Monster Lathe Phase One (and a "small dilemma")

[David DeCristoforo]

The manufacturer of the new "Dynamotor" is sending me a 1.5 HP 220v motor for "testing and review".
Motor.jpg
There are some advantages and some disadvantages to going this way. On the plus side, it's pretty much a "bolt on" solution. Everything is self contained in the motor itself although I will be rigging an on/off switch on the front side of the lathe (Mark provided a box cast into the front for exactly this purpose). Obviously I would like a more powerful motor but realistically, I'm not going to be spinning 48" diameter chunks of wood on this thing. At least not right away! And the whole thing can be upgraded at some point if I find I need more power. Also, this motor is designed to maintain a high torque level at lower speeds. Even so, the mfgr recommends keeping the motor at 600 RPM or better to maintain maximum torque. The speed range of the motor is 400 - 2400 RPM so some pulleys are going to be needed. The spindle already has a 6" pulley so I plan to mount two pulleys on the motor, a 2" and a 6". This will give me two speed ranges. With the motor dialed down to 600 RPM, I can get the low end spindle speed down to 200 RPM with 2400 RPM being the high end. This motor is full of "new age technology" and that's a lot of little gizoids and rizmos, something that I have always tried to avoid when making tool decisions. But it's a beauty and will look great hanging off the back of the lathe and, hopefully it will work well forever. A full review on this motor is in the offing.

As to the tool rest, here is my basic plan:
http://www.daviddecristoforo.com/Misc/tool_rest.pdf

Still thinking about this one but I sent a copy of this to Jeff Nichol and also to a welder friend who used to live here but moved "up north" and may or may not be able to do this. This is the biggest "sticky wicket" at this point because I have zero tools for making anything like this.

So that's it for now.......

[Rick Markham]

David, I will be interested to see what you think about the brushless motor. They tend to have some different characteristics than brushed motors. These are the first large AC motors I've seen, I know their smaller DC counterparts outperform traditional DC motors. Definitely let us know your thoughts, it should offer higher torque in a smaller package, with the benefit of outlasting traditional brushed motors. (They also tend to sound different)

[Mike Cruz]

DD, I picked up a VEGA bowl lathe with a 24" swing a little while back (ended up selling it when Jeff made me the other bowl lathe). It came with a 1/2 hp Baldor motor! Yes, 1/2 hp. The reason, is that it had a jackshaft, thereby increasing the torque. So, if you want to make "sure" that that 1 1/2 hp motor will be enough, use a jackshaft.

As for the tool rest, is that supposed to be bolted down? Might be a bit tippy if not...

[David DeCristoforo]

"They also tend to sound different"

That's one of the things the guy mentioned. He said, it's not loud but it sounds different from a "regular" motor. Remaining to be seen (or heard!)

"...tool rest...Might be a bit tippy..."

I'm thinking that the steel plate gussets should make it pretty rigid. I have not come up with "specs" on this yet but I'm thinking that the main column would be 2" steel pipe which should also be pretty rigid. I'm not wedded to this design and am open to any and all suggestions at this point. I was looking at some pre-made units like the one Robust sells but OMG! The prices! Like I thought hey... I could rig up a PM 20" bed extension and get a PM tailstock and have a "stubby bed" thing! That would be cool. But the bed extension alone is twelve hundred bucks! Not in the cards right now. I might still need to work out some kind of short bed/tailstock setup because it would be great to be able to bring a tailstock into play. And I'm already thinking about trying to find someone who could bore a 1/2" hole through the spindle to allow for vacuum chucking.

A jackshaft might still factor in but I would like to just lap the motor on and see how it works. Then, if it's needed, a jackshaft could easily be added. But if I can keep it simple for now, that would be good...

[Thom Sturgill]

One suggestion on the tool rest would be to make the foot adjustable vertically (with a locking mechanism of course). Floors are never completely level and true, and I'm sure that's true of your tent as well.

