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Member postings for Martin of Wick

Here is a list of all the postings Martin of Wick has made in our forums. Click on a thread name to jump to the thread.

Thread: Lidl Portable Bandsaw
11/12/2020 10:49:38

Michael, should have clarified, my comments on Femi vices were in regard to the 782 series, noted that other models are available!

The basic cutting of bar against the moving jaw is not really an issue on this device, especially if you mod it to restrict the jaw lift. It could become an issue if you are attempting 'precision cuts. In that case you may need to get inventive with various jigs, fixtures, fittings etc.

In my limited experience, the metal bandsaws I have seen, the blade rotation has been in the anticlockwise direction and wood bandsaws in the clockwise direction. I have used TuffSaws for replacements and for both types of blade, the tooth orientation has always correctly matched wheel rotation (ie haven't had to do any blade twisting).

Now I am not suggesting anyone attempt this, but if you felt really strongly that you absolutely had to cut towards the fixed jaw on the Aldi, because it would be a mortal sin to do otherwise, then you would have to find away to reverse the direction of the motor AND flip the blade so the teeth point in the direction of blade travel.

Clearly you DON'T want to be doing this if you are planning to use the saw in the vertical mode! And in any case, I am not sure what the practicalities are of reversing the motor direction on this device, whether you risk damaging the gear/drive arrangements, motor, controller etc. it is hard to say.

Nevertheless, If some brave soul wants to experiment with their shiny new saw and report back to enlighten the rest of us.....devil

10/12/2020 21:40:25

This brand of tool (Milwaukee clone) was originally designed for freehand use. The addition of the stand and vice was clearly an add on afterthought to extend the utility of the device- compromised by poor saw geometry and poorly designed mount location.

If you get a 'proper' fixed mount bandsaw, the vice will usually be set up with respect to the saw so the teeth move in the direction of the fixed jaw, for obvious reasons (see the usual 6x4s 3x5s offerings from China).

See also the bandsaws by FEMI where they have designed the complete saw and mounting arrangement to properly suit the saw geometry, so the vice is on the backside of the saw with the fixed jaw in the correct orientation with respect to blade direction and the swivel mount on the right.

But then hey! a Femi is 3 times the price of the Aldi offering, and for that, I expect all but the most seriously minted can put up with some minor inconvenience while finding some other way to dispose of the £300 saving..

Alternatively, just go back to hand sawing, if you prefer

03/12/2020 11:02:58

Keith, it is a perfectly capable steel cutting saw out of the box, especially  if it came supplied with an M42 blade. I had no trouble hacking off pieces of 80x30 hot roll steel - no idea what grade. It did charge through a piece of 1/2 in silver steel, but I don't regard that as much of a challenge for this tool. cutting bright  bar up to 40mm was no problem as long as workpiece is well secured. 

Just readback for set up tips and tension appropriately, select a sensible speed for the material - I use 1 or 2 for steel to avoid heating the blade too much. Use dry, do not press down on the saw handle when cutting, just lightly support the weight as it cuts through the workpiece. In sticky metals, or aluminium it sometimes helps to take the pressure of the blade occasionally to allow gullets to clear before progressing- you will sense when the blade bogs down, skips or galls.

The main problem is the supplied vice especially with small bar (say 30mm and below). As supplied, the jaw has a tendency to lift and the work can shift causing all sorts of trouble. Easily fixed by applying any or all of the vice mods suggested by myself and others in previous posts.

In some ways a better device than my CY90 and certainly cuts at 3 time the speed, but if you have sensitive hearing that you wish to protect, get some ear-plugs

 

Edited By Martin of Wick on 03/12/2020 11:10:53

Thread: Suggestions for lathe-only projects?
28/11/2020 21:28:56

I have never come across a commercial clamping set suitable for a Myford. Usually Tee bolts and nuts are available from mytholmroyd, but phone to confirm dimensions before parting with your money.

