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cncJim
28-10-2014, 10:42 AM
Hi All,

I have a Warco BH600g lathe which sits on a couple of cabinets.

13761

I would like to put it on some adjustable machine feet so I can level it (My garage floor is not particularly level). Like these:-

http://www.axminster.co.uk/axminster-adjustable-machinery-feet

My question is how many feet should I use? My first thought was just 4 But I am now thinking it may be better with more (4 on the larger cabinet and 2 on the smaller one?)

I like the idea that it would be more stable using more feet but I guess the flip side would be more of a faff to level?

Thanks,

Jim

EDIT:-
Just read that leveling should be done by shimming where the lathe attaches to the cabinets to take any twist out of the bed..? In this case I guess the more feet the better?

EddyCurrent
28-10-2014, 11:07 AM
What about a steel dolly underneath with a foot at each corner;

like this only DIY version and not castors ; http://www.axminster.co.uk/heavy-duty-machine-base

I generally find machines are too low for back comfort so raising them is a good thing for me, it woud also give some height allowing use of a recycled pallet duck board

Neale
28-10-2014, 11:07 AM
I've used those feet on my bandsaw and milling machine and they work well for levelling. Lathes can be a bit fussier, though. How stiff is the cabinet - would it be happier supported at 6 points rather than 4? Will the cabinet itself distort? How many mounting points did the manufacturer provide? I would be inclined to go for 4 as that makes the levelling and calibration easier. Not that I can talk - my lathe sits on thin MDF and ply packing...

cncJim
28-10-2014, 11:41 AM
Thanks for the replies! :)


What about a steel dolly underneath with a foot at each corner;

like this only DIY version and not castors ; http://www.axminster.co.uk/heavy-duty-machine-base

I generally find machines are too low for back comfort so raising them is a good thing for me, it woud also give some height allowing use of a recycled pallet duck board
That's an interesting idea....I will give that some thought. At 6'3 the idea of the lathe being raised up a little sounds very good!


I've used those feet on my bandsaw and milling machine and they work well for levelling. Lathes can be a bit fussier, though. How stiff is the cabinet - would it be happier supported at 6 points rather than 4? Will the cabinet itself distort? How many mounting points did the manufacturer provide? I would be inclined to go for 4 as that makes the levelling and calibration easier. Not that I can talk - my lathe sits on thin MDF and ply packing...
Well the cabinets are 4mm welded steel, so I think they pretty solid. There are 4 holes in the base of each cabinet and I was thinking about just tapping these but looking at there location they seem a little to close to the centerline (along the length of the lathe) for me to feel comfortable. I was thinking I would drill and tap some new holes further out.

Worth saying the lathe is currently not on the cabinets (still sat on the floor after picking it up!!) so drilling and tapping the holes is less of of a problem.

I also just read that I should be levelling the lathe by shimming where the lathe attaches to the cabinets and not try and level it by adjusting the cabinets alone??

So I guess I would level the cabinets first, stick the lathe on and then shim it to take out any twist in the bed?

Thanks,

Jim

Neale
28-10-2014, 12:07 PM
On my machines I used feet with stems that fitted through the clearance holes (mind you, that was 12mm on the milling machine anyway) and used nuts and washers each side to adjust and lock. That way, you don't need to turn the "bolt" in its foot - from memory, the feet I had didn't have a hex or square section to put a spanner on.

As for shimming - depends on the design. My Myford sits on a welded steel cabinet base, rather lighter than yours. With that, because the cabinet is relatively flexible, you make sure you have taken any wobble out of the base, then the lathe has adjustments where it bolts to the cabinet. My "new" lathe is a heavy ex-toolroom machine that weighs around 2800lb on its cast iron base. In this case, the base is part of the stiffness of the lathe itself and the bed is bolted tight to the base. It's difficult to believe that there is any scope for twist in that lot, but the recommendation for setting up both lathes is the same. Stick a longish bit of steel in the chuck, and turn both ends (near to and furthest from the chuck). Ideally, you use a test bar which has a reduced diameter in the middle so you only turn short sections at both ends. Both ends are turned without moving the cross-slide. If both end up the same diameter, you're spot on. Otherwise, put a tiny amount of twist in by tweaking the feet/adjustment bolts and keep trying. Sounds like your machine is another variation - as you say, level the stand, then shim the lathe mounting. Sounds like the most fiddly option, though, but at least you only ever do it once! I guess you have a way to lift the lathe on to its stand that you could use while shimming?

cropwell
28-10-2014, 12:54 PM
Hi Jim,
I have the Amadeal 290V-FF, which is a similar weight to yours. The cabinets are substantial but the tray is only .8mm steel. I am currently modifying the tray to put a drain slope in it for the coolant. When I installed the machine I put down a ply frame round each cabinet and set the frame tops level as I could. Then removed the cabinets and filled the frames with self levelling compound (add a bit more PVA to the mix). The cabinets are rag-bolted to the floor. The tray is being modded by putting a 25mm platform under the bed at each end. I need to raise the bed from the chip tray to give me space to clean out swarf. When I put it all back together I will check the shimming.

