# Help needed. Is this safe or do I have a bad threading?



## Eric_S (Aug 26, 2009)

I'm starting on my first bowl today. I have the outside turned using the faceplate that came with the lathe

http://www.harborfreight.com/12-inch-x-33-3-8-eighth-inch-wood-lathe-with-reversible-head-34706.html

Manual http://manuals.harborfreight.com/manuals/34000-34999/34706.pdf

The faceplate that came with it screws on just fine.
Notice the left side of image black faceplate perfectly aligning with the silver threading…









I just purchased my first chuck, a SuperNova 2. The guy at Woodcraft said I need the threading adapter for my lathe as well.

The manual for my lathe says its a 1" 8 thread right hand, which corralates to a Code D adapter for the chuck. I checked the bag of the adapter which also says 1"x8 and a D is also engraved into the adapter itself so I know the adapter is the correct one. The adapter goes into the chuck perfectly, but…. it doesn't screw onto the lathe all the way. It stops after about 3-4 threads. Ive checked the threads on the lathe as well as the inside of the adapter for debris or any burrs or anything that would prevent it from screwing on….









But no matter what, even when using wrenches, I can't get it on all the way. IS this safe? Is this correct? Or do I have a bad adapter? 









Like I said, the faceplate that came with the lathe screws on all the way without any difficulty. I'm afraid to turn the inside of the bowl until I get some feedback from more experienced lathe and chuck owners. Please help.

Thank you.


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## Arch_E (Jun 30, 2011)

I'm doubtful of its use, from what I see. I've got Oneway chucks and adaptors, so I can't help with the Nova equipment. However, on three lathes I've never seen that for the various chucks I have.


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## CharlieM1958 (Nov 7, 2006)

Eric, you don't show the adapter uninstalled, so it is hard to judge how much is screwed in. However I would thing if you are getting several turns before it stops, you should be okay.

Is it possible that there are 2 sets of threads on the adapter? From the photo, it almost looks like it is screwed in as far as it is supposed to go, and that the next set of threads are for a larger size lathe opening.


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## lew (Feb 13, 2008)

I'm afraid if you use this setup, you will jamb the head stock threads into the adapter so tight you may never get them apart.


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## Grandpa (Jan 28, 2011)

I have seen people not tighten plates on a lathe. When the machine tightens them they are on to stay. You don't want that. It there is a burr or something that you are not seeing and it does finally go past this point you are in that forever position. I think I would go back and talk to the store again. It could be a bad adapter since today most things are not 100% inspected in a manufacturing facility. It is still cheaper to toss you a new adapter that it is to inspect those parts. Some say there is now quality built into a part like this but we are still there. We followed the Japanese into this deal (no inspection). When they said this doesn't work, we said we will make this work so we poured more into it and the entire world has followed.


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## Eric_S (Aug 26, 2009)

Lew and Arch, I was afraid you'd say that. Its too hot to continue today anyways in the garage so I'll return it I think later and try again tomorrow. It is a Woodcraft brand adapter, maybe that is the problem lol.

Charlie, I've included a few more pics of the inside of the adapter. It looks like there is only one size threading in it and a little bit of space at the end so in reality it is probably only holding on to like 2-3 threads so I'm guessing its not going to be safe.



















Thanks for the help guys.


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## Grandpa (Jan 28, 2011)

take the chuck to the store with you when you return the adapter.


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## lew (Feb 13, 2008)

Another thought, this lathe comes from the orient, could the threads be metric. I had this happen on a Bridgewood product- also oriental.

I quickly scanned the manual and did not find an actual spec on the face plate threads but may have over looked it.


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## tierraverde (Dec 1, 2009)

It almost begs of being an incorrect pitch on either the adaptor or lathe head. (Chinese quality?)
I would take the adaptor back and have them try it on one of their lathes, just for safety sake.
From the looks of it, I wouldn't use it. I don't think there is enough threads making contact.


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## Eric_S (Aug 26, 2009)

Grandpa, there are no burrs I can feel on either the headstock threading or adapter inside threading and it looks well machined.

It is Central Machinery and I'm sure from China or somewhere else in Asia. This is the first issue I've had with it and id suspect its the adapter since like I said the faceplate goes on smoothly.

lew, that could be it. The only place it says threading is on first page of manual it lists specs and threading as 1" 8 Thread right hand


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## Eric_S (Aug 26, 2009)

Thanks Jim. I'll see if it goes on the stores ok. If it was metric what is 1"x8 RH equivalent to?


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## richgreer (Dec 25, 2009)

I doubt that it is unsafe but I think there is another significant problem. As you use the lathe, the adaptor could tighten onto the arbor to the point that it would be extremely difficult to get it off.

