BV20 Carriage Lock

[guerd87]

After playing around with my new lathe for a while I have found I really need a carriage lock when facing.

In the owners manual I got with my lathe it mentioned 1 bolt on the carriage as the carriage lock. It tightens down on the ways and I can see where the previous owner has done so.

I think that this also looks like the area where a Follower Rest should be mounted.

Are these bolts really for use as a carriage lock? I dont really like the idea of tightening a bolt to the ways and am considering building another kind of lock.

If this is normal please tell me as Im only new to working on Lathes.

Cheers,
John

 

[guerd87]

Also should mention:

I initially though the 14mm Hex head bolt was the carriage lock - it may even be.

If I tighten it up I can feel the carriage get stiffer but I can still move it quite easily when it is cranked down tight. If this is suppose to be the lock - How do I adjust it lock down tight?

 

[Wizard69]

After playing around with my new lathe for a while I have found I really need a carriage lock when facing. In the owners manual I got with my lathe it mentioned 1 bolt on the carriage as the carriage lock. It tightens down on the ways and I can see where the previous owner has done so.

The ways are the machined surface that the saddle rides on. From the pictures I can't determine if those are ways or not. They could be ways for the tailstock or just machined surfaces. Either way I see the manuals suggestion that these are for locking the saddle down to be bunk.

First and foremost you want. Your saddle locking to be a clamping action, this looks like it would tend to push the saddle apart or up from the ways. Even if that was the manufactures intention it is still nonsense.

I think that this also looks like the area where a Follower Rest should be mounted. Are these bolts really for use as a carriage lock?

I don't have that lathe so I can't answer one way or the other as to the manufactures intention but from the standpoint of lathe design I think it is asinine to clamp a saddle in that matter.

I dont really like the idea of tightening a bolt to the ways and am considering building another kind of lock. If this is normal please tell me as Im only new to working on Lathes. Cheers, John

I think your feelings here are leaning in the right direction, this is no way to clamp a saddle to the ways. As to normal for this lathe, I don't know but long term I don't personally like the approach. Like all things modern I'd look up saddle locks on the Internet to give you Brian a few ideas to digest.

 

[guerd87]

After doing some searching around I found a heap of cam activated lever locks and all kinds of goodies, way out of my league at the moment.

Found a few simple ones, here was one of them.

25x10mm Alloy flat stock and a little bit of work.

 

[mechman48]

guerd87

You were correct in the assumption that the bolts were for a follower steady (known as traveling steady here in the UK) Using the bolts as were you would have pushed the saddle up from the ways & marked the ways with bolt indents plus if the holes aren't tapped all the way through the you have the possibility of stripping the threads out or, in worst case scenario cracking that corner of the saddle.

Your method of clamping is correct, pulling down onto the ways, but the clamp is usually on the other side of the saddle (the tailstock side,) as you have it now you may have difficulty in fastening the clamp if you're too close to the chuck plus the possibility of catching your knuckles/hand on the chuck, plus it's much easier to clamp from the other side, be safe!

Regards
George

 

[guerd87]

Thanks

I was going to put it on the rear but no where to mount it. I think i may have to drill and tap some holes into the carriage.

John

guerd87

You were correct in the assumption that the bolts were for a follower steady (known as traveling steady here in the UK) Using the bolts as were you would have pushed the saddle up from the ways & marked the ways with bolt indents plus if the holes aren't tapped all the way through the you have the possibility of stripping the threads out or, in worst case scenario cracking that corner of the saddle.

Your method of clamping is correct, pulling down onto the ways, but the clamp is usually on the other side of the saddle (the tailstock side,) as you have it now you may have difficulty in fastening the clamp if you're too close to the chuck plus the possibility of catching your knuckles/hand on the chuck, plus it's much easier to clamp from the other side, be safe!

Regards
George

 

[hedgehogy]

Nice job on the clamp.

Have a look at http://www.cnc.info.pl/files/bv20_1_imp_537.pdf , page 24, part number 12 labeled "front strip"
It's an "L" shaped piece of metal that is bolted to the underside of the carriage to hold the carriage onto the bed.

In this manual there are 2 vertical cuts (the BV20 I owned had only 1), and a bolt going into the cut portion from the top.
That's your carriage lock.

 

[guerd87]

Thanks

This is the bolt I was referring to in the first post. It does not do anything when I tighten it down.

If there is only 1 slot it wont work correctly? Maybe I shall take the strip out and figure out whats wrong with it?

Cheers,
John

Nice job on the clamp.

Have a look at http://www.cnc.info.pl/files/bv20_1_imp_537.pdf , page 24, part number 12 labeled "front strip"
It's an "L" shaped piece of metal that is bolted to the underside of the carriage to hold the carriage onto the bed.

In this manual there are 2 vertical cuts (the BV20 I owned had only 1), and a bolt going into the cut portion from the top.
That's your carriage lock.

 

[Gedeon Spilett]

Yes, you have to remove this strip, and make others saw cuts to allow some bending upon tightening the hex bolt. It was also far too stiff on my own lathe, and after 2 more cuts, the clamping is now functional.
Hey, its chinese stuff, and needs a lot of tuning !

 

[hedgehogy]

Thanks

If there is only 1 slot it wont work correctly? Maybe I shall take the strip out and figure out whats wrong with it?

One or two slots should work.
With one slot it's the end bit that does the clamping. With two slots it should be the middle bit that does the clamping.

My late also had a problem with clamping when I got it.
What I found was that the bits were the same height, so when you tighten on the bolt it has no where to go. I took off the strip and filed down the top of the clamping part and everything worked after that.

Extending the slits could also be the solution.

With regards to the attached pic, the blue part needs to be slightly lower than the red part (say 0.5mm to 1mm).

 

[guerd87]

well after playing with it a bit it works - sort of

It has 2 slots in it - I made these a little deeper with the hacksaw. I filed down the clamping area by a fair bit. It clamps stiff when I try to push the carriage by hand, but if i turn the handwheel I can still move the carriage.

Not sure if its clamping enough or if the handwheel exerts so much pressure its slipping. I have faced with it and its giving me flat facing just want to make sure theres enough pressure on it.

My strip has 4 bolts holding it on and then the clamping bolt.

Thanks for all the help,
John

 

[RichD]

John,
On my Harbor Freight BV 920 the carraige clamp is on the right side of the carraige. An allen screw. It's roughly straight above the threading dial and to the left about an inch or so on the top surface of the carraige. If you visit Steve Bedair's web site he has some nice mods he did to his with pictures.
Rich