Another Gmaxx is born

[suicideneil]

I agree, the stupidly large & heavy tires are not the best choice for offroading, even though they do look cool. I think the thing is though, if I wanted to build a lighweight racer or basher, I would have! lol. I like to think of this as more a show truck that gets driven, so performance isnt at the top of the list; that said, I do have some roadrages and velocity rims, and I will be picking up some bowties at some point, just to see what difference it makes. RCwaffle doesnt have a good reputation for a few reasons, one of which is because he bought a members truck a while back (to part it out and sell on like he does), but when he received it he parted it out and put the stuff up for sale in seperate auctions, and then claimed he got a 'defective truck'. Thankfully he got busted for that and hasnt tried any more crap since that I know of- he does have stuff that people need, so thats the only reason I would buy from him, if I had no other choice.

Nothing wrong with the HvMaxx, only the underpowered motors, but they do their job well. The new Venom system looks interesting, there are a few similar ones coming out soon so it shoyuld be interesting to have some other 4s esc choices besides the HvMaxx and MambaMax.

Anyway, fun-time:













First MMM in the UK (probably), tested by Kulangflow so I know it works.

6s A123 pack, homemade, complete with balancing taps. I will assemble the other in the coming day or two, then start thinking seriously about a motor.
The soldering looks aweful, I will admit, but it is infact completely sound and solid. I need to move a few connections to streamline the shape for shrink-wrapping, and I may beef up connections I made on the ends of the pack (use another piece of wire). The balance tabs only had 4" wires on them, so unless I extend them, I think I'll be sticking the tab out the side of the pack (through a slit in the shrinkwrap when its applied). That will be fine I reckon, and a little diffeent looking to having it stuck out of one end like normal...

[TDC57]

Hay Neil... You got your MMM!! Outstanding.... I cant wait to see it installed and running.. Maybe you'll grace us "inpatient bastards" with a VID??

I'm looking forward to your motor selection, after all of the knowledge you have it will be extremely interesting to see what you’re going to get! Are you also updating your Trans too??

Will those bad boys fit under your body??, they look rather stout shall we say..

Thanks for the update..

Have a great one..

[suicideneil]

Hopefully one of the weather babes will give me some good news, but it looks like rain for a few days Im sorry to say. Anyway- me? knowledge? Na, I just make it up as I go along, basically looking at other peoples setups and then basing my advice on that; paractical knowledge always beats educated guessing. The tranny will be updated soon, but at the moment my 13/72 gearing has to stay put for the hvmaxx to work- my new motor will probably be either a Neu 1515 1Y, or castle neu (freaky fun on 6s of A123 Im betting). They will fit under the body no problem, I just need to get them shrink wrapped in the next couple of days since there are some very exposed connections at the moment, and the gmaxx chassis is nice bare metal, not a good mix.

[suicideneil]

Just a little teaser for you:







Perfect fit. The nicely curved upward edges of the battery plate hold the cells in perfectly, and length wise its a near perfect fit for the existing straps, though I may see about some more heavy-duty items if need be. I also finished the 2nd pack tonight, and re-jigged the 1st pack to tidy it up- hopefully the shrink wrap will come tomorrow so I can get them wrapped up and completely finished, ready for some high speed action when the weather dries up. Think I might put some bullet connectors on my Hvmaxx I so can swap it between the existing system and the MMM esc- 6s2p A123 should be interesting on a 3100kv motor.....

[TDC57]

Looking GOOD... I hope the weather holds up for you, Here in So-Cal we have nothing but sunny weather ahead.. (oooo) sorry about the one Neil, I didn’t mean to hit you below the belt.. LOLOLOLOLOL..

[Patrick]

Whats the weight of a 6s A123 compared to a 6 cell nimh? They'd be pretty similar wouldn't they?

that things gonna be wicked, are you gonna run two of those packs in parrallel? it will be nuts on 6s!

[suicideneil]

6s A123 does weigh about the same, if not a little less than 7 sub-c cells- my scales arent terribly accurate.

It will be ran in 6s2p configuration about the same as 5s lipo in voltage terms.

