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Old Mar 31, 2014, 03:06 PM
Ochroma Lagopus Tekton
Fly Wheel's Avatar
Blackstock, South Carolina
Joined Sep 2007
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Rant
Folding props

I'm referring to the part the blades attach to that is fitted onto the motor shaft (or adapter):
I have been looking for over a week trying to find one of these stupid things that will fit the 5mm diameter threaded prop adapter on my outrunner motor, but so far all I have found* are those that have an 8mm hole which is way too big for a 5mm shaft.

Am I missing a page? Is there some "sold separately" thingamabob that I don't know and none of the retailers are telling me about that I am supposed to buy so I can fit a 5mm shaft into an 8mm hole? Any motor or prop adapter for a motor that would have an 8mm shaft would be HUGE. Folding props are used on virtually every electric sailplane built, most of which use motors similar to the one I have. Unless it is for a very large scale NONE OF THESE MOTORS would be anywhere near big enough to have an 8mm motor or prop adaptor shaft; they would be around 5-6mm.

So where are the (totally nonsensical word removed by mod order) yokes that fit them?!

WHAT THE (Word with no meaning removed per moderator order) IS GOING ON??



(*straight bore, not tapered as in one that uses a collet)
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Last edited by Fly Wheel; Apr 01, 2014 at 11:32 AM.
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Old Mar 31, 2014, 03:22 PM
Registered User
United States, NY, Kingston
Joined Feb 2006
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Usually there is an insert that adapts it down...but I think it was tapered .... sorry
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Old Mar 31, 2014, 03:41 PM
Don't take your guns to town
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Thousand Oaks, CA
Joined Mar 2004
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The first "frak" that's going on is that you're not reading the instructions. Read items A thru D at the top of this page. The 8mm piece you show is never to be used directly -- it's part of a kit that includes other parts to mount on whatever shaft size you have.

The second frak is that you are using some screwy motor. You won't find an easy way to mount a folding prop onto a threaded shaft. Hopefully the 5mm thing is just a removable adapter and your motor has some standard 3mm or 3.2mm smooth shaft underneath. If not, you'll have to make a bushing to step the diameter up to 8mm.
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Old Mar 31, 2014, 05:35 PM
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gquiring's Avatar
United States, SC, Summerville
Joined Jun 2001
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Quote:
Originally Posted by Fly Wheel View Post
I'm referring to the part the blades attach to that is fitted onto the motor shaft (or adapter):

I have been looking for over a week trying to find one of these stupid things that will fit the 5mm diameter threaded prop adapter on my outrunner motor, but so far all I have found* are those that have an 8mm hole which is way too big for a 5mm shaft.
Can you take a photo of your motor with the shaft so we can see it? I have a feeling you are using the wrong end. Most motors come with a prop adapter for a regular prop. When using a folding prop adapter you turn the motor around and use the shaft end. In some cases you may have to remove the c-clip to get the shaft to stick out. Without knowing the details on your motor it's hard to say.

I included a picture of one of my motors. The folding prop adapter goes on this 5mm shaft which is never threaded.
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Old Mar 31, 2014, 06:48 PM
Ochroma Lagopus Tekton
Fly Wheel's Avatar
Blackstock, South Carolina
Joined Sep 2007
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Quote:
Originally Posted by vespa View Post
The first "frak" that's going on is that you're not reading the instructions. Read items A thru D at the top of this page. The 8mm piece you show is never to be used directly -- it's part of a kit that includes other parts to mount on whatever shaft size you have.
OK, so where do I get these parts? Or is that something 'everyone is supposed to know'? Because I'm not ashamed to admit I don't. And I really would appreciate someone telling me, as none of the places selling them will.
Quote:
The second frak is that you are using some screwy motor. You won't find an easy way to mount a folding prop onto a threaded shaft. Hopefully the 5mm thing is just a removable adapter and your motor has some standard 3mm or 3.2mm smooth shaft underneath. If not, you'll have to make a bushing to step the diameter up to 8mm.
Well if you consider an AXi Gold Line motor to be screwy, I'll acccept that as your opinion. Unfortunately, even if they are meant to be taken apart to reverse the (4mm) shaft so it sticks out the rotating end I don't know how to do it. Do you? (again, I would appreciate you telling me)


motor shaft is on the left (wired) end, bolt on adapter on the right (spinning) end.

I want to mount the motor in front of the firewall, because whenever I have tried mounting it behind with the motor shaft sticking through the result is a weaker firewall, not enough of the shaft sticking through for the collet to clamp onto yet still give enough clearance for proper cooling and I really don't like the idea of trying to route the wires back across a motor housing that may be spinning at up to 12,000 RPM in a confined area. I think this may be one reason why AXi offers the bolt on mount in the first place.
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Last edited by Fly Wheel; Mar 31, 2014 at 07:12 PM. Reason: added picture
Old Mar 31, 2014, 07:04 PM
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gquiring's Avatar
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The folding prop adapter goes on the left end. Remove the silver aluminum stuff off the right end. There should be 4 screw holes on the left end to mount to a firewall.
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Old Mar 31, 2014, 07:12 PM
Don't take your guns to town
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Thousand Oaks, CA
Joined Mar 2004
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Fly, the link I posted had the "prop shaft adapter" needed for a standard installation. You have about 3 options:

- Remove the threaded aluminum adapter and mount the motor/firewall the other way around such that the 3.2mm(?) smooth shaft is in the front. Buy a 3.2mm adapter for your yoke. This is the most common configuration for composite fuselages because it puts the firewall and front motor bearing very close to the propeller for good strength.

- Remove the threaded aluminum adapter and mount the motor the same way you had it, but loosen the set screw that secures the 3.2mm shaft to the rotating housing and turn it around such that it sticks out the other end. Buy a 3.2mm adapter for your yoke. This method works well with wood or foam fuselages. Your motor shaft may have flats or clip grooves that make this option work poorly, in that case you may need to buy a replacement shaft designed for the other mounting style.

- Make a bushing so that your yoke will fit the 5mm adapter already on your motor.
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Old Apr 01, 2014, 07:09 AM
Registered User
Romania, Dolj, Craiova
Joined Sep 2007
14,952 Posts
Or use this special yoke, designed to fit on 5mm ! round ! shafts, using on yours will probably destroy the thread, but will work, though.

http://www.espritmodel.com/folding-p...ree-twist.aspx
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Old Apr 01, 2014, 08:01 AM
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Here is a place I've bought replacement shafts...Head's Up RC
http://www.headsuphobby.com/main.sc
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Old Apr 01, 2014, 11:32 AM
Ochroma Lagopus Tekton
Fly Wheel's Avatar
Blackstock, South Carolina
Joined Sep 2007
1,829 Posts
I think I'm going to go with the bushing/sleeve idea. it seems the easiest way, and the plastic APC props do come with such a bushing. The hole is 5mm (I know because I use one on my Miss Stik) and I measured the prop hole and serendipitously enough, it is 8mm. So I'll buy a cheap APC, use the bushing in the folder yoke and find some use for the straight prop.

Thanks. and I apologize for my temper.
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