# Vibration Headache



## Wannabewoodworker (Dec 28, 2008)

Hello All. First off, sorry for this long post. This past February I purchased myself my first lathe. A Delta Midi Lathe 46-460. Since then I have been developing my skills over the past months making things from small bowls to a large variety of pens. I have even made good money with the selling of pens. It has been a pleasure for me to sit down and turn a pen up until now. Here is my dilemma. For the past few weeks or more every pen I have made has been having issues. Vibration issues. I turn both wood and acrylic. The wood hasn't been giving me much grief but the acrylic is killing me. I rough down my blanks with a roughing gouge and switch to a round nosed scraper for the final finishing. I have in the past gotten wonderful results. Lately I have a tremendous about of vibrations on the tailstock side blank. Every time I touch the blank with the scraper I get a high pitch whine and sometimes even a "dig in" I have little to no problems with the headstock side of the pen blank. But the further away from the headstock, the more the problems. Here is what i have done so far: Replaced mandrel twice (no change). Changed out original live center for a 60 Degree Live center (no change). Verified that centers of head and tail stock are aligned. Lighter touch on the roughing down part to minimize pressure on the mandrel and lighter cuts with scraper. I even double checked that my tools are dead sharp. After I am done shaping it, I am left with a pen blank that is good is shape, round with concentric ridges in it. I am able to sand these down, but it is very depressing to have to deal with this. It makes me not enjoy what I have been doing. Christmas is coming and I have to make a lot of pens. Can anyone help me diagnose my problem. If you have had the same problem and found the cure, please share. I would most appreciate it.

Thanks in advance,
Wannabewoodworker


----------



## duncsuss (Aug 21, 2009)

Have you changed the supplier of your pen kits?

I'm wondering if the tubes have a slightly larger inner diameter than your mandrel.


----------



## Wannabewoodworker (Dec 28, 2008)

Most of the stuff has been from Penn State. The kits from woodcraft come mostly from PSI as well. The most issues have been with slim lines and comfort pens. Both of them use standard 7mm bushings with the exception of the center bushing on the comfort pen. I will try a pen kit with a step bushing like a Polaris pen to see if I have the same issue. What other suppliers do you use?


----------



## duncsuss (Aug 21, 2009)

My slimline kits are from either PennState or WoodTurningz (a reseller of PennState kits, but I think they also have some of their own). If you started with one type then switched to the other, maybe try going back to the first one to see if that behaves the same way.

Have you tried a Mandrel Saver ?

It doesn't apply any pressure on the tip of the mandrel, and shortens the length of the mandrel. In theory this reduces the chance of the mandrel bowing.

Some mandrels (e.g. this one) have a locking mechanism at the drive end which also lets you shorten it to just the length needed for the blanks and bushings, again reducing the likelihood of the mandrel bowing.

Just brainstorming ideas of what might be causing the trouble ... :huh:


----------



## wildwood (Jan 25, 2011)

Is tailstock to tight causing mandrel to bow or tailstock not tight enough?

Bushings consumable components, I buy new ones after so many kits. If change vendors buy new bushings with kits. Kits and bushing made in lots at different times of the year and even different plants so can get variations in both over time. 

If bushing sloppy on the mandrel or sanded too thin time to replace.


----------



## wildwood (Jan 25, 2011)

Woodcraft once got their kits exclusively from Berea Hardwoods. If that is true for your Woodcraft store bushing tad bigger than PSI mandrel. Berea's A and B mandrels thicker than either Craft Supplies or PSI. I have no problems with CS kits and bushing on my PSI mandrel. Have to force CS & PSI bushings used as spacers onto Berea A mandrel. 

I only make kits that do not need a mandrel now. Use dead center in Headstock & live center in tailstock & bushings.


----------



## BigBull (Feb 10, 2010)

I don't know much about turning wood, but chatter in metal is usually caused by to many RPM's. Or to slow of feed. Have you changed the rpm to a higher rate? Have you slowed down your feeding of the tool to try to get a better finish? Just a couple of suggestions from my metal experance.


