1/8 scale Axial propeller for Hasegawa Dr.1

[Garuda]

Hi Sam,

As discussed by e-mail, the propeller was sent a few weeks ago now, and I am very happy to hear that it has arrived! I was starting to worry about it, since surely it should have only taken a week or so at the most, but the main thing is that it has arrived.

I am very happy that you are so happy with it! I would have sent it late last year, except that I really felt that the trailing edge adjacent to the hub needed some repairs, and modification of the shape. I had over sanded it and it was too round. The sharper lines are more correct, and being at the back it won't be a major issue.

The drawings I have aren't particularly high resolution, and after an extensive search I eventually found a photo which confirmed the sharper lines at the back of the propeller.

Thank you very much for your patience and support Sam! I'm working on a duplicating machine, so that future propellers won't involve so much tedious work. In the future I will keep at least one on hand as a pattern, and I should be able to knock them out relatively quickly.

Hi Ryan,

Thank you very much for posting the information from Paul Leamans' book.

I can't see it particularly clearly on this computer, but hopefully soon I will have a much better computer set up, and will be able to have a better look at it.

I'm sorry about the infrequent replies. This computer has a group of keys which don't type the letters correctly, so I have to copy and paste letters. It's a very slow and tedious task to even type a brief reply.

Best regards from Australia,

David.

[slhetal]

Hi David,
I'm making some progress on the propeller for the Fokker DR-1.
Sam

[Garuda]

Hi Sam,

It's looking great! Did you varnish it? Did you sand it very much after you received it? Have you modified the centre hole so that it will fit onto the Hasegawa kit supplied engine? I forgot to do that before I sent it, sorry! I was more concerned about fixing the back of the propeller, near the boss, and sanding the propeller to the correct shape. It would be great to see it fitted to your triplane!

Regards,

David.

[slhetal]

Hi David,
Only had to do minimal sanding and then a single coat of varnish. I just used a single coat of varnish because I don't want it to look plastic, I want the wood grain to show. The wood you used really stands out in dramatic fashion after the single coat of varnish. Have not modified the center hole yet, only want to do the bare minimum when I'm ready to attach to the engine. Thanks again for the fantastic job on the propeller, it's really a work of art!!
Sam

[Garuda]

Well done Sam!

I have noticed that original propellers tend to have a very light coat of varnish. Some experts even suggested that the finish might be French polish, or a similar finish when I provided an original propeller in original condition for them to examine. Having asked some Internationally renowned experts I am now reasonably confident that the finish was generally varnish, which was my original understanding. You have done the right thing by not applying it too heavily.

The timber species used are Australian Ash - which I suspect is much more closely related to our Australian gum trees than the European Ash used in the original propellers - and Fijiian or Honduran Mahogany. Australian Ash is a good visual match, particularly for a scale propeller, and shares most, if not all of the most important structural qualities of European Ash. Fijiian and Honduran Mahogany are reputed to be genetically identical to Brazilian Mahogany, which is used in the original propellers, and is also very convincing in a scale propeller. I have plenty of European Ash offcuts, but the grain is very large, and the summer growth rings are very porous. It would not be convincing at all in a scale propeller. The particular pieces of Australian Ash I used for your propeller had a very gnarly, angry grain and were very difficult to work with, but some of the pieces have a very nice affect when the light strikes them at certain angles, which replicates the effect I have seen in original propellers quite well. Most of the Ash pieces were planed in the thickness planer to a few mm over size and were sanded to their final thickness by hand. It was a very time consuming exercise! Next time I will try to find another species which is much easier to work with. The Mahogany was much softer to work with, and the grain was much straighter.

Regards,

David.

[rpcz]

Hi David,

I am also one of the person looking at a plastic prop on the Hasegawa DR.1. Would you still have time to fabricate a laminated prop for me?

Kind regards,
Rob

[Garuda]

Timber 1:8 scale replacement propeller for Hasegawa Fokker Dr.1

Hi Rob,

Absolutely no problem! I am very happy to make a 1:8 scale propeller for you. Presumably you already have the plastic propeller supplied in the kit, which by all accounts is not particularly accurate or realistic. I don't know how accurate the drawings I have are, but they were drawn by Achim Engels, so I would be very surprised if they are not the most accurate drawings for an Axial 110PS Oberursal propeller available. I only have very low resolution drawings and Achim is not releasing drawings any more, but I was surprised at how realistic the one I made for Sam turned out to be. It is a very angular design, which can be seen in original photographs of original propellers, but I was surprised at how angular it was. If, for example you look at the propeller in side elevation the front and rear of the propeller are completely flat about a third of the way from the centre towards the tip on the rear and nearly half way out towards the tip on the front. At a glance it looks very similar to but more angular than the Garuda propeller with the same specifications (although I understand that the Garuda made propeller was only used on the E.V / D.VIII, and not on the Dr.1) but it is much more angular when studied closely. It took me a while to get used to the strange angles and geometry, but when the propeller was finished I was very happy with it, and comparing it to photographs revealed that the drawings appear to be correct.

