My CRT.5 conversion w/ ET & radar data
 

Setup is a LMT 1920/10, MM, Align 3S 2100 20C lipo, 14/46 gears riding on the CRT pro kit w/ the ofna ext chassis. Weighs 2020g with the heavier 1:10 scale road rages pictured below (was a temp setup waiting for other tires to come in). Weighs 1900g w/ the buggy dirthogs & proline rims inc w/ the kit. That's lid, batt and all. The goal was a lightweight truck as a part time basher/racer. Drives absolutely wonderful and makes the Revo look like a slog in comparison.

Also have blue springs and slightly heavier oil (5pts) than stock. Went upto 3K oil in the center diff and seems about right. The shock settings may take a bit to work out. Having too much fun playing w/ it now.

Does about 42mph+ on radar w/ the above batt. Temperatures stay around 100 for the motor and the MM. I may go upto a 15t to even out the temps a bit, but either way it feels good.

I am waiting for a couple Neu 30C 2500 batts, one in 3S and the other 4S. The amp load is a little high for the 20C 2100 batt. Runtime is about 12min or so. I was aiming for 15min, so the 2500 should get me to my goal. The 4S batt should put be above 1000W and close to 60mph. The motor put my chunky 5.5lb rustler to 55mph on 4S and the M2Ks. The LMTs are awesome motors. Have plans to redo the batt tray slightly to move it a bit back and slightly away from the spur. Its tight, the the batt is quite safe. Mike's adapter is bigger than the spur, so provides a nice guard, but you can never be too safe. Really well done.

Nevermind the mismatched tires below in the topless pic. It was just for testing. Also, notice the huge amp spikes in the 1st graph. I'm not sure how accurate they are, but I turned down the punch control one step for the 2nd session. Since there is no slipper, no limiter is very hard on the driveline. The actual performance loss is not really noticeable. Calmed down the huge spikes tho, and the batt is getting nearly so hot (no wonder.)
http://i7.photobucket.com/albums/y25...4/IMG_5293.jpg
http://i7.photobucket.com/albums/y25...4/IMG_5294.jpg
http://i7.photobucket.com/albums/y25...4/IMG_5289.jpg
http://i7.photobucket.com/albums/y25..._14-46gear.jpg
http://i7.photobucket.com/albums/y25...46gear_3_1.jpg

Nice conversion!! How is the small Lehner liking the CRT.5? I have heard of that the 1920 is a little on the small side for a truck that heavy...

That is very cool. I like the fact that you are using some bashing tires on there, I want to get mine setup that way eventually.

The 1920 is fricken wicked. I don't see the need for a bigger motor than that. Its already overkill on 4S, I can't imagine needing to go up a size on the motor. Also, it stays really cool regardless. I put the huge mashers on, but didn't change the gearing. The temps really don't change. The amp draw went way up tho, and is putting out ~900W+,and top spd is faster. It still wheelies quite easily as well on the undersized 3S 2100. The motor is just smooth and powerful, but still controllable. I'm very happy w/ it.

In fact, it was driving it a bit Fri, I wheelied and flipped it going ~40.... holy road rash. It slid really far on the roof and actually ate all the way thru the antenna tube and sawed the antenna in half. Surprisingly the rx still works fine. I'll have to post a pic...

Hopefully my Neu 30C 2500 batts will be in next week (god they shipped slow...) It should easily do 60 on 4S, but I'll be mostly keeping it to 3S.

The mashers are funny on the little CRT. Like 40 series on a Revo. Tons of ground clearance and drives over everything. Cornering obviously suffers tho:lol:. Drives more like a MT. Have some buggy dirt hogs for going fast and bashing, but nothing beats the mashers for offroad.

I also added some LED headlights and taillights for those midnight bash runs...hehehe. Just came back from testing it and works great. I can only imagine what people in cars are thinking seeing a little flashlight zipping at 40 mph thru the grass in the middle of the night....

I tried to make it easily removable, 3 screws and two microplugs they are off.

Pics please....

Short video on the 3S 2100 batts. Just some bashing about with the mashers on. May need a little heavier diff oils, but gets over the rough ground really well.

<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/HuHAZkBmpgE"> </param> <embed src="http://www.youtube.com/v/HuHAZkBmpgE" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

Hey Finnster, is that 3s 2100 a MaxAmps battery? Is it really able to handle the current well, or does it get pretty hot?

Thanks.

That's actually a 140g Align battery I got on clearance. Its only 20c, so its a bit pushed. I did order the Neu batts (30C 2500) and they handle the current better. I have some ETs for that I'll put up when I get a chance.

