Australian RC Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
439 Posts
Discussion Starter · #1 ·
Why dont more cars use saddle packs?? Of all the cars I have been looking at only the xray t1 seems to use them (i am sure there are others) but the Mi2, TRF415, TBEVO3, corally assassinetc all use in line packs down one side of the chassis.


Is the weight of the motor/esc/rx and steering servo enough to offset the weight of the pack, especially with the ever increasing miniaturisation of parts?


And then people start talking about moving the pack forward or back on the chassis to increase under or over steer, surely it would have some bias to the side with the pack, unless u use heaps of ballast on the other side of the car, and then why bother getting a nice light weight CF chassis kit?
 

·
Registered
Joined
·
596 Posts
saddle packs are fiddly in comparison to both stick packs and side by side packs. stick packs are best for pure convenience and for newbies/kids as they are usually completely insulated so there is not chance of shorting out a pack





side by side is better racing as the use of battery bars between the cells results in lower resistance compared to stick packs which use sliver of tin spot welded to the cell.





most race cars are underwieght anyway and need wieghts added to them to be legal to race at most clubs
 

·
Registered
Joined
·
439 Posts
Discussion Starter · #3 ·
OK


so aside from space restrictions on some cars, why dont they run the side by side packs east west in the car like the tamiya ta04 does - heck even my old fox used a east west stick pack at least the weight is even left to right
 

·
Registered
Joined
·
596 Posts
the idea of running saddle packs on the xray is to keep the wieght as centralised as possible to get a better handling car. rotating the cells 90 degees would defeat the purpose of saddle packs as it moves the wieght away from the centre line of the car
 

·
Registered
Joined
·
439 Posts
Discussion Starter · #5 ·
I realise that


The xray gives you the choice of the saddle pack or the side by side down either side, or with the saddle having half the batts in the front on one side and half on the other side up front


what i am saying is why dont all cars have a setup where u have 3 cells one the LHS and three cells on the RHS for proper weight distribution
 

·
Premium Member
Joined
·
6,579 Posts
Japan's JRCM series that uses 23turn motors... they mandate racing only commercially-made stick packs. So all Jap cars must be able to accept stick packs, even the top class ones.


azenis said:
...why dont all cars have a setup where u have 3 cells one the LHS and three cells on the RHS for proper weight distribution

After the battery there's also this great big lump of a motor which is the next heaviest item. Its hard to balance when you've got that hanging off to one side too.


Talking of which, the 415 has that problem...



HPI's PRO3 put the battery right down the middle, as did Kyosho's KX1.


Tamiya never made a saddlepack chassis for TA04, but TamiyaUSA did. But the ones who tried it, there wasn't much tangible benefit anyway so most racers didn't persist using it. TRF414 (the car TA04 got its roots from) runs saddles but its balance & handling is nearly exactly same as TA04.
 

·
Registered
Joined
·
439 Posts
Discussion Starter · #9 ·
zoomer said:
there's also this great big lump of a motor which is the next heaviest item. Its hard to balance when you've got that hanging off to one side too.


Talking of which, the 415 has that problem...

Yes the motor is fairly heavy. The TRF415 seems to mount the motor a fair bit to the left of the car, with the pinion sitting much in the middle of the chassis, where the ta04 it seems a bit more centred, at least it looks that way inpics
 

·
Registered
Joined
·
439 Posts
Discussion Starter · #10 ·



Yes you can see here that the motor sticks out nearly as far as the wheel, the spur gear is on the motor can side of the lay shaft, with the lay shaft and belts down the centre of the car


As opposed to the ta04, which sits the motor under the layshaft, with the spur on the other side, making the motor sit right in the middle of the car


http://www.rczone.net/modules.php?name=News&file=article&sid=454
 

·
Registered
Joined
·
439 Posts
Discussion Starter · #11 ·
Looks like the Schumacher Mi2 has the same problem as the TRF415








And the Xray T1 uses the same system as the TA04, with the advantage of the saddlepack option as well. I want one.


Edited by: azenis
 

·
Premium Member
Joined
·
6,579 Posts
azenis said:
... The TRF415 seems to mount the motor a fair bit to the left of the car, with the pinion sitting much in the middle of the chassis

all that weight so far away from the "centre line" affects the moment for steering too... some say the EvoIII turns better as the motor is inline with the shaft and doesn't stick out as much. It depends on the track I guess, most pro drivers running Tamiya are still hanging on to their EvoIIIs.


And that motor is exactly where my EvoIII took a large whack, hard enough leave a dent on the chasis CF and broke the battery strap. (no prizes guessing which part I still CAN'T BUY as sparepart...)


Wonder what happens if the motor gets t-boned in a race!!?!
 

·
Registered
Joined
·
439 Posts
Discussion Starter · #13 ·
no joy at all



the mi2 looks a better layout in this regard compared to the tamiya, but still it puts the motor out to one side a bit much
 

·
Premium Member
Joined
·
6,579 Posts
imho Mi2's build quality isn't too flash but I guess it does its job. Its got heaps of fans here in Melb mainly b'cos its cheap & good value. But its not something I'd caress and admire just for its machining & molding quality & design.


Xrays aren't too popular here (dunno why) but they're everywhere in Sydney. Here in Melb you probably see more Corally Assassins than any Xray at the track. Both cars have great parts quality too.


(hmm... was admiring the Xray box too... its a foiled print of a starburst pattern in blue & grey streaks with chrome backing. If only I could do that on lexan...
)





As for "saddle packs"... a real saddle pack needs a centre wire, this is too much 'extra' wire for some.


I'm building all my side-by-side backs in 2 lumps of 3, connected by a short wire in the middle. This allows a bit of flex in the pack, I don't have trouble with the battery bars falling off midrun like some.
 

·
Registered
Joined
·
439 Posts
Discussion Starter · #15 ·
Also the saddle packs usually require mounting the ESC right up the front of the car also resulting in too much wire for some
 
1 - 15 of 15 Posts
Top