Converting a GST 7.7 to brushless. Help?

I'm going to run it with a 1527/1y 1250kv Neu motor. And btw, I can't remove any of the gears in the tranny. Atleast not the 2nd gear, it's attached to the centrifugal clutch house by bearing (The things I pointed at in the pic.)

Well,looks like you'll probably be running it until the tranny blows,or do what I would do and make a center diff mount or email mike to see if he can help you out to see if he can rework an existing mount or custom make a mount for you.--Josh

The center diff in the GST is really hard to turn around for some reason? Weird.

And, I've asked Mike for mount and center diff mount. He said he needed the car, and since I live in Norway, that's way too expensive to ship all the way to the US. I've asked some other companies though and waiting for answers.

How exactly do I use mechanical brakes on a brushless setup? Like, where do I plug in the servo? Do I use a Y harness wire, and plug both the brake servo and the ESC in there?

[lincpimp]

Originally Posted by Dj_Sparky

How exactly do I use mechanical brakes on a brushless setup? Like, where do I plug in the servo? Do I use a Y harness wire, and plug both the brake servo and the ESC in there?

Starting with this question, and will get to your gearing questions soon!

You can use a y servo harness, to spilt your throttle channel to the esc and the brake servo. However the brake servo will move with the throttle and unless you have a really fast servo (like a jr9100s) you will notice a lag in braking when going from full throttle to full brake. Not a huge deal but it will take some getting used to if you currently run a brushless setup with the motor doing the braking.

I would say that having a radio that can mix the 3rd channel with the throttle channel is much better. I have run both and the mixed setup feels alot better, and gives you alot more control over the brake servo. I had mine set so it did not move when the throttle was moved in the positive direction, and only moved when I moved the throttle backwards to brake. Depending on the radio you use (I had a futaba and the guy who wrote the manual was on heavy drugs!) it may be a big pain but is worth it.

[lincpimp]

Originally Posted by Dj_Sparky

From what I can understand by looking at the Revo locking guide, I have to simply remove this:



And just LEAVE this be, since the centrifugal clutch is already attached to the gear, which I assume is the SECOND gear?

Ok, you are correct. The second pic you have an arrow pointed to the centrifugal clutch that will need to be locked to the shaft. Various ways to do with, drilling a hole in the shaft and using a hardened pin is likely the best, but it most likely works like the revo clutch does so something like what people do to lock the revo would likely work.

You also need to figure out some method of of removing the external spur gears, and replacing them with a single spur, and a slipper clutch.

I would use a new emaxx transmission input shaft, as it is long. Not sure if it is the same diameter as the input shaft on the gst tranny, hopefully it is so you can use the same bearings. This will give you the correct end to mount the revo slipper components to. Inside the tranny you will need to cut the emaxx shaft to length, and attach the small gear that works with your now locked second gear. Remove all of the reverse gears as well.

Since you are using mech brakes, go into the casle link programming, set the reverse for 0%, brakes for 0%, and the completely flatten the brake curve. You may also be able to set the MMM for forward only, but I am not sure if that option still exists.

You can also set your radio to not give any negative throttle if you plan to mix the throttle channel and 3rd channel for brakes.

Not sure if that makes sense, but that ius how I would do it. Having the gear reduction of a transmission is very important for a heavy vehicle. It will allow your motor to work in the correct rpm range.

The 1717 should work very well, I have a heavy lst running the 1717 with a MMM on 6s lipo geared for 45 and it does not get the motor or esc over 130f. Batteries stay cool as well, zippy flightmax 5000mah 40c.

Ok, thank you very much. I only need to tighten the screws in the centrifugal clutch to make it spin with the shaft, but I can't remove the first gear on the same shaft -- it's attached by bearing to the 2nd gear or something like that.

I will try to get an Emaxx input shaft, that does sound like the best option for slipper.

I ended up buying the 1527/1y (1250 kv.) neu motor btw.

[lincpimp]

1527 is a beast, what esc and lipo do you plan to run?

The 1st gear you refer to is attached to a one way bearing. You should be able to slide that gear off after you remove the 2nd gear and clutch. If you allow those 4 gears to mesh after you lock the 2nd gear clutch they will not turn.

If you cannot remove the 1st gear, do not worry, just do not instal the smaller gear that drives it when you replace the input shaft for the emaxx shaft.

I plan to use Mamba Monster with 6s lipo. Low gearing of course.

Anyhow...

Both the 2 gear on the input shaft and 2 gear on the middle shaft are locked together. The gears on the input shaft are 1 solid unit. :S

[tashpop]

well i get to make this journey with you. i was really wanting to find a gsr, but i haven't found any rollers come up on ebay so i scored at gst roller yesturday. i really don't know which route i'm going to go for esc's i have right now are a hobbywing 12s 100a or a mgm22418. decisions decisions? i can't wait for this thing to arrive, i've never seen one of these trucks in person.

[lincpimp]

Originally Posted by Dj_Sparky

I plan to use Mamba Monster with 6s lipo. Low gearing of course.

Anyhow...

Both the 2 gear on the input shaft and 2 gear on the middle shaft are locked together. The gears on the input shaft are 1 solid unit. :S

The 2 gears on the input shaft are likely one solid piece. The other two gears have to be seperate, as they rotate at different speeds. The non clutch gear is supported by a one way bearing, and the clutch hold the other gear in place. They will be removable, somehow.

They are seperate, but the first gear (On the middle shaft.) is attached to the centrifugal clutch by a one way bearing. The 2nd gear is a part of the centrifugal clutch housing - The one I pointed to in the pic you posted.

[lincpimp]

You should be able to remove the 1st gear by seperating it from the one way bearing.

[tashpop]

do you guys know what bodies will fit these trucks? i have no real problem using a cen body, but i think i would prefer something else. i need to start gathering parts so i'm window shopping until mine arrives. thank you

Ok, thanks again linc.

How do you plan to convert it Tash?