I could prolly run that batt, but i'd have to cut the amp draw, basically lower the gearing. I'm saving it for more race situations where top end won't be so high.

With the 4S 2500 batt I was pulling 120A+, and ~75A pretty steadily. I had one peak of over 1300W IIRC. Insane. 3S is more the daily batt and runs really well but can still put out ~1000W.


The nice thing about the LMT is the gearing isn't picky at all. As long as its not grossly over or under loaded it runs cool no matter what.

wow! looks great. have one suggestion thugh- why not plane the MM over the center diff? it seems like it would run cooler because of better airflow. just my double pennies.

Here are some more ET data shots. These are the Neu batts. The first is the 3S 30C 2500 pack (14/46 gear), the 2nd is the 4S 30C 2500 pack (13/46). Both are with the big mashers on. The 4S pack doesn't have much data as the fracking kingpin bushing came out after I back flipped it at 40 something mph and skidded down the road. I drove it around for a little bit with the wheel flopping around, but had to end it early. It was on the run where I pulled nearly 1400W, but that power just sent the CRT on its lid. We'll have to work on it a bit, I really want to be able to hit 60mph. It'll have to be on the buggy wheels and with lots of luck tho. The runs on the 3S pack are clocking in at 46mph.

3S:
http://i7.photobucket.com/albums/y25...-46mashers.jpg

4S:
http://i7.photobucket.com/albums/y25...46mashers2.jpg
http://i7.photobucket.com/albums/y25...erswattage.jpg

Basically I wanted to keep everything low and compact. The MM is running very cool as it is, so the trade off in CoG is not worth it IMO. Plus, I want to be able to remove the CD as easily as possible. Its really the only way to get at the motor bolts to adjust gearing, etc., and I don't want to have to undo a lot of things to do it. As it is now, the CD is off w/ 4 screws.

I'll have to post some more pics when I get the kingpin bushings in and repaired. I'll show the LEDs, and also a side shot where you can see the CD top plate is about the highest point on the main chassis.

CRT.5 breaks 60mph!!!!
 

Got to do some spd runs this weekend and put the crt to the test. It was hard to do, but managed to break 60 on the radar. Lots of near disasters and high spd crashes (mostly due to 50mph+ wheelies when I finally open it to WOT.) Really wish I had a longer straighter road to really lay it out, but its the best I got for now.

Short vid w/ lots of crashes:
<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/XnjTrx_LLXo"> </param> <embed src="http://www.youtube.com/v/XnjTrx_LLXo" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

Damn! Didn't anything break in those crashes?! That thing was fast!! Very nice!:surprised:

Is that the RC Monster Battery Tray?

How big battery could you get to fit in a CRT.5? Would a regular 1:10 battery-pack be too big?? Going to order som MaxAmp LiPos for my B4 and later maybe convert a CRT.5, so if the LiPos would also fit in the CRT.5 I use in B4 I would save a lot of money :smile:

You can fit a normal 1/10 scale truck battery in it fine, even without the extended chassis. I will actually be running a 4s pack in mine on the stock chassis.

1.) What are the runtimes like with the Neu 3s and 4s 2500's?

2.) What do you use for a balancer?

3.) Could you post a few chassis shots with the Neu batteries

-Thanks, Brad

That's nice to hear. Thank you!:smile:

I got some ET data for some of the spd runs. Same setup as in the vid, but no radar, but spds are about the same. What is interesting is that the amp draw and wattage is so much lower than when I had mashers on with much lower gearing. Top spd then was only 50 on even with 1400W. Barely a 1000 and it pulls to 60. I could prolly even gear up a bit for a few more mph as I know the setup will handle it.

http://i7.photobucket.com/albums/y25...esspd_runs.jpg

Here is some ETs for 3s. Top spd was 50mph, Again, amps are pretty low.

Also, notice the little voltage spikes after the big drops from the spd run? I think that is from the motor braking. The graph shows a hard accel from a stand still (ramping up the thr gradually as not to flip,) finally WOT (the big spike halfway thru the peak,) wattage/amps tapering off at full spd, then thr release and coast for a few seconds, then motor brake to stop it. Then repeat. Cool:intello:

http://i7.photobucket.com/albums/y25...esspd_runs.jpg

To answer a few ?'s:

The batts trays I made from a project box from Radio Shack. This one I think Had to cut up and mod a bit to fit the batts tight, but works well. Its bolted down thru the chassis holes for the gas tank and engine. Added a couple screws since the vid for more security. Added two more from the top after the tray came apart at end of 60mph vid.

