ER40 collet chuck

[Jswain]

The tpi threads that you tested and measured, some being more then an inch and some being less...how does that correlate with the lever selection on the quick change gear box?

For some to be larger and some smaller two(or more?) Gears must be flipped?

Can you see the internals at all?

I guess what I mean is if it's the 86/91 reversed then the outcome would always be smaller or larger and not back and forth. But if you correlate say always larger when using A and smaller in B then good chance those gears are reversed?

 

[YotaBota]

As you bought it new, I think the dealer needs to prove to you that the machine works properly. Does the dealer have some one staff that can come out and demonstrate how to thread on that lathe? I ask this with a bit of sarcasm since some tool stores that sell lathes don't know how to run them.

If you can get the machinist to try it before going to the dealer that will either source out a procedural issue or give you ammo to fire at King.

 

[140mower]

I ask this with a bit of sarcasm since some tool stores that sell lathes don't know how to run them.

I was in one of the tool stores in Kamloops a few years ago and was asking about buying a new 7" wheel for my bench grinder. The salesman looks at me and says that it's an odd size and he didn't stock them and had no interest in getting me one as he didn't know me and didn't want to get stuck with it if I didn't come back. I mentioned that he probably should bring in at least one; boy, did I get a quick lesson in business and inventory...... Through this whole exchange, I have my hand resting on a dusty 7" Baldor grinder with no stones, when he was done, I said, "nice grinder, too bad you can't get stones for it" and headed for the door.... He tried his best to bring me back and order that stone, I just flipped him the bird over my shoulder....... Didn't need one that bad... Haven't even looked to see if they are still in business since....

 

[Brian H]

As you bought it new, I think the dealer needs to prove to you that the machine works properly. Does the dealer have some one staff that can come out and demonstrate how to thread on that lathe? I ask this with a bit of sarcasm since some tool stores that sell lathes don't know how to run them.

If you can get the machinist to try it before going to the dealer that will either source out a procedural issue or give you ammo to fire at King.

Although the staff at the dealer are great guys, they are not machinists, nor are they super familiar with the tools (other than the factory supplied information). The guy I have been dealing with is going to go up the chain of command to see what suggestions they have. I am anticipating this to be a bit of an arduous journey...

 

[Brian H]

I was in one of the tool stores in Kamloops a few years ago and was asking about buying a new 7" wheel for my bench grinder. The salesman looks at me and says that it's an odd size and he didn't stock them and had no interest in getting me one as he didn't know me and didn't want to get stuck with it if I didn't come back. I mentioned that he probably should bring in at least one; boy, did I get a quick lesson in business and inventory...... Through this whole exchange, I have my hand resting on a dusty 7" Baldor grinder with no stones, when he was done, I said, "nice grinder, too bad you can't get stones for it" and headed for the door.... He tried his best to bring me back and order that stone, I just flipped him the bird over my shoulder....... Didn't need one that bad... Haven't even looked to see if they are still in business since....

This has, unfortunately, become a trend. I think its a combination of internet shopping, lack of sales staff training and customer service going the way of the do-do bird in most retail stores. In my experience, in the establishments that have even a reasonable amount of sales knowledge and customer service, customers will go out of their way to buy there.

 

[Brian H]

So, I am very happy I finally got the threading sorted out. After much head scratching and seeking advice I decided to take a chance with pressing the center hub out of the large gear and turning it around. According to the "experts" at King this is just simply flipped around (even after explaining the center hub is pressed in and won't fit if you just rotate it).
The good news is it was the answer to achieving the correct 1.5mm thread pitch. I now have an ER40 chuck for my lathe!

 

[PeterT]

Yay! Can you elaborate on "(even after explaining the center hub is pressed in and won't fit if you just rotate it)."
Isn't that exactly what you did in the end? Do you mean this is what King was saying all along & it is incorrect?
Do you have any pics of the parts disassembled?

