Saddle Pack's For Axial Scorpion

[rockn]

I'm thinking about Dissecting my 3000Ah Ni-HM And making in to a saddle pack for my Axial Scorpion. I dare to ask Has it been done? Thought it might be cheaper then buying them.

[clockworks]

Converting stick packs isn't hard, as long as you've got the right tools for the job.

The cells in stick packs are joined together with thin metal strips, spot welded in place. You need a Dremel or similar to grind off the sharp pieces left after you've pulled the strips off with pliers.
You need a decent soldering iron - 60 to 100 watt and some multicore solder.

A battery jig is useful, for holding the cells while you solder them.
You also need some battery bars and wire.

[SaxtonSlaughter]

Fry's Electronics sells thin copper strips for connecting battery ends together. Makes for very clean connections and you can pick up battery shrink wrap at your local hobby store. Good luck!!

[ultimate_monkey]

just to point out the stick pack uses sub c cells which are much bigger then the 23A cells that are use in sadle packs..

it can be done but it wont fit as nice as a "proper" sadle pack

[2500hdon37s]

Originally Posted by ultimate_monkey

just to point out the stick pack uses sub c cells which are much bigger then the 23A cells that are use in sadle packs..

it can be done but it wont fit as nice as a "proper" sadle pack

do not do it! the sub c cells are too big and wont let you get full steer! just buy a nice 7 cell 1500-1800mah saddle pack 2/3a size cells

[SaxtonSlaughter]

Yep ur right! Good point.

[TruckerBrad]

JEracing from Kalispell has sub-C's on his axle. This pic is a little older, don't know if he's still running it like this or not.

[berg]

I am looking for the same. Are those the big cells. If so, I will make that.
Good inspiration

Ewoud

[Meatwad]

Was about to mention, sub c's in most cases need to be standing on the front axle in order to not be in the way

[rockn]

I did not relize the the C are to big. I'm glad i asked first. I'll just do the lipo and move the servo and stick the lipo up front.

[oldhippie]

Originally Posted by rockn

I did not relize the the C are to big. I'm glad i asked first. I'll just do the lipo and move the servo and stick the lipo up front.

Now you're doing it right I can't believe people still mess with nimh when lipo is so much better and no more money.:?

[clockworks]

Originally Posted by oldhippie

Now you're doing it right I can't believe people still mess with nimh when lipo is so much better and no more money.:?

I've got to agree - a single 1500-2200mAH LiPo, or a pair of 800mAH LiPos in parallel are the way forward.

I didn't realise that people were using smaller than sub-C cells for crawling. What's the current delivery like with the smaller cells?
I've rebuilt sub-C stick packs for touring cars (2x3 saddle packs) and for 1/12th carpet racers (4 cell side-by-side), but my crawler, B4 buggy and planes all use LiPo.

If only there was a way to get the equivalent to 4-cell voltage from a LiPo, for my carpet racer, I could give up with NiMH altogether. I just need to find a 30A BEC!

[xirtic]

Originally Posted by clockworks

I've got to agree - a single 1500-2200mAH LiPo, or a pair of 800mAH LiPos in parallel are the way forward.

For a comp crawler, go even SMALLER with LIPO. With the increasing C rating of current lipos, you can go with even a 1000mah 3 cell lipo and still get PLENTY of amps. I was running a 1450mah 3 cell Lipo (70mm x 35mm x 34mm) with a 30C cont / 40C Burst rating. For a comp crawler this added a lot more weight than necessary, but I wanted the discharge power. This large pack was just barely fitting on the axle of my Bully. And did I say that it was HEAVY?? Now I am running a 1050mah 3cell that is 40C Cont / 50C burst. IT is 1/2 the size (68mm x 34mm x 18mm) of the 1450mah pack, and still pushes plenty of amps. I think that the shortcoming of MANY packs that people purchase is the possible discharge rate. They try and get more MAHs out of a pack to get the POWER that their truck needs while suffering with a LARGER physical pack. When I ran an axial comp rig, I placed a 1250mah 30C pack on the axle with the servo....it barely fit....but it gave PLENTY of power. I could never imagine running a high MAH/Physically larger battery on a comp rig. I believe that the negatives of that choice are greater than the run-time increase gained. For a basher, this may change, but for a comp rig trying to get the most performance, go with a physically smaller pack....slightly lower mah....with higher C rating. Just my long-winded thoughts on the topic.

[clockworks]

If you can afford several very high-C small capacity packs, I agree that it's better for the limited runtime of comps.
For bashing, I'd stick with the cheaper option of lower-C, higher capacity packs.

