Adjustable Penobscot Møllegabet 52#-75#@28"

[Rowan Bows]

Hey Bowyers!
The Møllegabet bow is made from elm and the backing from black locust (heat treated). The bow is 166cm ntn unstringed.
It has adjustable draw weight in 3 positions. 56# 62# 75# are possible. At my draw it has 68# highest level.
Very easy to string and adjust the cables.

Shooting session: https://www.youtube.com/watch?v=wJj5Vylefgw

Sorry for the compressed pictures but Im only allowed to load up 4.
There are better Fotos here: https://imgur.com/gallery/6VznfqB

I wish you all a very nice Christmas, Peace, Health and Harmony with your family.

[Selfbowman]

Interesting bow but lots of mass. Fun project I’m sure.

[Rowan Bows]

Mass seems to be a problem with these bows thats why I heat treated the black locust. I think it became much lighter. Its fun to shoot.

[BowEd]

Cool bow.Nice work.Never seen one of this kind adjustable but it makes sense.A veritable type bow.You've definitely got the bow making bug.You'll have to educate your neighbors to stay out of trouble.

[bownarra]

These bows are wacky!!!
To gain some more efficency you can reduce those levers quite a bit. Even with the sharp reduction in width they don't need much increase in thickness to keep them stiff. I rough them out at 1/8ths thicker than the thinnest part of the working limb. Same with recurve thickness. Just think how little extra thickness is needed to produce a stiff spot on your working limb

[BowEd]

To get the look of these type bows is actually easy.Elm is an excellent wood for it because of its interlocking grain.The benefits from them is ease of draw because of low string angle and dead in the hand release.To appreciate the shooting & performance benefits takes a little more time.It's a final fine balanced tillering process on these types of bows removing material from these levers but still keeping them relaively stiff to see it happen.Length of levers can vary also with a shorter working limb.A person has got to remember stress gets less out towards the tip on all bows also so less will still hold up fine.
There comes a time though to know when to quit as a few grains [under 20] won't make much difference and will jeapordize the durability of the bow too.
Removing material from these levers a little at a time while testing it will slowly reveal the benefits 1 fps at a time.I've made them so narrow and needle like they almost bow a bit sideways.That's when you know you've gone too far.
Once a person gets familiar with different woods enough times I immediately know how deep and narrow to start with to reduce time in making them.

[Rowan Bows]

my english is not sooo good. you mean the needles of the mollegabets?

[simk]

One more nice bow 
Very good execution  I like it
Probably bownarra is right about the heavy tips - they could be made less thick. But the excess weight does affect speed less than one would may think; I once made this experiment with a 38# moellegabet: I removed 50 gramms of wood from the levers and only gained 5 fps. According to this 10 gramms of mass removal will provide 1 fps. But shooting comfort definitly was much better...

I have not done a penobscot myself and I dont fully understand how it really works. According to my understanding the secondary bow itself cannot store a lot of energy.....1 due to its tiny dimensions and 2nd due to the very bad string angle it has to work with; it has to work more like a cable backing...

I would be very curious to see te tiller of the main bow without the secondary bow and compared to the tiller with the secondary bow attached...how does the tiller shift??? Would there maybe more bend close to the handle without the secondary bow attached? could you provide this pic? 

Also I would be very interested in the fdc of these different bows. You see my rough estimation in a drawing  of course the curves  wont be so linear and I guess I got a too big difference in early draw weight in my drawing.... maybe I'm completly wrong...

Cheers and merry X-mas!

PS: https://www.deepl.com/de/translator works very well for translations - bow-building specific terms maybe not always 
PS: I like your videos too - very cool music jingle you have there 
 

[Rowan Bows]

No problem this is the tiller without the backing connected and a picture from the needles. I dont know how to show it but maybe you can get an imagination of the thickness. I had many problems with this bow before. First backing was way to weak. I tried to tune it with a sinew backing wich gained only 5lbs. So I thought you have to attach a really strong small bow. I gained much more draw weight but of course the backing was very heavy now. So I heat treated the black locust and the whole bow was much lighter and had not this handshock anymore.

[simk]

thank you! I dont have a picture of the profile from same angle to compare. But anyways: I mean when the bow is fully drawn....
In your full draw pic - secondary bow attached - the bend is concentrated on the outside. I expect it to be more towards the handle without the secondary bow...
I dont think the mass of the secondary bow does affect performance a lot. This mass does not need to travel very far...
The levers look like 18-20mm thick. 14-15mm would be enough...

[Selfbowman]

I see what you are saying Simk about the mass of the second limb. How does moving the string father out on the lower limb affect the tiller of both limbs. Maybe a braced look at all three weight limits would be interesting to me. Arvin

[Rowan Bows]

You think they could be even thinner? I know what you mean with the tiller. The backing defenetly affects it in the outer limbs. Maybe I can get some time to make a good tiller foto without backing connected these days. Merry Christmas !

[simk]

Selfbowman: I dont think moving the string on the lower limb affects the tiller a lot. But I think there's a noticable difference when you attach the secondary bow to the main bow... Also: How does the secondary bow change distribution of stress on the bow: Inners vs outers - back vs belly...?   To me it looks like it stiffens up the inners. I could also imagine the secondary bow relieves stress from the back of the main bow, but not from its belly. Of course also neutral plane is shifted somehow. Also I would expect a very progressive (not linear) increase of drawweight - that's why I was interested in the fdc's. I'm just tryi'n to understand how the system works.

Rowan Bows: It's about the love for bows. It's not about a few gramms +/- or a few fps +/- ....these really are details 
nevertheless optimizing never stops of course. I checked a bow from mine that I recently tillered. Also a reflexed lever-bow. Also from elm. It initially was 55#@28" ...now tillered down a little...
cheers   

[Rowan Bows]

7mm  thats brave.

[simk]

the mark actually shows 9,2 and 14,2mm