Redcat Sumo micro crawler (RSMC) parts breakdown and losi compatibility

[spoo76]

Losi calls the Micro Rock Crawler McRC
and the Trail Trekker Mc4x4 so i figure
the Redcat Sumo Micro Crawler = RSMC

so far its the same 7mm hex. losi wheels and BWD/crawler X hex wideners fit fine. though the barrel nuts do NOT. if you want to use them you will need to find barrel nuts with a thicker thread.
since the crawler X wideners are plastic you might be able to force the barrel not on and recut the threads inside

the ball ends and cups for the rod ends fit so that means the axles will bolt right up to your links as well as the shocks

the stub shaft has lots of thread on it which is great if you want to go even wider. though it's thicker and uses a larger wheel nut than the losi micro. however the stock wheel nuts are metal locknuts already.
here is the axle without Mc4x4 double thick hexes on the left and with the Mc4xx hex on the right.
as you can see with the Mc4x4 hex it takes up all the extra threading

redcat axles measure out to 104mm outside of tire to tire. 79mm from the flat side of the hub to the other
the axles have a spool diff not worm gears ( YAY! )

the male end of the losi driveshaft fits nicely in the female end of the sumo micro crawler (RSMC ) though oddly the losi female end wont fit with the male RSMC driveshaft.

the U joints appear to be the same size though i haven't taken them apart and tried to get them together

the RSMC doesn't come with any tools, but that's ok for the price.

the radio feels cheap, but so far works fine. again for the price any kit radio would feel cheap.

the motor and trans setup is interesting. they use a micro geared motor much like the polu motors. but its in a BIG plastic housing that the ESC/RX mounts to with more gear reduction inside

the servo looks like the cheap $5 servos you find on ebay or hobby king. plastic gears inside. I do like the slim servo horn

the bent links and rod ends are short but look decent

the tires and wheels are a hair wider than the McRC but you barely notice. tire height is in between a McRC and the taller Mc4x4.
Im not sure if losi tires fit on the RSMC wheels but honestly Im sure most people will swap both wheels and tires anyway.


I really like it so far though ditching the AAA batteries is a must. it just doesnt have enough power to get even out of a mild bind with AAA's. the RSMC would LOVE a lipo

Sorry for the crappy pix, i just took these with my phone

the gear motor and trans setup.
the motor is similar to the pololu gear motor

from left to right. the top end of the wheels on the axles were lined up flat against a straight edge so what you see is the TOTAL difference in width on the bottom side
RSMC with Trekker ( MC4x4 ) hexes
Mc4x4 with BWD wideners (McRC axles are the same as Mc4X4 just without the longer stub shaft and thicker hex)
RSMC stock width
McRC with BWD wideners
McRC with CrawlerX wideners
McRC stock

so it seems the RSMC is the widest followed by McRC with BWD wideners. I dont have a Mc4x4 But Im sure the trail trekker is no wider than the BWD
also a side note. because the RSMC stub shaft is thicker BWD and crawler X barrel nuts wont fit. you could possibly find the correct barrel nuts or maybe use the Mc4x4 extended hex?

tire height is in between the McRC and the taller Mc4x4.

I haven't taken apart the axles yet but this is the parts explosion it came with

center trans gears

axle

Ok it seems Photobucket unflipped the pictures, you'll have to deal with it

here are some pictures under popular bodies to give you an idea of scale

RSMC axle under the popular JK body

Losi micro axles

Lindberg 1/20 Toyota

Lindberg 1/20 Toyota
Front axles RSMC if you look close you can see the McRC axles under the rear

Someone asked for pictures of the link and shock mounts
if you swap the knuckles left to right you can move the shock mounts forward which may help in some scale builds

Servo removed. I like the servo saver and link. just a little longer and its perfect for a chassis mounted servo

LMcRC with lockouts on the left RSMC on the right

McRC left RSMC right.
RSMC springs seem a little more stiff than the McRC but the shafts should be more durable

here you see one of the many axle bushings. Im not sure if the McRC bearings will swap over.
The outer RSMC shaft mates up perfectly with the McRC inner shaft. the "splines" or hex cut ends are not the same between the axles.

Knuckle, the 2 sizes of bushings and the silver McRC inner shaft above the black RSMC shaft

I forgot to write it down but Im pretty sure the pinion is 13 tooth the ring gear is 24
the housing seems pretty thin. it should hold up to normal use but I wouldn't mind a stronger case and metal diff gears

Got everything back together and moved the steering behind the axle

Plenty of clearance once you mount the bar below the knuckles
even at full lock, though you may have to be careful with your lower links

stub shaft pix. note the RSMC stub shaft has thicker threads and needs larger wheel nuts.
the shafts are the same thickness so they should all be able to swap around
left to right
McRC
Mc4x4
RSMC

this picture shows the stock wheel hex on the left and the Mc4x4 double thick wheel hex on the right. its a little hard to notice but take note of how far the beadlock nuts are from the steering knucle

 

[BLADE]

Great Job thanks for the info.

