Going to the dark side. Jammin X1 CRT Conversion.

[Thirdgen89GTA]

The Emperor's Force Lightning is strong with me now.

Jeff (Jhautz), if you are still browsing these boards, it only took me 4 years to get away from the juice. Perhaps I will see you at the Friday night Kohls hangout with a crazy beast of a Hyper One Seven. I've already stripped it of all nitro parts to "motivate" myself.

Much thanks to those who answered my other questions in different threads. You have saved me both money, and time. And though I went slightly different than most (dual packs instead of a single) I am very happy with the balance of the truck. I need to weigh each corner individually but the truck has only gained about 1.2 to 1.9lbs based on the weight of the components I've taken out, and then the weight of the components I've added back in. I was concerned that the stock 13mm shocks I had couldn't take the weight addition. Plus they kept blowing out. The new 16mm big bores have a much better sealing setup, and they will perform better too.

I still have to solder the leads on to the batteries and ESC, however my 60w soldering iron failed, no longer gets hot. It was a cheaper radio shack one anyways, I should invest in a good station. I may also buy an external BEC to take the load off the ESC, as well as pickup the fan for the motor itself to help it stay cooler if its needed.

Jammin X1 CRT Pro

• Mamba Max Monster + 2200kv
• (2) Gens Ace 40C 5000mah 3S Lipo (The Stupidity batteries in series, also endurance basher batteries in parallel).
• (2) Gens Ace 40C 5000mah 2S Lipo (for the track)
• RCM Mount + Servo plate
• (2) RCM 150x50mm trays/straps

Now for the fun stuff!

Nitro Parts Weight list

• 370g - Novarossi 528XR Hot-Modded by Jim Hots (still F.A.F engine)
• 120g - Jammin JP-2 Hard coated pipe
• 60g - Hitec throttle servo
• 30g - Fuel tank, tubing.
• Total = 580g

Electric Parts Weight list

• 442g - (2) 3S gens ace 40c 5000mah lipos
• 288g - alt bats. (2) 2S gens ace 40c 5000mah lipos
• 425g - 2200kv motor
• 125g - MMM ESC
• Total= 1,126g - 1,434g

Subtract the nitro parts and I get between 1.2lbs and 1.9lbs added depending on which battery setup I use. With the 2S packs its still slightly tail heavy but its very close to 50/50, wish I had a 4 corner scale to measure the weight of the truck but they'd look at me funny at work if I brought the truck in and started weighing things!

One thing I noted is that i should have ordered a custom 140mm tray for the motor side battery tray. It was too long. So I had to cut the tray. But since I had concerns about the motor sliding forward into the pinion I cut up an A-arm holder for the jammin and screwed it into the mounts to keep the battery from sliding forward. I may still see if I can pick up some plastic blocks or something and drill it so its a little taller than the one currently in the car now. But it works and I'll have to make sure to keep the straps tight. But I won't be doing anything crazy with it for the moment.

since i reversed the center diff and I have the massive 62t spur I had to clearance the chassis. Since all I had was a hand held dremel and no vice or clamp to hold the chassis it became someone of a messy job. I plan to do the X2 conversion later on which will give me a slightly longer chassis, as well as the smaller differential so it won't be nessesary to clearance the chassis i don't think. I couldn't use spacers due to the fact that the X1 diff is already so tall the CVD angle is rather extreme with spacers. I wouldn't trust that they'd hold, no binding but they'd wear out really fast.

I need to buy some rigid CF 2mm or so and put trays both in front and behind the center diff. I plan to run a receiver box on the back between two battery packs on a tray, and in front of the tray (where the RCM servo tray is) I'm putting the ESC there once it extends forward enough so that I can mount it to the steering brace. For the moment the recv. is mounted on top of the servo. But easy splashes there.

So I guess thats enough of the talking, here are the pics.

[Thirdgen89GTA]

[Thirdgen89GTA]

[Thirdgen89GTA]

two last pics.

[Arct1k]

Dont forget the RX battery and the actual fuel itself... but you need to add the battery tray

[Thirdgen89GTA]

Originally Posted by Arct1k

Dont forget the RX battery and the actual fuel itself... but you need to add the battery tray

Yeah, I did forget about those for weights.

Either way, I'm happy with the weight balance. Which is once of the reasons I wanted the dual battery setup.

[Thirdgen89GTA]

Originally Posted by Arct1k

Dont forget the RX battery and the actual fuel itself... but you need to add the battery tray

I just cleaned up my old buggy to sell it and while I was assembling the radio tray I noticed just how heavy the battery was. Wow.

So this truck may be only slightly heavier than it used to be. might not have gained nearly as much weight.

The weight of the two servos, and battery was hefty!

I will definitely have to weight the truck now. Will be interesting to see what it comes in at.

I got a UPS notification that my new Solder station arrived. It was shipped to work so I'm going to go in and pick it up. While I'm there I'll use the UPS scales to weigh the truck.

[Thirdgen89GTA]

Grrr. This waiting for a new soldering iron is killing me. I wanted to save $10 so I ordered it online, I could have had this truck up and running but NOOOOO I had to save $10.

My 60w iron stopped working I guess. I plugged it in it never got hot. :(

So I am stuck with a completed conversion but no way to power it. Grrr.

