# Triangle bottom KTBH?



## kawayanan (Aug 11, 2006)

Jenn said:


> Hi,
> I am playing with designs for my KTBH. I am getting 2 packages and 2 medium nucs. I will be making KTBH and TTBH. I don't want to have 2 different lengths of top bars so want to make all of them 19 7/8" long. I wanted to see what width I needed for the bottom board. When doing a mock up of 1x12 lumber using 4x6 notecards, I noticed that the bottoms touched if the top width was 19 at an approximately 45 degree angle. Can I forgo the bottom board and just join the 2 sides? Do I need to make it longer to make up for loss in volume?
> Simple is good and if this design works, I can make the whole thing using 1 1"x12"x12' board.
> -Jenn


I'm not an expert, but I will make a couple of comments anyway since no one else has. 

First, if you make the top-bars 19 7/8" long, thats the outside dimension of the Langstroth hive. That may have been what you meant to do, but you could also make them 19" so they could sit inside a Langstroth hive like frames.

Second, if you use 12" sides at 45 degrees, they will meet at the bottom when the top-bar is about 17" long. If you keep the top-bar at 19", the angle will be 37.7 degrees. The comb depth would be either 8 1/2" or 7 5/16". Either way, I assume you are planning on having the hive be 6' long (two sides from a 12' board)? For the 45 degree example, that would give you a volume of ~85 liters. (the 37.7 degree example would be less). I can do the math, but here is where you need an expert. Have you read Dennis Murrell's discussion of TBH design considerations? (http://bwrangler.litarium.com/build-a-top-bar-hive/). The comb depth and volume you want can depend on your climate. You would have to make the decision on what would work where you are. Just remember, if you keep the your KTBH could end up with a much smaller volume than your TTBH depending on the comb depth.


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## Jenn (Nov 20, 2006)

Ok, I meant 19" bars to be compatible. And I was thinking 4' + with 2'- for either end.
-Jenn


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## BerkeyDavid (Jan 29, 2004)

*Hi Jenn*

Like Kawayan said you want to watch your volume. Not sure of the weather in SW Mo. but your design would be a little small around here.

I would consider less than a 45 degree angle to add volume.

THe other thing about simply joining the sides and eliminating the bottom is that a flat bottom of at least 3 inches width gives them more room to clean up. 

They have been piling up the dead bees at the entrance of my TBH the last few warm days. I am not sure how they would be able to clean out all those dead bees if the bottom wasn't flat giving them room. Although they are pretty resourceful.

Look at the angles Dennis uses on his. I think that is closer to what you want.

And just buy another board (or find some more scraps somehwere) and make it longer and wider at the bottom (my 2 bits). THe ones I have had fail have been the smaller ones.


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## kawayanan (Aug 11, 2006)

If you went with 4' long, that would put your volume somewhere around 56 liters, and I think that would be a bit small.

I was originally thinking of using 1x12 boards to make a hive too. For what I wanted, I found that 3/4" plywood would end up being cheaper. I should be able to make two hives (sides and ends) from one sheet. Its not solid lumber, but with paint I think it should hold up fine. If you wanted to keep it simple so that you wouldn't need a table saw or such, than it might not work for you though.


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## Michael Bush (Aug 2, 2002)

I've done about a 22 degree angle on all of mine. I would not exceed a 30 degree angle myself. With a 19" top bar, I'd do a one by ten for the bottom.


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## BerkeyDavid (Jan 29, 2004)

> I've done about a 22 degree angle on all of mine. I would not exceed a 30 degree angle myself. With a 19" top bar, I'd do a one by ten for the bottom.


Yeah that sounds real good to me. WIth 20 inches at the top and 10 at the bottom you should have a nice sized hive with a nice angle on the side.

The other thing that the wider bottom gives you is when you harvest your comb. I like to cut the comb so it fits nice in a little tupperware sandwich style plastic container. If its real pointy on the end or has a steep angle it is harder to cut to fit.


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## Keith Benson (Feb 17, 2003)

"19" so they could sit inside a Langstroth hive like frames."

One word of caution. Do not fill the box with these bars. There must be some small opening to insert a hive tool or the bees will glue the thing so tight it will be tough to get them out without a struggle.

Keith


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## Heritage (May 10, 2005)

I use 1X12 pine now for my hives. I cut a rabbet in the top and bottom of the sides for the bottom and a top bar rest. The bottom is angled on either side at 20 degree (so is the top bar rest) The bottom ends up being about 10 1/2 inches with an 18 inch top bar.

My first TBH was 3/4 plywood (not treated). I built the hive and cut the bars out of plywood. That was 3 years ago and I just moved them into a new hive. The plywood hive was still in good shape and they were still using the plywood bars! I was impressed.


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## popscott (Apr 12, 2005)

I'm a newbee to the KTBH. I have made my own Horz. longhives but have been studing the KTBH plans and construction on the web. The 45 deg and 22 deg and 37 you folks talk about are alien to me as I thought the idea of the angled sides were to reduce comb attatchment, and to do that the angle had to be a 150/30 deg, which matches the angle of a six sided comb cell? 

My example is here.....
http://www.freewebs.com/justkiddinfarm/comb.jpg

Thanks in advance,
Scott
http://www.justkiddinfarm.com/


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## Michael Bush (Aug 2, 2002)

>and to do that the angle had to be a 150/30 deg, which matches the angle of a six sided comb cell? 

Since the orientation of the cells varies from bar to bar, it seems unlikely a magic number of the angle is going to align with the cells and stop attachments. I have not seen much attachments with 0 degrees or 22. The 22 is how far off of vertical. If you're measuring the actual angle in relation to the bottom (in other words how far off of horizontal) then the 22 would become 112 degrees and the 0 would become 90.

The only use I see for the angle at all is a deeper comb gets more manageable because it can support itself a bit better. But if the comb isn't too deep it seems to work fine with 90 degree sides.


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## BerkeyDavid (Jan 29, 2004)

Hi Scott, nice drawing. HOw did you do it?

Anyway, if you look at the steeper angle it is closer and I wonder if it is because in your design / angle it almost seems to invite comb attachment since the side of the cell is parallel to the side. If you increase the side so it is most out of parallel to the cell it may discourage comb more.

Hard to explain without drawing it like you did.

But if you number the points of the cell going counterclockwise, with the top being 1, then the angle I am talking about would be the angle created by drawing a line through points 2 and 4.

I think this is a really interesting idea. I have always been interested in the interface of math and nature.


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