# Designing a shop-built bowl lathe, suggestions wecome!



## Visions (Jun 16, 2011)

I am beginning to draw up designs for a new shop-built large-capacity bowl lathe, and I'd really like some input from the members here in regards to design features they would incorporate if they had the chance to design a bowl lathe from the ground up. But first, I will outline some of my current thoughts on aspects such as dimensions, capacity, speed and power.
And just an FYI, my father is a machinist with 30+ years experience and will be making any machined pieces I may need, so I have that aspect taken care of. I am also a welder/fabricator, so I have that aspect under control (well, maybe:laughing as well.

Basic info on planned design: 
30" long long bed (measured from end of spindle)
18" from center of spindle to top of bed-ways
Motor: I'm thinking 2hp 1750rpm (3-phase would be nice, but likely won't be feasible) 
Power transmission: double V-belt (2-Power-Twist Link Belts) to jack shaft with 4 groove step pulley driving another 4 groove pulley on spindle (adjustable speed via rheostat or other speed controller is something I am researching)
Projected speed range: apprx. 100rpm-1500rpm
Head-Stock: 1/4" steel plate and angle iron or possibly 8" or 10" square steel tubing (wall thickness of at least 3/16", would be reinforced as well)
Spindle: 1-1/4" solid 4140 (others steels, including certain types of stainless and tool steels, being considered as well), turned down to 1" with 1"-8tpi threads for attaching chucks or face-plates. Will have greasable bearing blocks on both sides of headstock for spindle to ride in.

Basic construction: Bed will be twin I-Beams, similar to that of the lathe in photos below. Stand will also have a provision for a large shelf for ballast. Basically, I plan to make this as heavy as possible, but also design it so most components bolt together so it can be broken down for moving/transport if needed.


This is the lathe that inspired me to design and build my own.
http://www.finewoodworking.com/uplo...k/Image_Resources/Web_Only/99926160-01_md.jpg

http://www.finewoodworking.com/uplo...k/Image_Resources/Web_Only/99926160-02_md.jpg

I would love to have input from others, any thoughts, suggestions, stuff I missed, whatever it is just put it down! I want to hear it all, good, bad or otherwise.
So let's hear what ya think!!!

Wayne


----------



## BWSmith (Aug 24, 2010)

Headstock bearings would be my first and foremost consideration.Once that decision/criteria was met,it would all be downhill from there.

>Cheap and or free would be good here.Throw in an endless supply of'm(never plan on building "one" of anything)

>Accuracy,all I can get

>Adjustability for getting the most out of them

>Maintenance,what lube,how much and how often is it gonna take to keep them happy

>Install/design WRT to "wrappin" them into headstock

And WRT overall lathe design.....I'd probably be sportin a nice big pc of I beam.....in the 8x24 x however long it takes.As a foundation.....with 4" steel goin crosways under that,for pallet jack.

Probably go with a "balancing shaft" as used by early RR constructors(big azz wheel balancing).....In lieu of techno gadgets.And this coming from a guy who has a premier balancing software co. a few miles down the rd.

You said bowls,I'd still be planning on runnin some or have plans for adding some hydraulic capabilities......not only for plunge cuts,but to give some latitude in adding "tracer's".Probably go with straight cut gears on everything.Best,BW


----------



## woodnthings (Jan 24, 2009)

*Just a thought*

I have an old 13" South Bend metal lathe that more that one time I considered turning into a large bowl lathe. The lathe was free for the taking out of a basement shop in a hospital.
Anyway you get the whole headstock, bearings, threaded arbor, faceplates, and chuck in one ball of wax/cast iron. It has 4 speeds direct and a bull/back gear is 8 speeds total and heavy as a horse.
The headstock could be raised off the bed with a spacer and only the flat belt would have to be lengthened.
Just a thought, however the lathe in the photos is awesome! :thumbsup: bill


----------



## Visions (Jun 16, 2011)

BWSmith said:


> Probably go with a "balancing shaft" as used by early RR constructors(big azz wheel balancing).....In lieu of techno gadgets.And this coming from a guy who has a premier balancing software co. a few miles down the rd.
> 
> You said bowls,I'd still be planning on runnin some or have plans for adding some hydraulic capabilities......not only for plunge cuts,but to give some latitude in adding "tracer's".Probably go with straight cut gears on everything.Best,BW



Ok, I'm sorry if this sounds dumb, but you lost me here. 

With the "balancing shaft", are you speaking of a shaft to balance a wheel on, something like the old school "bubble balancer" used to balance car tires? Or some sort of counter-balancing shaft?
Also, what would I be using said balance shaft for?

