CHALLANGE At the Start of tuning blanks

[Sammy-2016]

Hi all,
Tonight I just turned my first 2 pen blanks.
One is hard wood (Violet Black Indian Rosewood) & the other is softer wood which looks like Mahogany.
With both, I had a challenge:
I tightened the knurled nut by hand as much I could.
When first starting from the square blank, as soon as the gouge touches the turning blank, the blank stops. All the turning videos I have been watching, the turner tightens that nut by hand. I have to take pliers and give it a little to keep the square blank from stopping. It took me forever to get blanks round. An then in the spot at the beginning of the blank on the right hand, I got chatter every time I cut the spot (see picture please).
What I am doing wrong?
Please look at the attached pictures to see how I have the pieces on the mandrel.
Thank you
Sammy

 

[Skie_M]

Well, with that level of information, all the advice I can give you is extremely basic ....

Keep your tools sharp, use the bevels while making your cuts, bump the speed up when you have it round enough to be stable, and don't share the sandpaper between those two blanks ... or anything else, in order to avoid color bleed.

 

[SteveG]

Sharp tools!! Many new turners do not really understand that. A lot of the newly bought tools are NOT sharp...they may be a little sharp, but not sharp like a turner needs them to be.

My second item to consider, is that you will usually want the tool rest to be very close to the blank. That calls for a short tool rest. Rick Herell (sp?) makes these...great tool rest at a great price.

A third thing you can do, if you get or have a short tool rest, is mount and turn only one blank at a time.

Do these three things, along with taking light cuts, and you will probably soon be smiling. It would be good at this stage to just get some scrap or inexpensive woods, and just practice learning to use the tools, the tool rest, the speed, etc. There is much, much more to discover and learn. So keep asking here. You will get lots of help, and really start having fun with with this (and soon become addicted, by the way ).

 

[1080Wayne]

Looks to me that the right hand piece has started to crack at the left end . Was the wood milled or sanded down to be flush with the tube end ?

 

[Skie_M]

Your chatter may be caused by a bent or over-stressed mandrel... don't over-tighten that nut! It can also be caused by dull tools or improper tool posture (tight against tool rest, press BEVEL against wood, lift end of tool handle to put edge in contact with wood and ride the bevel to produce your cut). The bend may not be apparent in your mandrel when examined, if the blanks are not properly squared it may make the mandrel bend a bit when that nut is tightened.

Put a lock-washer and a washer on either side at the end of the mandrel just before the nut or mandrel saver .... once it's tight enough that the blanks spin properly, that's as much tension as you really need. Too much and you stress the mandrel or bend it.

Try a mandrel saver or turn just one at a time (keep on left side, put a waste block on right side to take up the space). The mandrel saver is sold by Penn State Industries, and when properly used, all the stress is kept on the wood blanks and spacer bushings themselves, not the mandrel rod.

An alternative option could be the use of home made mandrels with a mandrel saver (which is what I do now...) I get some 1/4" aluminum rod that is straight, cut a piece off that will suit my needs, and SAND IT DOWN to the proper mandrel dimensions ... I then superglue a spare 7mm slimline bushing on the far left where it gets held by my 3-jaw chuck. It's only 5 inches long, so the chances that it'll get bent are very low, and I have several of them to hold multiple projects. I still have my full size mandrel if I want it.


The crack or gouge on the right blank may have been caused by a pen mill or by losing control of the tool (it's called a "catch"). You can avoid those by following the proper tool posture as mentioned above .... tool tight against tool rest, bevel against wood, lift to cut...



As I mentioned in my first post above, sharp tools ... right out of the box, lathe tools (especially cheaper sets like from harbor freight) are not sharp. Get them to a grinder or a sander and put a proper edge on them. Keep them cooled with water and maintain the same bevel angles as much as you can ... once you have extra tools, then you can play around with grinding additional shapes and experimenting with more bevel angles.

