Is a 1 hp motor enough for a lathe with 14" of swing?

[Malcolm Schweizer]

Is "swing" the right word? I am building a lathe and the height of the dead center over the bed will be 14". Also it has a spindle on the back for turning bowls. I want to do bowls mostly. I am a complete novice at turning, so chime in.

I just bought this, which will be mounted on a wood block to raise to 14". (Has yet to arrive- bought on eBay.)
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I already have this, which will bolt through a wood carriage.
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The base will be mahogany with a big mahogany beam for the headstock and live center to mount to. The motor will be mounted below with a tension pulley on the belt. I don't want the motor sticking out the back due to shop space, so it will mount under the headstock.

Originally I was going to build a treadle lathe, but I decided this is the easier way to go. I want to get a 110/220 motor in the 1 to 1.5 hp range. Most are saying they are around 1700 rpm. As you see, I have options to speed up or slow down with pulley sizes.

[Dick Strauss]

If you have 14" over the bed you can turn something almost 28" in diameter. For something this large you will want more torque than a 1hp motor can provide, even when geared down with pulleys. I run a 3hp 1750 rpm motor with 8 pulley combinations for a similar Franken-lathe. I also have a vfd to further control the speed.

You can try it with a 1 hp motor but I think it will be painfully slow roughing out a larger diameter piece.

Good luck with your build and keep us posted on your progress.

[Malcolm Schweizer]

If you have 14" over the bed you can turn something almost 28" in diameter. For something this large you will want more torque than a 1hp motor can provide, even when geared down with pulleys. I run a 3hp 1750 rpm motor with 8 pulley combinations for a similar Franken-lathe. I also have a vfd to further control the speed.

You can try it with a 1 hp motor but I think it will be painfully slow roughing out a larger diameter piece.

Good luck with your build and keep us posted on your progress.

Thanks for the reply. Glad I asked.

[John Keeton]

The other question that came to mind is whether the bearings in the headstock you show will withstand the stresses of turning something that large. With diameter comes greatly increased stress on the spindle. When one is making cuts on the rim of a large piece, the leverage is significant.

[Malcolm Schweizer]

The other question that came to mind is whether the bearings in the headstock you show will withstand the stresses of turning something that large. With diameter comes greatly increased stress on the spindle. When one is making cuts on the rim of a large piece, the leverage is significant.

I hate physics! ...but you have a good point.

[Dennis Ford]

Based on the picture, I think your head-stock is adequate to turn a 20+ inch blank ONLY if it is well balanced AND supported by the tail-stock. No reason to put a huge motor on a light weight machine. I am not trying to convince you to stop building, just want to keep expectations reasonable.

[Malcolm Schweizer]

Based on the picture, I think your head-stock is adequate to turn a 20+ inch blank ONLY if it is well balanced AND supported by the tail-stock. No reason to put a huge motor on a light weight machine. I am not trying to convince you to stop building, just want to keep expectations reasonable.

Thanks- I can lower my expectations quicker than I can raise my funding. The only thing I want to turn of any great size is to make a small table top about 24" diameter and 1" thick. I want to turn the lip like the one my grandfather built. If I have to do smaller work, no big issue.

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[Dwight Rutherford]

I think if I only wanted to turn one 20" table top like you describe, I might consider a trammel and router rather tan a lathe.

[Malcolm Schweizer]

I think if I only wanted to turn one 20" table top like you describe, I might consider a trammel and router rather tan a lathe.

True. Actually that's the one big thing. I want to make bowls and vases. Probably most bowls will be less than 18" diameter. I just want to make this once and be done, and if I make the odd 24" bowl or platter, I want to be ready. If it doesn't work out that way, I am ok with that.

I just priced a 3hp motor. Yikes!!!! No wonder lathes cost so much.

[Dennis Ford]

I don't think turning table tops will be a problem. Even though the diameter is big, it is not difficult to precut them almost round and the weight is not much compared to a large bowl blank.

ps; I have been turning on a home made lathe for over 10 years (I had three different home made lathes before that). Using home built machines is rewarding but don't expect to save money AND get it right the first time.

[Reed Gray]

With a table top like that one, make it thicker than you want for the finished piece. First thing you have to do when you put it on the lathe is to true it up, then you put the rim detail on it, which is not easy. Practice first on a small piece. I would love to see what the base of the table is going to look like.

Also, if there is a way to rig up some sort of variable speed for your motor, that is almost a necessity for bowl turning. For most bowls over about 12 inches, you can get it done with 1 hp, if you are not in a hurry. If you are turning chain sawn blanks, variable speed is almost a necessity because they are so unbalanced...

robo hippy

[Malcolm Schweizer]

I don't think turning table tops will be a problem. Even though the diameter is big, it is not difficult to precut them almost round and the weight is not much compared to a large bowl blank.

ps; I have been turning on a home made lathe for over 10 years (I had three different home made lathes before that). Using home built machines is rewarding but don't expect to save money AND get it right the first time.

Where I live there are no used options available. New is $$$ and requires shipping. I can't justify it. The one I am building will cost about $800 and with the wood being sourced locally, shipping for the smaller stuff isn't that bad. (My $800 figure assumes $300 for the motor.) Also, this is going to have to reside in the room adjacent to the shop due to limited space. I am going to build it like a piece of furniture so it is at least somewhat pretty to look at as opposed to a hunk of metal.

[Steve Peterson]

As others have pointed out, your configuration would be considered a 28" swing. 1HP would be marginal for a 14" swing, and certainly would feel underpowered if you were using the entire 28" swing.

I am basing my power estimate on my 1HP Oneway 1224 with a 12" swing. It seems to have tolerable power with my turning style. The thermal overload in the controller kicks in from time to time when turning items around 6-8" diameter. Usually this would be after an hour or so of heavy cutting.

Steve

[Malcolm Schweizer]

As others have pointed out, your configuration would be considered a 28" swing. 1HP would be marginal for a 14" swing, and certainly would feel underpowered if you were using the entire 28" swing.

I am basing my power estimate on my 1HP Oneway 1224 with a 12" swing. It seems to have tolerable power with my turning style. The thermal overload in the controller kicks in from time to time when turning items around 6-8" diameter. Usually this would be after an hour or so of heavy cutting.

Steve

Thanks- wasn't sure which calculation (radius or diameter) to use. I found a 3 horsepower on eBay within reason. I was hoping to stay with 110AC but looks like I have to go with 220.

Also in regards to comments about chain sawn rough blanks, I would saw them on a bandsaw first to close to round. Rough blanks kind of scare me. I have seen folks do that on YouTube and thought it was going to go flying.

[roger wiegand]

You only need a lot of power if you want to go fast. For rare usage just take very light cuts and take your time. The rim speed of a 24" piece turning relatively slowly gets right up there! There's some advantage to having your lathe not be able to completely overpower you when turning big pieces. I'd rather stall the lathe than break my arm with a bad catch.