Stage II electric conversion with a Scorpion 4035-400

[pappypower]

Been really busy lately, but I thought I'd update everyone about the Stage II conversion if you are using a Scorpion 4035 motor. As I mentioned in another post, it now uses M4 bolts, not M3. The really weird thing is that the box that the motor came in had M3 bolts, not M4... Apparently even Scorpion doesn't know that they "upgraded."

Since JB's Stage II kit was designed for M3 bolts, naturally the spacer won't fit without significant adaptation. He assured me that I would be able to enlarge the bolt holes on the spacer, but it looked iffy to me. I didn't want to use a Dremel, I didn't think that would be accurate enough to cut evenly. I tried to use a drill bit mounted in a drill press and sort of grind the opening larger, but that didn't work either. Finally JB kindly offered to let me exchange the Stage II kit for a Stage I, even though the spacer was chewed up and really couldn't be used anymore with 3mm bolts anymore. That made me think "I have nothing to lose, why don't I try using a Dremel bit in a drill press. If it breaks like I think it will, I can return it anyway."

I ran the Dremel bit (a straight bit, I'll add a picture of it later) in the drill press. The bit was a generic knock-off, just under 1/4". I held the spacing ring against the bit and ran the motor at medium speed and ran the bit up and down the inside of the spacing ring. You can see the results, it even looks pretty! "Use the proper tool for the job..."

Drilling out the motor mounting plate is easy. A 5/32 drill bit makes a nice snug hole for an M4 bolt.

I bought some 4mm x 20mm screws from the local big box store, but the heads didn't allow for clearance for the motor. I tried grinding the heads down, but that didn't work either. So I got the screws seen in the picture and chamfered the holes in the mounting plate. They work perfectly!

This sounds like a really difficult job, but once I got the right bit in the drill press, it went quickly and smoothly. I pressed the spacer ring into the bit while the drill press was running, which is kinda dangerous. If you don't want to offer pieces of your fingers to the drill bit gods, drill a hole into a 2x4 slightly larger than the spacer ring and place the ring into the hole and then push the ring into the bit.

If this isn't clear, I could take the assembly apart, but I really don't want to do that
Let me know if you guys have any questions.

[forvols]

Glad you were bale to make a go of it there Pappypower! I've got my new tail boom installed and new aileron servo (Futaba S9252) at the ready. Gonna go over the entire set up again after I receive a new main shaft. I've ordered the shaft along with a few tail pieces to have on hand as spares. Should have ordered a couple of std P50 booms as I no longer have any spare booms for my Nitro in the event of a crash there. Grrrrr... need to keep better track of inventory on hand.

Anyway, I expect JB will have my parts headed out the door as efficiently as usual and I should be back in business with the P7e for a "re-maiden" soon enough. Meanwhile, I'll be tearing down my P50 tomorrow afternoon to install a new ring. That should have me all set for the P50 and ready for another 3 years of flying the OS 50 Hyper. .

Glad you got your mounting issue sorted out. You should be getting close to having the Pantera airborne very soon! Please keep us posted and get some pictures up!

[pappypower]

Forvols, for some reason, I couldn't post pictures today, I'll have to figure out why. I'll post some when I am able.

The Stage II was easier than I thought it would be, once I figured out how to set the spacer ring in order. It's a testament to JB's design that, once put together, it fits perfectly, no fiddling with adjustments for me. Of course, I have the Pantera, maybe it's harder with previous designs.

When I talked to John on the phone, he expected that I'd one day want to convert the Pantera to a 700 class bird because I'd gotten the 4035. I don't have any plans for that yet. I could have gotten the 4025 motor which still have the M3 bolts, but I had the more powerful motor and didn't want to give it up.

[pappypower]

Now I'm able to upload the pictures, maybe I was trying to up load too many at once? Anyway, there they are.

You can see how much material was taken off the ring, but it still works fine. Just don't grip it too hard in your hands or it will go out of round!

The bit is generic, it's just less than 1/4". Works great!

[forvols]

That's very strange Pappypower. I've installed a 4035-400kv Scorpion motor in my P7e and did not have this issue. the supplied mounting screws worked fine. Due to circumstances surrounding my particular installation, I did wind up replacing the standard m3 screws with bevel headed equivalents and did a metric counter sink of bolt holes in the mounting plate. Still the same size (M3) bolts, but different heads.

You really had to remove a LOT of material in your adapter ring there! Looks like it turned out great though. Nice job dude!!!

[rfauske]

He has the new HK III with 4mm bolts, had to do the same with mine aswell.

[pappypower]

Thanks, forvols, I'm kinda proud of how it looks too!

Rfauske is exactly right, it's the new motor. Probably makes sense, a 4mm bolt is much stronger than 3mm for a more powerful motor, but then you do have to make adjustments for that if you get the Stage II. It's not that hard if you do it the right way, so no one should shy away from the Stage II if they want to get the 4035. The 4025 motor, of course, still uses 3mm bolts, so no cutting away of the spacer ring would be needed for that motor.

I can't wait to get this bird up in the air!

[forvols]

Ahhh.. didn't realize the newer version utilized larger bolts. Good info to have posted here regarding how you were able to resolve the issue.

I don't know what JB's inventory levels are like now, but when I purchased my 4035-400kv motor (not the newest version) the price was as good as anywhere else at the time. JB may be the "hot spot" for a 4035-400kv motor that won't require any modifications to the conversion kit.

[pappypower]

I got my motor from Audacity, and it's still the same price as everywhere else. Unless JB has some "old" motors in stock, though, if you want a 4035-400kv motor, it's going to use M4 bolts. Like I said, that shouldn't keep anyone who wants a Stage II from getting it, because with the right tool, it wasn't that hard to do.