I would like the whole machine to be lower as I have to sit to work. I can't stand for long due to arthritis, but I suppose the answer is a higher chair.

Cheers,

Rob

EddyCurrent
28-10-2014, 01:47 PM
Like this ?

http://www.mycncuk.com/threads/2148-Comments-sought-on-new-build-A-CNC-Router-for-RC-Gliders-and-Planes?p=58661#post58661

Lee Roberts
28-10-2014, 08:37 PM
Jim, Tom in the US did a two part video on this, check out the videos below, you should end up walking away knowing exactly what to do:

Leveling and Setup of the Metalworking lathe

Part 1:
http://youtu.be/zIDL77qt1tI

Part 2:
http://youtu.be/GErhXyUb2Go

.Me

cncJim
29-10-2014, 10:04 AM
On my machines I used feet with stems that fitted through the clearance holes (mind you, that was 12mm on the milling machine anyway) and used nuts and washers each side to adjust and lock. That way, you don't need to turn the "bolt" in its foot - from memory, the feet I had didn't have a hex or square section to put a spanner on.

Ah ok, thats a good idea - Saves having to tap the holes!



As for shimming - depends on the design. My Myford sits on a welded steel cabinet base, rather lighter than yours. With that, because the cabinet is relatively flexible, you make sure you have taken any wobble out of the base, then the lathe has adjustments where it bolts to the cabinet. My "new" lathe is a heavy ex-toolroom machine that weighs around 2800lb on its cast iron base. In this case, the base is part of the stiffness of the lathe itself and the bed is bolted tight to the base. It's difficult to believe that there is any scope for twist in that lot, but the recommendation for setting up both lathes is the same. Stick a longish bit of steel in the chuck, and turn both ends (near to and furthest from the chuck). Ideally, you use a test bar which has a reduced diameter in the middle so you only turn short sections at both ends. Both ends are turned without moving the cross-slide. If both end up the same diameter, you're spot on. Otherwise, put a tiny amount of twist in by tweaking the feet/adjustment bolts and keep trying. Sounds like your machine is another variation - as you say, level the stand, then shim the lathe mounting. Sounds like the most fiddly option, though, but at least you only ever do it once! I guess you have a way to lift the lathe on to its stand that you could use while shimming?
Just spotted the same operation in the video's Lee linked to. Perfect. As for lifting it to shim, I have a 2 ton engine crane so it should do the job. :)


Hi Jim,
I have the Amadeal 290V-FF, which is a similar weight to yours. The cabinets are substantial but the tray is only .8mm steel. I am currently modifying the tray to put a drain slope in it for the coolant. When I installed the machine I put down a ply frame round each cabinet and set the frame tops level as I could. Then removed the cabinets and filled the frames with self levelling compound (add a bit more PVA to the mix). The cabinets are rag-bolted to the floor. The tray is being modded by putting a 25mm platform under the bed at each end. I need to raise the bed from the chip tray to give me space to clean out swarf. When I put it all back together I will check the shimming.

I would like the whole machine to be lower as I have to sit to work. I can't stand for long due to arthritis, but I suppose the answer is a higher chair.

Cheers,

Rob
Yes, our machines do sound similar. The tray on mine is also thin but at least already has a slope to it with drain holes. I like the idea of putting down a self leveled pad for the lathe to sit on (sounds the best way...) but I am not sure I will keep the lathe in its current location. I have a feeling it will move a couple of time around the garage before I am happy with it!



Jim, Tom in the US did a two part video on this, check out the videos below, you should end up walking away knowing exactly what to do:

Leveling and Setup of the Metalworking lathe

Part 1:
http://youtu.be/zIDL77qt1tI

Part 2:
http://youtu.be/GErhXyUb2Go

.Me
That is great Lee, thanks for the links. Its one thing knowing the steps to complete a job but it really help being able to see someone do it first! Also the bit about the use and calibration of the levels was great! I guess I need to get myself a precision level. Does anyone have any recomendations? I see quite a few old ones on ebay.....

cropwell
29-10-2014, 10:56 PM
I looked at precision levels and, as an amateur, I thought they are pricey for something I won't use much.
Then I got to thinking..... Why should a lathe be exactly level ? Everything is relative to the axis of the lathe. Basically you want the headstock to point to the tailstock and the carriage to tram to the axis.
So you need to ensure the bed is not distorted. No twist sag or bow. You also need to ensure that cutting forces don't cause distortion.
A lot of this checking could be done with a laser system that fits on the spindle pointing at a tailstock centre. If you can adjust out any wobble and get the laser to align on the axis when you turn the spindle 360deg then the first part is done. next you need to check the tool path is parallel to the axis by mounting a plate with a pinhole at tailstock centre and run the carriage up to the headstock. If the laser beam goes through the pinhole and shines on the tailstock the length of the travel, then all should be ok.
Let me know (politely) if I have got it wrong, I am not an engineer.

