Ofna Hyper ST Conversion!
 

Hey guys, this is my first "big" brushless conversion. I am going to the LHS in about an hour to go put my deposit for my Hyper ST pro kit! They don't have it in stock at the moment, so I am going to put a deposit on it, and if I get there before noon, they can have it in by tomorrow! :yes:. My planned setup is the RCM mount and battery tray, Neu 1512 3D/F, MMM, and Protek 5s 4000 LiPo. Planned gearing will be somewhere around 52/16. Here is what I got when I calculated it.
Differential Ratio: 3.909090909090909
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 52
Pinion Tooth Count: 16
Total Voltage: 18.5
Motor KV: 1700
Tire Diameter (inches): 5.8
Tire Ballooning (inches): 0
Motor Current Draw: 70
Motor coil Ω: 0.012
Spur/Pinion Ratio: 3.25 : 1
Total Ratio: 12.70455 : 1
Tire Circumference (inches): 18.22 inches (462.82 mm)
Total Motor Speed: 30022 RPM
Vehicle Speed: 40.78 mph (65.5 km/h)
Estimated Adjusted Speed: 39 mph (62 km/h) - 5% loss
Effective KV Value: 1622.81
KT constant: 0.8 oz-in/A
Motor Torque: 0.29 ft-lbs
Final Torque: 3.68 ft-lbs
Final Power: 1295 watts (1.7 HP)
Hopefully the little 1512 will run cool in this truggy, because it is light. I still need to figure out what shock/differential oil I will buy. Any suggestions for a mostly bashing truck, and some track driving, (it will be on the one I am building, and it will have huge jumps!) You'll definitely see some huge air! I'll get some pictures tomorrow, of the box and building. I found a video showing the contents of the box, and apparently the differentials are pre-built, (a big plus for me because building diffs, IMO, is a pain.) I am going to try to keep this thing as light as possible with the battery probably all the way forward, the motor obviously behind the center differential, the ESC in front of the motor, (or maybe behind, depending on how much room I have because the MMM is big,) and the RX behind the battery (Airtronics 92836) using the XR3i I got from Lincpimp (thanks) and probably a Cirrus P-CS701BB that I have laying around to take care of steering. Only thing is, I don't know where to get a servo arm for it because the servo head is nearly 1/4" wide! Any ideas? The truck will most likely run on motor brakes, only because I don't want to deal with servo placement and such, and as I said before, trying to keep this thing as light as possible. Any thoughts on the project as a whole?

NICE start! why not gear it higher?

Where did you find your money tree? i have been looking for one :lol:

you might br able to use the stock throttle/brake servo if you chose to use manual brakes, just trim the servo tray

Somehow, stuff sold. Not quite sure how, but that was my first good luck in months. :yes: I really want great temps, and long runtimes, so I didn't gear it higher. Any thoughts on shock/differential oil?

The diff's are not prebuilt - The spider is but only with grease so you have to take it apart anyway... That was my fun last night...

I'll be using the same battery pack and same KV motor but with a 1515 2.5d / MMM. I'm using a HS5595TG for steering...

This is so wierd - I've never heard of this conversion. Then I get one and two more people sign up for them the next week!

Yeah, who else signed up? Are the differentials easy(ier) to build than other cars?

Finnster is getting one - They are actually a little harder...

There is no big seal just a small o-ring which was a little bit of a pain to get it to stay on... not a biggie though

The spider is a different animal - unlike a normal diff the body is in multiple parts with long screws holding everything together. You have to put some grease over the screw holes to stop the diff oil leaking out when you are building it... With the spider it is a little fiddly with 6 gears but with a little time it seemed to go togther ok.

I built the front end last night and it mesh seems a little tight in diff case but hope it will wear in.

Hyper ST officially deposited-- In by 1:30 tomorrow!! :party: :party:

I would go with a higher kv than 1700 on the 1512, shoot for 2400kv or so. That way you can gear it lower and spin the motor faster. That will help with the lower torque that the smaller motor will produce. The motor wil still run cool, as the neu motors are fine over 40k rpm, plus the lower gearing will help with amp draw.

Good advice- I'll go for the 1512 2d then, 2550kv, with a 10t pinion or a 2.5d, 2050kv, with a 13t pinion. Which one?

If you don't have the motor why wouldn't you go for a 1515...

I could, but I hear they're less "snappy." I could do a 1515- I probably will.

Well given how mike drove his 1515 2.5D in his 8T he had enough snap :)

Alright- which 1515 should I get?

well, a 1515 1y would be potent on 5s. Not sure if the protek lipos would keep up though...

Looks like the 1515 2d is the best bet.

1512 has more than enough torque to push a truggy. it is more powerfull than XL motor
it propels 13lbs maxx like it had a rocket engine while staying cool.

Maybe a Medusa 36-60-2000?

Good to know. What about the Medusa's?