 

[Brian H]

Yay! Can you elaborate on "(even after explaining the center hub is pressed in and won't fit if you just rotate it)."
Isn't that exactly what you did in the end? Do you mean this is what King was saying all along & it is incorrect?
Do you have any pics of the parts disassembled?

For some reason it won't let me upload the picture I took of the assembly. I was very nervous about destroying the two bearings in the gear (85/91T) so I went VERY gently in the press. I first tried with a small deadblow and appropriately sized socket but it wouldn't move.
I can't see the logic in having to do this to go back and forth between metric and imperial every time. I would presume this would wear things out fairly quickly. I want to see what another assembly would cost and have one set up for each application.

 

[Brian H]

 

[PeterT]

Is the issue that the idler shaft that mates the inner bearing race is just too tight & what is resisting gear removal? If so, I would agree. Removing & assembly is putting strain on the bearing race, not a good thing. It should be relatively easy to pull off & flip around so I think a slip fit on the shaft OD is appropriate because the washer & nut is anchoring the inner race to some kind of step on the shaft? So not sloppy loose but just a nice sliding fit. Sometimes oil can get gummy & act like glue. Or maybe machining/grinding tolerance. Or, if the shaft has a corner where the diameter increases to match the inner bearing race - if they machined it with a (incorrect) more generous fillet, then the bearing could be getting squashed & hanging up in that area even though bearings typically have a slight chamfer for that reason.

Anyways, the good news appears to be that the 'incorrect' thread pitch issue was related to gear selection.

 

[Susquatch]

I can't see the logic in having to do this to go back and forth between metric and imperial every time. I would presume this would wear things out fairly quickly. I want to see what another assembly would cost and have one set up for each application.

I can't see the logic of changing that pressed in system either.

Mine is VERY similar to yours. On mine, you don't reverse the 127 gear assembly. You reverse another gear that has a bushing on it. Installing the bushing toward the headstock causes the gear to run on the outside 127 gear, and installing the bushing away from the headstock causes it to engage the inside 120 gear.

In the photo below both smaller gears are engaging the 120 gear, and 127 just sits there spinning.



Reversing either bushing on either of the two smaller gears engages the 127 gear.

In my case, all my small gears are actually made with an integral bushing (you could call it a shoulder) so the entire small gear is simply reversed.

It could just as easily have been done with separate bushings.

Is it possible your bushings are just missing?

 

[RobinHood]

So, I am very happy I finally got the threading sorted out. After much head scratching and seeking advice I decided to take a chance with pressing the center hub out of the large gear and turning it around. According to the "experts" at King this is just simply flipped around (even after explaining the center hub is pressed in and won't fit if you just rotate it).
The good news is it was the answer to achieving the correct 1.5mm thread pitch. I now have an ER40 chuck for my lathe!

1. Congrats Brian on your success.

2. I don’t think there will ever be a need to go back to the way (wrong way) it was, even when SAE (inch) threading as long as you have enough travel on your banjo. Here is why: during inch threading, either of the 86T OR the 95T part of the compound gear can be used as an idler. Tooth count never matters when a gear is used as an idler. Only the driver and driven tooth count matters to give the desired ratio.

 

[Bandit]

Glad you got it figured. I have couple of spacers and washers in my gear kit, I use them as needed to space/aline the gears for as full engagement as possible. On my lathe the 127 gear is as @Susquatch picture in post 131, (to the outside) as other wise the gear will not clear the shaft on the driving gear (top most gear). It's a 33? or 36? tooth on my lathe for imperial threading
Make spacers and bushings as needed.

 

[Brian H]

I can't see the logic of changing that pressed in system either.

Mine is VERY similar to yours. On mine, you don't reverse the 127 gear assembly. You reverse another gear that has a bushing on it. Installing the bushing toward the headstock causes the gear to run on the outside 127 gear, and installing the bushing away from the headstock causes it to engage the inside 120 gear.

