Losi Xcelorin and LRP 5300 Lipo in Cat SX

[JackWood]

Just some pics of my recent build.

This is the first car I have built in 22 years, so if I made a FUBAR anywhere, please let me know.



Wires to the ESC are nice and short from the motor. This orientation means the LEDs on ESC are on the outside and easy to see.



The vertical outlet of the Corally works better with the LRP LiPo. It keeps the wires well away from the belts.



But you have to be very careful how you place the front as the bumps on the LiPo only have approx 1.5mm per side clearance of the 2 front pulleys.

You can also see the velcro I cut to shape on the LiPo and strap. I also used the locators to make sure the LiPo didn't slide around and hit the pulleys.

[MattADH]

When I tried the same 5300 pack in a CAT SX, I am sure that the inside hump on the casing rubbed against the pulley for the front belt. This was with the LiPo slammed against the servo as per the manual. And the servo position/spacing cannot be changed.

Has anyone had any thoughts/ideas on this?

[V-Rossi]

You didn't sand and glue the carbon fibre edges
I suggest doing this, as carbon fibre can split after a crash.

[JackWood]

Matt, if you push the LiPo against the back of the servo the hump DOES rub on the pulley. That is why I centred the bump between the pulleys, marked up the position, and glued the battery locators to the bottom, and then doubled it up by using the velcor to make sure it won't move. It works fine.

In retrospect, it would have been a lot easier to get Trakpower LiPos and then the position wouldn't matter. But I didn't know that when I bought the kit and battery

Rossi, I'm not sure if I can really be bothered doing that. Sounds like a lot of work. If it splits I'll just buy a new bit, I think.

[Chris Doughty]

could you space the servo a few mm out to give room for the LiPo?

[Southwell]

You can buy short Losi sensor wires

Can the cap or zip tie hit the fan in the event of a crash? If they can then you will break the fan blades, other than that it looks good.

Just get a screw driver and dab some glue on it, then run it around the chassis and towers.

[Southwell]

Originally Posted by DoughtyUK.net

could you space the servo a few mm out to give room for the LiPo?

I play with Ryans because he wasn't getting proper lock on the steering, they seem very sensitive to small adjustments and it took a while to get it right, it may work though.

[Chris Doughty]

Originally Posted by V-Rossi

You didn't sand and glue the carbon fibre edges
I suggest doing this, as carbon fibre can split after a crash.

I never bother doing any of that prep work to any carbon fibre that I run, it always holds up just fine.

its all internal stuff in the CAT SX anyway with the undertray on.

[JackWood]

There is plenty of room for the Lipo. Too much room. If you push it up against the back of the servo the bump hits the pulley. You need a packer between the servo and Lip really. The position of the Servo is not a problem.

Southwell, I'll take a look at the cap. The battery and motor leads were MASSIVE, but for some reason the Cap leads are very short. That is why the cap is hanging over the edge.

[Cassp0nk]

Servo size affect battery placement too. I've got a savox servo which is very compact and it means my battery has a lot more width that the instruction suggest.

[sime46]

I run the lrp 5300. I cut the hump off so it clears the pulley. I cleaned up the casing and filled the hole with sealant and smoothed it off. Presto, put the battery up to the back of the servo and can still run the servo without spacers. Perfect(in my opinion).

[Northy]

Originally Posted by sime46

Perfect(in my opinion).

If you want to fail scrutineering at a BRCA event

G

[sime46]

Sorry.

[Cassp0nk]

Originally Posted by Northy

If you want to fail scrutineering at a BRCA event

G

disregarding his mods, they allow 5300?

[sime46]

I'm assuming that altering casings in any way is not allowed then? Thats fair enough, otherwise its open season for cut and shuts. Are you allowed to glue stuff to the casings? The lipo locaters on Cats are glued to the lipo. Does that not compromise its structural integrity? Only a thought. I will buy a new lipo for brca events then. Need to know which ones are allowed then. Any news on that?

[sime46]

TBH I think 5300 is not allowed. Not sure but I think I read that its got to be 5000 or less?

[Mike Hudson]

max capacity is 5500 for the 09 brca lipo rules,
You should give patience and wait for the EB list of all the legal lipos for the 09 season which should be out late february sometime otherwise you'll be taking a big gamble on what cells will be legal or not as no-one knows at current.
Cutting parts off your case and filling in holes would most certainly be failed at scrutineering at a brca event. Glueing chassis locators onto a lipo should be fine, it's if you break through the case in anyway that isn't allowed.

[Cassp0nk]

So decent chance the high cap trakpower cells will be ok. I bought a 4900 for regs but would like to buy a 5400.

[Mike Hudson]

Originally Posted by Cassp0nk

So decent chance the high cap trakpower cells will be ok. I bought a 4900 for regs but would like to buy a 5400.

The main problem with all the current cells out at current like the trackpower cells is that they arn't factory sealed so will still be illegal! See the brca lipo rules for 09 below c&p'd from the brca web

3.3 Lithium based (LiPo) battery packs must have a hard, protective case that
completely envelopes the cell(s). The case should be made from ABS or a similar
material. The two halves of the case must be factory sealed in a way that any
attempt to open the case will destroy the case. The only opening in the case that is
allowed, is for the exit of wires.
3.4 For 7.4v Packs: The maximum case sizes allowed are as follows: -
Length: 139.0mm.
Width: 47.0mm. (The max. width includes any side exit wires).
Height: 23.5mm. (In addition, chassis location protrusions are allowed)
Saddle-Pack cells are allowed, and must comply with the above width and height
dimensions. Saddle-Pack cells must have a combined length dimension of 139.0mm
max when placed end to end.'
For 3.7v Packs: The maximum case sizes allowed are as follows :-
Length: 93.0 mm
Width: 47.0 mm
Height: 20.0 mm
3.6 The battery pack shall have leads extending from the case for the positive and
negative electrical connections using wire of adequate size to handle discharge rates
acceptable to racing applications. Alternatively, the case shall have internal
connection points for these wires clearly marked positive and negative so the user
can apply the lead wires. It is strongly advised that the link wire for Saddle Pack cells
utilises a plug which will separate with any undue force.
3.7 The case must have the original suppliers label intact, stating the rated voltage
and the pack capacity. Maximum capacity is 5,500 mah. The Brand name/logo shall
be easily readable.

[Cassp0nk]

But trakpower 4900 is already allowed isn't it?

Originally Posted by Mike Hudson

The main problem with all the current cells out at current like the trackpower cells is that they arn't factory sealed so will still be illegal! See the brca lipo rules for 09 below c&p'd from the brca web

3.3 Lithium based (LiPo) battery packs must have a hard, protective case that
completely envelopes the cell(s). The case should be made from ABS or a similar
material. The two halves of the case must be factory sealed in a way that any
attempt to open the case will destroy the case. The only opening in the case that is
allowed, is for the exit of wires.
3.4 For 7.4v Packs: The maximum case sizes allowed are as follows: -
Length: 139.0mm.
Width: 47.0mm. (The max. width includes any side exit wires).
Height: 23.5mm. (In addition, chassis location protrusions are allowed)
Saddle-Pack cells are allowed, and must comply with the above width and height
dimensions. Saddle-Pack cells must have a combined length dimension of 139.0mm
max when placed end to end.'