Not generally considered good practice to use ordinary reversed bolts as Tee bolts due to to small head size exerting a high point load and risking damage to the slot - but needs must if there is no alternative, just be careful you are clamping something solid over the top to protect the slot. Sawing up your own Tee nuts is a good discipline as is fabricating some Tee bolts

Myford x-slide tee nuts are pretty small, so that could be your first milling job to test the new slide, traditionally tapped 5/16 F but M8 would do as well if you are standardising on that studding.

Don't recommend using the 3 jaw to hold a milling cuter, too easy for the cutter to be dragged out of the jaws unless it is quite small. If you can't manage an ER collet chuck, then I believe ARC or the like can provide No.2MT collets in say M10 and M6 (or whatever to suit the mills you have available). M10 studding and a nut and washer will do for the drawbar.

Andy got there first with the finger collets!!!

 

Edited By Martin of Wick on 28/11/2020 21:30:11

Thread: Lidl Portable Bandsaw
24/11/2020 20:55:47

Ian,

Make sure the bearing plates are set correctly on the swivel arm thrust bearings (mine were set to bear on the flat surfaces!!). Grease them up and tighten up the big silver dome nut so it will comfortably hold the saw assembly under friction when raised from the job.

DONT use oil, completely unnecessary, cut dry only or use some candle wax if you get a squeal , my original blade was a quality item, 10/14 I think, so good down to 2 or 3 mm. It just rips through thick stock with ease and hardly seems to get warm, Find a suitable small plastic tray (eg food packaging) to blue tack into place under the blade for collecting the copious stream of cuttings that is generated.

The work piece clamp can be considerably improved by making a keeper (a sort of shallow threaded T Nut ) to place under the body, secured to the moving jaw through the slot in the clamp base, with nut and bolt. This minimises the tendency of the moving jaw to lift when tightened. The hardest bit is to get unscrew the clamp shaft from the moving jaw. The 12m nut on the moving jaw is threadlocked, so I resorted to jamming a screwdriver in the nut end and levering a stilson on the handle end.

You may also find, that the clamp body casting is unevenly cast with bulges towards the fixed jaw end, certainly the case with mine, so I passed a file over the high spot until tolerably flat. Don't attempt to press any bulges out - you will crack the casting (go on ask me how I know!). To get a perfectly 90 degree cut in the vertical plane, you can shim out whichever pair of fore/aft clamp mount points to suit.

Does involve a bit of work to fine tune, but really worth it if you expect to use horizontally. Probably lots of other simple mods could be done to improve utility. Geometry is a bit awkward for detail cutting arrangements in the horizontal mode, more of a bar shredder in that mode. I expect good things for detail work when set up as a vertical saw, probably with a 14/18 blade.

Thread: A milling cutter I couldn't resist
16/11/2020 18:27:48

I had a couple similar on No2 MT with triangular inserts 9mm and 6mm across a side.

Presumably TPKN or TPUN (no idea what the difference is). I have searched the usual outlets but have not been able to find any replacement inserts at those small sizes. Had thought of trying a TCMT in their place, but I suspect they would break because of the hole, if used for milling.

Pity because they were very simple to use cutters and good for chewing out metal at maximum RPM on the mill. Finish was adequate for most jobs.

Thread: Lidl Portable Bandsaw
13/11/2020 20:47:41

Afraid I weakened and after the dismal experience of Lidl's offering, decided to try the Aldi version (can always send it back, I reasoned and it might save me having to get a Femi!).

Arrived today, pleasantly surprised, substantially better made/finished than the Lidl version, in particular;

  1. metal motor body not plastic
  2. Thrust bearings on the radial support arm (almost assembled correctly!) and solid mitre mount
  3. Two M42 blades albeit rather coarse 10/14 odd length (1141) but sure that 1140 would fit
  4. Release lever tensions blade perfectly OK from A flat to F sharp
  5. Out of the box, even with the joker vice/clamp arrangement cut true to within 1 degree of vertical

So deemed satisfactory for conversion to a vertical bandsaw (subject to acquiring finer blades). Base and hilarious vice/clamp tossed into scrap pile for the time being, pending attention at a later date - with a bit of thought and effort may be made serviceable one day by cutting a thread on the bar and inserting threaded collar in vice casting, or something along those lines.