Is your model of any particular Dr.1, or is it going to be left uncovered? I guess most Hasegawa Fokker Dr.1's are left uncovered when finished. The reason I ask is that when I built the first propeller for Sam I took quite a lot of time to construct some templates, which was necessary for the construction of the propeller. This time I will make some more templates, which I really wanted to construct last time, but I didn't want to keep Sam waiting too long! It took quite a few months to make the first one, and I will try to be quicker this time but it is not an easy task and takes a lot of time.

Regards,

David.

[rpcz]

1/8 Axial propeller for Hasegawa DR.1

Goodmorning David,
Thanks for quick and positive response.
The plastic prop supplied with the kit is indeed far from realistic. For a while I have been tracing a Hachette prop for the DR.1 but without success, so I have abandoned that route.
I am still struggling with my intentional idea to cover half of the model. The colour scheme would be either of DR.1 545/17 of Ltn. Hans Weiss (Jasta 11) or DR.1 586/17 of Ltn. Hans Kirschstein (Jasta 6).
Number of laminations of the propellers are still very puzzling. Trying to find more info.
Regards, Rob

[Garuda]

No problem Rob!

Sam posted a comparison photo of the propeller I made for him and the plastic propeller supplied in the Hasegawa kit. The plastic kit propeller looks to be about the right shape and size but it does not have the distinctive laminations, and is not made from timber. What is the Hachette prop you mentioned? Do you mean you were tracing one or chasing one?

Half covering the triplane could be very effective, and I will be interested to hear what you decide to do as far as this is concerned. The reason I asked whether you had a particular triplane in mind is that every aeroplane had a distinctly different number and combination of laminations. If you are not worried about this level of detail I will just build a generic one. Interestingly, I have never seen photographic or physical (by examining a real propeller) evidence that the laminations were even and alternated in species in a predictable manner as shown in the drawings I have. In practice laminations can vary from about 11mm to 35mm or more, and they are not necessarily parallel to each other. The laminations can run out by as much as 5mm or 10mm on full sized original propellers, so using the laminations as reference planes is not necessarily an accurate way to measure a German propeller. There might be more extreme variations than the figures I have quoted, but these figures are from an original propeller I have measured. What appears in a photograph to be one lamination can in fact be two or more laminations of various thicknesses glued in sequence. There are some photographs in existence which show what appears to be examples of propellers which are made almost completely with Mahogany and / or Walnut, with one or perhaps two laminations of Ash and / or Birch (or possibly Elm, according to some sources).

The more you look into the number of laminations and the species they were made of the more confused you will become! I have had an original propeller examined on a few occasions and even expert furniture restorers can't agree amongst themselves about the species used. I believe that most propellers manufactured for use on the Fokker triplane and other contemporary designs were made of European Ash and Brazilian Mahogany, with some Walnut used in some cases. Earlier in the war even German propellers were often all one species. They appear to be made from Mahogany in many or perhaps most cases, although they could just as easily be made from Walnut. I have even seen an Axial propeller which appears to be made from Oak only. The reason I think it is Oak and not Ash is due to the presence of a Medullary Ray, which is one of the identifying features of Oak. Achim Engels and others have mentioned Walnut and Birch, so this should be taken into consideration, and taken seriously.

If you have a good photo of the aeroplane you decide to model, and it shows the number, combination and sequence of the laminations I could try to replicate these details for you if you would like me to. If you are not concerned about this level of detail, don't have a good photo showing the laminations of the propeller or decide not to half cover the triplane, thus replicating a specific triplane I could just build a generic propeller for you. As you can see from the one I built for Sam it still looks very convincing, even though I do not believe, or at least have never seen any evidence that German propellers were ever built with such precision. They seemed to use whatever was available at the time to a large extent, and they did not always alternate the species in a strict, predictable fashion. Each lamination seems to have been planed to the maximum thickness which was practical for that particular piece of timber. Laminations are typically joined lengthways as well. Typically each lamination is two or three boards wide.

Regards,

David.

