Wobbly wood.

[docusk]

Off the wall this one. I have just returned to turning after 5 or 6 years away. I had a good few items of wood, mostly bowl or platter blanks and a few squares.
I have not had much success, mostly because my new lathe was not on a rigid enough mounting. That now cured, I tried a lovely piece of walnut hoping to make about an 8 - 9" diameter bowl. To my chagrin, it caused the bed to vibrate and it appeared that there was what I think is called an"Oyster" or an extra heavy portion of the blank. Cracks appeared on the surface after roughing out with the large gouge and it wouldn't take a finish till I finally turned the outside at top speed with an oval skew. In the end the whole thing was a disaster for various reasons, mostly my stupidity but I then tried some other part-finished and completely raw from this batch of blanks. I can't really get a good finish on any of them; they remain rough to the touch. My immediate thought was and is that the problem is because the wood is too dry. It has been sitting in a corner of a warmish, dry workshop undisturbed for maybe 6 years!
Is this a possible cause of my difficulty? I know I haven't forgotten my turning skills.
Commentsand advice requested from you kind souls down under???
docusk. Reading, Berkshire England.

[Joash]

So are your tools sharp? This always causes frustation to a user, dry, would'nt haver anything to do with it, unless they were timbers like oregon etc:

Try rounding the blanks, or try something smaller, to see if theres no vibration, and see what finish you get.

Overall, I think it is the sharpness of the tools, also check for correct bevels.

Let us know how it goes:)

Joash

[Hickory]

If you are only accomplished in turning green wood then too dry may be an excuse but It has not been till thes last few years of my 40+ years of turning that I ever attempted green wood. An still prefer dry , especially Walnut as it is most dependable and allows such great detail. Albet it requires a sharp tool and a gentile hand remembering to take small bites as you wear down. As was said, try round blanks and well centered pieces as well a proper alignment techniques and play with the speed controls till you find good results. I fear you will never go back to the wet, messy sticky side of turning. Well cured wood is the best results. In my opinion. Although I am perfect in every way, there are those who don't agree with my opinion and for them I am truely sorry. The only thing wet I want is my Whistle and after an evening of turning walnut and the deep brown boogers clog your every pore and nostril. A good whistle wetting is in order.

Tis true that green wood turns so easy and the noodle curles are exciting to behold, I prefer dusty chips and the ability to start & finish a project w/o waiting for the wood to cure and then try to reshape the shrinkage or patch a check.

[TTIT]

Believe it or not, I actually agree with much of what Hickory says:eek:. If you were turning mainly green wood before, then the change to using very dry wood requires a change of technique too. Sharper tools, finer final cuts etc.

Sometimes I have to resort to turning wood wet because many of our desert timbers will split quite severely if the stresses aren't relieved by roughing out. Sometimes just because I found a new timber I haven't used and NEED to get into it immediately - and sometimes just for fun - noodles are cool;):D:D

[OGYT]

Yep, noodles are Kool.
Sharp tools and light cuts on dry wood, seems to be the order of the day.
I've also learned that just because wood is seemingly dry and well-aged, if you plane it, you need to plane both sides, or it will warp on you. Seems to me the same goes for turning. When you take a lot of wood off one side (or the outside in this case), then when you take a lot more out of the center, it'll try to do the same... thus, the checking. JMHO

[docusk]

OK Thanks for all yout input. Yes, tools are sharp. I've just invested in a "Tormek" wet grinder plus the turning accessories. Spent hours making sure they were all OK.
I have another possible pointer. I also have a new Record lathe with the bowl turning setup. I feel the toolrest needs to be lower than it is possible as it stands. The top of the rest is almost level with the centre 'pip' so I find myself having to attack the workpiece with just a slight angle downwards of the chisel to meet at the right level. I have been toying with the idea of having the top of the socket ground down by a few mm.
I agree that walnut is normally a very forgiving wood and looks wonderful when fully finished. This blank though definitely has some out of balance property. When the motor stops, the kind of bad bit always drops down to the bottom as if it had a bobweight in it.
Before I do much else, I shall take the advice from elsewhere on the forum and make a carrier for a few sandbags attached under the bench to dampen any vibes still further.
I'll get all the tools sharpened again and have another go. I have had some success before with this lathe - as you say, making sure tools sharp - and all have finished well. Thanks again chaps.

docusk

[baxter]

Hi docusk

Record lathes are not as popular in Australia as they are in England and I am not familiar with the newer models. However those that I have seen and turned on did not have any problem with the toolrest height.