I have been doing some bench testing as my heatshrink finally showed up, so I soldered on all my bullets, and added the bullets to the hvmaxx motor leads so I could use it with the MMM. I must say, I did have sone issues:

Castle link instructions could do with being a little clearer- I couldnt get the PC to recognize the esc until I started the software first, then connected up the esc to the castle (instruction booklet is a little vague there).

Calibrating the esc to the radio was a serious pain, as I have the throttle endpoints tuned for the hvmaxx esc, so it took alot of tweaking until the esc cold see full throttle correctly.

The esc sounds abit... dunno- its like some demented fairground ride or fruit machine chirping away.

Brakes- I have them set to 30%, and it still locks up solid.. and then goes into reverse without me releasing the throttle stick first. That worries me, as endos will not do this giant lump of metal any favours! I think I may be able to fix it by playing with low-throttle epa setting, and lowering the brake strength even further; dare I say it, but the hvmaxx esc actually is better in this department, even though the brakes arent adjustable per say.

Bench testing was cut short as the transmitter batteries went flat on me, but there will be plenty of time for more testing later- I dont think the hvmaxx motor likes 19.8v much, but it will have to make do until the Medusa 70mm motors are done.

[TDC57]

Hay Neil,
You're going to like the 6s2p / 5s setup.. Even those big tires wont be able to slow it down from that point..

Best of luck and hope the weather holds out for you!..

P.S.
Gas in S0-cal is $4.85 a gallon for supper, what the cost in England for a gallon of petrol?.

[suicideneil]

Weather is being kind at the moment, hopefully it will still be nice on thursday (day off) so I can take the truck to the park again, and see how the MMM really performs.

The price of petrol varies from place to place, but the average price is $10 a gallon. The world economy really is going nuts at the moment- food prices are rising sharply, house prices are dropping rapidly (good job I only rent), and fuel bills (gas, electric, petrol & diesel) are steadily climbing.... Think I might go live in a tent down the woods, shooting pigions and squirrels for dinner


EDIT: Fixed the brake issue- I had the esc in 'forward-brake-reverse' mode instead of 'forward-brake-reverse/lockout' mode. It works beautifully now with 50% brake power, and I can still fine tune it with my low-throttle epa settings if I like for a little brake power.

Gotta say Castle, you did a good number on this esc- just gotta get the bugs fixed with the escs that went to silicon heaven, and it'll be the best thing since naked ladies on the internet...

[TDC57]

Good GOD MAN... $10.00 a gallon! and it going UP?? woowoo..

I'm glad to hear that at least you like your MMM, lots of Negativity at the moment, people are starting to lose the faith!..

Brakes are always a good thing to have, but then I've seen you hit that kid in the park , so I cant imagine that you use yours that much anyway..

Have a great day / cheers!..

[suicideneil]

I was aiming at the kid though....

I decided to have some fun and built my own battery tray using 6083 T6 2mm thick aluminum:

















Suprisingly simple really, since the existing battery tray makes a perfect template for all the holes required, then you just design the chassis around that to get the desired length & width etc. I was planning on visting the local blacksmith to get the edges curved upwards like the stock item, but I couldnt be arsed and just added some 3/8" x 3/8" x 1/16" L channel to the egdes. I will add some extra foam padding along the inside edges to cover the exposed nuts. That sounds rude....

[TDC57]

Wow that really is a dam good looking truck!..

[jordan...]

nice work with the battery tray looks real professional. Can i ask how you cut those rectangular slots out? Oh and are you still going to get the Medusa?

jordan

[suicideneil]

Yep, still gunning for a 70mm medusa, or castle neu- time frame for each is similar so I'll play it by ear, as us brits say, lol.

As for the slots, I drilled two holes about 30mm apart, then used my trusty dremel with a cutting disc to join the two holes, creating a rough slot. I then used my selection of needle files to smooth out the roughness and square-out the ends, creating a perfect little rectangle about 30mm long by 5mm wide. It would be much easier with a vertical mill, or drill press even, but its still perfectly do-able with even the most basic of handtools.