Spinner lip?

[Paul Taylor]

I'm just curious if this lip on the spinner is really serving a purpose other than making sure the spinner is lined up as you screw it down?
I'm making one and I put on the model but if it's not needed I would like to delete it.
I will have to post a few pictures below for reference. Sorry for the multiple post but TapTalk only allows one photo per post.

[Paul Taylor]

Backplate

[Paul Taylor]

My model.

[Paul Taylor]

Finished product

[Michael LeGate]

The F/F folding blade setups don't look like they have a backplate at all. I've had older Williams Bros spinners deform at high rpms with the skirt unsupported at the crank end. A large stunt prop at moderate rpms might be ok.

[Mark wood]

Is the reason you ask because of the less than perfect fit to the spinner backplate due to a small radius in the corner of the lip overhang? Are you using support of any kind there while printing? Unsupported overhangs are hard to make nice parts without using support material. For PETG the best is PVA. My perspective is that it looks pretty good to me for a 3D print.

I would be concerned about the centrifugal loads on the spinner without the lip. The unsupported rim places more shear on the layers. The inter layer strength is much lower than the in path strength. I always design 3D parts such that the printing path and load path are the same. Or at least I try to.

If you have a lathe, I would simply use a cutoff or square profiling tool to postprocess the lip and square the corner a bit. You could 2D print a holding fixture so you could chuck onto it with the lathe and then turn the corner nicely. PETG actually machines fairly nicely. I make all kinds of tools and fixtures for parts I am machining.

[Paul Taylor]

Thanks Mark
It started with a Spinner file I got from Page. It's a 3 blade "Igor" spinner that has a trench in the bottom and then a ring it printed to fit the trench creating the lip. It was said it fits Igor back plates. I have not seen it. The backplate I have has a spinner with the lip. I can print it in the part the take a small sanding stick and clean the tree droppings off. It's a bit of a pain so was asking if it really serves a purpose. Sounds like the answer is yes.

[Mark wood]

Thanks Mark
It started with a Spinner file I got from Page. It's a 3 blade "Igor" spinner that has a trench in the bottom and then a ring it printed to fit the trench creating the lip. It was said it fits Igor back plates. I have not seen it. The backplate I have has a spinner with the lip. I can print it in the part the take a small sanding stick and clean the tree droppings off. It's a bit of a pain so was asking if it really serves a purpose. Sounds like the answer is yes.

I think the answer is yes. I could be wrong but the cost of a failure could be quite high. Shedding a peace of the spinner could hit a blade and cause some significant vibration. Or you could get lucky and it just shakes some. Or maybe it works and you just have that nagging doubt that hangs in the back of your head.

Igor's approach is solid. Me I'm a bit on the lazy side and just pay Lucien $7 for an airflow spinner. I save my design and printer work for things I can't buy cheaply or at all.

[Howard Rush]

I make spinners for Igor props. I use Great Planes or Gemfan backplates. I print the spinners from ABS flat on the base with a groove for the aforementioned ring. Maybe that's the file you got from Page.

I'd worry about the stability of a long spinner. Be sure to be at the other end of the lines when the motor starts.

[Paul Taylor]

Not sure why the spinner looks so long. It's not much taller than a DuBro. I'll add the ring.

[Paul Walker]

I like your spinners shape.
How much does your printed cone,  backplate  and screws weigh?

What is the backplate diameter?

Thanks

[Brett Buck]

I make spinners for Igor props. I use Great Planes or Gemfan backplates. I print the spinners from ABS flat on the base with a groove for the aforementioned ring. Maybe that's the file you got from Page.

I'd worry about the stability of a long spinner. Be sure to be at the other end of the lines when the motor starts.

  Exactly if you don't support it at the rear, it is just hanging from the spinner nut. I would think it would be very prone to whipping around at the rear.

   Brett

[Page Peterson]

Paul, my 1.5" spinner used a Bad Ass 1.5" spinner backplate. The spinner fit Igor 3 blade props. Page

[Howard Rush]

Sorry for taking credit for your spinner, Page. Cool you can fit that prop in 1.5". 

I think the BadAss backplates are same as Gemfan.

[Howard Rush]

Paul T., What's the groovy red stuff from which you made the spinner?

[Paul Taylor]

The spinner is held on with 2 M3x10 screws. The original spinner had aluminum M3 screws. I will get some. I made the slots for the prop over size for the APC so it would fit a Wooden BA prop. Going to try one on the plane.

The material is Silk PLA. From a few feet away the spinner looks like it's anodized aluminum.

@Paul W- I will get a weight when I get home from the flying field today.

[Paul Taylor]

The spinner weighs 8g, the backplate is 7g.

[Paul Taylor]

Exactly if you don't support it at the rear, it is just hanging from the spinner nut. I would think it would be very prone to whipping around at the rear.

   Brett

Two 3M screws hold it down at the rear. And a small lip around the brim.

[Paul Taylor]

I like your spinners shape.
How much does your printed cone,  backplate  and screws weigh?

What is the backplate diameter?

Thanks

The Cone is 8g the Backplate is 7 grams and my scale show the screws at 0g.
The backplate diameter is 1.25 in. Cone is 2 in tall.

[Paul Walker]

The Cone is 8g the Backplate is 7 grams and my scale show the screws at 0g.
The backplate diameter is 1.25 in. Cone is 2 in tall.

Thanks. Nice and light!

[realSteveSmith]

...my scale show the screws at 0g...

Where can I buy these?  I bet they're expensive.

[Paul Taylor]

Where can I buy these?  I bet they're expensive.

The scale was a gift but I think it's rude if I ask how much it cost. 🤣

[Page Peterson]

Howard, I based my little one off your idea for the backplate and the ring to join them.  Thanks! It worked very well. Page

[realSteveSmith]

...my scale show the screws at 0g...

Where can I buy these?  I bet they're expensive.

The scale was a gift but I think it's rude if I ask how much it cost. 🤣

I was more interested in the weightless screws than the magic scale. 

[Paul Taylor]

I was more interested in the weightless screws than the magic scale. 

I know. I was playing along. 🤣