need help with converting a hyper 7
 

I'm no newb when it comes to RC, but this is my first atempt at converting a 1/8 buggy, and I'm trying to do it cheap:whip:

my gear so far
tekin RS pro esc, with diffrent caps, and an external bec/rx pack
novak HV 4.5 motor
this motor mount
some misc. mg servo that I have laying around:whistle:
true rc 5000 hardcase lipos/protek 4000 lipos/gp3300s:oops::whip:


I only have the esc/batts as of now, but I'm seeing a problem on WTF to put the batts, I origanaly planned on haveing 1 pack on each side, but there too long to fit behind the diff, and too wide to fit on the side of it without riding up on the mudgaurd...:no:

I still want to keep a "saddle" pack layout, but I have no clue on how to mount the batts.:neutral:

I have basic tools to fab some parts up, but I would prefer somthing pre made:whistle::oops:


what kind of preformance/speed/gearing should I be looking at? it probably wont see any track time...

link to the motor
http://www.teamnovak.com/products/br...kits/OFNA7.jpg

mabey somthing like this? http://cgi.ebay.com/NEW-SAVAGE-FLUX-...QQcmdZViewItem

would both of these fit on the chassis at once??
http://www.shopatron.com/product/par...56.35136.0.0.0


just an observation, why does a 32p pinion cost $4, but once its been drilled out to 5mm it costs $10-$15...

I did a dual pack Hyper7. Used the rcporoducts designs trays, at 125 bucks each I would say they were a waste of money. You can fit a pair of trays, mot the best way to run them though, for ft to rr balance.

I think the novak trays will fit fine and the price is right...

those were the first ones I looked at and I almost _____ my pants....

They are pricey and they are way too heavy. I would se the novak trays, or maybe cut down an old emaxx chassis, I did that a few times to fit my hardcase trakpower lipos.

FYI: Mike can make trays to any size. And even the custom option is cheaper than the Novak trays by a longshot...

Saddlepacks really aren't needed for balance. I find that the motor on one side and 6S A123 on the other works out just about perfect for me.

I never thaught about the e-maxx chassis....

the way its looking I'll be going with the novak trays


are there any hints you can give to make my converson less painfull?:whip:

what would be the recomended gearing?


also, I'v seen people runing a kyosho plastic spur, whats the advantage of doing that???

The conversion is pretty straight-forward... Just keep an eye on your signal wires, and try to keep them as neat as possible.

I like the plastic spurs as they are much quiter. And if you really stuff it hard, or land very poorly the plastic will give a little, or break, saving the motor... I would rather replace a 4 dollar spur than a motor. Mainly I use the due to the noise...

Recommended gearing is going to be difficult. I would almost suggest going to the 5.5 or 6.5 novak. The 4.5 is a high kv, and it may be difficult to get a small enough pinion to physically fit.

Your motor mount link does not work, what does it look like? How does it position the motor?

The novak trays are less than 30 for the pair... One of Mike's trays costs more than that? Unless i am looking at the wrong thing....

Oops, I thought you were referring to the trays that were $125...

Thats is what I figured. Those trays are nice in the idea of them, but are way too heavy, place the batts too far out and are just a bit too bulky. And they are super expensive!

I would definately suggest Mike's trays to anyone using a larger lipo, as they are sturdy and will offer better protection. I would personally cut down an old emaxx chassis, as he only needs to fit 2s hardcase packs.

http://scriptasylum.com/forumpics/hyper8mount1.jpg



^^^
the motor mount


I want to run saddle, not for the balance, but because I think it will work the best with this mount, and I only have 2s lipos for now

enless someone wants to trade strait up, the motor is set in stone, because at $40 I couldn't say no...(yes it has the 5mm shaft)


if I don't go with the kyosho spur, I can have anywere from a 46t through a 52t on it, I think I have a 46 on it now...


I don't think it could be much heavyer, the H7 stock wights 8lbs

id still recomend a pair of trays from mike, they would be the easiest to mount will clear your mudguards and come with straps and all the hard you need.

I would buy a set of the rcm ones, but enless someone has a used pair that there willing to sell, I only have enough $$$ for the novak ones :(

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

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:surprised::great::yipi:
I have a slight problem though, I hit the 6.5v cutoff under "heavy"* accelaration:na::whistle:
* 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...":whip:

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.

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

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.

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...

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 :smile:) 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...

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:whistle: 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
http://i272.photobucket.com/albums/j...c/IMGP4656.jpg

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.

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??

4s on a 5000kv motor geared 46/9 will be running ~55mph. Way too fast for such a high kv. I can almost guarantee you are gonna have heat issues. With that high of a kv, I would go no higher than ~25mph, which is a 5T pinion (not available). You can run that motor, just don't expect it to last long, and your batteries and ESC are also going to be stressed.

Thats a neat motor mount, did you have it made?

You could run batteries in parrallel 2s2p - This might give you better gearing...

I like that, running a novak HV motor on LV (low voltage), funny. I still think a 6.5 novak would be a better choice...

And to get a 2s2p setup out of 2 2s lipos you would run them in parallel not series. Series would net 4s out of those packs.

hmm, that is a good idea, no need for a externeal bec ether...:neutral:

I'll give the 2s2p setup a try
mabey I'll stick to my 3300s untill I can get a diffrent motor, I don't think they could deliver the amps needed to creat a ton of heat

with a 13t pinion I should be just were I want it, but what about the torque?
would turning down the epa on my radio help???

any info on this motor???

http://www.rctech.net/forum/r-c-item...ver-raced.html

Not unless you get it for under $40 shipped - it is a feiago...

whats so bad about them??:neutral:

Well for that price you can get a new one almost - your money is much better spent on a relaible modern motor such as the medusa or a cc neu.

Medusas can be picked up around that price point and would be a better choice. If you want to get started they are a cheap alternative - just go cheap as you will end up replacing it.

what about the savage flux motor? there still made by CC, right? the seem to be foing for <$130 do they have mounting holes in the endcap, or do they have to be clamped?

http://cgi.ebay.com/Hpi-Savage-FLUX-...QQcmdZViewItem