Help creating a low budget Hyper 7 brushless

[DrKnow65]

Woohoo!!! And so it begins :-)

[DrKnow65]

OK, a quick update. I've made a few purchases to add to the 1518, still on budget but I've had to add a second round of buying for a later date.

So I've got the 1518, ordered a pair of turnigy 4s 40c 5000mah lipo's (to be ran in parallel for the time being), a set of dirt tires, a MMM, a Savox titanium ultra speed servo, a mod 1 16t pinion, a mod 1 14t pinion, and a pair of losi battery trays.

I fabbed up a quick and dirty motor mount plate that screws to the original diff bracket so I can play when the parts are all here (no jumping or hard core bashing with it).

I would love to see the RCM universal mount back in stock as it's what I intend to run long term, turnigy nano-techs in the USA warehouse, and the Mamba XL HV here at RCM (or anywhere else it may show up if not here).

[DrKnow65]

Will relocate the diff later when I get a long term motor mount and the correct length dogbones.

[DrKnow65]

Thanks for the heads up on the plastic vs. Aluminum, I knew the aluminum was more brittle but I really thought it was lighter. I do have a full set of spares I've never used, even after the runaway that killed it last time... Suppose the big bore shocks could replace those in the line of wanted upgrades. Off to put some in the eBay watch list. Thanks for keeping up the support, I really do appreciate the advise.

Ps. The snake is just a little Garder the kids wanted to save from the winter cold :-) My son has a beautiful 3 foot plus King snake that's a legit pet.

[simplechamp]

I really like king snakes, they seem to be one of the best colubrids to keep as a pet, more mellow than cornsakes, ratsnakes, etc. at least from my experience.

Anyway, back on-topic!

[DrKnow65]

Well, I've officially gone $82 over budget :-) decided I had to get a 1717 from castle before they were gone... It will eventually end up in some form of monster truck propably a MGT with a center diff conversion (I've got two extra ofna buggy spider diffs).

Yes, back on topic now

[simplechamp]

LOL this thing is going to be a real tank with dual 4S 5000mah packs and a 1717. Stock up on diff parts and CVDs, maybe even consider a Slipperential later on when the budget allows. Also, get some stiff springs for whatever shocks you decide on.

[DrKnow65]

1717 is a little much for this chassis, it'll be going in a monster truck at a future date :-) I'm crazy, not insane hahaha :-)

[el tomaso]

Still, even a 1518 is overkill in a buggy. Thats why I bought one for my new LRP buggy

Your conversion will be one of a kind, I like your layout plan.

Thomas G

[DrKnow65]

Well at this point I've patched the buggy togeather so that I could run it just to test the electronics. I found that the Savox ultra speed servo pulled way to much current from the MMM BEC circuit resulting in shut downs. So I grabbed my CC BEC and wired it in (still need to shrink wrap it again) to power just the servo. Works like a charm, this servo is really impressive on 6 volts with enough amperage to feed the beast.

I'm still planning on flipping the motor around and locating the CD at the back of the buggy but untill the RCM universal diff/motor mounts are back in stock it'll be in this layout. I think the steering servo can remain in it's location from here on out.

I hope the lipos will show up tomarrow (day #7 of USPS 1-3 day priority mail) so that I can start mounting the trays and experience this rig on 4S. I did my testing with a 2S maxcrapp that was salvaged from a 3S pack (4 months old and they wouldn't warantee it because I cut it open to isolate the bad cell and save the rest of the pack...)

So far I like the layout with all the stuff centered in the chassis, the motor is high above the chassis plate but I think it's a good compromise to be able to run a pair of large lipo's for power and run time. Can't wait to get the lipo's installed and running.

Here's a pic of what it should look like with the trays installed.

[DrKnow65]

Batteries showed up today and I found a critical flaw. I did all my measurements by the pack size, not accounting for the 8 gauge wires. The wires basically make the packs about 12mm wider on one end :-( that means I've got to relocate my radio and BEC.

I think the jist is that the Mamba XL and the diff relocation need to happen sooner than I had planned. I do see that the XL is on the castle sight now, but still no word on when the mount will be back in stock.

Here's a pic of the batteries in the chassis, not mounted but just for reference.

[DrKnow65]

Another update... I have been runnung the car some on 6S, just have the batteries ziptied down for the time being. I had to make a pair of chassis braces with some spare turnbuckles and a second CD top plate. (Pic to follow)

I found that the 1518/6S combo is way hard on tires (blew my new tires to pieces, shredded one spare, and I'm on the bald OEM ofna's as a last resort now...) so I've enabled torque control and lightened up on the throttle. Looks like I'm setting some $$ aside for a set of OFNA on road belted tredded tires and a set of dirts I'll have to tape myself.

I got a PM from Mike friday and it seems the universal mount will become available this next week, I went ahead and ordered the Mamba XL from castle as Mike doesn't have an arival date yet, so I can start running my matched 4S packs. Currently using a new 4S turnigy with an OLD max crap 2S in series to get 6S. It's a bad combo the MA pack runs hotter than the turnigy and drains much faster so I've got to limit drive time as the MMM LVC doesn't know if one pack is lower than the other...

I also opened up the spider CD and packed it with grease to help the front tires not unload so agressivley. The 1518 was turning them to pizza the moment they come off the ground. I also have to be good about backing off the throttle a bit to let the front contact the ground enough to turn :-) I'm loving it

[simplechamp]

I would definitely recommend not running the Turnigy and MA packs again in that series config. You have already seen how the packs will behave, and it's pretty much a recipe for disaster. If the MA pack goes it could take the new Turnigy with it, maybe the ESC and motor too. Hate to see something like that happen.

What did you have in the CD before packing it with grease? Try some 50k or 100k silicone oil next time you rebuild the diff and see how that compares to the grease.

[DrKnow65]

SimpleChamp, I opened up the CD to try to get an idea of what was in it, only to find they come lubed but otherwise dry from OFNA

I used the grease as I don't have anything else handy. Even with the severe drag of the grease the fronts still unload pretty heavily. I may look into a torsen diff if I can find one cheap.

The MA pack is holding up well enough now with the "Torque control" enabled. Seems that the MA pack has a low (actual) C rating, who would have thought

I did consider a pack failure... I suppose that aside from fire, if the pack goes dead short it will just act like a shunt between the turnigy and ESC, can't see that doing more than slowing down a bunch. If the pack goes to an open circuit it'll just shut the buggy down entirely. So as long as I pull the pack before flames go up I should be good. Either way I'm short cycling the packs to keep low voltage out of the equation, and I've limited the amp draws on them as well. Hopefully I'll get away with it till the XL arrives here.

[DrKnow65]

Just put in an order it Amain, should square me up. Now just waiting on the RCM mount and a couple custom length dog bones for relocating the CD...