Posted on Leave a comment

Dust extractor maintenance

I’ve written before about the need for regular dust extractor maintenance. An extractor with a filter is not ‘fit and forget’. My extractor is a cyclone unit and since I removed the internal wire grid that avoids the low risk of accidental contact with the fan, it is less prone to blocking up. After considerable use, it still seemed to be working OK. But when I checked the filter recently I found a great deal of fine dust in it. After cleaning it, the extractor worked a great deal better. Not really a surprise!

The deterioration in performance had been so gradual that I had failed to notice it. I needed an objective measure of performance and a proper dust extractor maintenance schedule. Just putting my hand in front of the inlet now and again to see if there is still suction is not good enough.

Measuring air flow

Performance equates to air inlet velocity and filter effectiveness. Dust build up in the filter actually improves its effectiveness, but it cuts the air flow. The flow can be assessed by measuring the vacuum in the pipe. A vacuum gauge permanently installed as part of the system, with an easily visible readout, would be ideal. However, I opted to measure the speed directly with an anemometer. A digital anemometer can be got very cheaply. I bought this one from Amazon.

It was impossible to get a consistent reading from it just by holding it in my hand. I folded a bit of steel strapping to make a holder for it, with a hook that clips on the edge of the extractor inlet to secure it at a fixed short distance inside. I take it out again after each reading.

The reading itself is less important than changes in the reading over time. So I noted the indicated air speed just after I had cleaned the filter. I can take further readings at intervals as dust starts to build up again. This will tell me how long it takes for the speed to drop by, say, 20%. Then I can schedule a regular filter clean in my calendar.

It was interesting to see how far from the inlet the suction extends. The answer is not very far at all. A small diameter inlet is only effective when very close to the dust source, which is not easy to achieve at the lathe. The 7 inch inlet I have at the lathe does provide quite good air flow at the tool tip where the dust is generated.

Cleaning the filter

Cleaning the filter was straightforward. I took the cartridge outdoors and stood it on end. Tapping it with a wooden batten dislodged the dust cake and it fell to the bottom. In some places the pleats were close together, and those areas took more tapping. I also used compressed air. At first, the supply of dust coming from the filter seemed almost infinite, but eventually it slowed down.

Posted on 1 Comment

Taking up woodturning

Using a lathe, you can make objects that are both beautiful and useful, often taking only a few minutes from start to finish. The process is fun, and no other form of woodworking is so immediate in its results. But if you are thinking of taking up woodturning, how do you start?
There are four things you need to become a woodturner: a workspace, the equipment, some timber and the necessary skills.

The workspace

This you probably have already, or you would not be considering taking up the craft. The space determines what you can do. Woodturning can be messy, and you need somewhere to store materials and valuable equipment, so the workspace is the first thing to sort out. A proper building that is secure, insulated, heated, powered, dry and well lit is ideal. But most people get by in a garden shed, basement or garage, and do great work.
Whatever you have, do your best to allow nothing in your workspace that does not relate to turning – no bicycles, lawnmowers etc. They take up the space that you as a turner will need, and detract from the proper dignity of the craft. And unless your workspace is large, try to find somewhere else protected from the weather for the wood pile.

The equipment needed for taking up woodturning

When you are taking up woodturning, the essentials are:
  • A lathe with a stand or a bench, and a chuck. The lathe should be the most substantial one possible. If you start with a cheap, flimsy machine, you will soon want to replace it. If space and budget are limited, a good quality mini lathe is fine, though it will restrict what you can do. A good used machine is much better than a poor new one.
  • A grinder for sharpening. Blunt tools will not give you the results you want.
  • A sharpening jig for gouges, though you can learn to sharpen gouges freehand if you take the trouble.
  • Some basic turning tools – a good start would be a small spindle roughing gouge, a 3/8″ spindle gouge, a small and a larger bowl gouge ground at different angles, a square nose scraper, a round nose scraper and a parting tool
  • An instructional DVD or book.
  • A face shield and dust mask
  • Sandpaper and the usual workshop tools – screwdrivers, power drill, tape measure etc.
With these, you can make bowls and vases, boxes, all kinds of spindles, and lots of shavings. Later, you may need a bandsaw, a chainsaw, a drill press, a dust extractor, power sanding equipment, additional turning tools, buffing equipment and lots more. No woodturner ever has all the equipment they would really like.

