Bl Cen matrix build

[jhautz]

I responded to your PM Ben.

Yea the CEN stuff has wierd gearing in the diffs... I would do whatever you neeed to do to get rid of that Ferris Wheel 66T center gear. It screws up you gearing choices as well as pushing the battery way out to the side.

What I did was replace the front and rear diffs with the Hotbodies 43/10 truggy diffs and then the center spur gear with a normal 46T buggy spur gear. It was a good setup. I took out the spacers that CEN has under the center diff mount that raise it up to work with the stock 66T gear, then the RC-Monster Cen buggy motor mount will work with about a 1/2 or so spacers on the top so the upper chassis brace can bolt on in the stock position. I'm not sure about the exact size of that 1/2" spacer any more. You would have to measure the height of the spacer that goes under the center diff mount and get something the same height for the top of the mount. Not quite sure from memory, and I dont have it any more to measure anything.

You can kinda see what I did in this picture. Hope this helped and good luck on the conversion. Its a great truggy for the price and tough as nails.

[lincpimp]

I was going to suggest the hb truggy diff gears, but did not know if they would fit the cen cups...

That looks like your best bet BB, plusit looks good, and you will have more room and centralized weight with the smaller spur.

[lincpimp]

Century make a 9t pinion, but only good for a plastic spur.

[BL_RV0]

Novak also makes a 9t gear:
http://www.shopatron.com/product/part_number=5109/135.0

[brushlessboy16]

Originally Posted by jhautz

Just a little bit on out outside edge of the cup to make the ring gear fit over it. I actually think I just did it with some sandpaper. It didnt take much at all.


I have a brand new Kyosho center dif here with a 50T gear on it. (It think its a kyosho anyway) Not sure where I got it but it doesnt look like it has ever been used and I have no use for it at this point. PM me if you want it. Not sure if a 50T will work for you or not. But it should drop right into the cen if I rmember right. I'll let you have it very reasonably if you can use it.

hmmm makes it alot easier and give me more room for gearing, i think ill take it :D

Originally Posted by lincpimp

Century make a 9t pinion, but only good for a plastic spur.

what happens if i use metal to metal?

i know that duratrax makes a spiral cut gearset for the raze (very stong i know from expireince) that might fit for diffs

[JThiessen]

Originally Posted by brushlessboy16

we do i just wouldnt think that lexan would be structurally sound..



plus i don think any place around here carries lexan

Its plenty strong - just a little on the heavy side. Any Lowes or Homedepot will carry it, and most hobby shops have smaller pieces. Another place to try is one of your local home window dealers. Call around and see if they have any scraps you can dig through - they might let you have it for free.

[brushlessboy16]

replied :D

Differential Ratio: 2.8888888888888888888889
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 66
Pinion Tooth Count: 13
Total Voltage: 18.5
Motor KV: 2200
Tire Diameter (inches): 5.65
Tire Ballooning (inches): .15
Motor Current Draw: 80
Motor coil Ω: 0.006
Spur/Pinion Ratio: 5.08 : 1
Total Ratio: 14.66667 : 1
Tire Circumference (inches): 18.69 inches (474.79 mm)
Total Motor Speed: 39644 RPM
Vehicle Speed: 47.85 mph (76.86 km/h)
Estimated Adjusted Speed: 45 mph (72 km/h) - 6% loss
Effective KV Value: 2142.92
KT constant: 0.61 oz-in/A
Motor Torque: 0.26 ft-lbs
Final Torque: 3.76 ft-lbs
Final Power: 1480 watts (2 HP)


thats with the stock diffs and spur.
needs a 13t pinion for 45mph. thats doable/


here is with 46t spur
Differential Ratio: 2.8888888888888888888889
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 9
Total Voltage: 18.5
Motor KV: 2200
Tire Diameter (inches): 5.65
Tire Ballooning (inches): .15
Motor Current Draw: 80
Motor coil Ω: 0.006
Spur/Pinion Ratio: 5.11 : 1
Total Ratio: 14.76543 : 1
Tire Circumference (inches): 18.69 inches (474.79 mm)
Total Motor Speed: 39644 RPM
Vehicle Speed: 47.53 mph (76.34 km/h)
Estimated Adjusted Speed: 45 mph (72 km/h) - 6% loss
Effective KV Value: 2142.92
KT constant: 0.61 oz-in/A
Motor Torque: 0.26 ft-lbs
Final Torque: 3.78 ft-lbs
Final Power: 1480 watts (2 HP)

would need a 9t for that, pretty sure no one makes a 9t lol

[jhautz]

