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Spinner Cut out help

douglassmt

douglassmt

Well Known Member
So I was working on the spinner yesterday, trying to get a nice accurate cutout for the prop and trying to figure out how I'm supposed to know how much the prop will rotate as the pitch changes, when it's sitting on my bench not connected to anything. I did the best I could, trying not to overcut. Then I emailed Hartzell last night to ask if it's possible to somehow rotate the prop on the bench so I can make the cutout just right. Well, they email me back a template of the cutout for their prop that I can lay over the spinner and get it just right. They suggest a clearance of 0.100" instead of the 1/8" that Van's suggests. This is definitely one of those "wish I had known" or "wish Van's had included the template in the kit" moments. I can email anyone the template if they send me a PM or email. Thanks to Hartzell!
 
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I used their template when I cut mine; it worked out very well. I also followed the advice I was given to tape a couple of boards around the prop and use them for a lever to rotate the blades (prop mounted on engine) so I could check the clearance over the full range of travel.

I was able to use the pieces I cut out to make the fillers behind the blades.
 
I have the template, but found it to be a little short. I was also concerned about the tolerance variance. I thnk 1/8" gives us a little more wiggle room.

I wrapped a towel around each end of the prop, then clamped a couple 2x4s to each end. This gave enough leverage that two people can easily rotate the prop.

I haven't cut my spinner yet. That's a project scheduled for tomorrow evening.

I'm curious to how many people used the template as is, with out alterations.
 
Patrick -

Send me an email and I'll reply with the template. I don't know how to do it any other way.
 
rleffler said:
I have the template, but found it to be a little short. I was also concerned about the tolerance variance. I thnk 1/8" gives us a little more wiggle room.

I wrapped a towel around each end of the prop, then clamped a couple 2x4s to each end. This gave enough leverage that two people can easily rotate the prop.

I haven't cut my spinner yet. That's a project scheduled for tomorrow evening.

I'm curious to how many people used the template as is, with out alterations.
Click to expand...

Worth noting is that the template is a flat projection of what is really a 3-D surface.

But I ignored that, then cut the thing out so it made a "female" template (center plug cut out of paper template). Made alignment mark from tip to base, then carefully taped on. The resulting shape made for the straight lines on either side of the blade not being parallel. I ignored that, too, and in the end you can't see it.

I did find that the cutouts I made resulted in clearance at or less than .10" everywhere, so I increased it as I felt was needed. In the end I wound up with at least 1/8" all around, possibly more. I think it was Paul Dye that pointed out how much a prop can move, after discovering that a spinner had been rubbing on a constant speed prop. Better a little bit much than not enough.
 
Bob,

I used the template as is, without alteration. Worked out fine. It was surprising how little clearance is needed to avoid rubbing throughout the full range of motion of the prop. I only have 20 hrs on my -10, but if it hasn't rubbed yet, I don't think it is going to.

Jim Berry
RV-10
 
I cut the spinner last night. I used my original template, but I did compare it against the template. The template was shorter and more narrow than the template I made. I'm happy with my results.

bob

FP16022011A00016.jpg
 
Too much

Well, after a couple days out of town I finally got down to comparing my cutouts with the template. I decided I cut out too much, by roughly 1/8+ all around both sides (there is almost 1/4" gap all around, more in a couple places, less in others), and I am not comfortable trying to build up the over cut areas on such a high speed piece of fiberglass. Turns out the new dome is only $96 so one is on order. My mistake was cutting before thinking/researching a bit more. However, the way I look at it, I made a $100 mistake but learned a $1000 lesson. Pretty good deal! I'll use the template as a starting point on the new one. In fact, I'll probably rotate the messed up spinner and try the template on it before the new one gets here. I still wish Van's or Hartzell would include the template with the prop.
 
douglassmt said:
Well, after a couple days out of town I finally got down to comparing my cutouts with the template. I decided I cut out too much, by roughly 1/8+ all around both sides (there is almost 1/4" gap all around, more in a couple places, less in others), and I am not comfortable trying to build up the over cut areas on such a high speed piece of fiberglass. Turns out the new dome is only $96 so one is on order. My mistake was cutting before thinking/researching a bit more. However, the way I look at it, I made a $100 mistake but learned a $1000 lesson. Pretty good deal! I'll use the template as a starting point on the new one. In fact, I'll probably rotate the messed up spinner and try the template on it before the new one gets here. I still wish Van's or Hartzell would include the template with the prop.
Click to expand...

For what it's worth, the MT prop on my hangar partner's plane came with a spinner. It has at least 1/4" of clearance all around, he's been flying it that way for years without issue. Lots of factory spinners I've seen have that much gap. There are some on this board (Paul Dye, I think, among others) who have written that a gap that big is not a big deal. Aesthetically maybe, but not functionally.
 
Done

Got the replacement spinner, and I used the Hartzell template, the outside line with the 0.1" clearance and it turned out very nice. A little touch up after twisting the prop and I think it looks great. I can also use the original spinner dome to make the inserts for under the prop if I need to make them just right.
 
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