Removing gap in lathe bed

[Spell]

Is there anything I should know before removing the gap in the lathe bed for a AL330?

Will it be hard to get it back in and to line up with the bed?

[Dave J]

Hi and welcome, :2tsup:

You will need to do up the nuts on the taper pins first to remove them, followed by the allen head bolt towards the headstock and the the 4 allen head bolts bolting it down.
At first it will take a tap with a soft hammer or prying it up with a large screw driver because it may be stuck with a bit of bog/putty.


When you replace it, make sure you clean both underneath the gap and the lathe bed, no need to go over board with a wire brush or anything as it just come out of there. Sometimes you will need to use a Stanley knife blade to clean up the edges where the bog split apart. If you do happen to drop something in the gap and raise a burr, you will need to knock it down with a scraper/chisel before replacing it.
Once clean, put the taper pins back in lightly and place a magnetic base on your cross slide with an indicator touching the way, and line up the back and front of the V way, then the rear way.
I found if my taper pins where tapped back in tight my gap would not line up, but if just replaced about 3/4 of the way down it was spot on.

I have lost count of the times mine has been out, and never had a problem putting it back, but it does take 10 minutes or so.

Dave

Edit
Just to add to above, with the allen head bolt towards the headstock, I usually do it up just enough to seat the gap back against the lathe ways before doing up the 4 hold down bolts. Also I use an extension bar on the 4 allen key bolts to do them up.

[Spell]

Many thanks, Will give it a go.

[Garry 3]

When I was a naive and beardless youth some twenty years ago I was about to pull the gap out of a Colchester to spin up a big job when I heard the dulcet Yorkshire tone of my Master; "what the bloody hell you doing boy?"

"Making room for a big one" said I, where upon I was given a lecture that just because it's there doesn't mean you should use it. Still remember that everytime I think about pulling the gap out. On the 1 and only occasion I did it took a fair bit of fitting to get it back correctly, so haven't bothered since. Not saying you shouldn't do it but expect some degree of trouble if you do.

Garry

[Dave J]

I found in the past few years that Grizzly the seller importer of machine tools in the US have a full explanation of how to take it out in there manuals, but in recent years they say if you remove it you should leave it out. I think this is because you get guys pulling it out and not being able to line it back up again. It does take some fiddling, but I think it was directed at people that didn't have a clue and where claiming it on warranty, so they started putting that clause on it in the manual.

The first time you pull it out can be worrying, as people new to a gap beds have heard rumors about removing it.
Once out, it may take a while to re align the first time, but after that it will become quicker each time as you get to know what needs to go where. Like I said above I found my taper pins only needed dropping in by hand and only a bit over 3/4 of the way and not fully seated.
If you just want to try it and don't have a job to do, take the gap out and in 2 or 3 times to get used to what you need to do. That way when you need to you know what to do and you will be a lot quicker doing it.

When I take mine out I don't usually replace it until the next day or so as I get the job done and clean up latter that night, but usually the next day or so. I have never had a problem replacing it yet.

One thing I didn't say above which would be a good idea, is to mount the mag base on the cross slide and check the gap with an indicator before you undo anything and take it out. This way if it is out to start with you will know and not be chasing perfect accuracy when it goes back in. I know they are supposed to be ground all in one, but with Chinese machinery who knows.
Also don't bother running a dial indicator on the top of the V way, it wont give a true reading as it's not precision ground or anything, just use the front and back side of the V way to align it and the rear flat way.

Dave

[Steamwhisperer]

I found in the past few years that Grizzly the seller importer of machine tools in the US have a full explanation of how to take it out in there manuals, but in recent years they say if you remove it you should leave it out. I think this is because you get guys pulling it out and not being able to line it back up again. It does take some fiddling, but I think it was directed at people that didn't have a clue and where claiming it on warranty, so they started putting that clause on it in the manual.

The first time you pull it out can be worrying, as people new to a gap beds have heard rumors about removing it.
Once out, it may take a while to re align the first time, but after that it will become quicker each time as you get to know what needs to go where. Like I said above I found my taper pins only needed dropping in by hand and only a bit over 3/4 of the way and not fully seated.
If you just want to try it and don't have a job to do, take the gap out and in 2 or 3 times to get used to what you need to do. That way when you need to you know what to do and you will be a lot quicker doing it.

When I take mine out I don't usually replace it until the next day or so as I get the job done and clean up latter that night, but usually the next day or so. I have never had a problem replacing it yet.

One thing I didn't say above which would be a good idea, is to mount the mag base on the cross slide and check the gap with an indicator before you undo anything and take it out. This way if it is out to start with you will know and not be chasing perfect accuracy when it goes back in. I know they are supposed to be ground all in one, but with Chinese machinery who knows.
Also don't bother running a dial indicator on the top of the V way, it wont give a true reading as it's not precision ground or anything, just use the front and back side of the V way to align it and the rear flat way.

Dave

Excellent info Dave. Even I have the confidence to remove the gap in my lathe now...and put it back, immediately. The vanguard lathe at work hasn't been put back for probably 50 years. It's hillarious because with the wear on the ways and the fact that the gap is nearly brand new you need to lift the carriage to get it up over the lip. Not great when trying to machine with accuracy. I will try to get a pic today.

Phil

[pipeclay]

Either replace your hold downs and dowels back in the bed after removing the gap or cover the exposed holes to prevent swarf from entering.

[Dave J]

Excellent info Dave. Even I have the confidence to remove the gap in my lathe now...and put it back, immediately. The vanguard lathe at work hasn't been put back for probably 50 years. It's hillarious because with the wear on the ways and the fact that the gap is nearly brand new you need to lift the carriage to get it up over the lip. Not great when trying to machine with accuracy. I will try to get a pic today.

Phil

Thanks Phil,
Thats taken leaving it out for a while to the extreme, LOL
Look forward to the picture.

Just remember to check the gap with a dial indicator before pulling it out. I never did it, but I have heard of guys trying really hard to get it lined back up and it makes you wonder if it was true before they took it out.

Dave

[simonl]

I've taken the Gap out of my lathe. It maybe a Chinese lathe but I didn't have any issues putting it back after having it out for about a month. Just made sure the dowel pins are clean along with the seat and then a few love taps with a soft mallet and all was forgiven! :U

Simon