The action of turning will cause the chuck to tighten onto the adaptor and the adaptor to tighten onto the arbor. They can get VERY tight, especially if you have any catches.

I actually think that they could tighten up to the point that you could not, without a propane torch, get the adaptor off.


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## Eric_S (Aug 26, 2009)

Yeah Rich I'm afraid to turn it on for that reason. I doubt it would fall off since it would just thread further on in use but yeah, based on how difficult it was to even attempt to tighten with a wrench I'm not going to try anymore. As soon as I find the receipt I'm heading back…

Here is one more picture with measurement of headstock threading….


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## tierraverde (Dec 1, 2009)

The more I think about it, DON'T USE IT! It's definitely unsafe. Its the same condition as a metric nut being screwed onto a english screw. 2 or 3 turns and it stops.
These adaptors are designed to bottom out on the shoulders, NOT on the threads. Richgreer is right.
When you put the adaptor on, the shoulders have to be clean and free of debris so as to bottom out and force parallelism. (Note the adaptor and chuck bottoming out.)
Thats why the threads stop before the shoulder with a relief undercut. To ensure the mating of both shoulders.


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## CharlieM1958 (Nov 7, 2006)

Yeah, after seeing that last photo, there is definitely a problem. Most likely it's the adapter. Simples fix to try is just get another one.


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## Eric_S (Aug 26, 2009)

Thanks everyone for your input. On my way to woodcraft I'll give an update later


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## Eric_S (Aug 26, 2009)

Well, just went to woodcraft 5 min from house  the guy I spoke to was actually very knowledgeable of central machinery and says he's had other people with similar issues. The machining is just not accurate on them so the faceplate works fine but any 3rd party adapters won't work really. He said some people got lucky and the adapters worked, others had same issue as me. His suggestion was to go to harbor freight where I bought it and see if they carry a central machinery brand adapter. He said all his adapters would probably have same issue so he just refunded my purchase. Lets hope HF has one that will work….doubtful


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## lew (Feb 13, 2008)

Another suggestion- now that you have already returned from Woodcraft- get yourself some of these-

http://www.woodcraft.com/Family/2021098/AntiLock-Spindle-Washers.aspx

Use them everytime you use the chuck/adapter- don't ask how I know this.


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## Eric_S (Aug 26, 2009)

Lew lol thanks for suggestion. I'm at HF now and don't see any adapters  only a CM screw chuck. I may have to look online. I think I'll risk going to rockler to buy one and if theirs doesn't work then return it as well.


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## Eric_S (Aug 26, 2009)

I think Im SOL. Should have bought a better machined lathe lol. Its worked great up to this point, heavy cast iron, centers align, but now that I need a 3rd party adapter I may not be able to. The headstock threading is removable, so could I possibly get a better machined threading from somewhere to use instead? Im guessing I may have same issue with that threading and internal headstock threading then. lol. I see harbor freight sells a central machinery brand chuck for $40. That sounds way too cheap and something I'd just regret, although it would probably fit.

Besides buying a new lathe, any suggestions? Don't say buy a new lathe lol. Am I going to have to make a wood adapter for the faceplate with t-tracks to hold jaws? How else can I turn the inside of a bowl without a chuck?


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## Grandpa (Jan 28, 2011)

You turn those with a face plate. attache it to the wood stock you are turning and dont take it off until you are finished. it keeps it all on the same centerline.


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## SCOTSMAN (Aug 1, 2008)

It must thread all the way home that is till it touches the shoulder of the spindle * Called the register*nothing else is acceptable. If it doesn't do this then you need to get it sent back and have them check it out, or make a bush behind it if the threads are too short whichever way you do it it must rest on the shoulder this reply and any book will tell you this must be done.Best wishes Alistair


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## jobott (Mar 13, 2009)

Eric,
I also have a SuperNova 2 chuck as well as the Nova 3, and there was a notice at my local Woodcraft that you could NOT use the Woodcraft adapters in the Nova chuck as the tolerances were different. As I think the problem you are having is not the adapter going into the chuck but onto the lathe, this may not be related. However, I had better results when I returned the Woodcraft adapter I had bought (same as yours, a 1×8) and bought the one made by Teknatool. More money but worked better. If you can find a 1×8 nut at a hardware store you could check it against your lathe to see it will thread on properly as well. Or bring the faceplate with you to a hardware store and try a 1×8 bolt if you can find one. I would think at this point that the adapter is still the problem. tho its possible the lathe is at fault, it would seem unlikely.


