Mill question

[mjbabcock]

I've got a line on a Nichols Mill and I'm trying to figure out if the semi-production version (looks to be automated with six buttons and air hook ups) has any limitations or disadvantages compared to a fully manual version.

Advise is appreciated

Jason

[EricKeller]

does it have a tool changer or something?

[mjbabcock]

I think it has some sort of pneumatic set up that controls some of the movements. It was described to me as, " you set it up to run an operation and it cycles through what you tell it to do…. Kind of like mechanical version of CNC…… Its not a manual machine and it would be tedious to set up to run a single operation… Im a blacksmith with very little machine tool experience so I really have no place to comment on if it will or won’t do what you want"

As the seller isn't that knowledgeable about the mill, I wasn't certain if there was a manual option on the pneumatic operation or not. I think it's like the one in this picture.

[EricKeller]

this is one step up from blind speculation, but it looks like it has a pneumatic cylinder driving the horizontal motion. It would be nice if it had an air motor driving the lead screw, but it doesn't look like that to me. If it still has a lead screw installed but disconnected, you have no issues. I don't know how much a lead screw would cost you.

Those machines are nice, I'm starting to think I want one.

The Y axis lead screw and knee screw are still there.

[cicli polito]

I use a nichols in the shop quite frequently. Adding to what Eric said:

It is possible to convert a "production" model machine to a "semi-automatic - standard" model easily, and it takes a substantial amount of work and refined machining skills to turn that into a "toolroom." I certainly wouldn't be able to make mine a toolroom model. I would guess based on that photo that the one in question is a production model. Both PR and SA models have rack and pinion assemblies in the table Essentially what this means is that you can remove all the pneumatic attachments, and then install a small pinion gear underneath the table which will mesh with the gear that's already equipped to most (from my understanding) Nichols millers. On some tables the pinion gear is already present.

What happens then is one of two things, if you have a leadscrew you can install a handwheel and you're good to go. If there's no leadscrew, but there should be by evidence in the casting, then you can find a scrap machine or fabricate one yourself/have one made. You'll probably also have to fabricate a half-nut for the leadscrew, they tend to get lost or broken if they aren't getting used in the life of the machine. Some later-model production millers don't even have provisions in the casting for a leadscrew (again, from my understanding and I'm no means an expert on Nichols, just use one), only rack and pinion.

Without a leadscrew, but with all the gears intact, you can still install a handwheel and use it to move the table back and forth along the x-axis by rack and pinion but without any adequate instrument of measure, so it makes it hard to center accurately and any adjustments need to be very accurately done and quite frankly, take forever.

If I had any advice to give you, I'd say consider this mill only if you want a dedicated, do-one thing manual tool with a permanent vice and/or fixture on it.

If you go to check it out, something to look for is whether the head still has it's counter-weight movement up and down. If the back of that head is covered in swarf and there's crud right above the head ways, that thing is probably stuck there. But again, if you're only using it for a one-operation machine, that table height can be dealt with by appropriate fixturing. The x- axis will largely be slop on all of these machines, but for something like tube mitering you only need the y (in/out feed toward the spindle) and that should be pretty tight.

Here's a great tutorial (not mine) on how to make your own half-nut, if you go that route:

http://www.docsmachine.com/projects/halfnut/nut01.html

hope that helps,
dan.