The materials

In the beginning, you can buy ready-made turning blanks. It’s what many people do when first taking up woodturning. But this is the most expensive way to buy wood. It is better to convert small logs and branches to turning blanks yourself, at no cost. You will enjoy turning unseasoned timber, and found timber can be the most beautiful. A band saw will pay for itself. You will soon find you have more timber than you can turn, and will need somewhere to store it, protected from the weather while it seasons.
For practice, almost any timber will do. But it is easier to turn wood that is straight-grained, free of large knots, decay and splits, and not too hard. It’s a mistake to buy tropical hardwoods when you are starting out. They are beautiful, but harder to turn than species such as oak and ash, which are just as attractive.
You will also need finishing materials, such as a can of danish oil.

The skills

A turner must be able to prepare the wood, sharpen and use the turning tools properly, and come up with pleasing shapes for the finished items.
When you are taking up woodturning, you have to develop these abilities. Study the books and magazines, watch the DVDs, take lessons from me or anyone else with the experience, and join a turning club. If you practice, you will improve. Practice some more. Eventually, practice makes perfect. Learn from people who have gone before, then go your own way to establish your own style.
There are two options for a turner. Some people use a lathe simply as a means to an end. They use any turning methods that get the result they need. As scraping tools are comparatively easy, that’s what they use. It’s a pragmatic approach that can make a lot of sense. With a little practice, and on suitable timber, scrapers can give excellent results. But they can sometimes leave a very poor surface, so that heavy sanding is needed. This can show in the finished product.
Others set out to learn the more difficult tools – gouges and chisels, as well as the scrapers. They value the craft for its own sake. These tools are quicker and more versatile in use. There are very competent turners who rely on scrapers and get great results. But getting to grips with the other tools pays off in the end.
Posted on Leave a comment

New website

Until recently I operated a website at www.turnedwoodenbowls.com. Because of technical problems with it, I set up my new website here. I think it already looks and works better for visitors than my old one, which I have now closed. It’s easier to manage too, though I still have a lot of work to do on it. I haven’t yet republished all of my old posts, and I still have to transfer some images.

I have migrated my list of subscribers. So if you are one of them, you will be notified when I add new posts, and I thank you for your interest.

I’ve published a couple of new posts here so far, on sharpening and on dust extraction. More will follow, so if you haven’t yet subscribed, please do.

Most of the wooden bowls and other things on my product pages here are new. In due course I shall list stock from my old site here. If you are looking for a specific item, just let me know.

Posted on Leave a comment

Getting organised in the workshop

Since my new Titan 315 lathe arrived the workshop has been in chaos. I still have both my old lathes. The Tyme Classic will go off to its new home in the next couple of weeks. Until then it is taking up space and getting in the way. The new lathe is bigger and I have had to move quite a lot of stuff around to make room for it. The process is not yet finished.

I’ve decided I can do without a cut-off saw. Until now I had a cheap Erbauer from Screwfix. I got it chiefly to cut lathe spindle blanks and to make segments for globe horizon rings. It did the former well enough, but was not very accurate for the latter. This was probably at least in part because I did not prepare the blanks well enough before cutting the angles. Its blade had got very blunt and I recently fitted it with a new one. Unfortunately the blade guard shattered when the new blade picked up a small off-cut. Spares are not available for these machines. Rather than replace the saw I have purchased an Incra mitre fence for my table saw. I shall use that instead.

The saw lived on top of one of my homemade chests of drawers. Without it, I was able to stack another chest of drawers on top of that one. It seems to work OK there and the move has given some welcome floor space. But I shall have to re-arrange the drawer contents so that the things I want most often are more accessible. A helpful suggestion from my daughter is to turn the higher drawers upside down so I can see what’s in them from below.