I would suggest either welding a nut on the end of the main 'L' tube and all-thread on the foot plate with a lock nut on the all-thread, or just duplicate what you are probably doing at the top for the tool rest post and drill a hole on the side of the L tube and weld a nut on so that a threaded handle can lock the foot post.

Making that adjustable also gives some lee-way on mounting that to the monster once its fabricated.

[Mike Cruz]

DD, two thoughts. If you really want a bed, see if you can pick up a used old parts lathe. I've seen 'em around. There's even a PM90 one on Ebay for $160 right now in CA. Item number: 350582420514

Secondly, here's a link to a guy's bowl lathe and how he tackled things. http://www.winburn.com/AboutMe.asp Maybe that'll give you some ideas...

[David DeCristoforo]

I've been looking at that lathe for quite some time now. That's very close to how I would like to do a bed. Only I might go a bit longer to accommodate a tailstock... Sure wish my welder buddy hadn't moved!!!

[Rick Markham]

DD, The brushless motors I have heard sound "off" for a normal electric motor, it's just enough different in motor noises that it would make you think something isn't right. (it's just different from what we think an electric motor sounds.)

If you had a friend at a machine shop, you could have him make you some beefy articulated arms, using large thrust bearings (like on the Kobra) for your articulated tool rest. If you used a stack of two like in your drawing you probably wouldn't even need a foot on the bottom (other than to keep it where it needs to be) I guarantee there wouldn't be any vibration/deflection. You could set two pickup trucks on it (you know you want to)

[David DeCristoforo]

"If you had a friend at a machine shop..."

I only wish. I used to have such a friend. He was an amateur machinist and had a "full on" machine and welding shop in his garage. Plus he was the kind of guy who would leap right off the wall at the mere mention of such a project. Unfortunately, he moved to Arizona some years back and , more unfortunately, his parting of the ways with his wife at the time was somewhat less than amicable and she made mention of the bottom of the Sacramento river when the subject of his tools came up….


I also had another friend who was a metal sculptor and ran the UCD welding shop. It was a "dream job" but he met a lady who lived in Washington and… well… you know how that goes.


So at the present time, I am bereft of such resources and lacking is any of the equipment needed to make this stuff. If I had some welding kit and metal cutting and drilling tools, I would be out on the back patio on my hands and knees right now...

"...You could set two pickup trucks on it...(you know you want to)..."

One pickup truck would do fine....

[David DeCristoforo]

Sometimes we all need a smack in the head! When I woke up this morning, I remembered that I still have a spindle that I had made years ago to jig up a faceplate to turn some radiused crown moldings. I dug it out this morning and it's perfect for a jackshaft and even has an 8" sheave on the end! All I'm going to need is two flange bearings, two pulleys and some belts. I can pick those up locally in the next couple of days.

monster_lathe_9.jpg


Here is what the final drive setup is looking like at this point. All of the speed ranges are based on not running the motor below 800 RPM.

http://www.daviddecristoforo.com/Mis...ive_config.pdf

[Roger Chandler]

On paper that looks like it will work, DD...........the actual hookup of every component will tell the story.......looks like you are on your way........good luck!

[Rick Markham]

If I had a knee mill, and the metal lathe that's on my eventual "to-do" list (right after the freestanding shop in my backyard, on said list) I would jump on the opportunity to make the parts.

Maybe it's time to make a new friend in the Metalworking section of the Creek. (If it's still on here and active)

[David DeCristoforo]

"If I had a knee mill, and the metal lathe..."

If I hade those things, I'd invite you over to help me make the parts!

[Rick Markham]

"If I had a knee mill, and the metal lathe..."

If I hade those things, I'd invite you over to help me make the parts!

If you had those and you invited me over you would probably have to chase me off LOL

[Van Huskey]

David, do you have a price on the Dynamotor? It can't be "cheap" but I have several projects planned using VFDs and I would love to try one if it is even in the ballpark for me cost wise.