My lathe design for your review

[Dennis Nagle]

Hi All.

Here is a very rough sketch up of the lathe I want to build. I have the 3hp, 3phase motor with VFD, pillow blocks with 2" bore bearings, shaft, angle iron, and 1/8" plate steel. This is meant to be a bowl lathe so that means no beds or tailstock but there will be provision for a bolt on bed.

I will frame it will angle iron, then sheet it with 1/8” steel plate, then I will fill it with concrete for weight.

The spindle will center at 44" tall and the main column is 1’x1’ then those angled legs are 2’ long at the base. It will hold about 10 cu ft of concrete at then weigh in at about 1750lbs!

I'd like to get all your expert opinions and suggestions so when I build it, I won't have to say "gee I wish I would have...."

As the design develops I'll make standard engineering drawings and materials list for who ever wants them.

Thanks in advance, I love a good group project.

Cheers, Dennis.

http://i9.photobucket.com/albums/a60/djnagle/lathe1_zpsd799557c.png (http://i9.photobucket.com/albums/a60/djnagle/lathe1_zpsd799557c.png)

http://i9.photobucket.com/albums/a60/djnagle/lathe2_zpsbaa22081.png (http://i9.photobucket.com/albums/a60/djnagle/lathe2_zpsbaa22081.png)

http://i9.photobucket.com/albums/a60/djnagle/lathe3_zps2712db01.png (http://i9.photobucket.com/albums/a60/djnagle/lathe3_zps2712db01.png)

http://i9.photobucket.com/albums/a60/djnagle/lathe4_zps1c58b230.png (http://i9.photobucket.com/albums/a60/djnagle/lathe4_zps1c58b230.png)

http://i9.photobucket.com/albums/a60/djnagle/lathe5_zps042fe8b5.png (http://i9.photobucket.com/albums/a60/djnagle/lathe5_zps042fe8b5.png)

[Nate Davey]

Nice design, the headstock and bearing arrangement look a little like my Nichols lathe. My headstock is filled with sand. I'll be following this thread with interest

[charlie knighton]

I'd like to get all your expert opinions and suggestions so when I build it

no expert, had trouble building my grinding station, but if i get to supervise, here goes a suggestion

number your pictures so we can follow whats suggested

in picture 2 , normally the blank spins in counter clock wise direction, your angled support are in the back and regular clock wise direction, you could turn in reverse, or switch the support for tool rest to the right size and motor support to the left size and turn normally (i see this because i turn multi-axis turnings which are not centered, and would like angled leg on side of regular direction of motion of blank, also help with out ob balanced stock)

paint it purple

[Bob Bergstrom]

I would use sand with an acess hole to vacuum it out so it could be moved, maybe either two articulated arms or a strut to avoid twisting of the tool support. It would be good to know where the center of gravity will be with a 200 pound block of wood on the spindle. Will you be bolting it to the floor? Just thoughts.

[Doug Herzberg]

I think you'll want a tail stock. You'll be limited in your choice of blanks if you don't have it. +1 on beefing up the tool rest. In fact, I would spend some time thinking about a low concrete "bed" with steel rails as a beefier base for the tool rest and for things that bolt on, like a steady rest, coring tools, etc. Bob's idea about sand for mobility is something I wouldn't have thought of, but it makes sense. I imagine there would be quite a trade off in rigidity, though.

[John Keeton]

Couple of thoughts - on Charlie's comment on the bracing, I would think the forces (pressure of cuts, catches, etc.) would push the lathe toward the rear, so the bracing appears correct for what little I know, though a large out of balance blank could present issues. I would consider the sand vs. concrete for reasons stated, and I would want some type of cover over the belt drive to avoid a chunk of wood dropping in the moving belt and throwing it from a pulley or worse.

Good luck on the build! Having looked at your website and seen some of your other projects, I have no doubt this one will be successful!!

[Wally Dickerman]

I used to own a Nichols custom made lathe (all of his lathes were custom...mine was a "lefty". The back is angled and holds the motor just as yours does. Some feature here that you might consider. The "double" bed...the top bed slides to give more distance between centers. A hand crafted tailstock. The widened footprint gives lots of stability. The heavy duty leveling jacks give a lot of height adjustment.

