cummins driver

My Feedback: (31)

Hey guys, I finally received my jammin truggy I bought used and just thought I would start a thread on it. I have been using an Associated Monster GT brushless converted truck for my brushless 1/8 beater, but even though the truck has been very strong and reliable, I have grown pretty tired of the handling as well as a couple other things.

So I picked up this Jammin X1 CRT PRO nitro roller for a good deal in the classifieds on rctech. I figure this thing should handle really nice for a basher as well as be pretty strong and it should be much easier to drive fast.

So I got the truck today. It has a broken front a-arm which isnt a huge deal. Im thinking the seller hasnt run the truck in a while and didnt know it. It has all the Pro options on it. The center driveshafts have a decent bit of slop at the joints, however I may run them until they give out. The U-Joints on the stub axles themselves look pretty good though. The pinion to ring gear mesh feels pretty good, but I think im going to pull the diff's and make sure they are shimmed correctly anyways. the ring gear for these things aint cheap. The wheels and tires are in great shape, the one body is in pretty good shape, and really most the rest of the truck is pretty nice other than normal wear and tear.

Anyways, this is going to get used somewhat like an MT (kinda like a Thunder Tiger MT4 G3 clone), so its probably going to wind up with some MT tires on it at least part of the time. Im anxious to get it going and try some different types of tires to see how it reacts and see which ones I like best. I may buy some badlands eventually, but we'll see.

So for the brushless conversion, I have a battery tray ordered, the A-Arms are ordered, I have the material I need to build my own motor mount, and I have a receiver box as well as all the electronics just waiting to go into the truck. Hopefully this weekend I will have the motor mount done and the battery tray may be here saturday. I decided I wasnt paying $85 for an RCM kit, so im building and putting it together myself. I think it'll turn out nice though and im really liking the looks of the truck so far.

Couple questions:
- Is the Z brace needed with a brushless conversion kit?
- What offset wheels are ideal for this truggy?

Now onto the pictures. I will update as I get things put together on it.

SyCo_VeNoM

half offset
http://www3.towerhobbies.com/cgi-bin...?&I=LXUVU6&P=7 (got these on mine)
http://www3.towerhobbies.com/cgi-bin...?&I=LXUVU7&P=7
http://www3.towerhobbies.com/cgi-bin...?&I=LXUVU8&P=7

as for the Z-brace good question seeing you are making a motor mount I'm guessing that lines up to the holes the nitro motor screwed into it wil probably be needed seeing the BL motor will try and warp the chassis in the same fashion the nitro motor would. If you used one of the kits where the motor bolts onto the center diff housing it would have been a no.


outta curiosity what battery box did you order?

BadMammaJammas

What brushless motor and ESC are you going to be running?

cummins driver

My Feedback: (31)

Thanks guys!

Syco- I bought a redcat XTE battery box. It was $15 shipped and looks really similar to a losi battery box. It has an ESC mount built on, but ill chop it off if i need to. It comes with staps as well and I believe it should work fine.

Also, on the motor mount, I believe I have a good way to mount it to the center diff just like the ones you can buy. Pretty sure I have that worked out [8D] Hopefully I can get it done Saturday. I was pretty sure the wheels were half offset, thanks for the confirmation! If im going to try and run MT tires at all, I think ill have to put some hub extenders on it to widen it out some.

BadMammaJammas- I have a Hobbyking 150a ESC and EZrun 3674sl 2350kv motor. I have been running them in my MGT for a good while with no heat issues, and this thing should be a decent bit lighter...

