Bolt it down dilemma...

[jwmay]

So how many of you have your Atlas bolted down solid?

I haven't done it yet. It turns accurately, but I can't get a center hole true to the axis. It always ends up crooked when I drill it. I figure this is because something is deflecting. So yes, even if I'm wrong, I know it needs done.
Below you see how the lathe sits. I'm having some trouble coming up with a flexible solution. The toolbox is at the perfect height. The lathe is exactly where I want it for height too. The toolbox is flexy. The concrete is not level. I want it to stay mobile. Ideas? I have a welded steel bench that formerly held the lathe, but its not mobile and has limited storage. Frank Hoose made it work with this toolbox and his PM machine. But I don't think the Atlas has the strength to sit where I've put it. Or... is this crooked center hole problem coming from something else? The tailstock is centered to within .003". That seems to be the best I can do.

 

[MrWhoopee]

I would say if it turns accurately you are very lucky and your hole drilling problem lies elsewhere.

 

[RJSakowski]

I would look for a twist in the tailstock. Check by measuring a pin with the quill retracted and again at full extension. The numbers should be the same. Erros can arise from a variety of sources; wear in the tailstock or ways, wear in the quill, or angular runout of the MT shank or the chuck.

 

[MrWhoopee]

I would look for a twist in the tailstock. Check by measuring a pin with the quill retracted and again at full extension. The numbers should be the same. Erros can arise from a variety of sources; wear in the tailstock or ways, wear in the quill, or angular runout of the MT shank or the chuck.

Not to mention the grind of the drill point. I would start with the simplest possible causes and work my way up the chain. The OP didn't state what size(s) hole, material, how deep or how far of center. I've seen 1/4" holes that were a full diameter off center in 4" depth due to bad drill grind.

 

[jwmay]

I agree that I am very lucky. Thanks fellahs.

 

[wa5cab]

Your first error is that the lathe stand is not anchored. And your second is that the lathe is not leveled and anchored. Without doing those two things, there is no point in the rest of us spending time on your problem. The Atlas lathes are not heavy enough in themselves to substitute for this. The way in which to do it is explained many places on the site.

After properly rough-leveling and anchoring the stand and leveling and anchoring the lathe, report how far off of the headstock or spindle center-line the tailstock is. Front-to-back errors are easily adjustable to zero. Vertical and angular errors are another matter.

 

[jwmay]

The toolbox is at the perfect height. The lathe is exactly where I want it for height too. The toolbox is flexy. The concrete is not level. I want it to stay mobile. Ideas?

This is actually what I wanted help with. I only mentioned the problem because I thought it's related.

I have a welded steel bench that formerly held the lathe, but its not mobile and has limited storage.

Putting it on this bench would solve the problem. Oak top, 3/8 angle iron frame, with anchor points on the feet.
Point is it'd be too short, not mobile, have not enough storage.
Anyways thanks to all. I was just fishing for an idea for something simple. I don't actually need any help. I know what needs done. Sorry for wasting your time.

 

[NC Rick]

My 10” Delta was only bolted to the cabinet. I would think bolted to some kind of toolbox or cart would be good. It could be on casters. Just because you don’t have your lathe bolted and grouted to a 10” slab with pillars driven to the bedrock shouldn’t stop you from making things. With a good drill bit (ground well) there is going to be run out or bend. Part of the game. We don’t want to use carbide stub length drills for every hole right? Do you use anything as a spot drill? A H.S. steel spot drill, say a quarter inch size, isn’t expensive. Get one that matches the normal point angle of your jobber drills (mine are all mostly 118 degrees) and just make a cone, under the full diameter of the spot drill and see if you can’t drill a nice hole with that. FWIW I totally screwed up a pretty nice keyless chuck (made in Poland) by using it with taps and end-mills in my lathe. Putting a drill in that chuck makes it point in all kinds of directions off center but with a spot drill it still starts on center but makes holes much bigger than the drill size and drags bad on pull out. Your question and what you are doing is great.

 

[cross thread]

I had a table saw that sat on a frame , you stepped on a lever and that would lower and lock the front two wheels to the ground . The back two wheels were already on the ground . You could get a set up like this to work on the steel bench and then have a jack at each corner to get level . To solve the anchor bit install female threaded holes into the concrete and anchor points on the bench to bolt it down .
I bought the frame from Rockler . There are some other roller frames at the bottom of this add . https://www.rockler.com/bora-port-a-mate-pm-1100-plywood-mobile-base-kit
Mark .

 

[mickri]

What you want to achieve is to eliminate any twist in the bed. The bed does not have to be level. It just can't be twisted. Definitely bolt the lathe to the bench. Then use shims to take out any twist in the bed. Depending the on accuracy you need it is probably ok to bolt it to the tool box it is currently on. The plywood that you have the lathe sitting on will most likely crush over time. The plywood does add stiffness to the top of the tool box. I would keep the plywood for the extra stiffness. Looks like you are using two pieces of plywood. You should use one piece of plywood that covers the entire top of the tool box.

The easiest way to adjust the bed in your set up is to have one nut with a big thick washer that holds the plywood to the tool box. Then use another nut with a big thick washer that the lathe sits on to adjust the bed. Once you get the twist out use a third nut to hold the lathe in place.