My LST and Muggy Conversion Thread

[bdebde]

I wrap a piece of electrical tape around the front end of the diffs so they fit tight in the bulkheads.

What Neu packs are you running? The 4100EP packs fit well in the losi battery tray (perfect actually) and I only had to drill one hole in the chassis to put the tray in there.

And yes it was a nice day today here in the Pacific Northwest (first day of spring, Yah). I had better get my Muggy back together so I can try out my 1520!

[riverat1540]

im still rocking the medusa 80mm 2000kv with great results but the 1520 would be a great step up.

[nitrostarter]

Have you reprogrammed the MMM?

My personal preference is to use 0-.1 on the ballooning. However, I do think 14/50 is geared a tad on the low side. a 16-18t pinion should really wake it up!

[JThiessen]

Well, thanks to Hootie, I seem to have a plethora of pinions to pick from. No, I haven't touched the programming on this one since the last official software update came out (I haven't put any of the Beta stuff on it). I'm definitly in agreement on moving up to about a 18.
I must have had a number wrong the last time I ran the calculator, 'cause here is what i got this time, using a 18t pinion. Which would be absolutely perfect...

Differential Ratio: 4.090909090909091
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 50
Pinion Tooth Count: 18
Total Voltage: 18.5
Motor KV: 1600
Tire Diameter (inches): 5.65
Tire Ballooning (inches): .1
Motor Current Draw: 0
Motor Coil Resistance: 0
Spur/Pinion Ratio: 2.78 : 1
Total Ratio: 11.36364 : 1
Tire Circumference (inches): 18.38 inches (466.81 mm)
Rollout: 1.62:1
Total Motor Speed: 29600 RPM
Vehicle Speed: 45.33 mph (72.82 km/h)
Effective KV Value: 1600
KT constant: 0.85 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

I'm actually thinking about finally pickup up an Eagletree system. I found out they are actually just down the road from me....The USB car unit looks good enough for what I need, and from what I understand, I'll need the brushless motor kit with it. Anyone have experience with that unit?

[nitrostarter]

Nice! I was thinking you were running 6s as well.

Yes, looks like the 18t pinion should really wake it up. I thought 14/50 sounded a bit slow as well.

[JThiessen]

Yep - ran it with the 18 and its much better. Might even jump up a little higher yet, but I want to run it hard through a pack frist and see what temps look like.

I swapped out the shocktowers, looked at it for a bit, tried a bunch of different body styles on it, and didn't like any of it. So I put the olds back on and just moved the shock to the inner mount hole. I'm happier with it like this, but had to try it.

Well, M'in Law is in the hospital, and i'm taking off for Montana in a week, so probably wont do much on these for a bit. Would be great to take this back to the ranch to run, but, they still have a foot of snow. With it warming up, its gonna be a sloppy mess working the moo cows this year.

[Kcaz25]

Those red 7075 T6 TRX rods are a great choice for chassis bracing, but I'd(and am using) use bigger rod ends(links). These (by Dubro)are about 20% percent bigger and are made up of harder plastic. The screw hole that attaches to the rod will need to be drill out a touch as they are too small. I highly reccomend them. I've got 12 of them on my truck LOL and haven't broke one after about a year.




The other 4 links are in the steering making 12 monster ball links in all.

Nice trucks by the way!

-Zack

[JThiessen]

Finally a bit of an update on the design. I decided to try a drop down center plate, and reversed the center diff and motor to get more of the cg to the front. Had to mock up the servo and front shaft to make sure there was clearance. Looks dooable right now. The drop is only a 1/2 inch - could go a little more. My original idea was to get it low enough that nothing was sticking up through the top - but that now seems to be a far fetched idea. I used the muggy center diff set up (1.806" tall).

[JThiessen]

one more pic...ready for the dirt!!!

[JThiessen]

Just a small update: I finally got around to starting some of the assembly.
Got the Diff's rebuilt and installed in new aluminum cups. Used Muggy ring and pinion in them to get the ratio down a bit more to help with spur/pinion choices later on. One thing I noticed is that the gear mesh (ring/pinion)changes rather significantly as I spun the gear. I've never experienced this with the Traxxas and Savage diff's that I have rebuilt.

Installed the diff's into the Hot Racing Aluminum bulks and rear bulk support. Also used Hardcore Racing titanium upper plate, and hinge pin retainers. And of course the Lunsford Ti hinge pins. One of the bulks did not get the holes tapped very well - every one of the fasteners on it was damn tight - even the hinge pins took some extra work to get in. The other side was fine. Also installed the Ti Arms and Dynamite carriers, and the Losi hardened skid plate.

Remember - I'm converting an original LST, so I wasn't prepared for the carrier pins to be too short. Luckily I had two new Muggy A-arms sets, and stole the pins out of those. But after installing them - it looks like they are too long. I used all the shims they gave me, but looks like there should still be more. I'm also not certain that I installed them correctly - should the shims be used on the inside, or the outside? I also did very little shimming on the hinge pins. Should these be kinda loose, or nice and snug (but still allowing the arms to rotate freely)??

[JThiessen]

Those Flextek's sure look nice. Will be interesting to see how the hold up to heavy bashing.
I'm putting this part together so I can get more measurements for the design part - gonna need to get some custom shafts made. Anyone know if mike can do shafts that will mount to the LST style center drive cups?

Gotta order some additional carrier pins for the front, and some XXL carrier bearings. Just about done spending bucks on this thing - I'd hate to add up all that I've spent on it so far - gotta be over a grand so far. Kinda wondering why I even bought the roller in the first place - I think I'll only end up using the shock towers, bumpers, and a couple bearings off it!!!

Couple more pics...

[pinkpanda3310]

Originally Posted by JThiessen

I decided to try a drop down center plate, and reversed the center diff and motor to get more of the cg to the front. Had to mock up the servo and front shaft to make sure there was clearance.

Am I looking at it wrong or are the chassis rails facing the wrong way?

For more rigidity you could extend the rear skid to connect with the centre. Didn't you pick up a hot racing chassis? you could run that current set up with a similarly low cog. Or is that a an XXL chassis in the mock up?

[JThiessen]

They could be facing the wrong direction. I questioned that when I first modeled them up, and never did get around to double checking that. Its easy enough to flip them around and move the cutouts.

No, I didnt get the HR chassis. Looked at it a bit, then just decided to get the XXL.

Anyone see any issues with reducing the ground clearance in the center with the dropped center? I personally dont think it will be that much of an issue.

[mistercrash]

Originally Posted by JThiessen

Anyone see any issues with reducing the ground clearance in the center with the dropped center? I personally dont think it will be that much of an issue.

Mine will have a lower center skid also and from experience with my E-Revo when it had the kershaw chassis, it didn't cause any issues. As long as the first things to hit the ground are the front and rear skids, it should be fine. If you happen to be so unlucky as to land the center skid directly on a rock from 15 feet or more well, that's just bad luck I'm sure it'll be fine. This design looks great.

[jpoprock]

Originally Posted by Kcaz25

Those red 7075 T6 TRX rods are a great choice for chassis bracing, but I'd(and am using) use bigger rod ends(links). These (by Dubro)are about 20% percent bigger and are made up of harder plastic. The screw hole that attaches to the rod will need to be drill out a touch as they are too small. I highly reccomend them. I've got 12 of them on my truck LOL and haven't broke one after about a year.




The other 4 links are in the steering making 12 monster ball links in all.

Nice trucks by the way!

-Zack

Great idea, but only IF you have a set up like this. I'm not sure where you would mount this stuff using a stock tranny and a Dude mount.