Scrimper's Fretworking Site

Please note that Diamond Fretsaws are no longer manufactured or available new. I include some information about them here because they were a well made machine made in the UK. They are often available to purchase second-hand so the information may be of use to buyers.

The Diamond heavy duty Fretsaw was designed, built and sold by the late Doug Woodward, it was built in Hinckley England and was advertised as being " Far more useful and versatile than any other machine of it's kind in the world".

Apart from the fact that it is of strong construction it's main innovation was that it can take any type of blade including standard fret blades, coping saw blades, hacksaw blades and even short lengths of bandsaw blade.

Another useful feature is the ability to turn the blade 360 degrees across the table enabling long work pieces to be cut.

The saw can accurately cut the finest veneers or cut soft and hard woods up to 4 inches (100mm) thick.

It is a great shame that production of the Diamond ceased after Doug Woodward passed away.

If you are considering buying a scrollsaw/fretsaw then you could do a heck of a lot worse than buying a Diamond machine. You won't be able to buy a new one, but they do often pop up for sale second-hand and because these machines are quality made most are likely to be in a very good working condition. They often sell for very little money and a second-hand Diamond will be far superior than any new economy saw that you buy, and in fact better than many expensive machines that are on sale today. These saws were built to last a lifetime unlike many sold now.

Another 'plus' point with a Diamond saw is that they are very reliable, but in the unlikely event that something goes wrong they are easily repaired by most people with a little practical ability and most parts are easy to replace.

Some of the saws sold today, often made in the far east, not only suffer from reliability problems but after a fairly short time spares cease to become available. In fact for some of the cheaper economy machines it is impossible to get any spares, even when they are still in production.

Diamond saws do appear on ebay or Facebook marketplace from time to time and sadly go for little money, certainly for less than they are worth. If you are looking to buy a saw do keep a lookout in case one should become available, it will be a much better saw than a cheap new one.

The Diamond was the first powered fretsaw I purchased almost 40 years ago I still have the machine and it still works perfectly. When I first bought the saw it was a revelation as until then I had always used a hand-frame or a Hobbies A1 treadle machine to do my fretwork.

However when I first switched the saw on the vibration was terrific and unless it was run on a very slow speed it was almost unusable. I contacted the manufacturer Doug Woodward who said that I must bolt the machine down firmly on a sturdy bench and if possible bolt the bench to the floor. He also advised me to remove the heavy balance weight that was fitted to negate vibration if the saw was not bolted down, but if bolted down to the bench it was better without the weight.

Blade holder and tension nut

The blade holders are very robust and good quality but they do have a drawback.

Fitting the blade in and out is simple with the Bakelite /metal wing-nut but there is no provision for quick blade tensioning, each time you remove and refit the blade you have to keep running that knurled nut up and down to tension the blade. This is a problem if you do fretwork with lots of internal cuts and it does tend be annoying plus if you are doing it every few minutes your fingers soon get sore! I spoke to Doug Woodward about this and suggested a cam device, he was working on this but sadly passed away before it was finished.

Alternative blade holders

The diamond has two types of Blade holders, Type 6 (shown above right) are the standard holders whereas Type 7 (shown above left) are for standard fretsaw blades only. Type 7 holders will only take the standard 5 inch fretsaw blades, they are designed with just a hole for the blade making it simple to insert the blade easily without even looking. Type 6 holders will take practically any blade from a standard 5 inch fretsaw blade up to a length of broken bandsaw blade so these holders will be able to take metal hacksaw blades of any size such is the amount of adjustment given on type 6 holders.

Other versions of the Diamond Fretsaw.

Left. The new Model D with Tool bridge & solid alloy table with 25 inch reach. Centre. The new quick change two position table. Right the complete machine! Comes with a very sturdy stand and fully adjustable swivel seat. The stand was said to be rock steady in use. The unit could be retrofitted to any diamond saw or in fact any other scroll-saw machine using the fittings supplied with the stand assembly.

The last Diamond Fretsaw?

This may well be the last Diamond Fretsaw that Doug Woodward ever made. The photo of the machine was kindly sent to me by Sam who bought the house in which Doug Woodward lived. Originally Doug made many machines in a small factory but in his later years he reverted to a shed where he made around two machines per week. Neither of Doug's sons were interested in continuing the saw manufacture and the machine in the picture was left in the shed together with a few spare parts.

Thankfully the saw has been saved and is now in the hands of a member of the UKworkshop forum who lives just a short distance from Doug's old house and workshop.

A few changes from earlier machines are clearly visible on this 'last' version - firstly it has a thicker bar on the top arm at the rear by the pivot point. Secondly the pump/blower is mounted on the side rather than attached to the rear of the cover. Lastly there is a small lever on the front of the top arm which I am told affects the tensioning but still not a full quick tension release as fitted to Hegner saws.

I have made a two part video covering the Diamond Fretsaw.

The video contains lots of information on the machine together with hints and tips on its operation.

