need help with converting a hyper 7 - Page 2 - RC-Monster Forums

whitrzac · 03.11.2009, 06:51 PM

Quote:

Originally Posted by lincpimp

Hey, for 40 bucks you cannot go wrong!

for 1... and I will get them eventualy, jsut like I will get a decent motor too

lincpimp · 03.11.2009, 06:56 PM

Nothing wrong with the novak motors for 1/8 buggy use. Not the most powerful, but they are a well made motor.

As for my previous statememt I meant the motor. You can get away with the novak trays, or a cut up emaxx chassis. I like mike's trays, but do not see the need for a really heavy duty tray for a hardcase 2s lipo.

whitrzac · 03.11.2009, 07:12 PM

Quote:

Originally Posted by lincpimp

Nothing wrong with the novak motors for 1/8 buggy use. Not the most powerful, but they are a well made motor.

As for my previous statememt I meant the motor. You can get away with the novak trays, or a cut up emaxx chassis. I like mike's trays, but do not see the need for a really heavy duty tray for a hardcase 2s lipo.

ohhh, it all makes since now.

just for fun I put it in my slash with a 9 cell gp 3300 pack

I have a slight problem though, I hit the 6.5v cutoff under "heavy"* accelaration

* I know its just the crappy batts, but I NEVER had that happen with my MM5700, or my novak 10.5

"now weres that batt adapter..."

whitrzac · 03.12.2009, 08:29 AM

what do you guys think about using the savage flux battery boxes?

lincpimp · 03.12.2009, 09:21 AM

Quote:

Originally Posted by whitrzac

what do you guys think about using the savage flux battery boxes?

They are designed to stand up, something like the novak trays are a better idea. A high profile box will not fit under a stock buggy body. Not much room under there.

whitrzac · 03.12.2009, 09:32 AM

Quote:

Originally Posted by lincpimp

They are designed to stand up, something like the novak trays are a better idea. A high profile box will not fit under a stock buggy body. Not much room under there.

ok, just bouncin ideas around...

so what gearing should I start off with? I realy don't want to spend $50 on pinions...

I have a 46t spur

lincpimp · 03.12.2009, 09:44 AM

Use BrianG's speed calc.

http://scriptasylum.com/rc_speed/_top_speed.html

Your results should look something like this:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 46
Pinion Tooth Count: 9
Total Voltage: 14.8
Motor KV: 5000
Tire Diameter (inches): 4
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 5.11 : 1
Total Ratio: 16.90598 : 1
Tire Circumference (inches): 12.57 inches (319.19 mm)
Total Motor Speed: 74000 RPM
Vehicle Speed: 52.09 mph (83.67 km/h)

An 8 tooth pinion looks like the best bet, however you may have some issues getting it to fit physically. Smaller pinions usually cause problems, as the motor can only get so close to the spur before it contacts with the diff output. The smallest hardened pinion Mike carries is a 9 tooth. I would give that a try... I usually try to gear for around 45mph, the 9 tooth will give around 50mph with that motor.

lincpimp · 03.12.2009, 09:46 AM

Novak also make a 9t pinion that is hardened. If you plan to use a steel spur, stick with Mike's pinions as they are the best hardened pinions I have found...

BrianG · 03.12.2009, 09:55 AM

Linc, aren't Hyper8 tires closer to 4.25"? That can make a substantial difference.

Also, what is the deal with such a high kv? Is the goal for a fast buggy? (I don't want to read through the whole thread - I'm lazy

) Besides, a pinion that small will see faster wear. Depending on exactly how fast you want to go, I would shoot for a slightly lower kv, something around 3500-4000 and use a larger pinion - something in the 14T range.

whitrzac · 01:01 PM

Quote:

Originally Posted by BrianG

Linc, aren't Hyper8 tires closer to 4.25"? That can make a substantial difference.

Also, what is the deal with such a high kv? Is the goal for a fast buggy? (I don't want to read through the whole thread - I'm lazy

) Besides, a pinion that small will see faster wear. Depending on exactly how fast you want to go, I would shoot for a slightly lower kv, something around 3500-4000 and use a larger pinion - something in the 14T range.

see post #12...

also, isn't the motor wye wound instead of delta so it would be ~a 3500kv sensorless motor?

I'f anyone is looking to trade I'm open...

lincpimp · 03.12.2009, 01:01 PM

Quote:

Originally Posted by BrianG

Linc, aren't Hyper8 tires closer to 4.25"? That can make a substantial difference.

Also, what is the deal with such a high kv? Is the goal for a fast buggy? (I don't want to read through the whole thread - I'm lazy

) Besides, a pinion that small will see faster wear. Depending on exactly how fast you want to go, I would shoot for a slightly lower kv, something around 3500-4000 and use a larger pinion - something in the 14T range.

Yeah, that is true about the tires...

As for the motor, he can get it for 40 bucks... I would try to sell it off and make some money, and then buy something lower kv, like a medusa 60-70mm motor with kv around 2200. On 4s that can take 14-16t pinions and run in the mid 40s.

If you want to sell me that motor I will find a use for it...

whitrzac · 03.12.2009, 01:12 PM

Quote:

Originally Posted by lincpimp

Yeah, that is true about the tires...

As for the motor, he can get it for 40 bucks... I would try to sell it off and make some money, and then buy something lower kv, like a medusa 60-70mm motor with kv around 2200. On 4s that can take 14-16t pinions and run in the mid 40s.

If you want to sell me that motor I will find a use for it...

well, since I'm in the market for a new motor, what does everyone recomend? no NEUs or $150+ motors please

if nothing else I'll keep it and sell my 540 novak 10.5

the HV found its home in my slash

I though at 5000kv it would be ~13.5, its closer to a 7.5

BTW that was just a mock up, I have all the wires right, and some 32p gears on it

BrianG · 03.12.2009, 01:16 PM

Yeah, I too would be looking in the 2000-2600kv range for 4s. Otherwise, you're gonna have a heck of a time gearing it down enough and/or use really small tires (smaller tires is like gearing down) to keep temps down.

The CC2650 motor (essentially a 1512/2.5d) would also be decent on 4s, geared around 46/14 would give you around 40-45mph speeds.

spaz163 · 03.12.2009, 01:23 PM

Don't forget about the Team Losi 8ight E battery trays as an option. They are very cheap!!

Tray

Straps for the tray

whitrzac · 03.12.2009, 01:42 PM

Quote:

Originally Posted by spaz163

Don't forget about the Team Losi 8ight E battery trays as an option. They are very cheap!!

Tray

Straps for the tray

I have the novak trys on the way here...

if I pick up a 9t pinion do you think it will be fine untill I can get a diffrent motor??