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Spinner fit to prop cutout ?

B

BillSchlatterer

Well Known Member
Sponsor
Just mounted the prop - Hartzell BA and now need to fit the spinner. 7a with o-360. It has not been run yet so there has never been any oil circulating from the engine to the prop.


  • Is there any problem twisting the prop from coarse to fine pitch by hand to fit the prop relief in the spinner cutout?
  • Any way to damage the prop?
  • Any way to make it easier?
  • How much effort would be "normally" required to twist it from coarse to fine?
Help appreciated!

Thanks Bill S
7a sorta finishing ;-)
 
Rope two broomsticks or similar with prop blade between to move it. Protect the blade with foam rubber or similar. Only damage would be from scratching the prop so protect well.
 
I used a couple of 3' 2x4s" and clamped them to the prop. With a couple feet of leverage, it still takes a little effort. Not too bad though, but it will tend to spring back.
 
Hartzell template

Bill, check you e-mail. I just sent you a template pdf that I got from Hartzell for a B/A prop.
 
I also used a couple of 3 ft 2x4s but I covered them with carpet first. Then clamped them to prop (carpet side to prop of course). Turning the prop shouldn't damage it. It worked for me.

Chris
 
Hartzell will send the template

I have forwarded the template to a few people but since this is Hartzell intellectual capital I should not really be distributing it. Hartzell support responded to my request for the template in less then a day.
 
Rick_A said:
I have forwarded the template to a few people but since this is Hartzell intellectual capital I should not really be distributing it. Hartzell support responded to my request for the template in less then a day.
Click to expand...

I'll give Hartzell support a shout.

Thanks, Bill
 
Is there another template??

I shared the template that Hartzell sent me with a few people and now I'm finally getting around to cutting the spinner myself.

The template I used just barely gave me enough clearance to get the spinner over the prop - no clearance for when the pitch is changed.

The template I used is labeled for "C2YR/7496 & 7497" . My prop is a C2YR-1BFP/F7497.

Does have a template for the -1BFP prop?
 
I've only ever seen the one template Rick, and that was one that Hartzell sent us when we had a clearance problem on one of our props. I must admit that I didn't use it, because we just put the spinner back on, measured the clearances on two other RV's, and then scribed a clearance line about 3/8"-1/4" from the blades.

I'm not sure of I'd trust ANY template over actual clearances on a specific spinner to be honest - too many chances of getting the wrong dimensions with print size variations, etc. I recall that the toughest thing about cutting the spinner was getting the holes big enough to get it over the prop the first time (without cutting away to much!) - once it was on, doing the final clearance cuts as a "custom" job was pretty easy. So I guess I'd use the template for that first rough cut, then fine tune from there. At least that was my experience.

Paul
 
Paul, I've got the spinner over the blades so I guess the template helped with the big cut out.

When you scribed the clearance line, did you do both a fine pitch and a course pitch line?
 
Rick_A said:
When you scribed the clearance line, did you do both a fine pitch and a course pitch line?
Click to expand...

I actually did it sort of incrementally Rick - mark it for the prop as it sits, then move it to the other stop and mark it again, and then make a nice "blended" average of the two.

Paul
 
Rick_A said:
Paul, I've got the spinner over the blades so I guess the template helped with the big cut out.

When you scribed the clearance line, did you do both a fine pitch and a course pitch line?
Click to expand...

Rick, I used the Hartzell template but it was not accurate at all. I recommend that builders DO NOT rely on it.
 
Using the Hartzell spinner cutout template?

I've read the mixed reports on using the Hartzell template but, like Rick in this thread, I'm thinking it ought to help with atleast the initial cut, if only I can workout the best way to use it.

I have the Hartzell spinner cutout template for my 7497 prop. I've made up the spinner rear bulkhead and used the template to make a cardboard cutout on the zero-clearance line. Holding the cardboard cutout over the prop with the edge against the rear edge of the rear bulkhead (i.e. cardboard forms part of a cylindrical shape coaxial with the prop hub & rear bulkhead) gives a good zero-clearance fit relative to the prop

But how have folks found the best way to translate the 2D cutout template to the 3D rounded cone shape of the spinner?

E.g. in the template the two side cuts are parallel and at 90 degrees to the rear edge of the spnner. However, on the spinner itself lines at 90 degrees to the rear edge of the spinner will not be parallel as they will all point to the apex of the cone.

Thanks in advance for any advice,
Steve

p.s. As a tip for finding the two reference points on the spinner to locate the cutouts, I found the rivet pattern on the rear spinner bulkhead made that pretty easy.
 
How about this for customer service?
I received an email direct from Hartzell in response to my previous post.

The key to using the template is the blade centreline......
- Print the template, ensuring the scale is correct
- Cut out the template from the printout using the zero-clearance shape.
- Mark the blade centre lines on the spinner (I used the rivet pattern on the rear bulkhead to identify the 180 degree spacing)
- Lay the template on the spinner, aligning the blade centre line you marked on the spinner (which you can see through the paper) with the template blade CL and hold/clamp in place
- Mark the outline of the template on the spinner
- Cut and file the cutout
- Repeat for the second cutout
- Now trial fit spinner to the prop/spinner rear bulkhead and fine tune the hole shape
- Take a cautious approach, keeping the cutout hole size to the minimum until after you've finally located both bulkheads to the spinner.
- Best to get the rear bulkhead finalised first then the front bulkhead
- The template assumes that only the spacer is fitted between the prop hub and the rear bulkhead. If you add any washers to the spacer then you will need to take account of this in the cut-out.
- Take care to check whether the back edge of the spinner is "true". The rear bulkhead, centred on a small turntable, can be used with a plumb bob to confirm the correct placement of the rear bulkhead within the spinner.
- If your spinner is like mine, the rear bulkhead will fit inside the spinner leaving approx. 1/8th inch of the spinner projecting behind it.
- Note that the point on the template where the Blade CL crosses the "Bottom Edge of Spinner Dome" reference line needs to align with with the back edge of the rear bulkhead flange. This is obviously rather tricky as, when you are first positioning the template on the spinner, you don't know exactly where the back edge of the flange will end up. I'm going to use the actual back edge of the spinner in the first instance and extend the shape after trial fitting.
- When finalising the front front bulkhead position you may need to use washers under the bulkhead to move it forward or else build up the inside of the spinner with fibreglass to meet the bulkhead.
- Once all is said and done, make sure there is no chance of the blade touching the spinner. You don't want any marks or damage on the root of the blade. There are posting elsewhere on VAF talking about methods of exercising the propeller pitch mechanism

One further note. If/when the propeller is serviced, it may slightly affect the location of the front bulkhead screwholes, which might need to be ovalled out sideways a bit.

I hope this is helpful to others. I know it has helped me. I cannot praise Hartzell highly enough for their responsiveness and customer service ethic.
 
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