that is what the linkage in the middle does, you adjust that so they dont fight each other....

i already picked up one of the JR high voltage servos and a Castle BEC so i can run at 7.4 volts which will let the servo pump 480oz of torque. about the best available from what i can find. i picked up these aluminum servo mounts on ebay that i plan to mount for both steering and brake. hopefully they are strong enough. i think they will work fine.

<a href="http://s471.photobucket.com/albums/rr77/ryujames/?action=view&current=alloyservomount.jpg" target="_blank"><img src="http://i471.photobucket.com/albums/rr77/ryujames/alloyservomount.jpg" border="0" alt="alloyservomount"></a>



as far as finding a "normal" center diff from one of the other 1/5 kits it aint happening. not by me anyway. i have looked everywhere. all the 4wd units use a conical style gear in the center. i have already posted some of my gear ideas from the other kits earlier in the thread. perhaps someone can tell me the diamater of the spur gear on the rear diff of the baja 5b. i would like to use that as a center diff and just have a custom mount made but i have no idea what size it is. i think it is too big though. can anyone tell me?

here is what i have decided to do. i ordered this spur gear in 37t. (a 43t is also avail.) it looks to be the easiest one to modify. all i will have to do is bore out the middle to 12mm and drill 4 holes to screw it down. i think it will work. if it does work i will can order the 43t and do the same to adjust gearing if needed. but i want a fast ride so i am starting with the 37t and see what happens.

<a href="http://s471.photobucket.com/albums/rr77/ryujames/?action=view&current=37tspurgear.jpg" target="_blank"><img src="http://i471.photobucket.com/albums/rr77/ryujames/37tspurgear.jpg" border="0" alt="37tspurgear"></a>

Very nice. I have the Rampge MT with a ported 30.5 CC engine. I hope you are able to drill holes in that gear to make it fit.

Do you plan to use mod1.5 gearing for the pinion and spur? Or mod 1? What is the diameter of the bevel center gear?

Ok, had a look for a 12mm bore, hubless, mod1.5 steel gear. Came up with this:

https://sdp-si.com/eStore/PartDetail...70&GroupID=591

Here is the pdf info on the gear familar, just look at the 36t hubless info in the 1st table.

https://sdp-si.com/eStore/..%5Css%5CPDF%5C78501072.pdf

At 22 bucks plus shipping it is not too bad. Diameter is 57mm on the 36t gear, so not sure if it is too big to fit with the stock center bulkheads...

If those links do not work, search sdp si on google, and put this part number in their search feature: A 1C 1MYK15036

Linc, you are the f-ing man!!

that should be perfect. the stock bevel gear is 54mm. i could probably get a gear as large as 60mm and be fine. that 40t might even fit but i already ordered the 36t one. so now all i will have to do is have my machinist drill 4 holes and in 5 minutes i have my spur gear. woo hoo!! and Mike said his pinion gears should be available for sale by Monday. 11t to 22t pinions! sweet!
cant wait!

assuming this works the next aspect to be tackled is the mechanical brake setup. i have already orded some parts for this and have an idea of how to make it work so i will post some pics when the parts arrive. probably wont be til monday.



<a href="http://s471.photobucket.com/albums/rr77/ryujames/?action=view&current=36tspur1.jpg" target="_blank"><img src="http://i471.photobucket.com/albums/rr77/ryujames/36tspur1.jpg" border="0" alt="Photobucket"></a>
<a href="http://s471.photobucket.com/albums/rr77/ryujames/?action=view&current=36tspur2.jpg" target="_blank"><img src="http://i471.photobucket.com/albums/rr77/ryujames/36tspur2.jpg" border="0" alt="36tspur2"></a>
<a href="http://s471.photobucket.com/albums/rr77/ryujames/?action=view&current=36tspur3.jpg" target="_blank"><img src="http://i471.photobucket.com/albums/rr77/ryujames/36tspur3.jpg" border="0" alt="36tspur1"></a>

Are you going to mount the motor to the front? If so where are you going to relocate the radio gear to?

