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Forum topic by Arthropod posted 10-16-2018 05:46 PM 522 views 0 times favorited 25 replies Add to Favorites Watch
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Arthropod

9 posts in 35 days


10-16-2018 05:46 PM

Hey folks, I´ve been looking for a method to hollow round logs (about 8 inches long and 4,7 inches in diameter) for commercial use.
Since I want to sell the products, the process should be quite fast and result in a clean hole. My best idea for now is attaching the log on a lathe and drill it with a forstner bit. Since I haven`t tried this, do you think it is even possible or du you have any better idea?

Thx for any feedback!


25 replies so far

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squazo

109 posts in 1823 days


#1 posted 10-16-2018 05:56 PM

chain saw

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John Smith

1452 posts in 340 days


#2 posted 10-16-2018 06:07 PM

what is the diameter of the hole you would like to have ?
will it have the same size hole in all the logs ?
or – will the thickness of the log dictate how big the hole will be.
will the hole go all the way through to make it completely hollow ?

.

.

-- I started out with nothing in life ~ and still have most of it left.

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Arthropod

9 posts in 35 days


#3 posted 10-16-2018 06:39 PM

Thank you for your quick feedback!

A Chainsaw is not an option unfortunately since u won`t be able to make clean holes. I already have a way to hollow the logs but with this current method it is not possible to make it clean. Since i want to sell the products, i need a more efficient and “better looking” way to make to holes.


what is the diameter of the hole you would like to have ?
will it have the same size hole in all the logs ?
will the hole go all the way through to make it completely hollow ?

The diameter of the holes are ranging between 4,7 inches (12 cm) and 2,7 inches (7cm). So yes, I am planning on making different diameters for different log sizes.

It will depend on the product, some should be completely hollow and some only half.

Arthropod

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HokieKen

6634 posts in 1316 days


#4 posted 10-16-2018 08:14 PM

In my experience, Forstner bits don’t play well with end grain. Twist drills do much better. I would probably use a large twist drill to rough it out then use a bowl gouge or carbide tool to finish it to the final diameter.

-- Kenny, SW VA, Go Hokies!!!

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John Smith

1452 posts in 340 days


#5 posted 10-16-2018 09:01 PM

just out of curiosity – what will the logs be used for once
you have found a way to process them ?

.

.

-- I started out with nothing in life ~ and still have most of it left.

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Arthropod

9 posts in 35 days


#6 posted 10-16-2018 09:11 PM



In my experience, Forstner bits don t play well with end grain. Twist drills do much better. I would probably use a large twist drill to rough it out then use a bowl gouge or carbide tool to finish it to the final diameter.

Yes, that`s what i thought. But do you think not even a metal lathe, with a lot of precision and control can do the job?
I have been using twist drills up until now by drilling a circle then hammering out the core. After that i finished it with a gouge like you mentioned. Unfortunately tho, by doing this the hole is very rough and i need it to be perfectly round and smooth. Furthermore this work is very exhausting and not doable on a medium scale in the long run.

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Arthropod

9 posts in 35 days


#7 posted 10-16-2018 09:38 PM



just out of curiosity – what will the logs be used for once
you have found a way to process them ?

For now I am using them for lanterns and nesting aids for insects. I am living in central Europe and they are getting more and more popular here.
But my plans are to make even more as i go.

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John Smith

1452 posts in 340 days


#8 posted 10-16-2018 09:50 PM

hmmmmm – - – I googled “insect nesting aids” and now I understand.
I saw something like that on a Nature TV show a while back . . . .
here in Central Florida, we just leave the garage door open for a day or two. (joke).
best of luck in your projects – not too many people realize just how important
the beneficial insects are to our own ecosystem. without the proper pollination,
we could very well starve to death in less than a century.
~but~ I don’t see any examples of insect nesting boxes that are perfectly smooth
and cylindrical on the inside (other than a pipe filled with straws or bamboo) – - – -
maybe you are overthinking your design just a little.

I APPLAUD YOUR EFFORTS !!!

.

.

-- I started out with nothing in life ~ and still have most of it left.

