LATHE GAP BED REMOVE/REPLACE

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ARM said:
Hi Guys
This may seem like a duh question, but it has to be asked. And we need to know. So kindly do overlook the ignorance.
We have read some place that it is a real pain to replace a GAP in the Lathe Bed and when once removed it might as well just stay off.
Now that is not how we would like our Lathe kept.
We have a small repair project we would like to tackle which requires that extra Diameter and are having doubts in our ability to be able to replace that GAP.
Is it really that impossible or is there a specific method or way in which it can be easily done with some patience or by marking prior to removal ???
Would immensely appreciate input from some of U experienced Gents here.
Thanks in advance
aRM
Click to expand...

11-19-14 SUB: Removing gap in a gap bed lathe.

Many apologies. I recently listed an overview for removing a gap in a gap bed lathe. I forgot to go over the removal of locating
pins ( some may be tapered ) in regard to the taper pins and/or cover, most likley the pin & cover will have a threaded hole(s). If this is the case you will have to machine a steel cup & determine the threads & obtain a bolt ( threaded rod would be better ) and in the closed end, of the cup, drill a hole so that the removal bolt/rod will just slip through the drilled hole. Thread screw/rod into pin hole, place cup over rod & screw on a nut (may have to make a nut that would be thicker than a standard nut). Screw down nut until you feel pin coming out. This should loosen the pin & then you can remove it. After pin (s) are removed then you can proceed to remove the gap. NOTE: taper pins are tight & make sure threaded rod is screwed in all the way. Also make inside diameter larger that the locationg pin for clearance.:))

Any questions feel free to contact me on this website.

Respectfully submitted,

jbollman
 
jbollman said:
11-19-14 SUB: Removing gap in a gap bed lathe.

Many apologies. I recently listed an overview for removing a gap in a gap bed lathe. I forgot to go over the removal of locating
pins ( some may be tapered ) in regard to the taper pins and/or cover, most likley the pin & cover will have a threaded hole(s). If this is the case you will have to machine a steel cup & determine the threads & obtain a bolt ( threaded rod would be better ) and in the closed end, of the cup, drill a hole so that the removal bolt/rod will just slip through the drilled hole. Thread screw/rod into pin hole, place cup over rod & screw on a nut (may have to make a nut that would be thicker than a standard nut). Screw down nut until you feel pin coming out. This should loosen the pin & then you can remove it. After pin (s) are removed then you can proceed to remove the gap. NOTE: taper pins are tight & make sure threaded rod is screwed in all the way. Also make inside diameter larger that the locationg pin for clearance.:))

Any questions feel free to contact me on this website.

Respectfully submitted,

jbollman
Click to expand...

Having read and re-read all of this we reckon it complicates matters even more, which now clearly goes to show that this is just not one simple straight remove-replace procedure. And the latent surprise discoveries, if any, are another contentious issue. No gainsaying what exciting/depressing discoveries, like what we have just been told by fellow well wishers, will be unearthed.
Heck Man, for rookies this is going to be like playing on the railway line.
To cut a long story short, methinks we rather go to someone with a bigger Turning Diameter and pay for the small repair job than mutilate our good machine.
Period.
We will be failing if we do not acknowledge our appreciation for Your esteemed input as not only us, but certainly numerous others as well, we are sure, would have benefitted from this discourse.
Thanks a stack once again
Take Care
aRM
 
This is my first post so here's hoping I get it right.

I have a 12 x 36 Chinese Lathe. Its just over 10 years old and I have used it commercially. I am very pleased with it. Yes, I have changed some of the bearings, and the motor, but its been a great machine.

Removing the Gap. I have mine in and out often and have modified it by drilling two holes in the base of the gap and adding two jacking screws to lift it clear of the bed on removal. Two grub screws fill the holes when the Gap is installed. Makes it easy for me.

Cheers,

Rangi.
 
Hi
when putting the gap back, is oil or grease the best for rust prevention.
thanks jeff
 
A Tos is a better and MORE EXPENSIVE lathe than the Asian ones. I'd EXPECT the gap in a TOS lathe to go back correctly. But,it really is a gamble taking the gap out of an Asian lathe. As mentioned,I have the SAME lathe at home as we had in the Tool Maker's Shop at the museum. The lathe's gap at work did not go back perfectly. Fortunately,MY gap did! That's a 50% chance of success!

It all depends upon how properly the cast iron was heat treated before the gap was ground in situ. I'd certainly expect the Tos to be built more carefully than a cheap Asian lathe.
 
george wilson said:
A Tos is a better and MORE EXPENSIVE lathe than the Asian ones. I'd EXPECT the gap in a TOS lathe to go back correctly. But,it really is a gamble taking the gap out of an Asian lathe. As mentioned,I have the SAME lathe at home as we had in the Tool Maker's Shop at the museum. The lathe's gap at work did not go back perfectly. Fortunately,MY gap did! That's a 50% chance of success!

It all depends upon how properly the cast iron was heat treated before the gap was ground in situ. I'd certainly expect the Tos to be built more carefully than a cheap Asian lathe.
Click to expand...

I hear ya, I don't particularly like taking the gap out because it weighs 150+ pounds and requires the use of the chain hoist, my only experience with Asian lathes is using an Enco in a customers maintenance shop, no spindle brake and some rather cryptic spindle speed controls, otherwise appeared to be a useful machine for hobbies and or general equipment repairs. I would not relish having to make 50 or 100 repeating parts on one.
 
I'm reading machinists afraid to remove the gap bed . With all the tools and indicators we own your afraid it won't fit . Really I just don't believe it , if it's to tough why did you buy it. I'd never be afraid to pull it. If it don't go back find out why and fix it , polish sand or lap . Shame if chips or grits there. But not use the feature ,NO WAY IF ITS THERE USE IT.
 
I tried to remove the gap from my 20" Lodge & Shipley lathe. Pulled the four bolts but could never get the dowel pins removed. Couldn't even get it to budge any at all. I estimated the weight of the gap piece at about 350 lbs! Yikes! Once it sells, I'll let someone else worry about removing it.

100_1574.JPG
 
Silverbullet, we have given sufficient reason for beginners to be concerned about removing and replacing the gap. I personally dislike having to, but when you're in this to make money, you do what you have to. I've had the gaps out of machines up to 72" swing, and it is no fun, and often takes longer than the job. My primary lathe I don't think I will take it out. I have other, larger machines that have already been through it, and will be used as a gap bed when needed.

But, there's no reason for you to run other guys down because they are rightfully concerned. It's not all about having tools and instruments. Everyone here is not a full fledged machinist yet, and could experience problems they don't know how to deal with. This forum is always a place to come for help, but not everything can be handled over the Internet. I'm sure they don't appreciate being called "afraid". I don't appreciate you calling them afraid. It goes against our mission of being a place where any question is ok, and no one will be allowed to berate or mock or ridicule other members. So, please keep those opinions to yourself. They are not welcome here. We're here to help the uninitiated, not to make fun of them.
 
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