Are you going to run that Mod1.5 gear of Mod1?

This thing will be nuts if you mount that 2230. I hope the diffs will take the power.

The diff gears were recently updated. They and the dog bone pins hold up OK as long as you don't land on power.

the only radio gear i have is a tiny spektrum reciever. i am gonna build a small waterproof box like i did with my slash and finding a spot for wont be hard as this chassis has tons of room.

i will be using mod1.5 gears. RCM is due to have the mod1.5 pinions anyday now i think and i have found a mod1.5 spur gear with the help of Linc the Pimp.

i dont think i am going to run the 2230 now. i do want tons of power but i defintiely dont want my driveline and gears busting everytime i get on it. i dont mind breaking my toys but i am starting to think the 2215 will be better suited. still not sure though. i am defintley keeping my 2215 no matter what. i will run it first and see how it does. if it feels underpowered or running too hot then i will worry about finding a way to get the 2230 in. but for now i am moving forward with full intention of running the 2215.

What ESC are you going to use? How many amps do you expect to pull?

Glad I could help! Nice to see someone tackling a big truck like this. I will be interested to see your success as I would like to do a truck like this.

thanks Man,

i really hope it turns out well. i am kind of a perfectionist and so i would like to think i will deliver a 1/5 brushless that will look factory. unfortunately for me (but fortunate for my wallet) the Redcat doesnt have near as many hopups available as the Baja.

Have you looked at 1/5's yet? you plan to do a 5b? or considering others?

i have looked at doing a 1/5 conversion for months now and i think the Redcat offers the best all around package for one.

$500 price tag
4wd
plenty of parts support and US made. HQ in AZ.
decent amount of hopups avail.
has its own forum
very large chassis/platform for easy conversion options
seems to be good build quality. its not like the FS or Smartech 1/5 stuff that is total junk.


by the time i finish my conversion i should have CAD files and stuff for a 22xx motor mount and different things and could perhaps do a couple of extra kits. not sure yet but i will be sure to post if its something i can make available.

i plan to use the Castle Hydra 240 HV, which is capable of 240amps. i will run to 5s, 18.5v, 5000mah, 30c packs in series. i may pick up some of the many differnt new 35c packs popping up everywhere now.

btw, do you have a rampage?

Yeah, but you inspired me to convert. Mine is still a gasser though. I love the power but I usually take it down to the state park to run it because of the noise.

That will give you close to 30,000 RPMs which is almost double what the 2 stroke gasser will make.

I think I might sell my helicopter that I've not done anything with in a while for funds.

lincpimp and others : Do you think the HV 180 would handle this OK?

Your conversion is coming along nicely! IMO it's smart to start off with the 2215, I am sure it has plenty of power for this application.

Thanks for the pics of the 2230, I've only seen a few pics of them. I can't imagine what a person could possibly use one of those for...

If you run 10-12s and are not trying to gear too high I am sure the hv180 will work. Up at 10 and 12s pulling more than 100amps is making some serious power. I used a 60amp esc on 8s in a savage and had no issues, so triple that rating with higher voltage in a 15th scale should not pose a problem.

RJ, can you weight the chassis without the motor or batteries as it sits with the tires on? Just wondering what it will weigh with my proposed setup, and I know the weights of all of the individual components.

I think I emailed castle last year about using the Hydra's in a Land vehicle.. they said it wasn't a good Idea, if I can remember...

It's been done though.

Ryu- Maybe you can do a watercooling setup for the hydra? I mean... you do have all that extra chassis space...

Just to throw it out there: my XLB (1/7 4wd 15lb center diff buggy) now runs a 1521 2Y on 10s 3700mah Lipo through a HV-110. It's geared for mid to low 40s but it pushes out over 5hp on peaks (loads of power). The HV-110 heats up to about 120-130deg. after maybe 10mins. I'm sure things would cool down a bit if I played with the ESC settings but this might give you an idea of what to expect from an ESC.