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Lazyman

2561 posts in 1565 days


#9 posted 10-16-2018 10:42 PM

You aren’t going to be able to find a Forstner bit big enough to drill out a 4.7” diameter log on the lathe. You would have to drill multiple holes on the drill press and hog out the rest somehow. To use the wood lathe, you could drill a single hole in the middle and then use a hollowing tool to remove the rest, working in from both ends. With the 8” length, you will need a pretty long tool to safely reach halfway in from each end. (If I remember correctly the rule of thumb is 1 to 5 ratio of length past the tool rest to behind it.) A tool like the D-Way hollowing tool would give you a long enough reach. Sorby may make something similar and I’ve seen some homemade versions of that tool online as well. You will need a chuck to mount the logs on the lathe.

I’ve never tried it but I wonder if you would be able to use a bandsaw to do that, sort of like making a bandsaw box. You would make an entry cut and cut a circle around the inside and exit in the same place you entered? Might be a challenge with an 8” piece.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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runswithscissors

2874 posts in 2202 days


#10 posted 10-16-2018 11:47 PM

Lazyman’s technique does require sawing in from a side, but after the center is out, you can cut off an end of the removed piece (for one that doesn’t go all the way through), and glue it back in, plus glue where the cut entered from the side. As he says, this is how bandsaw boxes are made.

Another thought: if you tilted the bandsaw table slightly, your center plug would be tapered, and would fit tightly if pushed through. (I realize that’s not very clear, but best I can do right now). In Belize, we watched a drum maker make a series of nesting drums this way.

-- I admit to being an adrenaline junky; fortunately, I'm very easily frightened

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Arthropod

9 posts in 35 days


#11 posted 10-17-2018 11:42 AM



hmmmmm – - – I googled “insect nesting aids” and now I understand.
I saw something like that on a Nature TV show a while back . . . .
here in Central Florida, we just leave the garage door open for a day or two. (joke).
best of luck in your projects – not too many people realize just how important
the beneficial insects are to our own ecosystem. without the proper pollination,
we could very well starve to death in less than a century.
~but~ I don t see any examples of insect nesting boxes that are perfectly smooth
and cylindrical on the inside (other than a pipe filled with straws or bamboo) – - – -
maybe you are overthinking your design just a little.

I APPLAUD YOUR EFFORTS !!!

Well thank you John!
But the nesting boxes you described is exactly what I am doing. I fill the Pipe with bamboo and drill holes in the outer ring. I already sold some “prototypes” on a market and was pretty successful doing so. This is why I want to perfect the product and why I`m not too shy about investing some money.


You aren t going to be able to find a Forstner bit big enough to drill out a 4.7” diameter log on the lathe. You would have to drill multiple holes on the drill press and hog out the rest somehow. To use the wood lathe, you could drill a single hole in the middle and then use a hollowing tool to remove the rest, working in from both ends. With the 8” length, you will need a pretty long tool to safely reach halfway in from each end. (If I remember correctly the rule of thumb is 1 to 5 ratio of length past the tool rest to behind it.) A tool like the D-Way hollowing tool would give you a long enough reach. Sorby may make something similar and I ve seen some homemade versions of that tool online as well. You will need a chuck to mount the logs on the lathe.

Thank you for your feedback Lazyman!
I actually found a forstnerbit this big on the internet and I originally planned on making multiple drills and using a bigger bit each round.
But you actually brought up another idea in me! What if I use a metal lathe and drill a first small hole (2 inches) in the middle with a twist drill. After that i use a long wood turning tool, mount it on the cross slide of the lathe and increase the diameter a bit more each round?

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Arthropod

9 posts in 35 days


#12 posted 10-17-2018 11:46 AM



I ve never tried it but I wonder if you would be able to use a bandsaw to do that, sort of like making a bandsaw box. You would make an entry cut and cut a circle around the inside and exit in the same place you entered? Might be a challenge with an 8” piece.


Lazyman s technique does require sawing in from a side, but after the center is out, you can cut off an end of the removed piece (for one that doesn t go all the way through), and glue it back in, plus glue where the cut entered from the side. As he says, this is how bandsaw boxes are made.