I have the Ofna ext chassis. The limiting factor is width. I chose the 2100 and 2500 batts are they are ~35mm wide. Compared to a 44mm wide lipo, they are much smaller, and fit perfectly on the chassis. I have a 4S 3200 batt for my rustler, and it looked way too big on the chassis, and dangerously overhung on the sides. It wouldn't fit under the std body. The RCM chassis is much wider and will accommodate std 1/10 scale batts, but obviously not the stock body.

I was aiming for lightweight, so runtime is, IDK, 12-15min driving hard. Really depends on driving. I am pretty sure it will do a 15 min race (which was goal) and 100% sure it will do a 10 min race. Bashing lasts a good long time.

The Neus have Kokam taps. The best balancer to get is the Astro blinky. Very simple, but will fit any type of tap out there. I have a hyperion and TP balancer, and an assortment of adapters, but w/ the Blinky I don't need any of all that extra crap and it works well. $25 too.

Pics as requested. Couple notes: The tray came apart at end of 60mph video. I used an ABS cement to put the tray together, but it didn't bond well to the plastic. I redid it w/ Gorrilla glue, but rear tray shifted during drying and backend sticks out too much from the side. Fit snug first time (see 1st pics in earlier post) and only over hung by ~2mm. Need to fix this, but, eh works for now. Pic makes the repair look worse than it is tho.

Basically the tray is the project box quartered, slimmed down to 35mm wide, and a single strip of ABS attaching all the quarters together. Thin padding foam from T2 batt tray runs the length. 2 3mm from below, now 2 3mm from top bolting all quarters down for extra strength.

Top w/ batt:

http://i7.photobucket.com/albums/y25...4/IMG_5339.jpg

3s batt from side:

http://i7.photobucket.com/albums/y25...4/IMG_5341.jpg

LED Headlights:

http://i7.photobucket.com/albums/y25...4/IMG_5342.jpg

Comparing 35mm wide batt to 44mm ("1/10th scale") batt. 35mm batt is shorter and less wide but taller. Fits better on OFNA chassis IMO.

http://i7.photobucket.com/albums/y25...4/IMG_5344.jpg

A few updates:

I fragged my LMT.... :(

I was running very hard in the grass w/ the 18/46 gearing. I should have changed it first, but thought I'd just go for a quick spin and pushed it too hard for too long. One solder trace melted (its not a hi-amp version) and the truck stopped. I fixed the solder traces, but the motor is still cogging. ESC os fine, so motor will need to get repaired....dammit.

On the upside a have a 540 12s that I put in, and so far so good w/ it. Much less TQ than the LMT, but that might be ok given just how powerful the LMT was. The feigao is fast enough but not so wheelie prone.

I also went up to 10K in the diff, 3K diffed out badly. I'm working on doing Go-ride's .5 shock mods bc the shocks are really lacking. Hopefully I'll get it all together for the little RCM mini-bash on June 8th @ barnstormers. Should be fun to run against some other BL CRTs.

Major updates...
 

Well, went thru a 12S after the 1/8" shaft snapped, then snagged a 50mm 2200 kv medusa, and now I run that on 4s packs. Very nice, and very reliable. Got some 4S 30C 2100 Zippy packs for less than $40 and they freaking rock. Standing backflips easy if you are not careful. Also did the BB shock mod a while back as well. Essential. Led lights were removed in front until further notice. Bad crash damaged one and haven't fixed it yet.

3K front diff/10K/2K
27.5wt oil in Ft on jato pink springs
35 wt in rear on HPI blue springs 71 gF/mm (from hellfire, slightly lighter than the LX1 yellow springs)

Got to race it against RCM Mike and Arct1k's .5s at the barn over the summer. Fun little race, but it was ran with the 12s. The medusa would have been nice for some extra punch, but otoh the setup was very light w/ align 140g 3s 2100 packs.

Race vid:
Also, the UTube link for the 60mph vid got messed. A redo:
BTW, the medusa/zippy is just as powerful. Haven't done a speed run, but the feel is awesome. Love the motor.

ET Data on newest setup: 13/46 gearing on Medusa/4S and Masher tires. 90A peaks on a half spent pack and I was only dropping 2V (3.9V ->3.4V/cell) That's a 43C load!
http://i7.photobucket.com/albums/y25...0Zippy_13-.jpg

Pics:
(Crt.5 vs Hyper ST)
http://i7.photobucket.com/albums/y25...4/IMG_5961.jpg
http://i7.photobucket.com/albums/y25...4/IMG_5963.jpg
The Fleet:
http://i7.photobucket.com/albums/y25...4/IMG_5969.jpg