Are you sure you are using the right front/rear diff ratio? I thought that the Truggy came with 38/11 diff gears on the Cen. The RTR Cen buggy comnes with the 26/9 gears and the pro buggy came with the 38/11 gears, but I thought all of the truggies came with 38/11 which changes your gearing picture quite a bit.

Double check the actual ratio you have. I could be wrong, but mine came with the 38/11 (3.455 ratio) if I remember right.

Originally Posted by brushlessboy16

replied :D

Differential Ratio: 2.8888888888888888888889
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 66
Pinion Tooth Count: 13
Total Voltage: 18.5
Motor KV: 2200
Tire Diameter (inches): 5.65
Tire Ballooning (inches): .15
Motor Current Draw: 80
Motor coil Ω: 0.006
Spur/Pinion Ratio: 5.08 : 1
Total Ratio: 14.66667 : 1
Tire Circumference (inches): 18.69 inches (474.79 mm)
Total Motor Speed: 39644 RPM
Vehicle Speed: 47.85 mph (76.86 km/h)
Estimated Adjusted Speed: 45 mph (72 km/h) - 6% loss
Effective KV Value: 2142.92
KT constant: 0.61 oz-in/A
Motor Torque: 0.26 ft-lbs
Final Torque: 3.76 ft-lbs
Final Power: 1480 watts (2 HP)


thats with the stock diffs and spur.
needs a 13t pinion for 45mph. thats doable/


here is with 46t spur
Differential Ratio: 2.8888888888888888888889
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 9
Total Voltage: 18.5
Motor KV: 2200
Tire Diameter (inches): 5.65
Tire Ballooning (inches): .15
Motor Current Draw: 80
Motor coil Ω: 0.006
Spur/Pinion Ratio: 5.11 : 1
Total Ratio: 14.76543 : 1
Tire Circumference (inches): 18.69 inches (474.79 mm)
Total Motor Speed: 39644 RPM
Vehicle Speed: 47.53 mph (76.34 km/h)
Estimated Adjusted Speed: 45 mph (72 km/h) - 6% loss
Effective KV Value: 2142.92
KT constant: 0.61 oz-in/A
Motor Torque: 0.26 ft-lbs
Final Torque: 3.78 ft-lbs
Final Power: 1480 watts (2 HP)

would need a 9t for that, pretty sure no one makes a 9t lol

[brushlessboy16]

i would need the whole diffs. i only have 80 dollars to my name right now, will be 60 when i ship the warhead.

[jhautz]

The HB ring gear fits the Cen dif cup with a little minor dremel work for fittng. I know I had a set on the CEN cups in a matrix buggy for a while. In the truggy I just swapped the entire diff to the HB diff. Either way will work I think.

See if you can pick up a used set of the HB diffs on ebay or something. You should be able to find something for that money.

[brushlessboy16]

what do you consider minor dremel work? i can do it on my schools lathe if neccissary..

[jhautz]

Just a little bit on out outside edge of the cup to make the ring gear fit over it. I actually think I just did it with some sandpaper. It didnt take much at all.


I have a brand new Kyosho center dif here with a 50T gear on it. (It think its a kyosho anyway) Not sure where I got it but it doesnt look like it has ever been used and I have no use for it at this point. PM me if you want it. Not sure if a 50T will work for you or not. But it should drop right into the cen if I rmember right. I'll let you have it very reasonably if you can use it.

[brushlessboy16]

ughh 66/13 comes to 41.5mm lol just my luck

[brushlessboy16]

i just checked tower, says the truggy is 9/26

[jhautz]

OK then. I'm probably just not rtemebering right anymore. I'm working from memory here and its not what it used to be. lol