I also discuss any issues with the machine.

Routine Maintenance and other service information.

The Diamond machine is very well built, sturdy and built to last for a very long time like many other old British made machines it is the sort of machine that is passed down through generations of the family . When new it carried a full unconditional five year guarantee.

I have to say that I bought my Diamond in 1988 and only one thing has failed on it - the speed control chip, which was replaced for free.

The first thing to take into account is that the machines are no longer made therefore no manufacturers spare parts are available, however the machines are very reliable and simple to repair. In this section I will try to offer some advice should any problems arise with the machine.

Before commencing any work on the machine please insure that the plug is removed from the electrical supply.

Do not attempt any electrical work on the machine unless you are qualified to do so.

If you are unsure - seek advice from an expert.

General Maintenance

All of the main bearings are of the sealed variety and require no attention. Every month or so apply a few drops of oil (3 in 1 or any other oil) to either side of the upper and lower arms at the pivot points at the back of the machine. Oil the pivot points on the blade holder rollers and apply a drop of oil to the end bearing of the motor. Every twelve months add a small amount of grease to the bottom arm and slide at the front and give the machine a general clean to remove any sawdust etc. It is also a good idea to spray some WD40 (or Similar) on exposed metal parts.

One of the things that could go wrong are the drive belts. Early models had Vee belts which are very long lasting however later machines were fitted with two elasticated rough finish belts as used on washing machines which when the saws were manufactured were widely available these today are hard to obtain. The belts were commonly known as "White spot" stretch belts .

My video (right) shows how to get around this problem.

The motor fitted is commonly known as a series wound motor or carbon brush type motor again this actual brand of motor was fitted to spindryers in the 1960's to the 1990's we knew it as a "Carter-Romford motor".

Series wound motors do run very fast and tend to be less reliable than induction type motors and do give more issues. first thing to check are the carbon brushes (right) if they are badly worn this will stop the motor working, sometimes a brush will stick in it's holder stopping the motor. armatures and field windings can also fail which means a new motor is needed.

Don't assume that the motor needs replacing in the event of a problem. If you suspect the motor because it is not working at all check the continuity - use a multimeter if you have one or you can use a torch bulb and battery to test the circuit - check in the control box but disconnect one of the wires to the motor before testing (to avoid a parallel reading).

If you have no continuity remove both carbon brushes - one could be sticking and not making contact or the brush may just be worn down too low.

If your motor is working but runs erratically or is sparking badly (a small amount of sparking is quite normal with this type of motor) it may indicate that the motor armature is faulty or it may just be due to a sticking carbon brush. Take both brushes out and check the ends - they should both be shiny with just a tiny burn mark on the trailing edge of the brush, if one brush is shiny as described but the other looks rough and burnt that indicates just a sticking brush. If both brushes are badly burnt it generally means the armature is faulty and a new motor is needed.

One other thing that can cause the motor to run erratically with bad sparking is a worn bearing allowing the armature to touch or rub onto the field windings making the motor run very noisily and cause slow rotation. Unless you can find a bearing to fit a new motor is needed.

It may be difficult to get the exact replacement brushes for these motors as they are long out of production, however all is not lost as it is possible to modify other carbon brushes to fit. simply file them down to the correct dimensions making sure they run freely in the brush holders. If you cannot get brushes with wires and eyelets at the tails find some with copper brush springs, these will connect to the holder and work. As a point of interest the Hoover company always used just brushes and springs (without tails) right up until the late 1990's.

The next thing that could possibly cause a problem is the speed control (shown Right).

The speed control is a very simple device (unlike the sophisticated electronics used on some makes of saw) it comprises just three simple easy to obtain components being a standard toggle switch, a potentiometer and a power regulator chip (basically a SCR or silicon controlled rectifier. for reference the regulator is a CSR604A all are fairly cheap to buy and replace or because it is a series wound motor you could use a standard speed control,

The wiring diagram is shown left the three items used are readily available from electronics parts suppliers. The power regulator chip is CSR604A [rated at 6anps] the variable potentiometer is 250k ohms. Note that the middle terminal is linked to the other side terminal that in turn connects to the neutral motor wire. The switch is just a standard one way toggle switch.

For a larger copy of the wiring diagram and or the control box image - click here or on the image

If the motor fails to run and you suspect the variable control unit is at fault you can easily check this by bypassing the control itself - to do this simply remove the motor wire that connects to the middle terminal on the variable control [potentiometer] and connect it directly to the wiring connected to terminal no 3 on the CSR604A chip - it the motor then runs then the chip itself the variable control or the wiring associated with them are faulty. Because the motor is a 230volt version you could if you were desperate to use it bypass the control and just use it via the on/off switch. The machine will of course run at full speed and be quite noisy and vibrate in use although it would be quite safe.

IMPORTANT! The earth lead makes its connection to the machine via a tag under one of the screws that hold the box on to the side of the machine- for the sake of electrical safety it is imperative that the screw is tight and a good connection made.