Neale
29-10-2014, 11:55 PM
This levelling business set me wondering as well. I can think of a few reasons for doing it. One is that it puts the machine in exactly the same orientation as when it was originally ground, so you should be replicating the original accuracy. But I can't believe that you need a precision level to achieve that - I'm sure that you could get close enough with any decent level. But a precision level might be able to check for twist by checking in various places along the bed and save time spent in machining a test bar until you were very close. If you also set the machine very accurately, you could also use the level for setting work later? I've never done that, but I can see it might be useful on a milling machine.
By the way, don't use the tailstock for setting up. The initial setting up is all about getting the headstock aligned to the bed (or vice versa). That's why you don't use the tailstock when doing the initial checks. The tailstock is usually adjustable, and has to be aligned with the headstock and bed later. I wouldn't trust tailstock alignment on a fresh-from-the-factory machine.

cropwell
30-10-2014, 06:48 AM
You are right about the tailstock as a primary reference it is inadequate. The first job would be to get the laser to point at a target at the tailstock end. When the dot doesn't move with the lathe turning (by hand) then the beam is directly on the axis. Then you can set up the tailstock centre, before checking the carriage. if you only want a relatively accurate level how about this one http://www.chronos.ltd.uk/cgi-bin/sh000001.pl?WD=level&PN=Miscellaneous%2ehtml#a30316004
You can always put it on the bed, zero it and turn it 180deg to check for any slope.

Neale
30-10-2014, 11:05 AM
A reasonable lathe is going to do better than 1 thou/20 micron accuracy - I'm not sure that a laser dot is small enough to do that well.

cropwell
30-10-2014, 02:29 PM
The cheap laser pointers have quite a wide beam but you can shine it through a small aperture (pin hole). If you can make a 1 micron hole, then you have a 1 micron beam width, which would remain in good collimation over a couple of metres.

Neale
30-10-2014, 02:46 PM
Dang - I'm fresh out of 1 micron drills!

cropwell
30-10-2014, 04:12 PM
Use something smaller then and ream it to size ! Make sure you centre punch it first :biggrin:

cncJim
31-10-2014, 10:28 AM
Dang - I'm fresh out of 1 micron drills!


Use something smaller then and ream it to size ! Make sure you centre punch it first :biggrin:

Lol! Nice replies! :hysterical:

Ok so I now have the cabinets drilled, tapped and have 4 adjustable feet on each! First time tapping anything so well pleased with the result!

Next step is to get the lathe on the cabinets.

Not sure what to do about the levelling part.... I would like to make sure the bed is accurately levelled but how accurate do I really need?

So there is this cheep and cheerful level:-
DIGITAL LEVEL BOX ANGLE SENSOR
ACCURACY: 1.75mm/m 3.5mm/m (O.1/ OTHER O.2)
14.95
http://www.chronos.ltd.uk/acatalog/info-30316004.html

And I found this "proper" level:-
300MM Precision Engineers Level
Accuracy 0.02mm/m (0.001?)
89.50
http://www.rdgtools.co.uk/cgi-bin/sh000001.pl?WD=level&PN=300MM-Precision-Engineers-Level-6947333%2ehtml#SID=63

Obviously the more expensive one seems is better in terms of accuracy (by my calculations....) but will it really be worth it? Or will the cheaper level be good enough?

Cheers,

Jim

EddyCurrent
31-10-2014, 10:36 AM
Jim, are you wanting the machine level or flat, I thought flat would be more important provided it's fairly level.

Also if you have a 0.1 angle over a length of 1000 mm the difference in height at each end would be 1.75 mm

cncJim
31-10-2014, 10:53 AM
Thanks for the reply Eddy.

I guess I am mixing terms. The only thing I really am interested in is making sure the lathe cuts as straight and accurately as I can manage. So I think I need to be concentrating on getting the bed as flat (no twist) as possible.

I will level the cabinets first (to provide a solid base) then put the lathe on. Then shim between the lathe/base as required until the bed is flat?