Tips for new owners...

  1. The alloy casting is as soft as Brie cheese and will cross thread if you are not careful, so I would get a decent quality M6 bolt that has a bit of a taper on the lead and run it part through the mounting holes in the saw for the radial arm support to start the thread. I say this because the on mine the threads were very tight and difficult to start accurately with the supplied bolts.
  2. Remove the radial arm support by undoing the silver dome nut on the mitre swivel, and attach the support to the body of the saw as it lies on the bench (this is much easier than attempting to hold the saw in one hand and accurately locate and tighten the attachment bolts with your other hand)
  3. Set the saw angle to the vice with a square and check work piece is resting on surface of vice by holding it down as best you can while operating the cam clamp - this may take several goes!

Speed 1 or 2 for steel and 3 or 4 for non ferrous seems OK - NO OIL. It is quite quick compared to a 6x4 type but also noisier.

Have fun with your new toy by gratuitously slicing up various materials lying about your workshop as a testing programme.

06/11/2020 20:27:37

Have to say, the Aldi offering looks rather better made/finished than the Lidl one.

I was planning some sort of simple wood holder on similar lines to hang the saw vertically on the wall at the end of the bench. Compact and accessible, taking up no bench space.

Maybe if these become available in Aldi stores in future, I might be tempted to try again.

05/11/2020 15:17:09

duplicate

 

 

Edited By Martin of Wick on 05/11/2020 15:18:05

05/11/2020 15:17:08

Great, Thanks.

I guess these products are all much the same in design but with varying build qualities. The lidl version looked to be extensively 'value engineered' and a Friday afternoon job (drillings off angle, poor threads etc). I did do quite an thorough check and strip down to assess blade run and look for any other means to take up blade slack, to no avail.

Could just have been down to a poorly sized blade, but by that time I had decided it was just not satisfactory as the basis for any project and time to get my money back!

I may pluck up the courage to try an Aldi version for conversion to vertical bandsaw one day, but one bitten... Now considering a small, cheapo upright wood bandsaw frigged with a 10:1 gear reduction on the motor as an alternative route instead.

05/11/2020 10:44:24

Thanks to all for the responses,

I was wondering if anyone with other makes could chip in and say if their models have a mechanism for setting blade tension in addition to the cam mechanism that releases the blade for replacement?

In the Lidl offering I had, there is only the cam adjuster for both blade release and tensioning and when at full lock, there is no other means of blade tension adjustment. For whatever reason, my blade was so loose that it would constantly stall in softer metals because there was insufficient pressure on the rollers for a good grip.

Lidl v good -refunded no questions asked, and no, I didn't want another of the same ilk, ta very much!

I might consider trying again with a better marque, but only if I can determine if there is a proper blade tensioning adjustment mechanism and preferably if blade guide adjustments are possible as well. However, I suspect guide adjustment may be unusual, given this type of bandsaw was originally designed for freehand use.

Older, certainly - wiser? well maybe!

04/11/2020 15:31:04

Managed to get one of Lidl's bandsaw offerings with the idea of hacking it to make a compact light duty vertical band saw for fine cuts etc ( already have a CY90 which I have fettled to cut bar very accurately)

Irrespective of the useless vice arrangement and awesomely poor build quality, it was very disappointing - in fact if I was being generous I would describe it as total carp, with a useless uninformative manual included .

I am considering whether to persist and attempt to fettle the product into some sort of usable condition or return from whence it came.

So have the following questions for guidance from those with more experience of the product...