[rpcz]

Goodmorning David,

The propellor supplied with the DR.1 "Hachette" kit was a wooden one as per the early Hasegawa kit. However, this propeller was not the scale neither the type were i was looking for.

I have decided to cover half of the triplane (586/17) using the "black & white" dazzle stripes used by Ltn Hans Kirschstein (Jasta 6).

This same triplane was flown at a later date by Ltn. Ernst Udet of Jasta 4 with an added LO marking. Although, some discussions are going on if Udet changed the B&W striping into a "Blue and Red"stripping.

Based on the description of Jasta 6 pilot Richard Wenzl and the photo in Franz Hemer's diary, I am convinced that the B&W striping is the correct one.

Regarding the lamination of the propellor, you are more than right. The more you look at the available photo material, the more difficult it gets. The number of laminations on the photos vary from 1 - 7.
Although, I have seen somewhere (but can not find it anymore) on the internet or books that a 7 layer system was used for fabrication of the propellers???

What I have seen on the available photo material of the 586/17 is that the propeller is very dark colored. On some photo's you can see some lamination shading.
Based on this i presume that only dark types of timber were used for this particular propeller.

Kind regards and awaiting your comment/response,
Rob

[Garuda]

Hi again Rob,

I remember now seeing your reply. If I don't reply straight away I'm likely to forget or get distracted, so I apologise for the delay.

That's a very nice colour scheme Rob! It will look absolutely stunning half covered. Do you have larger photos which show the laminations more clearly? In at least one of the photos the propeller looks like a British, or more likely French built le Rhone propeller, rather than the distinctive Axial propeller. Bear in mind that other German companies such as Heine made propellers for the Oberursal and / or the le Rhone, where fitted.

Regarding the reported 7 layers, Achim Engels specifies this, and alludes to Paul Lehman also specifying 7 layers in his book. From my experience it is not so easy to generalise. The number of laminations, species used and the order in which they are used vary enormously, as do lamination thicknesses.

I had a website which I co - founded and from which I was expelled, along with one of the other administrators, who has since started his own Forum. Neither of us believe we did anything wrong, and we were both cheated out of about $1,000. I have recently joined his Forum, and I noticed that there is a thread titled "Props now available". I will post a link to this thread on his site, and will post a link to his site here in this thread. I am sure it will be of great interest to many members here.

I have not read the thread in its' entirety but I will continue to read it. So far I have only seen reference to 1:32 scale propellers. I don't think propellers as large as 1:8 are offered. Presumably they are for plastic kits, but I will keep reading with great interest!

http://forum.ww1aircraftmodels.com/i...27.0;topicseen

Regards,

David.

[rpcz]

Hi David,
Thanks for your response. Number of laminations will always stay a point of discussion. On the photos I attached earlier, you indeed can see whatever you wish to see on number of laminations and color.
What can be concluded from the photos that the DR1 586/17 ahd different propellers. On the smaller photos the propellor seems less wide as on the larger photo.
The larger photo is from the latter period Ltn Udet was flying the 586/17 i.e. probably the propeller has been replaced.

Have been in contact with Douglas Craner in the UK via the ww1aircraftmodels forum.
Your initial assumption was correct that the propellers Doug manufactures were to a 1:32 scale. Although, Doug confirmed his willingness to manufacture a propeller on a 1:8 scale.
Doug is of the same opinion that the photos show different make propellers (Axial for the smaller photos and Wollfe or Garuda for the larger photo).

Since I am not building the Udet version, it becomes clear to me that the propellor should be a Axial one. Do the propellers manufactured by Axial also differ in number of laminations?
Regards,
Rob

[Batleyr]

Hi David,

I haven't logged in to the forum for quite a while, but I thought I'd check in and see if you were still producing one of your fine DR1 props for me?

Ryan

[Nighto]

hello there
i couldnt find the laminates thickness of this fokker in ur thread .
i have a better vector version of that propeller , but i dont have the proper laminates thickness relative to the propeller diameter , so how did u figure out the right thickness

regards Nighto

[slhetal]

Correct Propeller

If someone needs a correct propeller for their Fokker DR-1 then I can attest that there is no better propeller builder than David. I did six months worth of research on Fokker propellers before I contacted David. I have built several scratch built mahogany antique speed boats. I have also been a project manager on building several custom electric guitars where we used maple and mahogany combined (mahogany bodies and maple tops). We also used various burled woods for laminations. In short, I love to see beautiful woodwork and appreciate the artisans who can do that work. I am extremely happy with the 1:8 scale propeller that David did for me. If anyone has any questions or needs pictures then please contact me via a note in this forum. Thanks!!
Sam Hornsby
South Florida