What about this? Motor is a AXI 2826/8.
Differential Ratio: 3.909090909090909
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 52
Pinion Tooth Count: 21
Total Voltage: 18.5
Motor KV: 1130
Tire Diameter (inches): 6.6
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 2.48 : 1
Total Ratio: 9.67965 : 1
Tire Circumference (inches): 20.73 inches (526.66 mm)
Total Motor Speed: 20905 RPM
Vehicle Speed: 42.41 mph (68.12 km/h)
Estimated Adjusted Speed: 40 mph (64 km/h) - 6% loss
Effective KV Value: 1130
KT constant: 1.2 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

I read some things regarding the diffs, and I guess many didn't like the orings and had sealing problems. There are Kyosho gaskets tho that are a perfect fit and keep the diffs sealed.




I just got one too:yipi: but...... I screwed up the 10% coupon on ebay I had and didn't get it applied before I paid....:slap: <----me to myself.


i'm hoping he can cancel the sale so I can rebuy it. I was trying to hurry as my wife was giving my boy a bath and messed it up.....DOH!!!!!!!!

The Hyper ST is really common over here. I was wondering why there weren't any conversions. I'm going to be interested in how these conversions go as I may do one instead of a buggy but I would rather do a buggy.

Should be deccent, I would say that a 1512 would be slightly more powerful, but the medusa's have a great price. I have the 60mm 1500kv model in my hyper8 buggy and it does great.

Since I'm going with Masher tires, I'm going to use the 1515 2d instead of the 1512.

Ok guys, got my Hyper ST! I'm assembling the front upper arms, and what they call the 5x33mm turnbuckle I cannot find!! I found 2 of them, but they don't fit in the arms! The part number is 88079. Any help please!!

i have 2x hyper st 's

1x is 1512 2050kv with 14T pinion , MM , 4s temps perfect , great setup
other is 1515 2200kv mgm16018 with 13t pinion , 4s, again temps perfect great setup

both trucks run about the same speed (both with bowtie LPR ), the 1512 feels more punchy than the 1515 but i think that is due to the mgm poor programming ( as i dont have a usb com as yet )

im probly switching the mgm for another MM , as i think these are awesome esc's for 4s.

PS you will love the hyper st's ive had mine over a year and ran hours and hours on them and never broken or replaced 1 part !( but i think the centre diff needs a new bearing now)

Yep, I am very impressed with the quality of the kit, I'm trying to post pics but the f---ing USB hub doesn't recognize my card hookup. :grrrrrr:
Also, those rear upper a-arms are a bizznach and a half to build!

Have you considered direct drive?

:no:

think about it like this...

its one less Diff to build:rules::lol:

It's already built/installed. Curse my camera and these rear upper a-arms!!!!!

How do you install the front brace?

i bought my pro kits as pre built RTR and sold off the nitro gear and electrics. works out much cheaper. keep on building buddy !

I just finished building with the exception of gluing the tires, and installing the front brace, which just completely doesn't fit.

UPDATE-
Got the tires glued but still cannot get that f--- front brace to fit. My guess is that it's a faulty part. Also, decided exactly on my setup. Neu 1512 2.5D/F, MM Pro, 5s 4000 Protek LiPo, with 13/52 gearing. Calculated:
Differential Ratio: 3.909090909090909
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 52
Pinion Tooth Count: 13
Total Voltage: 18.5
Motor KV: 2050
Tire Diameter (inches): 5.7
Tire Ballooning (inches): 0
Motor Current Draw: 78
Motor coil Ω: 0.006
Spur/Pinion Ratio: 4 : 1
Total Ratio: 15.63636 : 1
Tire Circumference (inches): 17.91 inches (454.84 mm)
Total Motor Speed: 36965.6 RPM
Vehicle Speed: 40.09 mph (64.4 km/h)
Estimated Adjusted Speed: 38 mph (61 km/h) - 5% loss
Effective KV Value: 1998.14
KT constant: 0.66 oz-in/A
Motor Torque: 0.27 ft-lbs
Final Torque: 4.19 ft-lbs
Final Power: 1443 watts (1.9 HP)

very nice, have u looked at zippy lipos?

Yeah, I have 2 2s 5000 that I run in my E-maxx. They're okay, but I like the Protek packs better. Plus they're on sale for $83.

Mine is done too... Battery tray mounted last night, spur guard fab's and fitted, ESC mount made and elec's installed.

Pretty darn happy with the results to say the least... The steering articulation and speed with the 5955tg is scarey!

I have the MM in there now and probably won't risk 5s with that - I'll wait until my MMM gets back!

I should hopefully get a thread up with pics tonight or over the w/e.

Great. When I get home in a couple hours I'll give my camera reader one last shot, and hope it works. So to fit the mount on, you had to cut the CF radio tray, right? How hard was it to do that/what did you use? Is there any word on how long it would take for Mike to ship me a Hyper mount and make a custom sized battery tray for the Protek pack? My idea (since my receiver is so darn small) is to mount the RX upright on the front of the radio tray with the female plugs (CH 1,2,3) in the front, and then mount the MM Pro behind that so that I get the battery plug coming out the left side, and the motor wires coming out the right side. I'll also have the battery mounted about an inch behind the steering assembly. I'm also thinking of making a battery tray out of some relatively thin sheet metal with my dad's 90* angle bender, and then probably wrapping it in shrinkwrap or something for aesthetic reasons. Ideas?

what rx are you using?

Airtronics 92836.