Blade

 

[spoo76]

Thanks again! I'm resisting the temptation to order another one from you with a EX5.5 haha 8)

 

[spoo76]

BTW anyone that would want to run these axles on a McRC or Mc4x4 only needs to snap on the links, and shocks to the ball studs. the driveshafts have the same D shaped hole going to the axle/transfer case and are interchangeable.they are about the same length as the MC4x4 driveshafys. in fact if you have the male end of the McRC/Mc4x4 driveshaft on the motor/trans it will slide right into the female end of the RSMC driveshaft

Center transmission. It might make a good transfer case for front motor builds
the top gear in the pic is
a 13 tooth pinion for a D shaft
center gear 9 tooth
output gear 19 tooth

so excluding the gear driven motor the teeth are
13/9/19 in the trans and then 13/24 in the axle

this is the motor with lots of tiny metal gears i wasnt about to count haha

I really like this thing so far and cant wait to see all the builds with these parts. anyone looking to pick one up should take advantage of the free shipping while it lasts
Its also discounted now i see http://www.crawlerx.net/index.php?main_page=product_info&cPath=41&products_id=126

 

[BLADE]

Thanks again! I'm resisting the temptation to order another one from you with a EX5.5 haha 8)

Well what you waiting for there on sale and free shipping lol www.crawlerx.net

Blade

 

[Midlife Crisis]

Well what you waiting for there on sale and free shipping lol www.crawlerx.net

Blade

Pimp that shiat Brother! ;-) I haven't even played with #1, but I already want another!"thumbsup"

 

[BerticusPryme]

I have to say this ahs ben the most informative teardown I have seen. I was curios as to what parts would swap between the two. my question is how would you go about attaching the axles to a smc kit? I am about o start a scaler build and if a nice way of installing them on the smc chasis I may sut have to order one of these instead of a mcrc.

 

[Elastokinematic]

Very nice write up. "thumbsup" love them axles.. Im sure someone will use those to make a microFoFF sometime. Thanks for all that. Great info!

 

[spoo76]

I have to say this ahs ben the most informative teardown I have seen. I was curios as to what parts would swap between the two. my question is how would you go about attaching the axles to a smc kit? I am about o start a scaler build and if a nice way of installing them on the smc chasis I may sut have to order one of these instead of a mcrc.

You would make extended links with all thread and ball cups. check the micro mod bible. the RSMC uses the same ball studs and the drive shafts swap with losi

 

[Midlife Crisis]

Spoo, are the outputs of the xfer case the same sized "D" too?

 

[spoo76]

yes the RSMC drive shafts have the same D as losi and are about the same length as the Mc4x4 trail trekker.

The male end of the losi driveshaft also fits in the female end of the RSMC driveshaft but not the other way around

 

[BerticusPryme]

no I know how to build extened links and such. I am looking at it trying to figure out how to attach the rsmc to the smc chassis with leaf springs. using the wider axles on the 5.5+ smc chassis would be awesome on a 1/20 body.

 

[spoo76]

you might possibly be able to fit the crawlerX SMC springs on the RSMC axles considering the springs attach to the servo mount. but I thought you were talking about using the chassis with shocks & springs.

I wonder if crawlerX will eventually sell the chassis with shock mounts or at least without leaf springs

 

[BLADE]

you might possibly be able to fit the crawlerX SMC springs on the RSMC axles considering the springs attach to the servo mount. but I thought you were talking about using the chassis with shocks & springs.

I wonder if crawlerX will eventually sell the chassis with shock mounts or at least without leaf springs

I am working on a kit that uses the shocks.

Blade

 

[stomper4x4.com]

Thoughts

I have to say the more I work on and run this little truck I really like it. I put bearings in the axle hubs earlier in the week. I ordered a complete set so yesterday I tore it down and did the axles. This baby is really well built and has to be considered a good deal. The LIPO makes all the difference and this thing is really quiet compared to my other crawlers. The pumpkin is kind of big since it's a ring & pinion type design.

The guy I get my parts from is going to figure out a price for complete bearing sets. Too bad they come stock with bushings, but the good way out weighs the bad on this little new entry in the 1/24th market!

 

[johnnyh66]

spoo76, thanks for doing this man, it really helps "thumbsup"

 

[spoo76]

I have to say the more I work on and run this little truck I really like it. I put bearings in the axle hubs earlier in the week. I ordered a complete set so yesterday I tore it down and did the axles. This baby is really well built and has to be considered a good deal. The LIPO makes all the difference and this thing is really quiet compared to my other crawlers. The pumpkin is kind of big since it's a ring & pinion type design.

The guy I get my parts from is going to figure out a price for complete bearing sets. Too bad they come stock with bushings, but the good way out weighs the bad on this little new entry in the 1/24th market!

I agree lipo is needed, bearings are a great idea. i noticed the smaller losi bearings fit but didnt try to swap the bigger brass with the losi bearing. have you swapped that one? if this person has a full bearing set for both axles and the trans Im down for a set. otherwise ill order the losi parts.
I think this is perfect for the micro market. slightly wider axles, rear steer, spool diff. and with another crawler X chassis we should see even more builds pop up "thumbsup"

 

[spoo76]

spoo76, thanks for doing this man, it really helps "thumbsup"

Nope prob. this is all info I wanted to know, I was sure i wasn't the only one haha

 

[Midlife Crisis]

After running mine for a day, while built well, I totally think it is a turd. Granted, I mounted up my vertex's and Miclaw's before it's first run. Reverse REALLY sucks, it just stalls out. I think the turning radius on the Losi crawler is sharper than the 4 wheel steer of the Sumo. I attribute this to the tie rods smacking the diff housing and not allowing full turning capability. But, a little modding and this little bugger will do better. I really hope a LiPo will wake this thing up!

 

[spoo76]

After running mine for a day, while built well, I totally think it is a turd. Granted, I mounted up my vertex's and Miclaw's before it's first run. Reverse REALLY sucks, it just stalls out. I think the turning radius on the Losi crawler is sharper than the 4 wheel steer of the Sumo. I attribute this to the tie rods smacking the diff housing and not allowing full turning capability. But, a little modding and this little bugger will do better. I really hope a LiPo will wake this thing up!

Lipo is a must! on AAA's a turd is putting it mildly