----------



## Wannabewoodworker (Dec 28, 2008)

I guess the question to ask is how do you know your tail is seated correctly against the mandrel? I have heard some say to unwind the tail stock crank till the live center starts to turn off the spinning mandrel. I have also heard of seating the two together and tightening it a smidge. Another thought is about the morse taper for the mandrel. That is one thing I have not replaced. I have changed out the threaded mandrel each time so far with no success. I did also forget to mention I purchased the mandrel savor. I was not impressed by its loud noise while rotating at 4000 rpm


----------



## john lucas (Sep 18, 2007)

Give up on the scraper and learn to use cutting tools. With a sharp cutting tool like a spindle gouge you can take really light cuts with very little pressure on the bevel. Then if you get chatter simply use your fingers on the backside of the spindle to apply pressure opposite the bevel of the tool. I turn very small finials for ornaments with no tailstock using this method. I could not do that with a scraper. 
Many people suggest using scraper on acrylics because they claim they get tearout with a gouge. That means the tool isn't sharp enough and they are feeding the tool to fast. When you slow down and get curls instead of sawdust you are doing it right and the acrylic will thank you with a beautiful finish.


----------



## Wannabewoodworker (Dec 28, 2008)

That is some sound advice John Lucas. I have yet to use a spindle gouge. It has a much less angle of presentation and pressure on the mandrel. A good buddy of might does all his pens with scrapers and I just followed suit. He also used a 1 inch scraper vs my 1/2 inch version. What size spindle gouge would be best? Bigger the better for shaping or smaller for detail....or possibly both. Also interested in what speed are you turning at.


----------



## wildwood (Jan 25, 2011)

I use nothing but roughing gouge, skew, and parting tool to turn pens. Whether turning wood or acrylic may start and finish with sharp ¾” roughing gouge and start sanding with 320-400 grit. 

Some folks prefer ¼”, 3/8” or 1/2'” bowl or spindle gouge, other folks swear by carbide tools. 

Fellow over at IAP sell Woodchuck Pen Pro especially for pens. He also makes other style carbide tools and prices not bad.
http://www.woodchuck-tools.com/Tools.htm

If tools sharp, lathe, mandrel, and live center squared away would look for bushing slop. True if pressing too hard can also give you a sqeal.


----------



## rejames44 (Nov 9, 2011)

Captn Eddie has some of the best carbide turning tools anyone would ever want and at less than half the price. and a Great fellow turner out to help all turners. Here's the link below check it out.

http://www.eddiecastelin.com/


----------



## Wannabewoodworker (Dec 28, 2008)

Hey guys. Just tried using a 3/8 spindle gouge on acrylic for the first time. After all, pens are still spindles. Not used to the way I have to shape it. It will take some practice but I think it's do-able. Now that I have bought a mandrel saver and a 60 live center. Should I send either one of them back? Or is there another use for either. Spend 22 dollars on one and 27 on the other. It just seems redundant to have both for same job. Any ideas? Another question I have is about the scraper. What does everyone use them for. Since there not the best for pens, what are they good for?

Thoughts?

Wannabewoodworker


----------



## wildwood (Jan 25, 2011)

Have no advice on mandrel saver or live center, we all have some tools that seem to collect more dust than use. 

While prefer tools that cut (gouges, skews, parting tools) over scrappers, scrappers have a place in our tool kits. I never use a scrapper on spindle work, but plenty of turners do. I do use scrappers on bowls and small hollowing turnings.


----------



## Kirkus (Dec 19, 2010)

Thank you for this thread, wannabe. I logged on to the forum to ask this exact same question. I've had a little more education now and will give some of these ideas a try.

I hope you've worked out your problem... or will in the near future. I'll be curious to hear how it goes.


----------



## Wannabewoodworker (Dec 28, 2008)

Hey everyone. I just wanted to give you guys an update on my dilemma. I attempted to take the high road and start using my skews and spindle gouges for the pens. Unfortunately I have had no success. I have been able to shape the pen nicely will little issue on the headstock side. As I move tailstock side, vibration creeps in. I don't think it has anything to with technique, the sharpening of the tools, or the bushings. All of them have been analyzed. Even cleaned out the morse taper. I checked the belt for wear. I am at a loss of what to do. It makes me want to give up pens and just make bowls. Any chance a bad set of bearings cause this issue? I just got the lathe in feb of this year. Is it too earlier for a bearing to go bad? Any suggestions on where to go next?


----------



## Kirkus (Dec 19, 2010)

This isn't going to help you fix the vibration, but maybe it will help you to know that you're not alone. I still have the exact same problem with acrylics. Wood, soft or hard, turns like a dream. Put an acrylic blank on there and the tail-stock end goes crazy with vibration.

I'm not turning acrylic much anymore because of this, and because of the mess acrylic makes.

Sorry, wannabe. I hope you get this figured out. I know how frustrating it is.