They also say not to run the MM past 3s :wink:

There are people successfully running Hydras in cars and trucks, the biggest issue is heat dissipation but if you're running a 240 amp ESC and drawing half that you should be able to get some decent run time out of it before letting it cool. If you feel like voiding the warranty even further you could modify the ESC to take heatsinks, but you would probably need some kind of thin heatpipe cooler in this application.

yes. i have a nice little digital scale i picked up a few weeks ago for weighing RC stuff. it will weigh up to 30lb i believe. as soon as i get back home i will post the weight of just the roller.

I had an FG monster truck awhile back in need of a steering servo. I too was concerned about the relatively low torque ratings of the 1/4 scale servos out there and picked up two 1/4 scale 200oz hitec's. Thankfully I tried using just one first and ended up returning the other as it turned the wheels like my 9100T did on my Revo. Also the 1/4 servos have stronger gear sets in them to take the higher shock loads a heavier truck will see. I was also powering the servo directly off the reciever battery instead of through the reciever, which alot of 1/5 guys do. It gives the servo some more power and insures the reciever doesn't burn out from the increased load placed on it.

Edit: Cool project man, I really dig the large scale stff, can't wait to see it finished with vids.

so do you think i should go with a 1/4 scale servo then? i heard the JR HVT has huge teeth on the gears. the stock setup on this uses a 1/4 servo for the steering and a standard servo for the brake. i was just going to use standard for both. i did find these 1/4 servos. defintely the strongest i have found so far in the 1/4 size.

http://www3.towerhobbies.com/cgi-bin...&I=LL6955#tech

http://www3.towerhobbies.com/cgi-bin...XVPF0&P=8#tech



to linc:

i weighed the chassis as a BL roller and it weighs 19.3 pounds. that was with the battery trays on it. so here are the other stats, according to memory.


servo: 2.5oz each. x 2
2215 Neu: 25oz.
NeuEnergy 5s Lipo: 22.5oz x 2
Hydra 240HV ESC: 7.7oz



So all together i get a weight of roughly 24.5 pounds. I am gonna add on another 8 to 16 ounces for wire, screws, mech brakes, mounting hardware for esc, etc. so the finished product should weigh in at 25lb or just over.

This is the first build i have done where i havent tried to shed weight and been concerned with weight.

I can't wait to see this come together. Your builds are top notch.

The MT gasser with those HUGH tires weighed 37 pounds! I calculated hte impact force of it hitting something at 35 mph and it came out to around 400 pounds.

I'm currently using a scanner-rc.com servo for steering. 348 ounces at 6V. It is digital and works well for the price of $60. None of the US distributors carry that one so I have to get it from the Canadian distributor. $60 shipped to the US isin't bad though.

What about using this motor? http://www.innov8tivedesigns.com/pro...roducts_id=515 The power seems to be similiar or am I missing something?

if you still wanted a center diff,what about making a mount for the baja diff,then using an idler gear of some sort to get the pinion to it.it might also offer some more gear reduction if needed.just a thought...

Just go one step further, and use the entire 5b tranny, make a motor mount, and attach the 1st gear in the the tranny to the motor shaft. Kinda like sikeston's direct drive emaxx tranny setup.

that motor is more like the size of a Neu 1515 (14.8oz). i have seen those motors but have never heard of anyone using them. i think my buddies might use those for some budget planes they build.


hey,
does anyone know why this servo says to use NiCD packs only?

http://www3.towerhobbies.com/cgi-bin...XVPF0&P=8#tech

COMMENTS: Use with NiCD batteries only
A note on Coreless motors: Conventional servo motors have a steel
core armature wrapped with wire that spins inside the magnets. In
a Coreless design, the armature uses a thin wire mesh that forms a
cup that spins around the outside of the magnet eliminating the
heavy steel core. This design results in smoother operation and
faster response time.

