Quick Tip - How to Straighten a Bent Prop, Main Gear or Brushless Motor Shaft.

For reasons I still can't figure out I ended up with a bent Main Gear Shaft on my new Dromida Vista FPV... and no, I didn't crash it. I didn't even come close to a crash with it. But none the less, I discovered a main gear shaft was bent. They are soft and bend easily from what I understand. I would have upgraded them but at this point I can't find a suitable hardened alternative for them.

Okay, so it's bent, easy to replace, and inexpensive enough, so just run up to the local hobby shop pick up a set and replace it right? Wrong. All my local Hobby Shops were out and one hobby shop informed me they had been back ordered for a few weeks now. And it might be a couple weeks before they came in or so they thought. WHAT! I just got it and finished making some mods and tweaking it out. I'm not going to fly it with a bent shaft! So I set out to see how to fix it and scoured the web to find out if and how it could be done.

There's a few methods on the web showing a couple methods on how to straighten out a bent Prop or Main Gear or Brushless Motor Shaft on your Multirotor or Heli or what have you. Like me you may have taken a look at them. Some involve pliers or drills or hammers and vises. I know because I looked at most of them.

I don't have a vise though I have a small hammer. I don't have chunks of steel or metal lying around or a drill press, I don't want to take vise grips or pliers and mar the shaft up. So how to straighten it?

Well I'll tell you how. Or at least how I straightened mine.

A few weeks back Dremel had a sale going on for the Pine Derby Days with a display of all the Revell Pine Derby parts and accessories. Of course I looked it all over. Added stock to my brain filing cabinet. And one of those things added was a Revell Pine Derby Axle Straightener.

And I looked at my Main Gear Shaft which are the same as seen below...

And looked at the Pine Derby Car Axles that come in their wheel and axle kit...

And thought, "those Pine Derby Car axles are about the same size as my Main Gear Shaft... Hmmmm... I wonder...? And the gears in my head started turning. So I ran out and picked up the Revel Pine Derby Axle Straightener as seen below.

I followed the same directions, (kinda), on the back of the package to straighten out axles which you can download a pdf of HERE. You simply put it in the axle straightener along the groove and tap it, turn it, tap it, etc. You get the picture. And you know what? It worked!

Now I will give you a tip before you try it on yours that I discovered doing mine. If your prop shafts or main gear shafts are from a Vista or Ominus or any other UAV that the metal is considered "soft" and not hardened. Or has a key way cut in the shaft. Do just like it states in the instructions. TAP it wth the hammer. Don't hit it like your driving a nail in. More like your just starting a nail. A few taps. Not too lightly that you don't straighten the shaft, but not so hard that you crush or mar the shaft with the groove in the straightener.

You have to find the sweet spot of how hard to hammer it. And just keep turning it 45 degrees and tap it again a few times till you've gone full circle. And it should be straight. If not, do it again till it is.

If you happen to hit it too hard and mar the shaft, take a little sand paper or jewelers file (the small files or even a nail file should do) and take the burs off. Not too much, just lightly smooth it out.

No guarantees but from what I saw of the videos on the other ways to straighten out a bent prop shaft or main gear shaft, this way is much easier than pulling out a drill or drill press or vise and beating or bending it in hopes you straightened it out.

And be fore warned that the Revell Axel Straightener isn't exactly inexpensive at some places (like Micheals), over priced is more like it. Go to Walmart - they have them for under $12 and I'm sure even less elsewhere.

Your prop or main gear or brushless motor shafts may not come out "perfect", but at least if you can't get another set right away, you can fly with the repaired one till you can if you take your time and do it right. Or just wait for the new ones to arrive in the mail.
As for me, I'm going flying tomorrow!

Dromida Vista FPV

Repaired and ready to fly

Hope this helps,

Till next time...

Keep those props turning.

- chase -