Posted on Leave a comment

Turning spindles on the Titan 315

It’s possible to turn small items on any big lathe, but it may not be as user-friendly as a small machine if the tailstock and toolrest are heavy and clumsy. Most of my work is quite small and I knew I would be getting rid of my smaller lathe, so I made a point of turning spindles when ‘test driving’ the Titan 315 before I bought it.

Turning spindles

Now I’ve had time to turn different items in my own workshop, I’m very happy with the result. I made a batch of long spindles. Because I don’t have another rest the right length, I used the long asymmetric one. It needs a wooden strut at the thin end to stop vibration, but with this I had no trouble at all. The rest holder and the tailstock slide freely and lock securely. A little bit of WD40 on the bed helps with this. A rub of wax on the top of the rest lets the tools slide smoothly. The spindles were rock solid between the centres. I didn’t feel at all that a smaller machine would be better for the job. I did find I shall have to take extra care if I go on loading the blanks without stopping the lathe when turning spindles. The powerful motor, heavy toolrest and solid grip mean I really don’t want to get my fingers caught!

Then I set up a larger piece – a reclaimed baluster made of pine, 500 mm long with a maximum diameter of 200 mm. I wanted to reshape it for another purpose.

I tried earlier to do this on my old Tyme Classic lathe but found it tough going. The Titan makes it easy, although the wood is very gritty and full  of cracks.

Posted on Leave a comment

Magma Titan 315

Yesterday I posted about turning a bit of 2″ diameter mahogany in my new Magma Titan 315 lathe and had to admit it wasn’t much of a test. Today though I put an 11″ diameter, 17″ long freshly felled log between centres. It would not have fit on either of my old lathes. This was quite a heavy chunk, and its ends were not cut square. I lined it up by eye, not very accurately as it had a definite heavy side that gravitated downward.

Vibration

I thought I would try the traditional vibration test, so balanced a £1 coin on its edge on the headstock, stood well back, and started at the lowest speed on the fast pulley. The Magma Titan 315 is not bolted down, but the coin didn’t begin to wobble until I took the speed up to about 430 rpm. I turned the speed down to about 275 rpm to begin the turning – this was not a piece that I wanted to come loose.

I used the long (about 600 mm, 24″) asymmetric tool rest. It was disappointing to find it distinctly flexible towards the unsupported end.  I was not really surprised at this, although I had been assured that it would be rigid.

Tool rest

This rest is heavily built, but it only has one stem and overhangs too far to be rigid. This makes anything but light cutting at that end difficult or impossible. Perhaps it would be better with a steel web welded at right angles to the main rest bar. This would give it an inclined T or L shape in cross section. However, a loose wooden strut slipped under the end braces it either to the floor or the lathe bed. It then becomes much more solid and will certainly be very useful. The taper helps with this as it allows for some height adjustment.

I turned a ball from the log. It will live in the garden next to the workshop door.

Posted on Leave a comment

Titan lathe – smooth and vibration free, with a better finish from the higher speed.

My new Titan lathe is up and running, though I haven’t had time yet to do much with it. I started with a bit of mahogany about 50 x 150 mm between centres. Not exactly challenging, but I didn’t have a usable chuck or faceplate yet). The tailstock ram has a nominal 200 mm travel. With a four prong drive centre in the headstock, the No. 3 MT ram felt as if it could happily force its way right through the mahogany and out the other end. The blank felt rock solid. There was nearly a foot of clear space between the blank and the bed. I switched on.

Titan lathe noise level

The Titan lathe has two different ramp speeds, one that reaches full speed almost immediately, and a slower one that gradually winds up to speed and down again, safer for large blanks. The lathe made a bit more noise at full speed (3000 rpm) than I hoped, but not excessive. At about 1000 rpm it was quiet. I suppose large bearings cannot run silently at speed.

I took a cut with a roughing gouge and in two or three passes made the blank into a cylinder. There was no hesitation or vibration whatsoever. The toolrest is very heavy (40 mm stem) and too deep for the underhand grip that I use. If I don’t get used to it I can easily make up some smaller rests for detail work.

