Janus) made some custom length drive shafts a few years ago. He cuts them and glue them together by using a small tube.

I thought about this as well - even tried it once for an onroad setup. It's not something I can base my design around just in case it's not durable enough. However, it is a very interesting technique to look at for testing an optimized design of the suspension and driveline geometry once I have a backup system So I guess I might start off with 'short' arms and try out longer ones later on with the geometry as intended.

As for the driveshaft lengths... The DEX410 shafts are 61mm (rear) and 77mm (front) - the DEX210 shafts are 65mm - the Xray XB4 rear shafts are 68mm I found out, so very interesting to look at. Lastly, the Tamiya DF03 shafts are 70mm, so together with DB01 axles that might work as well (though 70mm after a good look seems to be just slightly too long).

[janus_77]

Originally Posted by Tomboo_91

Mr. Dremel (Janus) made some custom length drive shafts a few years ago. He cuts them and glue them together by using a small tube.

http://www.xfactoryrc.com/rc/Tech/ModifiedCVA.php

[Skidrow]

I can make CVD bones of B4 type in any length requested in steel one piece if interested-race tested

[Origineelreclamebord]

Thanks for the comments and help lads I've found a solution that I will start out with:

- TRF201 Axles+Driveshafts (64mm)
- DEX410(R) Hubs+Casterblocks

The car will end up being 240mm-ish, not 245 or 246 like I'd prefer to, but geometry-wise it seems to work fine.

I'm kind of finishing up the design right now... The main things left to do were to optimize the battery tray, make the rear shock tower and finish the electronics install:



It's a bit tight on space if you are not using the top deck, but it is possible, even with the huge Futaba receiver and bulky HobbyKing ESC I will be using.

I hope to have a mockup of the front end on the table soon - Fingers crossed!

[Gayo]

Fantastic! I like the layout and the fact that the steering link is not on the way of the lipo.

[Origineelreclamebord]

Thanks, I'm glad you like it I packed it as tight as possible really, and with the inboard shocks out of the way I could move the steering up.

Anyway, today I decided to model a bodyshell for it:



I want to emphasize here, this was just for fun! I'd prefer to avoid the effort of making a mould for a single shell - this car is still very much a prototype, so it's preferable to avoid making a mould for a single shell

It does give a good idea of the kind of shell the car needs though: rather narrow, and quite high (the sidepods are 50mm high with the scoops a whopping 55mm - the cab is about 85mm high. I don't know of a body of these proportions, so I might need to get creative again on an existing body to make it fit

[Typpo]

Originally Posted by Origineelreclamebord

Thanks for the comments and help lads I've found a solution that I will start out with:

- TRF201 Axles+Driveshafts (64mm)
- DEX410(R) Hubs+Casterblocks

The car will end up being 240mm-ish, not 245 or 246 like I'd prefer to, but geometry-wise it seems to work fine.

I'm kind of finishing up the design right now... The main things left to do were to optimize the battery tray, make the rear shock tower and finish the electronics install:



It's a bit tight on space if you are not using the top deck, but it is possible, even with the huge Futaba receiver and bulky HobbyKing ESC I will be using.

I hope to have a mockup of the front end on the table soon - Fingers crossed!

An additional driveshaft option (should you need it) is Kyosho LA-231. It is 68mm pin to pin with the option of changing the axles. Note the cross-pin at the diff side is about 2mm diameter.

An example can be found here for the picture:
http://www.rc10talk.com/download/fil...0068&mode=view

and here for the thread:
http://www.rc10talk.com/viewtopic.php?f=30&t=29607

[Gayo]

What is the bit protruding on the right side supposed to be?

[Origineelreclamebord]

Originally Posted by Typpo

An additional driveshaft option (should you need it) is Kyosho LA-231. It is 68mm pin to pin with the option of changing the axles. Note the cross-pin at the diff side is about 2mm diameter.

An example can be found here for the picture:
http://www.rc10talk.com/download/fil...0068&mode=view

and here for the thread:
http://www.rc10talk.com/viewtopic.php?f=30&t=29607

Thanks for letting me know! So is that axle on the universal shaft a front or rear axle? If it's a rear axle it may work very to get this car close to that 250mm

Originally Posted by Gayo

What is the bit protruding on the right side supposed to be?

Hehe, it's one of the posts that holds the battery holder in place. The battery holder is the front half of the right sidepod - it's fitted with one body clip on the side, and one at the front below the steering rack. It's all a bit tight - to get the battery out still requires a small trick or two, but in practice it should still prove more convenient than the the old system!

[Origineelreclamebord]

http://www.youtube.com/watch?v=RwbeRkIuSUc

Better late than never... I drove the car on tarmac again to show it to a friend - he was so kind to get some footage of the car. You can see it's got brakes unlike any other car And as you can see, two rear wheels are overrated when it comes to cornering, too!

It's just lovely how agressive it can be driven into corners The corner speeds is amazing, the only thing I need to reduce is wheelspin and tire wear out of corners (though admittedly, with all the braking to make those stoppies happen, the already worn front tires were completely bald in two batteries)

Data on conditions/setup/etc:
Front tires: Proline Caliber M3 Wide/Rear (About 2mm of tread left at the beginning of the run).
Rear tires: Losi (something... Stud?) tires, 4WD Front (reasonable tread left).
Damper setup: Same as on dirt/clay (see page 7 or 8 for reference on that).
Ride Height, Front: 21mm with 12-ish mm droop.
Ride Height, Rear: 26-ish mm with 1-2mm droop.

[mrspeedy]

Looks ace !!! Lovin' how it corners like a 80's hot hatch ...

Have you thought about a weighted pinion gear ? It might help thow a little weight forward on acceleration ... kinda like the opposite of a 4 gear tranny on a mid motored buggy ..

[johnnygibbon]

Looks so sharp and can obviously handle the power
Good choice on the 210 gear box ( upgrade the slipper spacer though ) and its tough and reliable , are you running a gear diff or ball diff , my 210 diff has been great with buds balls ceramic kit in it no probs through months of racing but for the intense pressure and ability to almost lock it with thick fluid a gear diff may be good . Nice to have the option any way

Love this car far to much
Kept up the good work

[Gayo]

The car seems indeed to handle really well! Oh and those stoppies...

[Origineelreclamebord]

Hehe thanks guys The car goes much better on high bite than I expected: The forward traction doesn't seem to be the limiting factor to overall pace, agressive turn-in is possible (in fact, it seems it goes quicker that way) and I've yet to see it grip roll - I can only hope that applies on carpet too. I do know it does stoppies even better on carpet (with the same droop setting on the rear)

I have considered experimenting with flywheels, but it was decided to postpone such mods as I knew quite early on that a next prototype would utilize a DEX210 gearbox. It's adjustability with regard to rotation direction of the motor and internals (in one casing) is after all very useful for this project.

I will try out rotation direction of the motor first, but I'm sure along the line it will get to trying out custom parts to try and find the things in the drivetrain that give the edge!

As for the DEX210 gearbox, what's wrong with the slipper spacer? Is that related to the issue with the bearing that tends to break down on the slipper axle? And are there any more things besides that? (Note: my DEX210 is of the very first batch - where everyone was trying to solve those diff issues).