I guess I am talking myself toward the more expensive level! It say an accuracy of 0.02mm/m which sounds crazy... Would you really be able to see that difference with a bubble!?!

cropwell
31-10-2014, 11:08 AM
Jim,

I just don't know the effect of a lathe bed being off level. I guess that the more important thing is that there are no forces distorting the bed. To my mind it might be more practicable to set up with a cheaper level. but before bolting down put the bed on some sort of metal filled epoxy cushions that settle out any twisting forces. Then, when they have set can the fixing bolts be tightened.
As I have said before, I am not an engineer, so some of my thinking is 'outside the box'. I am in the middle of raising my lathe off the tray to give me more room to clean up. So when I have made the platforms for the headstock and tailstock I will either need to get them surface ground or concoct some thing else like liquid metal shimming.

I am certainly following this thread for advice.

TTFN

Rob

Neale
31-10-2014, 12:09 PM
I think the levelling business is to take the worst of the twist out of the bed and bring it close to its original just-ground level of accuracy. However, that isn't going to guarantee the accuracy that the lathe should be able to achieve. Once it's levelled as accurately as you can manage, then you switch to the "machining" test - the test bar machined at both ends. As long as the bed is not worn, there shouldn't be any need for grinding. That's already been done and you are just tweaking out any slight twist that develops in the casting as it ages and stresses release. The instruction manual for my lathe - cast iron integral stand, etc - recommends the "machining" test after setting up with a level, and then rechecking over the next few months. I think the BH 600 will be second-hand (although rather newer than my lathe) so it's likely to be fairly stable by now. I would set it up with a level as close as you can get and then fine-tune by machining. I can't see any point in using self-levelling techniques as they still won't give you the ultimate accuracy although it will certainly help overcome the problems of an uneven floor when first installing.

EddyCurrent
31-10-2014, 12:24 PM
I've just been to the smallest room where I do my best thinking and I thought, things can be relative to a datum or relative to each other.
So using gravity as the datum, a level is placed at the headstock end for example and that is brought into alignment with the ground.
Next everything else is brought into the same alignment either by making it relative to the ground or relative to the headstock. I would suggest relative to the headstock being the most accurate in this instance.
The tools required for alignment should therefore be chosen to achieve these requirements.

Neale
31-10-2014, 12:42 PM
I think you're right, Eddy - the bed does not have to be level to micron accuracy to work OK. However, it's just easier to aim at "level" across and along it than to get to take out twist by making it the same amount off-plumb all along. As to accuracy required - and I'm thinking out loud here so no guarantee of logic! - then a bed that's as about as wide as the centre height will need to be levelled to about the same accuracy as the lathe could be expected to cut. Say, 1 thou in 12" would be pretty good. That's 1 in 12000, which is about 0.005deg. That's a pretty good level...

cncJim
31-10-2014, 12:58 PM
That's 1 in 12000, which is about 0.005deg. That's a pretty good level...

So this level could be just the job then?



And I found this "proper" level:-
300MM Precision Engineers Level
Accuracy 0.02mm/m (0.001?)
89.50
http://www.rdgtools.co.uk/cgi-bin/sh000001.pl?WD=level&PN=300MM-Precision-Engineers-Level-6947333%2ehtml#SID=63

Neale
31-10-2014, 01:09 PM
Looks it - could you lend it to me when you're done?

Just joking - I still think that "reasonably level" followed by a machining test is the way to go, but certainly a decent level should get you pretty close more quickly.

cncJim
31-10-2014, 02:50 PM
Looks it - could you lend it to me when you're done?

Just joking - I still think that "reasonably level" followed by a machining test is the way to go, but certainly a decent level should get you pretty close more quickly.


I agree, i must admit though, with my inexperience I have no idea what "reasonably level" looks like! Machining test after levelling will be done - I think i will be following pretty much what the guy in the videos (that Lee shared) does.

Maybe when I get more comfortable with the machine (and actually make some cuts!)/get some experience/learn about what kind of accuracy I am happy with etc, my feelings about the process may change! :)

Cheers

Jim
(PS - Neale - If I do buy one you would be more than welcome to borrow it anytime!)

Lee Roberts
01-11-2014, 12:18 AM
Yea, Jim hit the nail on the head it's about the lathe staying true over time, any foundation is only as good as it is level? Its counter productive to fight with inperfections if they can be mostly removed first, don't forget Tom uses those levels because he's got them and also uses them for other things.

.Me

Jonathan
01-11-2014, 12:35 AM
I agree with the comments about the purpose of 'levelling' being to help maintain the accuracy of the machine by ensuring the bed isn't twisted. However I'd be careful with using the word 'level' as to me that word imply relative to the surface of the earth, which is a somewhat arbitrary reference (at least in this situation). So long as the bed isn't twisted it shouldn't really matter if it's tilted one way or the other, within reason. I guess it just happens that adjusting to 0 on your engineer's level is convenient...

Also bear in mind that if you're only ever going to be cutting fairly short parts on the lathe then you wont notice errors in diameter due to bed twist, so get it close but don't worry about it too much if you don't need it.