----------



## Wannabewoodworker (Dec 28, 2008)

I guess that is the funny thing. I am having the same difficulty with wood and acrylic alike. The closer to the tailstock, the higher the whine. i have a buddy that told me to contact the manufacture. Delta says it has a 5 year warranty with its products. I am pretty sure that this would be a qualifying issue. Either give me the solution to the vibration or replace the thing. That is how I will put it t them. I just got the thing in February. I will not be happy with anything less.


----------



## Robocop52 (Jul 25, 2011)

Hi,
I had a Delta lathe up until 5 years ago, i had the same problem and changed bearings but to no avail, is it on the metal leg frame? if so try removing them an bolt it to a sturdy bench it could be that the vibration is coming from the legs, i purchased a new Hegner and give the Delta to a retired friend who bolted it to a bench with a 2"top and frame he hasn't complained yet!


----------



## wildwood (Jan 25, 2011)

Can also get vibration if lathe bolted to bench unevenly. Lathe speed can also cause vibration, just find sweet spot.


----------



## Wannabewoodworker (Dec 28, 2008)

Hey guys. I just want to clarify what I mean by the vibration I am having. This is not the kind of vibration you get when you have a out of balance bowl blank on the chuck. This vibration is much more subtle. So minimized it can only be felt and heard while turning around the tail stock side. Might have to wait till after christmas to have it looked at. Till then...I have to make the best of it.

Wannabewoodworker


----------



## wildwood (Jan 25, 2011)

On wood lathes vibration/resonance can occur at different frequencies or miss-matched or worn parts. Sometimes can reduce speed or take lighter cuts to reduce or eliminate problem. 

No one can tell tailstock a problem from what you have posted. Not saying you do not have a bad tailstock, but would like to rule it in or out with simple test.

Do you get vibration turn wooding between centers? Use a piece of wood, and spur center, live center that came with your lathe. (fig. 5 in owner manual) I would use both small and large tool rest and different lengths of wood. Run through speed range while turning. 

Goal here is to pinpoint where vibration/resonance coming from. (speed, depth of cut, cheap aftermarket parts, or worn parts)

Next use 60- degree live center you bought to make pens. 

Mandrels another consumable piece of turning gear. Once bent replace! 
The amount of pressure applied should be just enough to stabilize the mandrel shaft and minimize vibration from the turning activity. Too much pressure
bends the shaft or causes vibration. 

Many turners stopped using mandrels and use dead and live centers.

Inexpensive 60- degree live centers sold to pen turners notorious for problems. 
A crooked live center point will also cause the mandrel to operate eccentrically and cause vibration. Check for wear spots or distortion in dimple at end of mandrel shaft.


----------



## angelo49 (Apr 7, 2009)

I didn't read all of the posts, but you should check to see if the point of the live center is bottoming out in the mandrel.
This will cause problems as mine made that high pitched shrieking sound.
If it is hitting bottom you need to redrill the end with a center drill.

Angelo


----------



## Wannabewoodworker (Dec 28, 2008)

Hey wildwood,

I know it has been a couple days since this post but you said that some pen turners have stopped using mandrels? How are the putting individual blanks on the lathe between centers? And what about the bushings? Sorry I am not familiar. I like your approach to testing the tail stock. Still finishing up Christmas presents at so I will go at it after the holiday. Woodcraft also wants to see the tailstock before I go the manufacturer. That's where I bought the lathe. Hope it is an easy fix.

Thanks

Wannabewoodworker


----------



## wildwood (Jan 25, 2011)

Called turning between centers use a dead center in headstock and live center in tailstock, insert bushing into blank and bring tailstock and turn. I have the HSS dead center wish had gotten carbide-tipped one. 

http://www.grizzly.com/products/Carbide-Tipped-Lathe-Center-MT2/H7967
http://www.grizzly.com/products/HSS-Lathe-Center-MT2/H5789

Can only turn one pen blank at a time, but eliminates problems with mandrels. I have never turned Slimline, between centers normally use bushing that come with kits. Those bushing not real good because they don't go into tubes. (see link below for bushings) Have turned more than few Cigar blanks one at a time with no problems. Kit bushing must fit into pen blank only drawback so I buy kits that bushing go into pen blanks. 

Many folks buy bushing and dead centers from Johnny CNC. Can check out turning between centers video there too.
http://www.penturnersproducts.com/


----------



## zacker (Mar 25, 2010)

is the live center sitting in the tail stock correctly? have you cleaned both the center and the inside of where it sits? is the tip / point of the center worn out or rounded from the pen mandrel? i use the center witht he hole in it that the mandrel goes into, much nicer than ruining my tailstock live ends.


----------