[oldhippie]

Originally Posted by xirtic

For a comp crawler, go even SMALLER with LIPO. With the increasing C rating of current lipos, you can go with even a 1000mah 3 cell lipo and still get PLENTY of amps. I was running a 1450mah 3 cell Lipo (70mm x 35mm x 34mm) with a 30C cont / 40C Burst rating. For a comp crawler this added a lot more weight than necessary, but I wanted the discharge power. This large pack was just barely fitting on the axle of my Bully. And did I say that it was HEAVY?? Now I am running a 1050mah 3cell that is 40C Cont / 50C burst. IT is 1/2 the size (68mm x 34mm x 18mm) of the 1450mah pack, and still pushes plenty of amps. I think that the shortcoming of MANY packs that people purchase is the possible discharge rate. They try and get more MAHs out of a pack to get the POWER that their truck needs while suffering with a LARGER physical pack. When I ran an axial comp rig, I placed a 1250mah 30C pack on the axle with the servo....it barely fit....but it gave PLENTY of power. I could never imagine running a high MAH/Physically larger battery on a comp rig. I believe that the negatives of that choice are greater than the run-time increase gained. For a basher, this may change, but for a comp rig trying to get the most performance, go with a physically smaller pack....slightly lower mah....with higher C rating. Just my long-winded thoughts on the topic.

I'm running these little 500ah Xcite lipos for comps and they have plenty of power for my moa.
http://www.xcitebattery.com/newfrontpage111V.htm
With only 10+ min of runtime I don't use them for practice or bashing but the little weight savings in a comp helps.

[xirtic]

Originally Posted by oldhippie

I'm running these little 500ah Xcite lipos for comps and they have plenty of power for my moa.
http://www.xcitebattery.com/newfrontpage111V.htm
With only 10+ min of runtime I don't use them for practice or bashing but the little weight savings in a comp helps.

I have read up on the batteries mentioned above....and the size is SWEET. I am just curious how that little pack that pushes 20amps is able to truly give you all the necessary power?? A 55T motor will pull up to 35amps at full stall. So 2 of them will pull 70amps at full stall....and the steering servo can pull 5amps....so WORST case, it will pull about 75amps. Using that number, even the packs that I run are lacking....but that is where my curiousity about the 20amp mini pack comes in....how can that provide truly enough punch? I notice the difference between the COMP packs that I run versus the cheap BASHER 20C packs that I run. The PUNCH is far superior on the better packs.

[2wheeltyson]

i had also thought about rebuilding 2 of my 2/3a 5cell reciever packs into a 6 cell crawler pack.

[oldhippie]

Originally Posted by xirtic

I have read up on the batteries mentioned above....and the size is SWEET. I am just curious how that little pack that pushes 20amps is able to truly give you all the necessary power?? A 55T motor will pull up to 35amps at full stall. So 2 of them will pull 70amps at full stall....and the steering servo can pull 5amps....so WORST case, it will pull about 75amps. Using that number, even the packs that I run are lacking....but that is where my curiousity about the 20amp mini pack comes in....how can that provide truly enough punch? I notice the difference between the COMP packs that I run versus the cheap BASHER 20C packs that I run. The PUNCH is far superior on the better packs.

Not an engineer, just saying.....

[clockworks]

Does a 55T motor really pull 35A? I thought that 27T motors were rated at less than 20A.

I've got an old ESC that I use in my 1/12th carpet racer. It's basically an "unlimited" ESC from about 10 years ago, but is still highly regarded in the price-limited formula here in the UK. This thing is fitted with a 40A blade (auto) fuse, and I've never blown it, despite having used it with a 14x2 motor.

[xirtic]

I had a hard time believing the amperage pull at STALL for these brushed motors. I have not done the testing myself, but I did do a search on here and found threads quoting Holmes.

Motor Amp Load/draw

An example of this information is in POST #13 of the above thread.

I would have to say that that all may be accurate...I definitely trust electrical information from Holmes. I have seen my 45T handwounds on varied Lipo Packs. The LOWER C rated like a 1500mah 20C Burst definitely had less PUNCH than my 1450mah 30C (Burst 40C). That being said, the motors must be wanting more amps than the 1500mah 20C pack can provide under heavy throttle or higher amp draw situations. Since stalling a motor takes even more amps, I am not surprised by the spike that is explained by 35amps of power draw. In an Axial with 1 motor this effect may not be as noticable on a lower C rated pack. I run a 1250mah 20C pack on my Axial based scaler, and it provides plenty of power. (Thru a GOAT 18.5 brushless system that is supposed to pull 17 amps or so)

Simply, the correct battery can definitely impact truck performance. The wrong spec'd pack can also really negatively impact that performance as well. RX pack batteries are usually VERY low C Rated...and I would expect that they may run hot or you may see sluggish servo response with some glitching.

Originally Posted by clockworks

Does a 55T motor really pull 35A? I thought that 27T motors were rated at less than 20A.

I've got an old ESC that I use in my 1/12th carpet racer. It's basically an "unlimited" ESC from about 10 years ago, but is still highly regarded in the price-limited formula here in the UK. This thing is fitted with a 40A blade (auto) fuse, and I've never blown it, despite having used it with a 14x2 motor.