[magman]

I noticed you dremeled out part of the chassis for the spur....another option and what I did under my center diff mount is install some small washers. I needed more clearance for the 1520 CC motor I am running in my mbx5t. Nice job.

In looking at the same pic again, I would definitely add washers under you center diff mount just to bring it up a bit more

[Thirdgen89GTA]

Originally Posted by magman

I noticed you dremeled out part of the chassis for the spur....another option and what I did under my center diff mount is install some small washers. I needed more clearance for the 1520 CC motor I am running in my mbx5t. Nice job.

In looking at the same pic again, I would definitely add washers under you center diff mount just to bring it up a bit more

Because the X1 uses a 62t spur the CVD angle was unconfortably high. There wasn't any binding, but its already a large angle due to the height of the center diff.

You can almost see the extreme angle of the CVDs in this pic.
http://gallery.me.com/thirdgen89gta/...13257464680001

I didn't take any good pics of the angle. But in order to make it fit I needed to put 4mm of washers under the diff to raise it up enough so the spur didn't contact the chassis.

I wish I had a drill press, or a mill then I could have done it a ton cleaner. But all I had was a dremel and a grinding stone.

[Thirdgen89GTA]

Conversion is FINISHED! Sadly, its dark now, and the 2nd battery is taking its sweet time to charge. Its almost done, or has to be close as the charger is only putting out .1a @ 12.59v so and I had set it to do a Balance charge. The 1st battery is charged. 2nd is still charging.

Conversion came in at 10.22lbs w/o the ESC mounted.

The ESC is 125g according to castle, and brings the total weight up to 4.76kg, or 10.5lbs.

[Thirdgen89GTA]

I had some initial head scratching about the calibration since no matter what I did the car ran in reverse with forward throttle. I swapped 2 of the motor wires like the manual said but it did it again. Doubly confused. Turns out I had an odd setting on my transmitter limiting forward throttle to 68% (not a normal endpoint setting but a global adjustable trim setting I forgot about). And this somehow confused the ESC during calibration. As soon as I put the forward travel back to 100% on the ESC and recalibrated all was well.

There is an initial Arc when connecting the battery packs, especially big if I connect the series connector last instead of the two individual batt. connectors. Overtime I can see this causing the connectors to wear out. Has anyone had experience with this? Is it harmful to the batteries/esc over time? I've read about it, and on some ESC's they put in a small resister and separate connection to "pre-charge" the caps. But I know the MMM manual specifically states against this so I wont.

The Maiden Voyage wasn't so much a voyage, but more like a hop, skip, and a step before returning to base. I was careful to tighten the set screw on the pinion because I remember stripping them out as a kid. Well, Guess I didn't have this one tight enough because the pinion walked forward on the shaft. Thankfully since I have the battery tray like I do, an unintended side effect is that the pinion is "captured". It bumps against the tray and won't fall off the shaft. I took it out, put some loctite on it and set the position again before tightening it down. Waiting for it to cure now. I'll try again in a little bit.

Initial Impressions: I need better tires, or rather tires more suited to the terrain I was running in. Panther Switch 2.0's do not make great grass tires, they are more like slicks at that point. I don't have anything good for grass really. Next best thing is a set of proline crimefighters but they are worn and really meant for loose dusty hard packed clay like most outdoor RC tracks. I had set the punch to 50% just in case, but even so it was wheel spin everywhere. How much of that is the wrong tires and how much of it is power is anyones guess right now. The track has Nitro practice tomorrow so I can't go, and its only for 2hrs so its not worth it. Next week perhaps. Or if there is open practice during the week I may head up and try it out.

I imagine this truck will be insanely fast. But I'm taking it easy right now. Next week when I go to the track I'll likely run it in 3S2P so I can get a ton of practice in, and once those discharge I'll switch to the 4S setup.

[Thirdgen89GTA]

Well, I thought it cured enough so I took the truck out again.

OMGWTFSTUPID^6S. I wanted speed, but I think I need to throw another half pound in the front of the truck. If it weren't for the front end unloading and turning tires into pizza cutters I would have been on my lid like 10 times. I underestimated just how fast it would accelerate and when I hit the brakes I realised it was going TOO FAST to stop before I hit the wall. Thankfully, I DID get off it soon enough cause it slid to a stop about 10-15ft from the concrete wall.

The neighbours got a chuckle out of that one.

But here I am back again, about 3 minutes into the last run the set screw backed off again on the pinion.

Its OMGWTFWheelieTime all the time with this truck now.

[magman]

What diff fluid are you using any way. In my 5T, I have 100K in the center to all but eliminate ballooning...besides taping the inside of the tires

[Thirdgen89GTA]

I thought I had 100k in the center diff, but maybe thats only in the buggy. I don't enough 100k to fill the diff, but I will probably buy some this week.

I didn't really see the ballooning on pavement. It was mostly in the grass. I ripped the bead on one tire, I'll have to reglue it before any stupidity again.

I'm probably going to run it tomorrow on a single 3S pack.

I'm curious though, what did your truggy come in at weight wise? I was expecting it to be much heavier than 10.5lbs with 6S power. And I didn't think I'd get it under 10lbs on 4S at all.