Help: Rotol experts please

Hi Elliott,

Thanks for the reply and the PM (pls see my PM reply).

The story of the hub is slowly evolving. I was able to acquire the Rotol series 4 and 5 maintenance manual for internal cylinder props. This is very useful, but lacks the detail I seek. I also have RX manuals, but the later external cylinder props are quite different and share little in common. If there are any other R series manuals, I would be interested to know of them.

I have not visited the FAAM, although I did email someone there without reply. I shall call next week.

My intention is to dismantle the hub and assess whether the hub can be the basis of an safe and accurate rebuild for ground running. I would like to know the profile for the 191/A blades as part of this assessment.

I appreciate any information you and other Rotol experts can assist with.

Regards,

DAI

Hello Dai

I’m sorry for the delay. I have had a look through my manuals – I can add that the spinner for the Fulmar I is the ES/3.

I don’t have any blade profiles i’m afraid but I have PM’d you contact details for where you might find some drawings. When you first contacted me you asked about manuals, which I do have, but you seem to have efficiently gotten copies of these already!

My blades are the wooden DB1140 type which actually fit a later hub (RS5/26) with the external cylinder. The RA4042 blades which fit the R5/2 hub are metal, unfortunately I don’t have any good examples of these but there are some on display in an aviation museum although I don’t think they would have too much in common with your DB191/A blades.

Have you contacted the FAAM? They have a Fulmar and may well have some early blades in store.

Out of curiosity, what is your intention? Are you planning on making new blades?

Good luck
Elliott

Hi Dave,

I do not have any tools for the R5/3 hub. From what I understand, Rotol tools are not that common between hub types, as the diameter of the blade roots vary.

However in recent days I have compiled some engineering drawings of the hub for some tools to be fabricated.

The hub will need to be held very solidly before the blade nuts can be loosened, as something in the order of 10,000 lbs/ft of torque will be required to crack them loose!

DAI

Rotol hubs

Hi DAI,

That hub looks to be in excellent condition. I’ve got a Rotol hub from a MkI Hurricane, in not so good condition! I would be interested to know if you have any of the special tools for dismantling these hubs.

Cheers,
Dave

Hi Peter,

The last information I have uncovered is that the blades are DB191A (Weybridge) blades with the 166mm root giving a diameter of 11ft 6in and weighing (with adaptor) 46lbs. The whole prop weighed 305 lbs (approx). Its GA was drawing RA1571. It was controlled by a GR/2 governor.

I do not have a good photo of the Fulmar MkI blades, but the photo below is apparently of a MkI with a later hub (RX5/9 ?). The blades may be similar to the 191/A.

I am still hoping to hear from Elliot (whitley_project) on DB191/A profile info, as his blades are also for an early R5 hub.

Cheers,

DAI

David

Looking at photos, is it possible to tell if the blades are broad Hurricane type or Spitfire-like or something else? The profile may be optimised for the fact that the Fulmar is specifically a low altitude aircraft.
Also, do you know the diameter, and does this match any other type?

Pete

Hi Dai

Give me a few days and I’ll sort some scans out for you.

Cheers
Elliott

Hi Elliott,

Have you had any luck locating info on these blades?

In recent days I have been told that the blade profiles are also defined on a Rotol drawing: GA1571, but have not located a source.

Thanks,

David

Hi Peter,

Yes, the plated finish exists over all of the rear half of the hub and some of the front.

I have been cleaning off the remaining mild corrosion and removing some ground-in dirt in come areas. I have been able to ‘peek’ inside by removing the six set screws that would be used for mounting the front hub cap; looks promising inside!

If I could locate the two pipe connectors for the rotating collar, then I would force oil into the mechanism and determine whether I could rotate the collar 😉

DAI

Hi David

Is that the original plated finish that we can see? Looks quite good.

Pete

Hi Elliott,

Many thanks for any info on these blades. 😀

Regards,

David.

Hi Dai

Give me a few days and I’ll sort some scans out for you.

Cheers
Elliott

Bump…

Since my earlier request, I have located the blade ID on the cuffs of the blade roots, as blade DB191/A.

Would anyone have any profile data for these blades pls?

Thanks,

DAI