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Hobbymat MD65

I′ve owned this lathe from new, bought around 1982.

Review

Specification:
Centre Height: 65 mm (2.6")
Between Centres: 300 mm (12")
Turning diameter over carriage: 62mm
Cross slide travel: 80mm
Headstock: MT2
Headstock bore: 12mm
Tailstock: MT1
Motor: 250W
Spindle Speeds: 250, 500, 1000 and 2000rpm

Price: you can pick up a Hobbymat MD65 lathe on ebay for between 300 and 450.

Have had this lathe for more than 25 years and it still does as good a job now as ever.

For a 25 year old lathe it cleans up rather well and with careful care, adjustment and oil the results are still as good as when it was new.

The spindle speeds are limited as you can only go down to 250rpm, but the swing over the bed is limited and so this lowest rpm is not that much of a handicap.

Turning

The lathe shown in the process of being used to turn a wooden ring. I must admit that it is not really correct to turn wood on a metal lathe as the dust gets into slides and bearings and does damage. However, only having one lathe means that sometimes it is necessary.

The thing to do is to hoover the lathe carefully afterwards and then oil the slides and leadscrews.

Turning a ring using a support bar in the tailstock - see Rings.


Thread Cutting

The spindle is driven with a belt and pulley system with an intermediate reduction pulley that can be seen on the left hand side of the image.

A gear is located on the spindle (behind the pulley in this image) and this has a key to locate it on the main shaft.

The set of gears here have a large reduction as the system is set up for a fine traverse.

The pillar at the bottom of the image has a lever that operates the dog-clutch to engage and disengage the leadscrew.

The saddle is permanently engaged with the leadscrew, this means that once you have made a cut you need to stop the lathe, reverse the motor direction and wind the leadscrew back to the start of the cut - leaving the dog-clutch engaged all of the time.


In this image you can clearly see the drivetrain.

With change gears there is quite a lot of setting up of the gears and care needed to get it right.

The middle intermediate pair of gears have a metal carrier that is also the bearing. This is adjusted on the aluminium plate that in turn can be moved get the correct engagement of the gears on the main spindle.

As these are plastic gears I have left them dry, but they do pick up quite a lot of dust from the workshop, to date this has not done any serious damage and these gears have been used for around 30 years, ok fairly light use.


A box of spare gears used to create the other spindle to leadscrew relationships.


Gear Cutting

Have just been cutting some gears and thought it worth taking some photographs and writing up some comments.

The topslide is removed with four caphead bolts.

It is rather awkward that there is a pivot post protruding from the cross-slide as this stops you easily fitting just any angle plate. The angle plate that comes with the lathe has a hole to allow for this.


The angle plate is a large piece of cast iron and was primarily supplied with the lathe so that you can use the lathe as a mill.

I modified the angle plate with additional 6mm threaded holes that allow me to bolt the Unimat 3 mill column to the plate.


You do have to be a bit careful as there is quite a lot of extra mass on the cross-slide once the head and motor are attached as well.

It is worth tightening the cross-slide to reduce any possible chatter - as with any milling machine it is best to reduce movement in all axes other than the one you are moving.


The dividing plate fits to the shaft where the pulley collar currently sites.

I just undo the grub screw, remove the collar and in it′s place put the dividing plate and use the grub screw to fix it in place.

It is best to remove the drive belts as it is too easy to switch the lathe on instead of the milling machine....


Here the setup is complete. Unimat 3 milling pillar onto the angle plate on the Hobbymat cross-slide, an indexing plate onto the back of the lathe spindle, a Unimat 3 milling head with gear cutter and I′m able to machine small gears.


The top edge of the angle plate does limit the lowest position of milling head, but even so with the quill travel it can easily reach the centreline of the lathe.


A bent arm with a pin plugs into a fixing on the bench and has enough spring for me to pull it out, move the dividing plate around and then release the arm to again fix the position.

The pin is tapered and this locates the plate very accurately and securely each time.


Very easy with an indexing/dividing plate to lose count as to where you are and where to move next, one hole out when making multiple cuts would be horrific as you would need to start again, so I mark the holes I′m going to use with a permanent marker.

I also mark the first start finish point (the "O" on the outer rim), just makes it easier to know exactly where you are - light at the end of the tunnel!!


The indexing point is just a point that a tapered point that locates in a hole. The point is brazed to a 5mm diameter piece of silver steel and then locates in a hole in a wooden block that is fixed to the work bench.

The silver steel is springy enough that you can pull the point out of the index hole, rotate the indexing plate and then fix in the next hole.

Just remember that the rigidity of the lathe head is defined by how rigid this bar and fixing is as this is all that stops it rotating.


A small amount of force is applied to remove the point from the plate.

Just make sure the milling tool is clear of the part before you move the index on to the next point.


In this case you can see the part after the first cuts. I then move the tool in further and once again make each cut and then index the part round.

Take your time as the milling head is not as stiff as it could be when mounted to the saddle.

However, the results are worth waiting for.


Conclusion

I′ve used this lathe for over 25 years and it still as strong as when I first bought it. The on-off switch gave up some years ago and I replaced it with a switch from Maplins, otherwise it is perfect.

I actually think this is a better lathe than one of the Mini Lathes in various colours from China. You can buy a secondhand HobbyMat for under 500 as of 2012.


Picaxe Robot

The wheels for the robot along with some other parts were machined on the Hobbymat MD65.


Lamp Post Steam Engine

A single cylinder, single acting steam engine built onto a lamp post...mostly machined on the MD65.

V-Twin Solenoid Motor

A V-twin four stroke solenoid motor.

Solenoid Engine

Not sure if you call this an engine or an electric motor.

Wagon Wheel Stirling Engine

A stirling with a horizontal flywheel that looks rather like a wagon wheel - hence the name.

5 Cylinder Rotary Engine

A 5 cylinder rotary engine that runs on compressed air.

Wood and Metal Beam Engine

A compressed air beam engine built from metal and wood, the idea deing to build an elegant pretty engine - well hopefully - this may be very hopeful as I'm starting the wrong way round...

Low Temperature Stirling Engine

A home design (maybe more of an evolution) low temperature stirling engine that runs using the heat from a mug of hot water.

Two Cylinder Two-Stroke

The two cylinder two-stroke aero engine was designed around a commercially available piston, liner and connecting rod from an OS 25FSR. The crankshaft was made in parts and the crankcase machined from a solid billet of aluminium. Model by Nigel Taylor

Single Cylinder Four-Stroke

This engine is very agricultural in appearance and design, but was the first engine that I designed from scratch and fabricated everything for (apart from the spark plug). Model by Nigel Taylor

See also: Tools.