Another thought: if you tilted the bandsaw table slightly, your center plug would be tapered, and would fit tightly if pushed through. (I realize that s not very clear, but best I can do right now). In Belize, we watched a drum maker make a series of nesting drums this way.

I thought about this idea myself a lot but I am not a huge fan of cutting up the log and then gluing/screwing it back together. If there is no other way, I will probably go for this method but until then I am searching for other ways.

Thank you for your input tho!

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OSU55

1930 posts in 2167 days


#13 posted 10-17-2018 12:20 PM

yes it could be done on a metal lathe with a boring bar, or a wood lathe with a hollowing tool. Either would use the same cutting tool, a small dia carbide or square 3/16” hss bit. Depends on what you have access to or $ you want to spend. Either would use a drilled hole to get started. For a wood lathe look for a captured hollowing tool, not a free hand type. I like Lyle Jamieson’s design, but there are many, including articulating. Either metal or wood lathe can leave a decent surface finish. My have to clean up with a scraper and a little sandpaper – dont know just how smooth you want it. Provide more details of tool access and finished product description.

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Arthropod

9 posts in 35 days


#14 posted 10-17-2018 01:02 PM



yes it could be done on a metal lathe with a boring bar, or a wood lathe with a hollowing tool. Either would use the same cutting tool, a small dia carbide or square 3/16” hss bit. Depends on what you have access to or $ you want to spend. Either would use a drilled hole to get started. For a wood lathe look for a captured hollowing tool, not a free hand type. I like Lyle Jamieson’s design, but there are many, including articulating. Either metal or wood lathe can leave a decent surface finish. My have to clean up with a scraper and a little sandpaper – dont know just how smooth you want it. Provide more details of tool access and finished product description.

Thank you for your input OSU55!
Could u maybe link me one of each cutting tools as example since there is a lot of stuff out there and I am completely new to wood turning. Wouldn`t you say a methal lathe would be better suited since you can easily mount the boaring bar on the cross slide (This one e.g.) which is even self moving?
Since wood lathes are cheaper I would prefer them of course, I`m just not sure how it`s supposed to work without the rails etc.?

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Lazyman

2561 posts in 1565 days


#15 posted 10-17-2018 01:05 PM

Thank you for your feedback Lazyman!
I actually found a forstnerbit this big on the internet and I originally planned on making multiple drills and using a bigger bit each round.
But you actually brought up another idea in me!if I use a metal lathe and drill a first small hole (2 inches) in the middle with a twist drill. After that i use a long wood turning tool, mount it on the cross slide of the lathe and increase the diameter a bit more each round?

- Arthropod

I just did a quick search for 4” forstner bit. Most of the ones I found are intended to be used more like a hole saw in thinner stock for putting a large pipe through a board or drywall. They have 1/4” shafts on them so I would be skeptical that it could handle drilling a 4” deep hole in end grain. I did see one on Grizzly.com that has a 1/2 shaft and carbide cutters that might be beefy enough but it would probably still be a good idea to make multiple passes with successively larger bits and/or drill a more shallow hole.

Your idea to mount a wood turning tool on a metal lathe might work but might be pretty slow going. You will have to make sure that you have the log well mounted in a chuck. If it shifts at all while hollowing you’ll have a problem. Might be a good idea to shorten the log to 6” to make that easier as well as faster to hollow.

Since your goal is to fill it with bamboo to create the nesting tubes here are a few thoughts. First, instead of hollowing and filling with bamboo, why not just drill a honeycomb of holes from each end with an appropriately sized (3/8”?) drill bit. The holes probably only need to be an inch or 2 deep at most but you could go as deep as you want. You could even vary the sizes of the holes to give a more interesting look which might even be better for different types of bugs. This could be easily done on a drill press and maybe even just with a hand drill. This might actually be a more stable design as well. A tube of wood exposed to the elements might crack and fall apart fairly quickly? If you want to stay with the bamboo, then perhaps you could simply hollow out about 2 inches from each end and just insert a bundle of shorter sections of bamboo in from each end. This would be easier than trying to completely hollow the entire 8” log and may result in a more weather stable design. You would need to use some epoxy or maybe even hot glue would work to secure the bamboo bundle.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

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