SyCo_VeNoM

I'll say with that Kv of a motor try and find the smallest pinion you can.
Think I have a 14 or 15t on mine and it will pop wheelies like no tomorrow with a 2200kv motor.

cummins driver

My Feedback: (31)

I did some gearing calculations and decided on a 14t pinion. At nominal (14.8v) voltage, It should run 41mph. Should be about right for a basher It shouldnt balloon the truggy tires too awfully bad, but im sure it will the MT tires, but I may have a fix for that as well

cummins driver

My Feedback: (31)

Ok guys, made some great progress today as far as im concerned. Ill try to keep this in order and not toooo long :P

First I modded the servo tray setup and removed the radio boxes which was a simple process of cutting off the throttle servo mount from the steering mount and unbolting what wasnt needed:


Finished:


So after debating on building a motor mount out of some steel I bought, i got to looking at my old E-savage transmission plate and noticed it would fit very nicely to the center diff support with some drilling and trimming. I used the two holes that hold the brake calipers and then drilled 2 more in the center diff support at the bottom where a brace goes across. All the screws tightened good and snug

Before holes drilled:


After drilling holes:


The motor plate after trimming and drilling:


Motor plate mounted up:






Mounted on the truggy:






With the motor on it:


So with that ready to roll, I was on with the receiver box. I had a NIB traxxas E-Maxx waterproof receiver box I bought for another project that didnt get used. I paid about $6 shipped for it I think. I was trying to find places to put it and was thinking behind the front shock tower might be good. To my surprise there were 2 holes on the tower that lined up absolutely identical to the rec. box holes. So, some quick disassembly, and mounting had that done





Thats all the progress for tonight, but im very happy with how its turned out. The motor mount is very sturdy, and the rest of it turned out good too. All I have left to do is a couple maintenance items like refilling the shocks and checking/shimming the diff's(which ill do tomorrow), and mounting the battery tray and ESC. I think i know how ill mount the ESC, but ill have to mount the battery tray first and go from there with it. The 7 cell was only to show the room available. Also, the truck weigh's less than 9.5lbs with everything but the battery tray, ESC, and receiver mounted, so it should be about 10lbs with no batteries id say. Not bad considering my MGT was over 13lbs...

SyCo_VeNoM

Looks aight
not a bad idea for a radio box hmmm.....
think I got one of those box's laying around from my ex slash 4x4 (rebuilt to a pede)

cummins driver

My Feedback: (31)

Thanks, Im pretty happy with how it has turned out.. In total I have $110 in the truck, $15 shipped for the battery tray, and the rest of it I already had. I do have $10 in some A-Arms since the front one is broken. So if i count the stuff i already had, I only have $135 in the truck. Not bad at all IMO. I like the RCM mount, but I couldnt justify it for the money they want.

With that said, She is finished!

I ended up going through the shocks last night, cleaning them, and rebuilding them with fresh oil. So today I was just going to check the diffs as preventative maintenance, however, my battery tray was in the mailbox which is all I was missing B)

Here is the tray. Its from an 1/8 scale Redcat truck. Brand new off ebay for $15 and it has an ESC mount that worked out better than I thought it would. Just had to drill 2 holes and elongate another hole to mount the tray. It feels very sturdy and there is over 1/4" of clearance of the spur gear which should be plenty. I was also able to keep the Z-Brace, which is nice






Then I just had to stick the ESC to the built in mount, and tidy up the wiring best I could (i hate wiring), and find a servo horn and I was pretty much done:









The maiden voyage went great. I only ran it behind the house some, but I didnt have a single issue. Temps's seem good and this thing handles great. It will pull the wheels if I nail the throttle hard anywhere under 10mph or so, but I have to really try to pull the wheels up. It stays planted and takes off hard anytime I want it to B) I may thicken the center diff fluid some, but I really like the handling. It just slides sideways when you cut the wheel hard and you can drift this thing pretty nicely on a dirt/gravel road

Let me know what you think guys. May have some video before too long

cummins driver

My Feedback: (31)

I weighed the truck earlier and it comes in at 11.5 lbs with two 2s hard case lipos in it. Not too bad. I have ran 3 sets of packs through this thing today and it has been nothing but a blast. I took it to the rock quary and got some video.

I knew the truggy would climb good with a low COG and center diff, but i was definately impressed. It wont go anywhere in thick grass, and the deep ruts and little humps bottom it out easily enough, but if you stay away from that stuff, its a beast

Keep in mind all this is still with the broken from arm- Should have my new arms this week...

[youtube]http://www.youtube.com/watch?v=jMlJZydvpAo&list=UUqlgVSE0wpmCmGpTe2iruRw&index=1&feature=plcp[/youtube]