 

[TimS124]

Make sure the knurled nut isn't bottoming out on the end of the mandrel's threaded section. Looks like you should have enough spacers on there, but check to be certain. It's a more common problem when turning single-piece pen bodies but can happen with some of the newer, really short bushings for slimline, etc.

 

[jttheclockman]

Sammy welcome to the site. The rosewood blank will give you the toughest fight because it is a hard dense wood. As mentioned all above good advice. Sharp tools is a key. I would suggest a carbide tool would really help you but it can be done with standard tools. The tools you have are also a key. Some cheaper tools just wont take a sharpening as well as good quality tools no matter what you do. Then when you do get them sharp they do not hold the edge well. You are going to have to learn how to sharpen the tools. Then you are going to have to learn how to present the tool to the wood. This shows up all the time when trying to spin tougher dense woods. Not so much with soft woods such as mahagony.

The other big thing with those dense woods. only turn one blank at a time. You then can shorten up on the mandrel and you will not get that vibration and bounce when you spin them. It keeps the wood closer to the head stock and makes for a better controlled cut. Trust me on that one point. Good luck and try to learn how to use a skew. It is still the best tool in a turners arsenal.

 

[leehljp]

Its been mentioned above:
1. No need to over tighten. You are cracking the wood. The problem is not the tightening, it is the technique. Your focus is in the wrong place (tightening).

2. Make sure the tool is sharp sharp sharp. Sharp is sharp. But to the beginner, there seems to be degrees. What "feels" sharp enough to most beginners is not sharp enough for the wood.

3. Your technique is TOO aggressive. Take smaller, much smaller bites. Anyone can make a blank stop every time if they try to cut too big of bites. Patience. It is not instant. I can also turn a blank round without tightening it more than barely snug, but it takes patience and tiny bites.

4. Describing good "technique" involves "subjective" wording, as each of us have our own definition and "feeling" of what aggressiveness and patience is. Therefore: Practice your turning technique on scrap wood to get the "feel" for you.

It just hit me while reading JT's response. Over tightening on a mandrel will cause chatter. I don't usually use a mandrel. NEVER use pliers to tighten. If you need pliers, then tightening is NOT going to help.

Quite often the problem is not a "single" problem but a COMBINATION. Fixing one problem will not cure it.

 

[Chasper]

When it stops, what stops. Is the lathe bogging down and not turning, is a belt slipping? Is the mandrel continuing to turn but the blank is stopped? If that is the case and if your tightening nut is tight, then the wood may be stopped but the brass tube still turning, the adhesive bond between tube and blank is broken.

Chatter is the result of pushing your tool into the blank too hard or not holding the tool firmly.

 

[lhowell]

If those blanks have not been sanded yet then I would say a big culprit is dull tool edges judging by the tool markings on the blanks. Also, make sure you have the tool at the proper angle as it could be catching.

Chatter is almost always caused by either dull tools or a mandrel that is bent (caused by overtightening or too much pressure on one side) or a combination of both.

I threw away that knurled nut as bought a mandrel saver. I got mine from PSI https://www.pennstateind.com/store/PKMSTS2.html just make sure you get the proper morse taper (MT1 or MT2) for your lathe.

 

[hilltopper46]

I think a lot of your problems are you don't have a 60-degree live cente rin your tailstock.

A mandrel saver as mentioned by others will resolve that issue as well.

 

[Culprit]

I agree with the others about sharpening tools, taking light cuts, trying a carbide tool, etc.

But in the mean time while you're learning all that, you can cut the corners off the blanks so they are closer to round when you put them on the lathe. A table saw, band saw, belt or disk sander are all popular choices. Some freehand them, some make cutting/sanding jigs and sleds. There are many ways to skin the cat. Some people even use an angle grinder with sanding wheel, or a round over bit on a router table.

 

[leehljp]

I think a lot of your problems are you don't have a 60-degree live cente rin your tailstock.

A mandrel saver as mentioned by others will resolve that issue as well.