It's says "NiCd only" because they don't want you to use alkalines, but they haven't kept up with the rimes to include NiMh and lipo etc.

Personally I'd run a 1/4 scale servo. The two you linked still have alot of torque and either should be plenty. Also I don't care how big the gears are, there's no way they can be as big as a 1/4 scales, it's physically impossible. And what about the gears in the JR is big, the teeth, dia, width? Usually what happens in standard servos is the gears get wider to increase the contact area of the gears making them stronger. Even though the standard has more torque than the 1/4 scale, the 1/4 has stronger gears so it can stand up to the shock loads that get past the servo saver.

makes sense. thanks for the advice.

Mod 1/5 pinions are here!!!
 

THE 8MM, MOD 1.5 pinions are avail on RCM now. i ordered a few for the conversion. also, i met with machinist to start on motor mount


http://www.rc-monster.com/proddetail...=rcmbajapinion
<a href="http://s471.photobucket.com/albums/rr77/ryujames/?action=view&current=mod1_5pinion.jpg" target="_blank"><img src="http://i471.photobucket.com/albums/rr77/ryujames/mod1_5pinion.jpg" border="0" alt="mod1.5pinion"></a>

So I was thinking...you aren't going to be able to run mechanical brakes that way you have it now. The brake pads ride on 50024 and 50074 which is connected to the D gear on the outside of the gearplate 50011. You have all that removed in order to run a pinion / spur to the center diff...which seems like the best idea.

http://mysite.verizon.net/tbtjsnyder/rampageexplode.jpg

In this picture the upper gear mounting plate is turned around to face the side that the pipe is normally on.

http://i471.photobucket.com/albums/r...s/DSC01180.jpg

I think you are going to have to rely on ESC brakes...

Brakes? We don't need no stinkin' brakes! :lol:

You bring up a good point. I wouldn't rely 100% on ESC braking when it comes to something with that much kinetic energy, not with modern ESCs at least. I'd set the brakes to 10-20% on the ESC and come up with some mechanical brakes that will work. Running brake discs at the center diff like it's supposed to be will interfere with your gearing options unless you go for some really puny brake discs. I think I'd go with brake discs on the diff input cups or even 4 wheel braking. It'll take some work to figure it all out, but this conversion is going to be worth it.

I say front disk brakes for a 5b.. not sure on the hex size but they sure do look sexy...
http://i79.photobucket.com/albums/j1...tBrakes007.jpg
http://i79.photobucket.com/albums/j1...tBrakes023.jpg

Baja disk brakes will be the best idea. I don't think there will be a way to get pads on the diff cups.

I assume that Dave's has those brakes? Link?

Redcat hex is 22mm, baja is 24mm. The Redcat can run the baja rear hexes all around, either way you need new wheels or new brake discs made for the smaller 22mm hex.

Why can't the stock brake be run again? I thought it was in the front of the diff opposite the gear. I guess motor clearance is a concern with the motor mounted up front? Can we get a pic with the stock brake disc in there?

IMO it's time to figure out the target speed and do some math to determine what the size of the gears will be to see what will fit with the stock brake. Unless of course you want to adapt brakes at each wheel anyway.

Stock brakes are on the shaft that come off the gear reduction cluster and goes to the bevel gear, so he has that entire assy removed. Either putting disks on the diff inputs, or preferably on the wheels would be the other options.

I have Dark Soul Baja hexs on mine now as I am running Desperado / BowTies.

You can see better pics on the RedCat site: http://www.redcatracing.com/RC-Cars/1-5-Scale-Gas

I don't know if the brake will mount up to the hub carrier.

Oh, ok. I was wondering why NONE of the pics had the brake on the center diff! Brakes on the wheels get my vote then. If he's got a machinist to make the motor mount, make some new discs with the 22mm hex in them. I'd think that would be less expensive than machining a new shaft and mount for the center diff to accomodate a brake. Plus brakes at the wheels would be more powerful and fade resistant, important considering the weight of this thing.