In the photo below both smaller gears are engaging the 120 gear, and 127 just sits there spinning.

View attachment 48087

Reversing either bushing on either of the two smaller gears engages the 127 gear.

In my case, all my small gears are actually made with an integral bushing (you could call it a shoulder) so the entire small gear is simply reversed.

It could just as easily have been done with separate bushings.

Is it possible your bushings are just missing?

I certainly like your system WAY better than this one.
No. the shaft of the upper gear is too short to add a bushing so it always has to contact the inside gear and lower smaller gears could be installed either direction.

 

[Brian H]

1. Congrats Brian on your success.

2. I don’t think there will ever be a need to go back to the way (wrong way) it was, even when SAE (inch) threading as long as you have enough travel on your banjo. Here is why: during inch threading, either of the 86T OR the 95T part of the compound gear can be used as an idler. Tooth count never matters when a gear is used as an idler. Only the driver and driven tooth count matters to give the desired ratio.

Interesting, although the difference of the teeth and which gear it engages will change. That being said, I wonder if that is also why the inch threading is out slightly... I should do a test...

I did ask King about sending me another gear/hub assembly that I could orientate opposite the original to save having to switch it around. The other option is to make a hub for inside the bearings and a separate spacer that stays on the banjo bolt.

 

[Brian H]

Glad you got it figured. I have couple of spacers and washers in my gear kit, I use them as needed to space/aline the gears for as full engagement as possible. On my lathe the 127 gear is as @Susquatch picture in post 131, (to the outside) as other wise the gear will not clear the shaft on the driving gear (top most gear). It's a 33? or 36? tooth on my lathe for imperial threading
Make spacers and bushings as needed.

As I mentioned in my reply to RobinHood's post, if King won't send me another assemble I will make a hub with a separate spacer to correct this design flaw. If I recall for imperial both top and bottom gears are 40T on this set up.

 

[Susquatch]

Hey @Brian H, I confess I have some trouble accepting the situation you find yourself in.

I went back and reviewed the whole thread.

In post 13 you provided a photo of your gear chart. I have marked it up.



According to this chart, it clearly shows that the bottom gear is reversed for a 1.5 pitch metric thread and also elsewhere in those photos IT LOOKS LIKE that gear either has a bushing under it or has an attached bushing.

The bottom gear is gear G. Can you please remove it and see if it is reversable? Maybe take some photos of the gear? It might explain everything.

Try to think about this whole matter as if someone (either before or after the sale) broke something or lost something and repaired it by substituting stuff that doesn't belong.

Certainly, that chart suggests that your bottom gear G should be reversible.

 

[Jswain]

Hey @Brian H, I confess I have some trouble accepting the situation you find yourself in.

I went back and reviewed the whole thread.

In post 13 you provided a photo of your gear chart. I have marked it up.

View attachment 48187

According to this chart, it clearly shows that the bottom gear is reversed for a 1.5 pitch metric thread and also elsewhere in those photos IT LOOKS LIKE that gear either has a bushing under it or has an attached bushing.

The bottom gear is gear G. Can you please remove it and see if it is reversable? Maybe take some photos of the gear? It might explain everything.

Try to think about this whole matter as if someone (either before or after the sale) broke something or lost something and repaired it by substituting stuff that doesn't belong.

Certainly, that chart suggests that your bottom gear G should be reversible.

Effin eh, good catch!

 

[Tomc938]

Watched the video. Now I’m much more confident engaging my half nut. If he can go for it, so can I!

 

[Susquatch]

Watched the video. Now I’m much more confident engaging my half nut. If he can go for it, so can I!

I've described that same method many times on here. I'm sorry that you had to wait for the right youtube video to learn that.

I know it's hard to read my ramblings and even harder to follow them. I'll have to try harder to be short and succinct. Maybe I need to be serious more often......

It's a good method that actually works well for imperial threads too. Especially if you are always inclined to use 1 on your thread dial cuz you don't have to wait for it to come around.