Out of the box, I don't seem to be able to get any real tension on the blade - with the red cam lever is in the fully locked position and the blade correctly located in the guides, the blade set is very flabby with an inch of sideways play and a distinct curve. As a consequence the blade stalls frequently. Surely this cant be right- I would expect to tension to about the musical equivalent of C flat. Does anyone know if there is any other adjustment possible of the jockey wheel to increase the blade tension? If not , do I get blades made up 5mm shorter to mitigate the issue?

Fault two - as set up on the pivot, the blade ends up angled about 5-7 degrees off vertical (as reported by someone else in this thread). Can't see any obvious adjustment to mount or the blade guides - they appear to be a single unit locked into one position - does anyone know any different ? It may be possible to shim these blocks closer to vertical.

The thing can be made to cut metal (just) but only where no real cut accuracy is required. I am doubting if it is of sufficient quality to become a useful tool either as a vertical bandsaw or as a rough cutter.

Thanks.

Thread: Myford set up.Time to get it right.
03/10/2020 16:25:16

Paul,

The 'made for myford special chucks' do not have a backplate in the conventional sense, what you are assuming is the backplate is in fact an integral but threaded part of the chuck, as shown in the picture below.

You take it apart by undoing the socket screws and splitting the two parts with a hide mallet.

if inconsistent or large TIR is an issue for you the easiest route is to purchase a new chuck (of the non integral variety) and new unmachined backplate, machine said backplate on your lathe to mount your new chuck. dont expect less than 3-6 thou TIR as a repeatable error (you might get better - just don't expect it!).

Your other more time consuming choices are:

determine the cause of the error -

is it badly worn jaws - if so you could attempt a jaw re-grind to minimise the runout, you should be able to reduce it slightly but not remove it entirely (google / utube is your friend here)

worn or damaged scroll - you are stuffed - you can tell by inconsistent runouts at differing diameters if runout is a problem you will need a new chuck

deformed , (ie bent off axis) chuck mount (hard to believe but entirely possible- that was the problem with the one in the picture) - you can tell by putting a dti on the back of the chuck and check for axial wobble - you may be able to effect some sort of correction by shimming the downside on the rear chuck part.

001.jpg

Thread: VFD. XSY AT4 220v 1phase to 380v 3phase advice sort
05/08/2020 11:50:30

Greg,

If it is truly an AT4, you should have no trouble setting P0 to default 380v and usually they arrive correctly programmed anyway. Check the boards as Andrew suggests. Usually AT1 have the earth on the incomer side and NOT on the control side as with the AT4 - but there could be variants.

I strongly suggest before you resort to resetting, that you fully work your way through the manual and parameters and understand the important ones that relate to your intended operation. A full reset may result in some very strange parameter conditions and unintended consequences (in my experience).

Set up on the bench and go through all of the significant parameters as stored in the device and write them down. try to check and change the ones you want again and check the running. Try to understand the manual - most of the info is there, just not in a helpful form.

If you really want to do a full reset have regard to Parameter P77 and the associated reset condition 54321. but take heed, you are likely to get some unexpected consequences and may need to re enter some of the parameters you wrote down from interrogating the registers. In my case I was able to restore most functionality except for the ramp times which now requires dividing the required Hz/s by10!

Take very, very great care with these AT4 devices, they output very high peak voltages at high currents.

26/05/2020 18:23:30

If it is of any comfort, my devices all bear that label, but I wouldn't set any great significance to that. I doubt the QA extends to identifying the numerous production variants. Once the box has left the factory, you are on your own and up the creek.... Just sayin!

Until you really know if you need to modify the torque curve, best keep it linear as per the defaults. Shovelling more amps and volts into the motor at its most vulnerable (reduced RPM) is a good way to shorten its life.

wouldn't worry to much about the indicated currents as long as the motor isn't overheating. I doubt this device samples or filters the values so you are seeing the peaks.

Strange that one of the phases is 20% out. If true, and happens on all motors, that is quite significant and could be a cause of rough running. Not encountered this problem before.