My "lefty lathe" gave me years of great service. The oly reason I changed to a Oneway was that my teaching changed from classes at a faciliy to one on one in my shop....Had to be a left or right handed lathe.

[Wally Dickerman]

Tried to edit my post and couldn't.....My Nichols lathe weighed 700 lb. The entire inside was a sand reservoir. I added 400 lb of sand and it wasn't half full. It had a 26 inch swing over the top bed and a 38 inch swing over the bottome bed.

If I raised the jacks the lathe rested on heavy duty wheels. Pretty handy in a small shop.

The only unsatisfactory part of the lathe was the tailstock. Was okay for bowl blanks but not so good for spindle turning. But then this was a bowl lathe and a good one

[Richard Coers]

Make sure you have room for bigger pulleys on the main shaft, or more of them. Turning the really big stuff will take slow RPM, but you may want the rpms up on the motor to stay in a better place on the torque curve. I would like a place to mounted a steady and an articulated hollowing tool. I would also suggest more distant available for the tool rest. You might want to do a large wall turning one day. Do a Google search for Elephant Bowl Lathe. Those guys showed up at the AAW symposium one year with a couple unique machines.

[Harry Robinette]

Dennis
When I was looking for weight I found out that by volume concrete dry mix is heavier then sand. I have concrete bags on my General. Concrete mix is 40# per a bag 4" x 8" x 16" or close to it sand is only 32# for the same size. This is what I was told when checking into this,I checked with a number of concrete contractors.
Just a thought.

[Richard Coers]

Dry portland cement isn't as caustic as wet, but not as benign as sand either. I would still vote for sand.


Dennis
When I was looking for weight I found out that by volume concrete dry mix is heavier then sand. I have concrete bags on my General. Concrete mix is 40# per a bag 4" x 8" x 16" or close to it sand is only 32# for the same size. This is what I was told when checking into this,I checked with a number of concrete contractors.
Just a thought.

[Thomas Canfield]

The use of angle iron for frame and 1/8" plate skin does not seem like it will provide the rigidity you will need for 3HP and large bowls unless it is balanced stock that you are working with. A skin frame is hard to make ridgid and provide bolting surface without large inserts. You should give some special attention to the belt/pulley sizing for the reduction and speed range you are planning to use. It might be that a jack shaft should be added to give greater speed reduction and also consider a couple of speed ranges. I like the idea of sand fill to add weight, but still have some ability to move the lathe. Leveling jacks are a good suggestion also.

[charlie knighton]

where are the controls???? foot pedal????? oneway control setup????? wireless???????

[Grant Wilkinson]

I have the Vega 2600 bowl lathe. Your design is interesting, but I would suggest considering some way of including a tailstock. Without it, you are really limiting the way that you can mount blanks to chucks or faceplates, taking away much flexibility. As others as said, your design also seems to mean that you cannot use coring tools or steady rests. If that is to your liking, go for it. But, I do think that down the road you will be saying "I wish I would have".

[David DeCristoforo]

Being the proud owner of a custom built lathe, I do have a couple of thoughts here. First off, the large triangular ballast on the back and side is a good idea. Secondly, a bed of some sort is something you will wish you had. My thought at this point is to adapt something like a PM 24" bed extension which would allow the use of a tailstock and banjo. Of course, these items are totally out of my financial reach at this point. I would not want a permanently fixed bed. Part of the reason I wanted a lathe like this is so I would not have to navigate around the bed. But there are times when you want to bring a tailstock into play.


When you have your main spindle machined, have a 1/2" hole bored through it and have it reamed for a morse taper. That will allow you to use a vacuum chuck as well as various drive centers.


Don't underestimate the need for a really stout tool rest. I would suggest taking a look at the VicMark unit I just mounted on my lathe, It works really well and can be configured in a number of different ways. If I were to do it again, I would attempt to construct something that emulated this unit.