Chuck insert

My Vicmarc 120 chuck had an insert threaded for the Graduate lathe. I remember that I had trouble fitting this insert originally. Because it sometimes came loose when unscrewing the chuck, I used some Loctite bonding agent in the thread. This worked perfectly – so well that even with a large pair of Stilson grips it was impossible to remove. Warming the insert with a small blow torch softened the cement and it was then easy to undo. Loctite doesn’t seem necessary with the new insert.

I screwed the chuck on the Titan, but found a small amount of run-out. This is not a problem with the lathe, it means the insert is not seated properly in the chuck. I was too impatient to correct this, so loaded a small bowl rough-out for a trial cut. This was smooth and vibration free. I compared a cut at about 1000 rpm with one at full speed. There was a big difference at high speed, with much less tear out. The surface was slightly burnished, without ripples.

 

Posted on Leave a comment

Magma Black Line Titan lathe

Some time back, I saw a Magma Black Line Titan lathe being demonstrated at the annual woodworking show at Cressing Temple Barns in Essex. They allowed me to try a cut on a bowl the demonstrator was working on. It was impressive, to say the least.

The Titan is expensive, and for some time afterwards I was able to convince myself that I didn’t need one. I already had two excellent lathes – a Tyme Classic and a Graduate short bed. But on my larger pieces they are sometimes at the very limit of their capabilities. The capacity over the bed of the Classic is not enough for some of my work, and the big discs I turn for globe stands need more torque than the Graduate motor could deliver. I was able to turn long items, and wide ones, but not things that were both. So eventually I felt myself giving way.

Thinking that if I were to buy another lathe it should be the best I could get, I took a trip to the showroom of Classic Hand Tools Ltd where they had a couple of Titans set up for customers to test drive. I took along some tools and bits of wood and spent some time trying out the machine. Again I was impressed and decided to place my order.

Which model?

The Magma Black Line Titan Lathe comes in two models, the 315 and the 400, those being the spindle heights over the bed, in millimetres. This would be the last lathe I ever buy, and not wanting to be limited by the lathe, I chose the 400. I paid my deposit a few weeks back. But I soon changed my mind. The 315 can turn up to 25 inches over the bed, and unlimited diameters with the headstock swiveled. Realistically, this is more than enough. I don’t really have the space and equipment to handle pieces bigger than that. CHT agreed to change the order. I paid extra for the 3HP (2.2KW) motor option and a 500mm bed extension, and for help setting up the lathe.

Delivery

CHT delivered my Magma Black Line Titan lathe with a couple of helpers. It came broken down into parts, each of which was a challenge to get into my workshop. This, with assembly and set up, took several hours of hard work. The most difficult job was lifting the headstock assembly on the bed, but we managed by using an engine hoist.

Already, the Classic and Graduate are looking small in comparison with the Titan. My workshop is in chaos as we moved lots of stuff to make way. The priority is getting rid of the Classic, which is now badly in the way. I shall have to keep the Graduate for a while as I must adapt my ball cutting jig and make sure I have accessories to fit the Titan before the Graduate goes. I have lots of work to do before the workshop is properly organised.

Posted on Leave a comment

Record grinder and bandsaw each took a lot of work to make them fit for use.

Today I visited a friend who is fairly new to turning and is getting his own workshop ready to make some wooden bowls. He has been having problems with his Record grinder and bandsaw. They are both new machines and it was disappointing to find that each needed attention to make them work properly. This is quite a common thing these days – the maker leaves it to the customer not just to assemble, but to finish the manufacture of the machine.

It’s not just the Record grinder. Machines of various makes may need adjustment and because of poor design may even need modification before they work properly. It is well worth spending a bit of time to sort out the deficiencies. But someone without experience of woodworking machinery may not know how to make these adjustments, may be afraid to modify the equipment, and may not be aware of how a machine should perform. They may blame themselves.