As well, you totally lost me with the "hydraulic capabilities" for plunge cuts and adding "tracers". 
And what should I be using straight-cut gears on? I plan to belt drive the machine if that is what you're referencing. Myself, I've never seen a gear-driven wood lathe, and honestly, that kind of engineering is beyond my abilities. 
Sticking with my planned belt-drive is likely my best bet, and probably my best choice if I ever want to see this thing actually turn and not become a shop ornament!:laughing:

If you could please explain to me what you meant with the above statements as far as the terminology (ie: "tracers", "hydraulic capabilities", etc, etc), as well as what some of the items are and how they would be applied in this application, I would be very appreciative.
And again, sorry if I sound numb for not knowing what this stuff is. It may well be from my being mostly self taught and not hearing people "in the know" speak of it.

Thanks!
Wayne


----------



## Visions (Jun 16, 2011)

Woodnthings, the South Bend lathe sounds like quite the find! Even as is it would make for one heck of a wood-lathe! And it would make turning precise parts easy (ie: tenons and straight shafts of a specific diameter and length, etc.), as you could use a self-ground bit shaped for wood cutting in the tool holder and get some real precision out of it.

I had actually tried to locate a donor machine such as your South Bend, but I have yet to have any luck. The few suitable machines I have found have been priced above what I would like to spend. And since saving money is one reason why I want to build my own lathe, I'm trying to keep my budget as low as possible without skimping on the quality, durability or strength of the end product. 
The other main reason is being able to design it to the exact size I need, and a donor machine likely won't be close to the dimensions I really want.

That said, I wouldn't have turned down that South Bend! Though I'd likely be using it for metal turning rather than wood.

Thanks
Wayne


----------



## BWSmith (Aug 24, 2010)

Oops....I thought you were talkin big bowls.And/or designing a lathe that either dosen't exist or was off the $$ chart(as it relates to really big bowls,turnings).

If above two assumptions are in fact incorrect....agree with Bill,you can snag heavy US iron,be it WW or MW(metal wackin)....so much cheaper than anything you can possibly fabricate.And if you get somthing "old'ish"(pre 1970's)it'll look tonnes cooler than anything you can fabricate as well.

Google balancing train wheels,you'll see how they balanced them in the mid 19th century.You were kinda close with the auto bubble balancer......but you are in the wrong plane.Blance shafts are horiz.I was thinking large...really out of balance wood bowls.But its not just bowls,wood by nature isn't balanced which is why WW lathes have "speed limits".Some of this phenom can be "tuned" out with balancing shaft.

If you incorporate a gear train(hence straight cut vs helical gear comment),you have opened a door,designly speaking for "timed" operations.Like a metal turning lathe with threading and pwr feed options.Its pretty easy to do.As a note, "speed lathe" in metal world is a lathe without above train....its used for polishing and is usually sold at bargain prices.They make dandy wood lathes.

Hydraulics are for big stuff,where the waste that comes out of a big bowl hits us in the wallet.On these you do plunge cuts with shaped cutters that are forced into work with hyds.You can have hyd tracers on smaller work.But theres simpler and to be honest,more accurate ways of doin tracers for anything smaller than a newel post,again I was thinking you wanted sumthin big......un-availible....and cheap.Good luck,take pics......BW


edit to add....and you better look quick,cause it'll time out.

http://www.ebay.com/itm/Vega-170-VS...082?pt=LH_DefaultDomain_0&hash=item35b46ee0d2

This next one isn't for purchasing,but rather to show design features that I'd be studying if;building a "dedicated" bowl turner was on the menu.

http://www.ebay.com/itm/Lodge-Shipl...189?pt=LH_DefaultDomain_0&hash=item48382af33d

This next one represents what we look for....IE, For parts not working"

http://www.ebay.com/itm/Barnes-Anti...409?pt=LH_DefaultDomain_0&hash=item2eb73666d1

This is a hyd copy'er

http://www.ebay.com/itm/Locatelli-A...525?pt=LH_DefaultDomain_0&hash=item2c57835fad


----------



## Manuka Jock (Jun 27, 2011)

So in reality this is not a dedicated bowl lathe but a conventional one with an 18 inch swing , is that right ?


----------



## Visions (Jun 16, 2011)

BWSmith, 
I appreciate your suggestions, but the second lathe you posted a link to is scaled far, far beyond my needs or desires. As well the hydraulic copy lathe is more complex than I desire. And as for "re-fitting" an existing unit, whether it be WW or MW, I just don't think it's right for me and my intentions. As well, I will get more satisfaction from fabricating it myself. 

As for what type of lathe it will be, it will be designed specifically for bowl turning with no considerations made for spindle work. So in such, I would call it a bowl lathe. 

