Making plans to build a concrete bowl lathe - opinions welcome.

[Nathan Hawkes]

Did You have a soft start programed on the VFD Nathan?
I am working on a tensioning devise for the motor....Pondering...

The rockwell had a 1phase motor without a VFD. It was definitely NOT soft starting!

Before I decided to just leave it, I had envisioned a plate at a right angle to the motor shelf, with an arc cut into it, and a tensioning bolt that anchored into another plate screwed to the frame. I wish I were more computer savvy---I need to learn googlesketch.

[Mark Norman]

The inserts worked out well but I have other ideas in mind....Will do for now though..

[Mark Norman]

The rockwell had a 1phase motor without a VFD. It was definitely NOT soft starting!

Before I decided to just leave it, I had envisioned a plate at a right angle to the motor shelf, with an arc cut into it, and a tensioning bolt that anchored into another plate screwed to the frame. I wish I were more computer savvy---I need to learn googlesketch.

Like an automotive belt tensioner?
I'm thinking along the lines of a turnbuckle theme with spherical rod ends.

[Mark Norman]

Turned out distorted big time...
Pounded it in the hinge....LOL LOL



On my second attempt I turned the bushing down and it fit much better...

[Kim Ford]

Mark;

I am following this closely and am very excited for you. However, and there always is a however. Share with me you plans for stablization for the x axis. (Front to back is y; left to right is x; and vertical is z.) It looks like y and z are covered and you may be planning a bed that will accomplish this but I just wanted to ask.

I assume you are going to pour some type leveling feet in the immediate spindle base as well.

[Mark Norman]

Kim,
Reference post 86 you will see some big rebar, I will cast the body with the four pieces of rebar sticking out of the face way down low. Then ref post 61 and you will see the 8" water main pipe I plan on using for the body under the ways. Somewhere up there^^ I mention the process for casting the machine.
No, no leveling feet, I will dry-pack grout under it as needed/if needed.

And thanks for sharing in my excitement...

Back to work

[Nathan Hawkes]

Like an automotive belt tensioner?
I'm thinking along the lines of a turnbuckle theme with spherical rod ends.

That's exactly what I had in mind with the auto belt tensioner. How would the spherical ends work??

[Mark Norman]

That's exactly what I had in mind with the auto belt tensioner. How would the spherical ends work??

Hi Nathan,
The rod ends allow for misalignment in the members in which they are attached. I'll post up a pic later this evening when I get the mock up done. One of the design obstacles is the fact that the motor needs to allow for lateral movement for belt changes and so does the tensioner. I think I have it figgured out but I won't be sure until I get it mocked up and see how it all works together.

I just got home from work and soon to head out to the shop for more tinkerin

[Richard Madison]

Hey Mark,
This is great fun for us watching your project evolve. Very considerate to take time to keep us posted.

Just realized I have not seen the lift eyes or slots for fork truck forks. Probably just missed that post, as am confident that you have provided for moving the lathe when complete. I think that your hinge and bushing motor mount is going to work fine.

[Mark Norman]

Thanks Richard, I think part of the fun is sharing with you all and the encouragement you all provide me.

I'm getting a little frustrated with it tonight. The further along I get the more complicated it gets. All the things that need to be considered gets a little overwhelming.
On the surface it looks fairly simple but in three dimensions things start getting in the way of each other. I have to keep in mind the thickness of the wood forms that will go away after its cast.... I even considered loosing the jack-shaft altogether but I will work it out.

I haven't really considered lifting the machine because I don't plan on moving it once complete but I guess now is a good time to think about it (like I didn't have enough to think about ) I don't think it would be real tough to attach something to the myriad of hardware I have sticking out of the concrete...lol lol Heck, I would bet you could lift it by the spindle, but I wouldn't...lol

BTW, I have an overhead trolly crane in the workshop capable of lifting a ton,,, literally... And I plan on positioning the lathe directly under one end of the hoist so I can use it to get large blanks up on the spindle as I age...

I just came in the house cuz its getting real cold out tonight. 36 outside now and its April!!!

[Mark Norman]

Let the pics speak for me...















My trolley hoist I built into the shop when I built it..



Its holding a BBC 454 at the moment..




Edit...one more pic.

Cant wait till I get the sheaves tomorrow...

[alex carey]

looking great.

[Mark Norman]

looking great.

Thanks Alex...

Feels great too...

[Steve Frederick]

Nice solution with the tensioning device!
Will the end toward the floor get threaded LH to act as a turnbuckle?
Looks awesome!

[Mark Norman]

Nice solution with the tensioning device!
Will the end toward the floor get threaded LH to act as a turnbuckle?
Looks awesome!

Thanks Steve,
and yes, with a lock nut.