LumberJocks

Acceptable

  • Advertise with us
Review by Woodknack posted 09-06-2016 03:46 AM 3237 views 0 times favorited 4 comments Add to Favorites Watch
Acceptable No-picture-s No-picture-s Click the pictures to enlarge them

Background: I purchased this lathe used from a woodworking club and it saw plenty of use. I have owned it for about 6 months. They were having a problem with it overheating and shutting down and sold it relatively cheap. The control box has vents on top that allow dust and chips to fall into the box and it had become packed with detritus blocking airflow to the electronics. After cleaning out the box I’ve had no problems with it shutting down. This is the 4th lathe I’ve owned and the newest (most modern).

Things I don’t like:
  1. Belt changes. The variable speed I built for my other lathes goes from about 250 – 3,000 rpm but the Comet lacks that range without belt changes. To move the belt you need to loosen the motor and then slip the belt off one pulley and onto another but even with the motor as loose as it will go, the belt barely has enough slack.
  2. Motor mount. It’s awkward and clumsy to loosen or tighten for belt changes and it doesn’t feel solid. The lathe needs to be elevated or on the edge of the stand or the lever that moves the motor up and down won’t have enough travel.
  3. Knobs in general. All the knobs require that you turn, lift, back up, let them down, turn again, lift, back up, let them down and turn… Very annoying. I might replace them with regular star knobs.
  4. Parts available through dealers only. I would prefer ordering online, through a catalog or website. Just put the parts online Teknatool.
  5. Tailstock quill doesn’t have much range, couple of inches maybe. When drilling you have even less depending on the length of the drill chuck arbor. I get maybe 1.5” movement when drilling.
  6. Belt cover has a goofy latch which requires a quarter or screwdriver to turn. I leave it unlatched and let gravity hold the cover in place.
  7. Control box vents easily allow dust and chips to enter and block airflow.
  8. A single turn of the tailstock locking lever is not enough to secure the tailstock. I’m knitpicking but it comes back to those annoying levers.
Miscellaneous that may be normal wear and tear:
  • Occasional ticking and/or growling. I believe this is a bad bearing(s). I bought new bearings but haven’t installed them yet. It gets worse as the lathe warms up. Teknatools calls for 6005ZZ (ZZ=metal shielded) bearings but mine has 6005RS (RS=rubber shield). So I don’t know if Teknatools switched to ZZ bearings or maybe they aren’t the original bearings.
  • The motor bounces. This is a weird one. I have disassembled and reassembled and tightened everything and improved it slightly but if you have the belt on the far left pulley which gives the belt the greatest leverage on the motor, the problem is worse. Might be related to a bad bearing. I’ll know for sure after I change them.
  • The tailstock doesn’t align with the headstock. I know this controversial but no matter what people may say, it does matter. Not counting this as a negative since it’s possible the tailstock was switched out at some point (actually I suspect it was). Teknatool makes a tool for aligning head and tail stocks so I’m assuming there is a way to adjust them, just haven’t looked into it yet.
What I like:
  1. Quiet
  2. It actually stops when I turn off the switch (my other lathe motor has a big flywheel and takes a bit to spin down).
  3. Modern compared to my other lathes

I know my dislikes are bigger than my likes but I actually do like it. Really I like the conveniences of a modern lathe vs the vintage lathes. Some of my complaints have already been addressed by Teknatool so newer versions won’t have those problems.

  • Knob threads are M8
  • Spindle Bearings (2 each) are 6005ZZ (60052Z)

Vid of motor bouncing.


View on YouTube

-- Rick M, http://thewoodknack.blogspot.com/




View Woodknack's profile

Woodknack

12329 posts in 2495 days



4 comments so far

View Mark Wilson's profile

Mark Wilson

2229 posts in 1178 days


#1 posted 09-06-2016 07:59 AM

Oh, how I’d love to have a “modern” lathe, Rick. Especially a Nova. Namely, a Galaxy, like Jim has. My sixty-year-old SS gets by, though just barely.

-- Mark

View Mike_D_S's profile

Mike_D_S

482 posts in 2330 days


#2 posted 09-07-2016 03:00 PM

Rick,

I have this same lathe, but mine may be a newer version so my comments may not apply 100%.

1. My belt cover has a star knob you have to unscrew to open the cover. I bought mine used from the local woodcraft where it was a demo machine for classes, so that may not be stock.

2. In the pics, you don’t seem to have the locking level for the top of the tailstock. If you have it and it’s not in the pic, then no worries. But if not, I would suggest getting at least an M8 bolt to put in there. While you can probably get by without the locking aspect, on mine the tail stock quill rotates without the level being installed which can be a hassle. The tail stock was dropped on accident at the WC and the threaded insert had knocked loose. I used the lathe a couple of times before tack welding the insert back in and found the quill rotated some an also has a tendency to creep a little so on mine I had to keep tightening it down every 3 or 4 minutes.

