|
Richard John Torrens |
| |||||||||
| Dorset holidays | Electronics & DIY | Family History | Cigarette Cards | Misc | Natural History | Wild Food | Walks | ||||
| For sale | DIY tips | Sinclair Radionics | Circuits & technical | Risc OS | |||||||
This page is still under construction - there is lots more to add - mostly not very favourable!
This is a review of a 6-in-one multipurpose machine sold via KKMoon on AliExpress and other places. The kit assembles to make a variety of mini-machines. It is described as "6 in 1 Lathe Tool Kit Jigsaw Grinder Driller Plastic Metal Wood Lathe Drilling Sanding Turning Milling Sawing Machine Tool Kit"
There are some extremely serious problems wuith some of the assemblies: these have been hi-lighted in red.
The most serious problem is with the grinding machine.
Consider also the safety of the metal working lathe.
First impressions: a clever design. If it works it could be useful. Or is it little more than a toy? There are two versions: an all-metal version and one which is partly plastic. The instructions say "Metal 6 in 1 is stronger and durable". Which is fine, but you are still going to require replacement tools and spare parts. These do not appear to be available!
However there is a large jpeg of the instructions which the manufacturer send, when I requested a pdf (which would have been far more use!). They did not answer several other points I made!
A large jpeg is less than ideal so I have split it into a 14 page pdf of the 6 in 1 Mini Multipurpose Machine instructions which can be printed out A4, so is much clearer. However even enlarged, the photos are not always clear.
Photos usually (and in this case definitely) are not as good as drawings, so this is rather puzzling as the KKMoon page selling these has some very good drawings - which should be in the instructions!
Most use for me would be as a micro-lathe. So I go straight for this.
So I get the lathe assembled to the point that I am trying to clamp the metal-working tool in place. It is completely impossible, from the 30mm x 25mm photo, to see how this is mounted. The two clamps are plastic z-shaped pieces. The two arms are different as shown in the side view. But the photo from the instructions just shows some sort of screw and nut arrangement to clamp the tool and it is indistinguishable which way te clamp is to be mounted. The holes in the clamp are much larger than the M4 screws provided and, as the third photo shows such a nut-and-bolt system does not fit squarely and could never safely clamp a metal-working tool.
So, having in my possession a suitable Z-shaped aluminium piece (a heatsink from an old 2QD controlled which I designed and sold), I decided to make a proper, safe clamp as shown. But even when clamping this, the clamping action is not solid as the plastic of the slide beneath gives, so each of the screws (only 3 mate with the supplied tool) has to be tightened and retightened. But I think this clamp will probably cope with an 8mm x 8mm tool.
The main problem with the lathe unit is that there is no vertical adjustment of the tool, which seriously limits its usefulness - especially as 4mm lathe tools appear to be unobtainable. Some adjustment could be made by padding the tool but this would be in the wrong direction.
These collets are nicely and accurately machined and work nicely.
The main criticism is that, because the chamfer is at the root of the collet rather than the tip and is at a shallow angle, the collet has a tendency to get stuck in the tapped shaft, with the inserted tool retained. If the chamfer was at the tip, as shown on the right, any sticking would be in the cap nut, which is being unscrewed so will remove the tool as it is unscrewed. This version would also require less force to clamp the tool as the clamping is applied at the collet's tip so there is better leverage.
The collets are also very robust so that they will not easily clamp significantly smaller than the designed sizes.
The nut to tighten the collet is 15mm across flats. 15mm is not a common spanner size so most users will need to use an adjustable spanner.
The only criticism is that two rods are supplied to adjust it by locating in holes in the chuck. But the diagram in the instructions is so small it is easy to misread which holes to use! One important hole is in the back knurled section. There are three more holes in the plain section to allow the front rod to be moved from hole to hole. Obvious once you have seen it. The fit of the chuck is so good that visual inspection does not show the join between these two parts of it!
Be careful not to widen the grip too far or one of the jaws will fall out!
fits a standard M12 bolt
">The Wheel is moulded with a standard M12 thread, pitch 1.75mm. A standard M12 machine screw (not part of the kit!) fits if nicely. But the shaft onto which it should fit is M12 fine - a 1mm pitch! This is a silly mistake which should never have happened. The machine in this guise is unusable! Clearly a mistake has been made in specifying the component and the producer has no quality control checking!
However once you have worked out which bits to use, the jigsaw fits together well. The drive mechanism is an eccentric ball-race mounted on a shaft that uses the 6mm collet. The ball-race slots into a rectangular box on the vibrating shaft that holds the saw blade. This box comes packed with grease so should last a fair time, provided the grease doesn't get too polluted with abrasive particles. When you dismantle the saw, most of the grease comes out on the ball-race of the eccentric, so you need a small polythene bag to store this component in.
The table screws onto the jigsaw base with two self-taping Philips screws so might not take too many disassembly-reassembly runs unless care is taken to use the original threads - the way to do that is to turn the screw slightly anticlockwise, feeling for a slight click as it locates the original thread.
The saw blades are tiny - about 1.3mm wide with a tooth pitch of 1mm. 15mm length protrudes from the table, so they could cut intricate shapes in thin material.
The next bit of the instructions says"M4x8 screw through the drilling table and twist them with the M4 slot nut into the T-shaped slot in the middle of pattern 2." What is pattern 2? It does not help that the instructions are mostly for the all-metal version. The metal plus plastic version is significantly different. I found the instructions at this point impossible to follow but, having printed out the enlarged instructions A4, I could work out from the pictures how to assemble the machine. You have to take apart one of the small slide units, unscrew the grub-screw in the adjusting knob and remove the threaded adjusting shaft. The knob itself is captive so cannot be removed as the instructions suggest. The smaller half of the slide then must be mounted on a "intermediate piece" taking care that the slot on the back of this piece in vertical and not horizontal. The slide should be well oiled (the instructions suggest vaseline).
This same system can be used as a mill, when the slide unit should not be taken apart. The two bottom slides adjust the table so shapes can be milled. This mill also works nicely.
Forunately I have a supply of such leads so was able to find a correct one.
After referring the problem and trying to get them to understand, I took the photos of the mismatched thread to KKMoon, they said they would have to contact their suppliers. That was 19th January - a month later.
No response from KKMoon. I again contacted them 19th January. Their response was "Don't worry .... I have reflected this question to our suppliers".
Another month passed, time to get over Chinese New Year. This time KKMoon said "The supplier said that the product has no problem."
Now I see only two possibilities: either this stupid mistake has been noted and new stock has the correct "sanding wheel". In whch case it should not be difficult to supply one.
Or the mistake has not been found and the wrong wheel is being supplied. In this case the chinese parties are calling me a liar who is faking the above photos.
The saga continues. The moral is - if you expect support from Chinese suppliers, it is not very common. You pay your money and take your chances.
I had originally requested a refund of the kit, finding the instructions too small to be of use and the lathe tool clamp unsafe. I suspected more problems would emerge (as indeed they did). This request was turned down without investigation.
Then I contacted them again in February and had great difficulty in making them aware that there were severe problems. Eventually the complaint was referred to their review team. I await response.
Page design by Richard John Torrens.