What I plan to build will be sort of a mix between the home-built lathe in the above link, a VEGA 2600 and an EBO model 40.
http://vegawoodworking.com/
http://www.eboinc.net/supporting/images/gallery/round_lrg.jpg

I would like to keep this lathe as simple as is possible, mainly because simplicity in operation and design makes for a less stressful working experience and allows for complete concentration on the task at hand, rather than making adjustments to the lathe or other such bothers.

I am going to pick up a 6' long 8"x12"x1/2" thick I-beam on Monday that I paid $35 for, essentially giving me my bed. As well I found a local guy who has several electric motors in the 1.5 to 2hp range that he is willing to sell cheap, so hopefully I can pull a motor out of that deal.

And don't worry, it will be plenty big n' heavy! If all goes as planned, it will be able to spin 30"+ with no issues.

Thanks again BW, still looking into the train wheel balancing stuff, might be of some use too!

Wayne


----------



## Manuka Jock (Jun 27, 2011)

Wayne , 
what lathes do you turn on at present ? 
Your own ones or the local club's ones ?


----------



## BWSmith (Aug 24, 2010)

Never intended any of this as "suggestions" more of "any thoughts".Well maybe snaggin an existing lathe?

And knew before posting,that the Lodge&Shipley was gonna draw comment...oh well.That was more about study and thought provocation....look at big disc sanders(20" and better,purpose built)and you can spot some resemblences.Best of luck,BW


----------



## Visions (Jun 16, 2011)

Manuka Jock said:


> Wayne ,
> what lathes do you turn on at present ?
> Your own ones or the local club's ones ?



I have three different lathes that I turn on, a 10"X18" Central Machinery lathe with a duplicator that I use mainly for production of pens, another Central Machinery 12"x36" swivel-head lathe, and an old Walker-Turner Driver-Line that I believe is about a 12" or 14" x 40" or somewhere around there (never measured it, it was my Grandfather's).

The project lathe has had some progress now, as I now have two 3' sections of 8"x14" I-Beam, a bunch of 3/16" and 1/4" plate, a 2hp 3450rpm motor, all the bearings needed, the jack-shaft and a piece of 1-1/2" steel rod my father ordered for the spindle (can't recall the alloy, but he ordered it specifically for the job).

I would have some pictures, but this darn hurricane coming through has had me running like crazy trying to get everything out of my yard and into my garage and everything else buttoned up. I'll be glad after it's passed!

BWSmith, please don't be offended, really. I appreciated everything you posted and have looked the stuff over since several times. I have also looked at many other big machines, looking at how things are mounted and designed. I have gotten some good ideas from it as well. 
I guess I came across the wrong way before, and for that I apologize.
I just have this vision in my head of what I want, and while I do need help figuring out the best way to get there, I don't want to deviate too much from the overall "design" I have in mind.
After turning on other lathes and seeing what I have to do to make things work, I have some good ideas about how I want things set-up so it's easier for me to work around.

The things I don't know, are how big of belts I should be using, thickness of steel where the bearings for the spindle mount to prevent vibration (cast iron would be better, but I don't have that option), and other technical stuff. 
If anyone has a big lathe and could tell me any of this stuff, i would surely be appreciative!

Wayne

Wayne.


----------



## BWSmith (Aug 24, 2010)

No offense taken........its your build.Heres a book I keep in the truck for reading if theres a wait.Think this one actually came from B&N?Anyway,have read it probably a dz times and pickup a little tid-bit everytime.It has a nice presenting tone to it.......it would really be a help to you on this build and can HIGHLY recomend it.

The section on flame straightening alone is worth the price of admission.But is chock full of practical engineering data as it applies to fabrication and steel.Best,BW


----------



## Visions (Jun 16, 2011)

Thanks BW, I will pick one up!

As for progress, I-beam has been cut into two-3' lengths, sandblasted and is now at the machine shop awaiting the top flats and their edges to be machined true.
Also had the plate I picked up blasted as well, as it had spent some time outside.

I'm going later in the week to look at some 10" square tubing that is said to have at least 1/4" wall thickness, maybe thicker, as the seller isn't sure and has yet to measure it. I'm thinking it may make an excellent headstock housing.

It's starting to look like this may come together before winter!

Wayne


----------



## Fred.chen (Sep 13, 2011)

Learn how to design a shop built-in bowl lathe


----------



## Visions (Jun 16, 2011)

Fred.chen said:


> Learn how to design a shop built-in bowl lathe



Was there supposed to be something else there, or are you saying I don't know what I'm doing???


----------



## woodnthings (Jan 24, 2009)

*It was spam*



Visions said:


> Was there supposed to be something else there, or are you saying I don't know what I'm doing???


He wanted to post his links to bearings. :thumbdown: bill


----------