BINGO on the chatter!. I didn't look at the lathe picture. You need a 60° live center in the tail stock. The tail stock you have doesn't fit right for mandrels and causes all kinds of minor but aggravating problems. The tail stock you have is meant for wood. The mandrel is metal. The cup in the metal needs a made for metal live center, hence 60°.

GOOD CATCH, Tony!

 

[Sammy-2016]

This is going to be a LONG reply:
I thank everyone for their replies and advices. This is really overwhelming support.
If you don't mind, I would like to answer all of you in one post:
1. My lathe is a Harbor Freight. I called the company (central machinery) and they said it was too old to get a belt for it (Just pointing that out). This model has NO TAPER for any morse attachments. At the motor end, there is a shaft with a male ¾-10 thread on which I had to buy an adapter or from ¾-10 to 1"-8 so I can use the mandrel you see. The adapter and the mandrel was purchased from Penn Industries.
2. To answer Skie_M (1st & 2nd Post): I just bought this $29 tool set and the are NOT SHARP. I noticed that. As for the mandrel, It has either been bent when I got it or the shaft threaded end of my lathe is not true. I check that mandrel turning as soon I installed it and its threaded end move s. I cannot use a Mandrel Saver on this lathe. Thank you for the advice.
3. To answer SteveG: The tool rest on this lathe is too long for pen turning (I tried to get as close as possible almost touching the mandrel adapter on the left). I understand your advice, I need a SHORTER Tool Rest. And I will start turning ONE Blank at a time. And I will practice with scrap pieces  (Thank you Steve).
4. To Answer 1080Wayne: I used the pen end mill. I just examined that end and the crack is really a scratch I made with the tool .
5. To Answer TimS124: Then Knurled nut is not bottming out but I understand your advice. Thank you.
6. To Answer JTtheclockman: I usnderstand you very well. No I am convinced that my tool is not sharp. I was having to push to get it to cut. I will have to learn how Sharpen the tools and practice Presenting the tool. I will start turning one blank at a time. I am not how to shorten the mandrel other than machine my own (not on this lathe). Thank you for the great advice.
7. To Answer Leehjp: I honestly like your explanation of my issues. I think I was too aggressive. I just couldn't wait to turn these blanks all the way down to the spacers.  I thank you for your advice.
8. To answer Chasper: when it stops, the wood and tube stops. The tubes are still glued to the wood. I think I was pushing too hard due to unsharpened tool. Thank you
9. To Answer LHowell: These blanks have been sanded (I am not sure if I sanded enough). I cannot use any tapered attachments on this lathe. Thank you very much.
10. To Answer Hilltopper46: I am not sure what a 60 deg live center is. Also I cannot use a mandrel saver on this lathe. I wish I had bought a REAL lathe . Thank you
11. To Answer Culprit: This is EXACTLY what I was going to do. Except I will fabricate a jig out of sheet metal to grab a drilled & milled blank and I will cut the corners with my miter saw (like a dummy, I had sold my table saw last year and not planning to buy one soon). I was wondering why don't every pen turners do that ??? Doesn't the process of turning these square edges put too much pressure and shock on the mandrel ????? Well advice is well taken. Thank you
12. To Answer Leehjp Again: Would you please explain to me what a 60 deg live center is? Thank you again.
Thank you all AGAIN for your support and your many many many pointers.
Sammy

 

[leehljp]

# 12 Answer:
Look at these page in Grizzly:
Notice the points on these, which are at 60°.
http://www.grizzly.com/products/Live-Center-MT2/G5686
http://www.grizzly.com/products/Live-Center-MT2/H3408
Live Center Set - Taper: MT2 | Grizzly Industrial

Now, Notice the points on these which are sharper.
Live Center Set For Wood Lathe - MT2 | Grizzly Industrial

Next look at the tiny cup in the end of the mandrel. That cup in the end is machined to hold a 60° point. The mandrel itself is metal and must be used with a live center made for metal. Some people get this confused because they think of making a pen to be wood.