It seems strange that Record would manufacture a lathe that has such a problem and this leads me to think that there may be some other cause that is stopping the toolrest from lowering to a workable height.

I would not start grinding anything off the socket until you have explored other avenues, including taking up the problem with the retailer.

A few thoughts that come to mind. Is the bottom of the cross bar of the toolrest hitting the top of the socket? If yes, is this the correct toolrest for that model? Could you try another toolrest which might be thinner in depth.

If no, is there something (a blank etc.) under the toolrest post which is stopping the toolrest from dropping down far enough?

Just my immediate thoughts, however I would certainly not start grinding anything off the lathe until I had investigated other alternatives.

[hughie]

Tis true that green wood turns so easy and the noodle curles are exciting to behold, I prefer dusty chips and the ability to start & finish a project w/o waiting for the wood to cure and then try to reshape the shrinkage or patch a check.
[/QUOTE]

Hmmm for me its a bit of both. Some timber like Camphor Laurel work really well with green and meths/DNA.Redgum I prefer dry.............
less hassles :D
I was offered some 100 years old Jarrah sleepers, looked at it and passed em up. Very hard and decided to let some body else battle 'em.
But on the other hand I have a small piece of very old Lignum Vitea, magic to turn...in fact I wish all timber turned like this.......sigh.

So for me it depends on the type and its properties etc...horses for courses.

[rsser]

I have some blanks of Plane and the like that dried in a hot shed. They don't turn well; the timber feels brittle and rough and no amount of sanding deals with it. So maybe you're right docusk about the effects of this kind of drying. I have heard turners saying not to use kiln-dried timber.

[docusk]

Thanks Baxter, I think I'll call Record helpline about toolpost height. No there's nothing obstructing the toolrest dropping down to zero . The problem is usung a scraper (yes I know but I do use it sparingly) the top of the chisel, bit with a burr on it, is about 1.8" above centreline of the blank. I can just get any pips off with my oval skew.
Another question, has anyone experience with the Chatter tool? Like to hear what good/bad points before I buy one (or not)

docusk

[baxter]

Thanks Baxter, I think I'll call Record helpline about toolpost height. No there's nothing obstructing the toolrest dropping down to zero . The problem is usung a scraper (yes I know but I do use it sparingly) the top of the chisel, bit with a burr on it, is about 1.8" above centreline of the blank. I can just get any pips off with my oval skew.
Another question, has anyone experience with the Chatter tool? Like to hear what good/bad points before I buy one (or not)

docusk

docusk, using a scraper is not as frowned on as it used to be and is actually becoming quite acceptable. Richard RAffan (google if you haven't heard of him:) ) extolls the virtues of the scraper in the appropriate circumstances.

If you have a bevel angle of between 80 and 90 degrees on a scraper then it should actually be presented below centre height. With a scraper you allow for the wood to come onto the top of the scraper and don't push the scraper into the wood. Also, don't allow the full wide of the scraper to make contact at the same time.

But you say that the top of the scraper is 1.8" above the centre line of the blank. Do you mean 1.8mm????:confused:. Initially you indicatedthat you were turning bowls. Is this when you are turning bowls? Stupid question, but you don't have the scraper on its side do you?:D :D :D :D

If it is only 1.8mm then you can pull the toolrest further back from the blank and allow the scraper to slope slightly down towards the blank. This will get the scraper at or below centre.

Another question, why are you using an oval skew on a bowl (either outside or inside)? Use probably anything but a skew on a bowl:D

Let us know how you get on with the Record helpline.