The Record grinder

We started with the grinder. The first job was to tighten the loose retaining nuts on the grinder wheels, which meant taking off the side guards. Before we replaced them, we had to straighten one of the bolts, which was bent. Then we had to get the grinder wheels to run true, using a diamond dressing block. We let the machine run up to speed, then switched off to let the wheels turn more slowly. The vibration was then less severe, making it easier for the diamond to cut back the high spots. We could hear the tick-tick as the diamonds did their stuff. After this, the wheels cut better, more quietly and with much less vibration.

We did not attempt to true up the sides of the wheels although they have a lot of side to side run-out. This is due to the extremely small size of the shoulders on the spindle against which the wheel flanges bear. There is no easy fix for this. The design and construction of the spindle are simply inadequate. But at least we got the edges running true.

The tool platforms on the Record grinder are small, flimsy, flexible and out of square. They can only be adjusted in and out, not tilted. They are of little use for sharpening turning tools, and probably not for other purposes either. One option is to cut off the part of the fixing that prevents the platform from tilting. The thin steel of the platform would bend to make it level. But we decided it would be better to cut off the platforms completely with a hacksaw and make adjustable ones out of plywood. This is a job for later.

The bandsaw

The bandsaw was next, as it was not cutting properly. It was very difficult to adjust the guides, or even to see the lower ones. Adjustments should be easy, because it may be necessary to re-set the guides each time the blade is changed. We started by removing a small plastic shroud beneath the table. It made it impossible to see the lower guide rollers. This shroud prevents accidental contact with the blade between the lower guides and the table.

We then slackened the guide wheels and thrust races so they were well clear of the blade. But in order to do this, we had to remove the table tilt locking lever. And free up the seized lower thrust race adjuster too. This needs more attention as it is still binding and hard to use. Access to it is obstructed when the locking lever is in place.

With the blade able to drift freely, we put on the tension in stages, adjusting the tracking until the blade ran centrally on the wheels, turning them by hand to allow the blade to find its preferred position.

Then we adjusted the guide wheels so they gave good support to the blade above and below the table without binding or deflecting the blade, and set the thrust races to almost touch the back of the blade. We could then replace the tilt locking lever and do a test cut, which showed that the saw now works. It easily cut through some 2 inch scrap wood. And quickly sawed a small log into spindle turning blanks.

A lot of trouble to get two new machines fit to use. Thanks, Record.

Posted on Leave a comment

Turning MDF is easy with scrapers, but it’s dusty and blunts the tools quickly.

I’ve been turning MDF discs. MDF is a plain material without visible grain. The discs need a hole drilled in the middle after turning, and I mark the spot for the drill with a little depression turned with a skew chisel. With this material it is not easy to see the exact centre of the spinning disc. Of course a pencil will mark a circle, but I found that if I make a quick random squiggle of pencil somewhere near the middle before mounting the blank, when it spins the centre magically becomes easy to see. This takes just a second when preparing the blanks.

MDF turns well

MDF is easy to turn,  and I use it a lot, often laminated into blocks, though the fibres are a bit woolly when cut. I use the moisture resistant kind as it has a higher resin content and gives a better finish for painting. Some grades are better than others, and this shows when you cut into them. Turning MDF blunts the tools quickly, but the work on these discs is quickly and easily done with scrapers. They are very quick to sharpen if you have the angle set up on the grinder platform. I usually get two discs from one sharpening. I use a round nose scraper to rough out, then a square nose to refine the shape. Finally, another round nose to make the last cuts on the concave detail after the first has done most of the work. The shavings are very long.

It is much easier to turn from the face of the material than the edge because of its structure. MDF is quite strong, but can easily delaminate and split if small diameters are turned. It has a hard surface skin and a softer, more porous core, so sanding is always needed, and the exposed core needs sealing before finishing. You need to take care not to cut too deep into the soft parts when sanding. It’s easy to change the shape.

Dust

It’s very dusty to turn, and good dust extraction is essential if you do it often. Its dust is sometimes said to be particularly dangerous, but there is no evidence that I am aware of to support this. It is as harmful as any other wood dust, but not more so. If turning MDF is more dangerous than turning natural wood, I think that is because it makes more dust.