3. Agree on the levers, I’ve pretty much got mine setup so I can lock down pretty good with 180 degree turns, but it’s a hassle. A little higher thread pitch would be better.

4. My belt may be stretched, but I can give it a push and rotate the pulleys by hand to change pulleys without actually loosening the motor. The ribbed belt is a little finicky to get set exactly right, but I can change pulleys in a minute or so. Maybe you don’t have the stock belt?

5. Agree with the control box vent comment, it’s just a crap design choice.

6. I’ve actually had a chance to play with two of these, mine and a buddies. Both of them develop an annoyingly loud tick on highest speed pulley with the lathe running fast. I suspect it’s the bearings as I can’t locate any possible points of contact anywhere else. But with that being said, I also made a redneck timing light using a piece of posterboard, a 3/4 dowel and a black cat strobe light I put out at halloween. I marked an X on the posterboard with a marker and then screwed it into the end of the dowel. I ran it at speed and played with the strobe until the flash was about the right frequency. While the lathe ticks annoyingly, that tick doesn’t seem to translate to the spindle motion. That doesn’t necessarily mean anything for your lathe, but since I’ve seen two do the same thing and the tick doesn’t seem to impact the spindle rotation, I’ve sort of chosen to just ignore it as I rarely use the high speed pulleys anyway. Also, I don’t have any growl, just the tick.

While I’m not an experienced turner and don’t really have any experience on other lathes, other than sometimes wanting a bigger one, I don’t have many complaints about the lathe itself and it seems to work as required.

Mike

-- No honey, that's not new, I've had that forever......

View Woodknack's profile

Woodknack

12329 posts in 2495 days


#3 posted 09-07-2016 07:02 PM

Good commentary.


2. In the pics, you don t seem to have the locking level for the top of the tailstock.

4. My belt may be stretched, but I can give it a push and rotate the pulleys by hand to change pulleys without actually loosening the motor. The ribbed belt is a little finicky to get set exactly right, but I can change pulleys in a minute or so. Maybe you don t have the stock belt?
- MikeDS

2. It was missing so I made one from Delrin and an M8 bolt.

4. Looks like an original belt.


6. I ve actually had a chance to play with two of these, mine and a buddies. Both of them develop an annoyingly loud tick on highest speed pulley with the lathe running fast. I suspect it s the bearings as I can t locate any possible points of contact anywhere else. But with that being said, I also made a redneck timing light using a piece of posterboard, a 3/4 dowel and a black cat strobe light I put out at halloween. I marked an X on the posterboard with a marker and then screwed it into the end of the dowel. I ran it at speed and played with the strobe until the flash was about the right frequency. While the lathe ticks annoyingly, that tick doesn t seem to translate to the spindle motion. That doesn t necessarily mean anything for your lathe, but since I ve seen two do the same thing and the tick doesn t seem to impact the spindle rotation, I ve sort of chosen to just ignore it as I rarely use the high speed pulleys anyway. Also, I don t have any growl, just the tick.

Mike

- MikeDS

I can’t imagine what would make the noise if not spindle related, maybe the electronics?

Vid of motor bouncing added to OP. You can also hear the growl that occasionally happens.

-- Rick M, http://thewoodknack.blogspot.com/

View Mike_D_S's profile

Mike_D_S

482 posts in 2330 days


#4 posted 09-07-2016 07:56 PM

Interesting, if your knock was a little higher pitched, it would sound like my ticking noise and be just about the exact same frequency. Maybe my motor is bouncing as well, but the size of the bounce is just a little smaller and I didn’t pick up on it. I’ll have to try it out tonight.

It does make sense that it might be motor bounce, with the motion being larger or smaller and producing a slightly different sound. The next test would be to remove the belt entirely and see if it still does it without the deflection force on the shaft. My guess is no, but you never know.

I work in the oilfield and we see all kind of complex harmonics in rotating equipment with bending moments applied. Thinking about it, the noise could be rotor slap due to harmonic resonance in the motor itself. A bit farfetched, but maybe the little motor isn’t really rated for side loads on the shaft. A little bit undersized shaft coupled with a small weight imbalance in the rotor and you could get something like this I think. Removing the belt and/or lowering the tension down a bunch should produce some change in the behavior if that is the case.

I don’t have any kind of noise like that growl. To me that sounds like straight bearing wear.

I did notice that the indexing plate on the spindle was loose on mine. I don’t remember it making any real noise, but I caught it early when I was just going through the machine after getting it home, so I may not have actually run it. I doubt that is your issue, but I’d check the screws on the indexing plate anyway.

The videos really help out.

Mike

-- No honey, that's not new, I've had that forever......

Have your say...

You must be signed in to post the comments.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics

HomeRefurbers.com