Author Topic: Shars 8” machinists level advice  (Read 597 times)

DABCI

Shars 8” machinists level advice
« on: April 06, 2020, 10:23:42 AM »
I have one of the PM 1340 lathes. I have finally gotten around to installing the three phase conversion and I’m getting ready to level the machine. I have an 8 inch Shars machinist level. Unfortunately, the instructions are in we could best be described as Changlish and I can’t figure them out. The only video on YouTube is narrated in Chinese.

It seems that the bubble is not In the middle of the level. I understand this is not important as long as it’s in consistent position. Is this true? Can anybody give me some advice on how to use this thing?

woodchucker

Re: Shars 8” machinists level advice
« Reply #1 on: April 06, 2020, 10:33:34 AM »
so that bubble should be adjustable.
you want to find a fairly level surface, and flip the level 180 and put it in the same spot. if the bubble winds up at the same spot you are good, if not, adjust the bubble 1/2 way between, and flip it 180.. rinse and repeat until you are good.


you only need them to read the same 180 from each direction... then you know you are coming back to the same spot, and that you are are consistent.
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

GNAP

Re: Shars 8” machinists level advice
« Reply #2 on: April 06, 2020, 11:29:23 AM »
I’m somewhat confused are you talking about the lathe being level or the readings of the level??


Does a lathe have to be perfectly level, no, as long as the lathe is straight, think about a lathe on a navy ship, the ship is constantly moving, so what was level 30 seconds ago, may not be level now.

Getting a lathe as close to level in a shop as possible, is basically the easiest way to make sure it’s straight.

 As Woodchucker said, by rotating the level 180 degrees and see if the reading is consistent, is the way to check the actual level itself, if it’s off by a mark, and you rotate the level, if it’s accurate it will still be off, by the same amount.

jpigg55

Re: Shars 8” machinists level advice
« Reply #3 on: April 06, 2020, 11:41:28 AM »
It's my understanding that leveling ensures even loading on the bed to prevent induced error due to torsion on the bed.
Machine doesn't have to be level as long as it's not torqued out of square.
Made sense to me anyway.
SB 9A, Clausing 8520, Sanford MG 612

Carpenter84

Re: Shars 8” machinists level advice
« Reply #4 on: April 06, 2020, 11:42:28 AM »
I think he's just trying to calibrate his level.

You don't need the video from Shars or a video specific to that exact level, any of the machinist leveling videos will suffice. I have the same Chinese level, but sold by accusize. It's a bit mind numbing to calibrate them. The machinist levels are stupidly sensitive.

Here's Tom Lipton's video on calibrating levels.

https://youtu.be/zIDL77qt1tI


Edit: I could also be wrong. He's just trying to understand the level.
Yes, I suppose if the level isn't calibrated it can still be used. You just won't know if the lathe is level, but it'll at least be straight with no twist
« Last Edit: April 06, 2020, 11:44:18 AM by Carpenter84 »
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

chips and more

Re: Shars 8” machinists level advice
« Reply #5 on: April 06, 2020, 02:09:49 PM »
Hi and welcome. The lathe does not need to be “level” per-say. BUT, the bed/ways should be straight. You can check straightness using a level. And your level does not need to be calibrated either. All you need to do is understand that the bubble/vial reading MUST be the same in your findings. Do not rotate the level. Just move it up and down the lathe bed/ways in the same orientation and position when you take your readings. Good Luck.
« Last Edit: April 06, 2020, 02:11:37 PM by chips and more »

woodchucker

Re: Shars 8” machinists level advice
« Reply #6 on: April 06, 2020, 02:53:27 PM »
a friend who is a machinist told me that while not required to be level, there are times where you want it level. The reason being is that you may use a level to setup a jig. If the ways are level you can rely on a level reading to set something.


or you could use an inclonometer to read the parts angle..


but no you don't need level.
just no twist, and sometimes you need to induce twist to get the lathe to cut straight... yes... if it taper you  may need to adjust and induce twist... too complicated to go into here right now... I'm working
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts

4GSR

Re: Shars 8” machinists level advice
« Reply #7 on: April 06, 2020, 04:45:43 PM »
Welcome to the forum.

Since you have a new lathe, you want to set it up and level it so there is no twist in the bed.  You don't care if the bed goes down hill or up hill, or tilt in or out.  Just want to get the same readings from the headstock end of the bed to the tailstock end of the bed with the level.  As long as the level is kept in one direction and not turned 180 degrees.  I know, it's thick as mud.
Ken

DABCI

Re: Shars 8” machinists level advice
« Reply #8 on: April 08, 2020, 08:52:21 AM »
So as I understand that there’s no necessity to have the bubble directly in the middle of the level To have it work correctly?

chips and more

Re: Shars 8” machinists level advice
« Reply #9 on: April 08, 2020, 09:22:49 AM »
If you want your lathe/machine to be “level” and have straight bed/ways, then yes the level must be calibrated/bubble in the middle at all orientations.

If you just want a straight bed/ways then I would set-up the level so the bubble is just kissing a line and not in the middle of lines. This would give you a better resolution instead of guessing how centered the bubble is…Good Luck, Dave

DABCI

Re: Shars 8” machinists level advice
« Reply #10 on: April 08, 2020, 09:27:21 AM »
I guess my question is how do I know that I have a completely level true surface as a reference point  so when the bubble goes to the center I have a true horizontal surface? I was just trying to get my head around this I’m sorry if it appears to be a stupid question

woodchucker

Re: Shars 8” machinists level advice
« Reply #11 on: April 08, 2020, 09:34:15 AM »
watch the video link Shawn provided. It explains it all on how to set the level.


Easy to understand if you watch it. I provided a text but the video should clear it up, if you didn't understand what I was writing (often the case  :73: )
Jeff
Clausing 8520   SB Model 9a - power hacksaw, Milwaukee band saw in a table.  Delta Rockwell Surface Grinder (not online yet .. being rebuilt where am I going to stick this)
For pics: https://imgur.com/user/woodchucker/posts