Prop hub inserts

[Marty_d]

Hey all,

 

I want to mount the Bolly soon and looking at the hardware included - there are 6 bolts from hub to engine (drilled head M8x75), but no inserts for the prop flange.

 

So are those press fit things?  Where does one get them - are they a Bert Flood thing?

 

Thanks for any advice.

Cheers, Marty

[IBob]

They are........that or Aircraft Spruce.
And they are a very tight interference fit in the Rotax...I froze them, greased them lightly, then pulled them into place in the Rotax before mounting anything to them.
So sort out the required bolts and spacers to pull them all the way in before going to the freezer...)

Edited May 14 by IBob

[Marty_d]

On 14/05/2024 at 4:47 PM, IBob said:

They are........that or Aircraft Spruce.
And they are a very tight interference fit in the Rotax...I froze them, greased them lightly, then pulled them into place in the Rotax before mounting anything to them.
So sort out the required bolts and spacers to pull them all the way in before going to the freezer...)

Thanks Bob.  I bit the bullet and bought them from Bert Flood, and they're sitting in my freezer now.

I assume when you talk about pulling them into place with bolts and spacer, the spacer is a large socket or similar with the bolt and washer going through it, into the threaded insert on the back of the flange and tighten the bolt?

 

Also assuming it'd be wise to buy separate M8 bolts for this process and not use the ones that are going on the prop?

[Marty_d]

Ah - just found this advice which also meshes with yours.

"The manual states never to hit the prop shaft with a hammer (regardless of size or composition).  Correct procedure is to lightly coat the bores of the prop hub with anti-seize as well as the lugs themselves.  Using an M8x1.25 bolt (for the metric lugs 842634) and a deep 3/8 drive socket, draw the lugs into the hub by tightening the bolt.  This will get the lugs in 99% of the way.  Once the prop is installed and torqued to its specification, the lugs will seat themselves 100%.  "

[facthunter]

Also never use a rattlegun on anything with gears opposing it. Use a soft steel washer to protect the flange surface. Scratches are crack starters.  I see pictures of the engine being supported by the drive flange. I wouldn't do that either. Nev

[Marty_d]

Well, in the end they went in quite nicely.  I gave them an hour in the freezer, used a bit of WD40 and pulled them through with an M8 x 1.25 bolt.  No problem.

 

Thanks for your advice guys!