You could see if making small changes to the carrier frequency P22 on VFD1 makes any difference ( no more than + or - 5 from the default value of 10 in either direction). Beware that increasing the frequency significantly will increase the running temperature of the motor (but make it quieter as somebody has pointed out). And vice versa.

Sometimes you just have to fiddle and even that doesn't always do the trick!

Edited By Martin of Wick on 26/05/2020 18:26:11

25/05/2020 12:08:35

And just for further information,

If you set P73 at 31000, I think you may get the external pot to control between 0 to 65Hz (if you have set 65 in P06)

BUT when you switch back to panel control you will find that you can control the frequency OK (0 to 65) but only over half the span of the panel pot!

To restore full span control on the panel pot, you have to bring P73 back to 61000 and probably the source of my confusion - panel and external don't set up the same way on this device and the manufacturers supply on the assumption that the panel pot will be the primary control, but don't bother informing you of the parameter changes needed for external control.

25/05/2020 11:46:16

Further tests.... I am beginning to doubt my own sanity...Some apologies due.

Something Dave said made me think.. Managed to find a 25k pot to replace the 4.7 and set up Result Max Hz 31 !!! How could that be? I was expecting 0 to 65 Hz but controlled only over half span.

So looked at P73 setting and reduced it to manual setting of 31000 as a trial - low and behold the full range of 0 to 64 Hz restored.

So apologies for misinformation - Bad to rely on my memory, but I would have sworn when I tested months ago I had to have P73 at 61000 for full speed and left the parameter in that state for later installation, obviously I was not paying attention at the time.

Suffice to say, have a go with the info sheet values input in P73 and 74 and see what happens.

Rough running of motor - is that at low speed? sometimes too high a value in P72 torque compensation will cause 'cogging' of the motor.

 

 

Edited By Martin of Wick on 25/05/2020 11:49:19

25/05/2020 10:59:27

Andrew,

lashed up an arrangement with the AT4.

Voltage across the VR (5V to Com) was 5.1 volts

Potential on earth (PE to 220v mains incomer) 0.02V max

couldn't find my 10k pot but with 4.7k I get about 0 to 29 Hz across the range which is about right as I set the max frequency at 65Hz in the table.

James, it is always useful to see what parameters others are using in their set ups.

 

 

 

Edited By Martin of Wick on 25/05/2020 11:20:36

24/05/2020 13:36:51

Just to avoid tail chasing,

we are sure that it is a new and/or tested 10k Pot and that P10 is set at 2 with P11 set at 2?

Edited By Martin of Wick on 24/05/2020 14:02:38

24/05/2020 13:19:49

Andrew,

Some mistakes in my original post - I referred to P74 and P75, when I should have said P73 and P74.

Originally out of the box, P73 was set at 61440 and P74 was set at 4096.

And P75 was set at 4196 with P67 at 45000.

I don't know what P75 and P67 do but have recorded the fact that they appear to change the reported output current and voltage on the VFD display.

I checked and confirmed with a clamp on that changing P75 did also appear to change the output current very approximately inline with the observed variance in the VFD display. Couldn't check the voltage as I don't have a filtering voltmeter.

As you see, all supplied values differ from the info sheet. Clearly the thoughtful manufacturers have provided a generic info sheet and couldn't be a***d to amend it for different products.

When I did the unit reset, all values returned (approximately) to those on the info sheet, but the AT4 was definitely not working as it should. Normal function was only restored when I re-entered the 'as supplied' parameter values as above.

On set up, I only checked to see if there was a voltage from the PE terminal ( you can actually just see it marked in your photo) to the mains earth and there was no potential, but then I wasn't expecting any - maybe I should check again because all may not be well if there is a voltage present.

I didn't ever record the voltage across the VR as it didn't seem to be an issue at the time. Unfortunately, my unit is not on the bench at the moment pending works to the drill for which it was purchased for. I will see If I can cobble something up tonight and let you know.

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