[Dennis Nagle]

Hi All. Thanks for some much great input. Some of these things I've never thought of. Instead of doing a bunch of quotes, I'll just respond to what I read.

The lathe will spin in a counter clockwise direct so when I am standing at it, working on the outside of a piece, one angled support will be going directly away from me (that is the one the motor is mounted on) and the other angled support will be going off to my left.

paint it purple - OK

Lots of discussion of sand vs. concrete. My thinking is 1. I don't plan on moving again so it is my kids problem when I am gone ;>) 2. Sand will fill the body of the lathe and provide good weight but concrete will tie all the components of the lathe together so it will all be as one. I don't plan on bolting it to the floor as it will weigh in at 1750 lbs and the C of G will be fairly low.

The tool rest as it is drawn may look like it is dangling in space but in reality the upright tube is square and solid steel and will sit on the floor. I do plan on making it longer than drawn though. Here is a pic of one I am copying.

I plan on including bolt holes in the pattern of the PowerMatic bed extension so I can include a bed and tailstock when and if I need one AND I can afford it.

I plan on making a cover for the shaft, bearings, and pulleys.

I will use two or three speed flat belt pulleys to have better control of the speed and torque.

The control module will mount in front. I may include a foot control someday.

Yep, the shaft will be bored for a vacuum system and will have a #3 morris tapper.

P.S., I just learned how to use Google Sketch Up a couple days ago and I am still working on a more detailed picture.

[charlie knighton]

sounds like a plan Dennis, please post pictures of your lathe when built and some shavings flying. i would like a set of your plans and while i do not have the skills to build it, i could put the concrete in and paint it, i do know of a good machine shop, just have no idea $ wise what it would cost, i expect it to be considerable less than some of the lathes discussed on forum lately.

[Dennis Nagle]

no problem Charlie. I am working on drawings now, but those will change with the build. I'll pass them on to anyone who wants them.

I am doing everything I can to save money on this one. For angle iron, I buy bed frames from salvation army, for concrete fill, I look for free concrete rubble on CL so I don't have to buy 20 bags of concrete. When this is done, and if the motor and controller fall through and I have to buy new, I figure I'll have $800 into it. If a couple leads work out, I'll have $200 into it.

I told a friend that if he bought two of all the bits and parts, I'd build him one and keep one for myself. In that case I'll have nothing but time into it.

I'll do all the fab work so that is one less expense.

[Jamie Donaldson]

I have never liked the use of sand as ballast because of its presence around my bearings and electronics, and it will find a way to escape no matter how well sealed the enclosure. I have always used washed river gravel as a much more user/tool friendly substitute that achieves the same goals of stability and vibration dampening, and much easier to add/subtract when a machine might need to be relocated.

[Richard Coers]

Check that bed frame idea. Those things used to be made from some alloy of carbon steel for strength, and didn't weld worth a hoot. Maybe todays, Chinese made frames are just mild steel, but check it before hauling home a dozen.

[Dennis Nagle]

Thanks for the tip guys. If worst comes to worst, there is a guy a couple miles from me that sells 20' long normal 2"x2" 1/8"
thick angle iron for a buck a foot. I figure two of these would work.

[Dennis Nagle]

I have never liked the use of sand as ballast because of its presence around my bearings and electronics, and it will find a way to escape no matter how well sealed the enclosure. I have always used washed river gravel as a much more user/tool friendly substitute that achieves the same goals of stability and vibration dampening, and much easier to add/subtract when a machine might need to be relocated.

With the stone I still have the problem of the stone being just and only fill without tying the whole thing together.

[Dennis Nagle]

I got my pillow blocks today. Big suckers. the bore is 2 15/16"


The mount bolt pattern is 9" wide!

[Nate Davey]

To echo Wally's post, here is an end shot of my Nichols.

[Dennis Nagle]

Very similar indeed. For the time being, this will be a bowl lathe only, but someday I may add a bed and tailstock.

[Dennis Nagle]

I just brought home all the steel for this project. Can't hardly wait until the weekend to start welding.