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## donjohn24 (Oct 15, 2010)

I'm not quite sure if Grandpa's first response is suggesting that NO inspection is/was carried out by Japanese manufacturers, but my understanding of the situation was that they moved away from the idea of making lots of parts, then inspecting them all and throwing out the bad ones.

They started using systems that checked parts as they were being manufactured, and made adjustments to the process BEFORE parts started to go outside limits. Eventually other countries started to catch on to the fact that Japanese stuff was very accurate, and that they themselves were losing money making bad parts. Certainly in the UK, the spring manufacturer for whom I worked started to use these sorts of methods. The idea was that good quality was *built-in* to parts, not poor quality *inspected out.*

Although these systems implied that 'final' inspection was not needed, the checking of relatively small sample lots and the application of statistics - using 'normal' distribution curves, mean and standard deviation, etc. - changed the whole attitude to inspection during the 30 years I worked for the company.

If I misunderstood Grandpa, or I am trying to teach grandma (pa) to suck eggs, I hope he'll forgive me


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## rance (Sep 30, 2009)

FWIW Eric, chucks etc. are meant to fully thread onto the headstock spindle. If it won't go all the way to the spindle, then you can't be sure that the chuck is true. The face of the spindle(where those wahsers that Lew linked to above, sit against) is your reference surface that keeps the chuck running true. If it is held tightly by the threads alone, you run the risk of the chuck not running true. It could run differently each time you thread it on and tighten it up. See how the chuck rests on that flat spot on the adapter, this keeps it true. See how the adapter does not rest against the flat on the spindle? This is not guaranteed to run true.

It is not right, not safe, and you should not use it as it is.  Just my 2c worth.

Edit: What Alistair said is exactly right.


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## Eric_S (Aug 26, 2009)

Jobott, thank you for the suggestion with trying a 1×8TPI threaded nut(assuming I can find one) before buying a more expensive adapter. Yes, the threading issue is on the lathe side. It threaded perfectly with the chuck.

I did go to Teknatools website, and actually their adapters are a couple bucks CHEAPER than woodcrafts go figure, although thats without shipping The threading looks fine to me though, but it probably would be a smart idea to buy a cheap nut from the hardware store first and test with that before dealing with online order and possible shipping back. Great suggestion.


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## tierraverde (Dec 1, 2009)

Don Johnson,
You are right on the money. My manufacturing company practiced these methods of ensuring each department was making flawless components before moving on to the next operation(s). It was written and documented to our ISO plans.
When we actually did what our procedures stated, our quality AND margins went through the roof!
ISO was the best thing that ever happened to my company.


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## PurpLev (May 30, 2008)

for what it's worth, I bought adaptors from woodcraft for my grinder that were suggested by woodcraft folks for my grinder specifically that didn't even come close to a fit. so I would be more inclined to think that their adapter is the one with the lower tolerances than the spindle on your lathe, especially since you (I presume) are able to fit your face plate on your spindle correct?


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## Grandpa (Jan 28, 2011)

Well, we did move assembly and manufacturing into small focus factories hoping that by seeing how the part is used then you could correct the problem without flooding the warehouse with hundreds of bad part or the inspection station when it was in another part of the plant. Then there are parts that are not immediately used in an assembly. The parts that had fewer defective items got less attention but when that happens there are many bad parts int he system. Some were used in house in the next assembly, some were sold to the outside buyers for repairs. That is how bad parts get out. I would get calls to come and look at parts that were out of tolerance, I would be asked to "buy them" as they were this one time. they are only out a couple of thousandths. Well, my personal policy was if I can buy them once then I need to change my drawings to reflect this. If I do it once they will make them this way everytime. If I cannot or am not willing to change the drawing then they are junk as far as I am concerned. I don't care how badly we need them to make the next assembly. I don't want to go pay good money for bad parts like Eric has done. We don't know the problem but evidently there is a problem here. Either this company didn't "build in the quality" or someone surely slipped up on the job. I personally don't think you can build as much quality into your work when you hire the first employee and with each successive hire the quality goes further down. I know there are exceptions but they are rare. People do just enough to get by and it is killing the industry.


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## LONGHAIR (Dec 16, 2007)

How about cleaning up the threads with the correct die? It can't be that far off


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## Eric_S (Aug 26, 2009)

Purplelev I'm thinking the same thing after reading some other forums about their adapters. My threading doesn't look off, they are all evenly spaced and all seem to have similar pitches when I look with just my eyes. The faceplate threading goes on super smooth and doesn't wobble or have any give so I'd say its woodcrafts as well. I'm going to the hardware store tomorrow to find a 1"x8tpi nut and try it out and then buy a $20 adapter directly from teknatool.


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