[docusk]

Oh. Baxter. Sorry, my measurements depend on my age (see profile) and it was meant to comvey one eighth of an inch, I'm so old I never took to these new fangled metrics! That would be about2 mm. They should have waited till all us old codgers died before changing over!!!

Now, I rang Record as I said I wood (see what I did there?!) and he said for my scraper AND the oval skew I should have the tool rest HIGHER than the 'Pip' and the chisels angled down at about 45 degrees. He says if I do that I should get a shaving off like a pencil sharpener. Can't wait.
Even better, I'm going to the D & M show at Kempton Park later this month and the helpline chap will show me exactly what I need to do. So. Watch this space eh?........

docusk

[baxter]

Docusk, I thought about 1/8" after I posted - was it just a typo, . & / are next to each other on the keyboard. You might say "vintage", I would just refer to it as maturing gracefully but good to see that you are getting back into something you can enjoy.

Have noticed the advertisements for the D&M Show in the Woodturner Magazine. Looks like it could be a Woodies toyshop. You are lucky that it is not that far down the M4 from where you live so you will be able to buy lots of goodies. I have been down the M4 a number of times. Pity I didn't know about the show when I was there in 2000.

You must tell us about the show in later posts.

OK, it looks like you are using the oval shew as a scraper. You won't have to do that once you get the knack of using scrapers - I am sure that you will end up with more than one.

Still doesn't seem to answer the question why the toolrest doesn't go any lower.

[docusk]

OK, I'll post my thoughts when I come back. From what Tony at Record said, the toolrest is OK, just me lack of knowledge of scrapers and their use. (In the nicest possible way.)
I am going out first thing this am but I'll be atacking the jobs out there with more zest.

docusk

[baxter]

I am going out first thing this am but I'll be atacking the jobs out there with more zest.

docusk

Go for it and leave no pip unscraped:D :D :D

[ubeaut]

The unbalanced wood may be because the timber was stored on end and not laying flat. This drains the timbers moisture to the bottom of the wood and makes it off balance. If when you stop the lathe the timber always goes to rest in a certain spot then this is the problem.

Your other problems with roughness sound to be purely due to poor or incorrect tool technique. However there is 1 problem that is often encountered here in Aus with Queensland walnut. the timber has a high silica content and will take the edge off HSS tool in a matter of seconds.

If your timber is doing this, take it inside and chuck it in the fire. No amount of scraping or cutting will work in this stuff.... Well it will but it'll drive you nuts doing it.

Cheers - Neil :)

[docusk]

Well, I finished the walnut bowl but had to excise the broken bit in the middle so I'll have to make a shaped plug to fill it using a shoulder to make it look good. The finish is not so hot but it does glow a bit now. Problem is I compare finishes with a bowl in Cocobolo that I did about 10 years ago. My late wife saw the blank in a woody type showroom near Bath, now closed, and loved it so we bought it (her taste much better than mine) and it's the most beautiful thing I ever made. Maybe I'll post a picture of it one day.

docusk

[baxter]

Docusk I saw the review of the Wood Show that you posted in the General Woodworking thread. Good review and I am glad that you had a great time - you were lucky with the weather, you woodn't :o have known what to do if the sum had been out:D . Your scooter obviously came in handy to carry some of the goodies that you brought.:D :D

You didn't mention whether you sorted out the problem with the height of your toolrest. Was there a problem or was it purely in your imagination:rolleyes:

P.S. it is a pleasure to use my 100th post communicating with such a nice gentleman:p. Get the computers fixed and get out into the shed:D

P.P.S. still waiting for the pictures

[docusk]

OK to that, thanks for the compliments
The problem with the toolrest was, as you suggest, in my mind. I needed a lesson in using the scraper. One of the other goodies I got at the show was a lesson from one of the experts on the Record stand.
The computers have gone down to one and this one is an absolute b....r. The customer will get a shock when he gets it back ( my partner will also have one when he finds I couldn't pssible charge for what has been done).
The picture of the cocobolo bowl will get done sometime next week i hope. Last 'puter will be finished by pm monday.

docusk