The problem comes in because the point of the wood live center is sharper. When pressed against the cup of of the mandrel, it sometimes bends the tiny end of the sharper point that is made for wood. This bending of the point plus the larger hole of the mandrel cup causes "play" or slack and often results in out of round (not technically correct term) and in some situations - chatter.

Don't feel bad about this, this is very common mistake and easily corrected. Just get a 60° live center. There are other places other than Grizzly to get them. I just used Grizzly's link because I am familiar with their site.

 

[Skie_M]

2 years ago, before I bought my lathe, I had picked up a 1x30" belt sander with 5 inch disc sander combo for around 40 dollars. The belts were also on sale at the time, 5-pack of 100 grit and 180 grit were under 2 dollars each.

I use this for most of my sanding project needs, and I also used it when I first sharpened my lathe tools. The 5-inch disc has long since been removed (lost somewhere in my shelves now, I bet), and replaced with a pair of 4-inch buffing wheels sandwiched together and held between fender washers. A 1.5 inch 10 metric fine machine screw happens to match the threads in the disc sander's attachment perfectly, so it simply screws on nice and tight ... I've been using it for so long now that those buffing wheels have worn down to about 2.5 inches, so it's time for replacement.

Anyway, the buffing wheels are used to buff the back (bevel) of my lathe chisels after I touch up with the belt ... the resulting surface is very sharp and mirror smooth. Final touch-up of the edge is done with a diamond sharpening hone. The smoother your bevel, the smoother the finish on cuts that use the bevel.

 

[Tim'sTurnings]

I don't think this question has been asked, if it has please disregard. This problem would occur if you didn't put the brass tubes in the bodies of the pen blanks. If you do have the brass tubes in there you need to make sure you mill the ends of the blanks so the bushings on the mandrel press on the brass tubes to hold the blanks in place, not the wood blank. I hope you have the issue resolved but I needed to ask about the tubes.
Tim.

 

[Sammy-2016]

I don't think this question has been asked, if it has please disregard. This problem would occur if you didn't put the brass tubes in the bodies of the pen blanks. If you do have the brass tubes in there you need to make sure you mill the ends of the blanks so the bushings on the mandrel press on the brass tubes to hold the blanks in place, not the wood blank. I hope you have the issue resolved but I needed to ask about the tubes.
Tim.

Tim,
Yes glued the brass tubes in the blanks with Gorilla Glue and let it set overnight. then I used my pen end mill to square the blank just to the tube. The blank never are glued fine and they did not spin on the tubes.
Thank you for the comment/advice.
Sammy

 

[JimB]

In one of your posts you asked why more people don't take off the corners on a sander or saw. The answer is simple. You already have the best tool to do that, your lathe. That is what a lathe is for, to make things round. Once you properly sharpen your tools and learn how to use them you will find you can take the corners off faster than you can walk over to one of your other tools.

There are a few exceptions. There are some materials that will tend to chip when knocking off the corners on the lathe if you are not careful but those are the exceptions.

 

[PapaTim]

Looks like you have all the advise you need to fix the issues so I'll just provide a tip. If your mandrel isn't adjustable in length you can use a spare 7mm tube as a spacer to turn one blank at a time. Best of luck.

 

[donstephan]

Don't think I saw one additional suggestion. Look for a woodturning group in your area. Almost certain there will be pen turners in the group, and you can get one on one mentoring and assistance in using lathe tools, turning pens, and sharpening tools.

 

[Sammy-2016]

Don't think I saw one additional suggestion. Look for a woodturning group in your area. Almost certain there will be pen turners in the group, and you can get one on one mentoring and assistance in using lathe tools, turning pens, and sharpening tools.

Thank you Donstephan, I would love to do that.
I am in the city of Riverside, So Cal. If someone in my area is willing to assist me with some pointers, sharpening tools, holding turning tools properly and guiding me, I would really appreciate the help.
Sammy

 

[ken ledger]

Why not try a hollow revolving tail stock center, you dont need the knurled nut then. You tighten the tail stock up and the pressure goes straight to the bushing then the headstop.

The mandrel does not have any end pressure at all.