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Member postings for WALLACE

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

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Thread: LEDs ... The Good, The Bad, and The Ugly
29/11/2014 11:14:33
Yep - going to do a few more tests today and will post the results later.



W.
28/11/2014 22:55:39
Finally - after fixing the scope - I fed a 60 led 12 volt bulb with various amounts of AC via a variac.


All very interesting - the output of the little driver pcb is around 17 volts for an input of about 5v up. There's plenty of 50Hz ripple at this voltage but that all disappears around 8v - above that, the only high frequency switching ripple is in the microvolt range. Switching frequency is high and doubles at various discrete input voltages. Certainly, there isn't any issues with strobing or flicker on this particular make of bulb.


Very, very clever !

I didn't try finding out what the maximum voltage it would take was as I couldn't see the point of frying it but it worked ok on the 14 1/2 volts coming of the lovolite transformer on the lathe.

To my mind, the light angle is a bit wide for a machine luminaire - the 3 led one might well be more suitable - I'll play around with it tomorrow when it's not so late !




W.
Thread: Brain fade!
27/11/2014 18:50:41
Bored out a lathe faceplate once to the outside diameter of the required thread as opposed to the core diameter....the Loctite came in handy to fix that one....



W.
Thread: 12v DC Motor
27/11/2014 10:37:50
10amp 12 volt motor controllers are available on ebay very cheaply. I imagine they'd be happy enough with the slightly higher voltage from a basic battery charger and you'd get variable speed as a bonus.

Doesn't have to be dead 12v for the motor anyway - peak car volts are going to be nearer to a charged lead acid battery voltage of 13.8v.

If it's still a worry, I'd just run a few 10amp rectifier diodes in series with the supply - they'll drop 0.7v each independent of the load




W






Thread: Myford service
26/11/2014 09:32:43
With all due care taken over safety etc, a long screwdriver with the handle up against your ear and the pointy end on various suspect bits of the lathe should help pin it down to a specific area or even bearing.

Safer - if costlier - alternative is a 'mechanic's stethoscope' .. ebay probably the cheapest source.



W.
Thread: Marlow 3A Mill
21/11/2014 08:51:47
The knurled peg definitely engages the back gear. It pulls up to disengage the bottom cog from the drive pulleys.

I have a funny idea the other hole lines up with a lubrication grove between the back gear and the top pulley....however - as usual - I'm nowhere near the mill at the moment so can't confirm the later !



W.
21/11/2014 08:51:24
The knurled peg definitely engages the back gear. It pulls up to disengage the bottom cog from the drive pulleys.

I have a funny idea the other hole lines up with a lubrication grove between the back gear and the top pulley....however - as usual - I'm nowhere near the mill at the moment so can't confirm the later !



W.
Thread: Mega Adept
16/11/2014 08:08:42
I'm just looking forward to seeing the 5" gauge 'Mallard' locomotive you're going to machine up on it - and serialise in ME over the next 37 years... ... .



W.
Thread: Laser Centre Finder
12/11/2014 23:58:53
Hello Nobby.

Lasers that produced a line are available very cheaply on ebay - I'm thinking a couple of those mounted on the mill head would work for finding an edge - one each for the X and Y axis.

Not sure what the beam angle is - the listing I had a brief look at didn't mention it.

But for just under a tenner for 5 (!) , I might just order some to play around with !

W.

Ps...I haven't forgotten about the LED bulbs Michael - just been very tied up with helping brother to move house !
Thread: Mega Adept
11/11/2014 22:53:39
I do appreciate the challenge Neil !

It's just that I've been looking at YouTube clips of an Australian guy casting iron with a home made crucible furnace and I'm itching to give it a go .. unfortunately, it's going to have to wait for the next house......



W.
11/11/2014 20:24:33
Call me 'negative', but I'd have been more tempted to build a home furnace, melted it down, added a few bits of scrap iron and cast a completely new lathe.... ... .


W.
Thread: Marlo A3 Milling Machine
02/11/2014 09:37:02
Hi Gary.

Yes....but I also use it to drive the lathe and I prefer the slower run up as it's quite big - the 4 jaw is a 9"....


It's a bit awkward as well - it's done by a preset on the main pcb - it's a home made one based on the Elektor design published quite a few years ago.

I've got used to it now and will wait before taking a cut - I have half a broken 16mm end mill on the shelf as a permanent reminder !


W
02/11/2014 00:33:26
Hi Robbo.

Mine's the same as Phils - and changing belts is a doddle. Just wondering if it's possible to convert a foot mount motor to a flange one ? Can't imagine it would be too difficult to add a flange to the existing end plate of the motor with a lathe ! Do you have the original motor mount and pulley guard with your machine ?

I also run mine of a vfd - the one disadvantage I've found is the few seconds it takes to run up to speed - if you try to take a cut before it has,it's easy to break the cutter !!

No feed on mine so I can't help you there I'm afraid - but I do like my machine - the eventual plan is to cnc it which will be fun !



W.
Thread: FreeCad
14/10/2014 12:53:44
It'll certainly be worth while whatever it is Neil !

I'm looking forward to it !!


W.


14/10/2014 11:30:45
I think Neil will need to upgrade his suit of armour..



W.

13/10/2014 20:35:13
Hi Neil.


What a good idea !



W.
Thread: Tailstock never stays aligned.
09/10/2014 07:55:18
I think there's one either side and another on the back to lock it all up - typically, I'm nowhere near my L5a at the moment to check !

Mine had quite rough as cast 'lump' that the screws made contact with which I machined flat on the mill. I also cut them at an angle and at the same angle setting, milled brass inserts to go inbetween the screws.

The rationale behind this was that the original rough surface tended to twist and lift the upper part of the tailstock, machining it smooth stopped this from happening with the machined angle now effectively pulling the two parts together.

It made adjusting it a lot easier - beforehand, you'd get it spot on, give everything a final tighten and then find you were miles out !



Hope that makes sense !!


W.
Thread: LEDs ... The Good, The Bad, and The Ugly
07/10/2014 16:56:36
A few pics of two dissected 12v MR16 bulbs in my album.

Not a very thorough investigation as my meter is somewhere else ! I'll do a better test when I have it back, both on ac and dc - the meter is true rms reading and I'm interested in seeing the current difference between the two - plus any 50 or 100 hz ripple on the output.

The scope pic is the output of the 61 led bulb pcb,0.01v and 2us per division - ac coupled with the bulb running on 12v dc.

The blue, red and black wires in the photos were added by me - they're not original.


W.

06/10/2014 15:17:49
I just put a scope across the output of the pcb in a white 61 led MR16 bulb....

There is ripple or spikes on the output - but it's very little - just a couple of millivolts. The oscillator works at around 180kHz..

Annoyingly, I can't do any current measurements as I left my meter at home....so I'll probably leave running it on ac until I have it available.

Pics will go in an album when I get better internet connectivity.

W.
Thread: Turning down weld
04/10/2014 12:29:00
Probably a reason why Sir J's weld turning down looks good is the heavier machinery he probably has don't complain as much with an interrupted cut !


W.
<< First < Prev 1 2 3 4 5 6 7 Next > Last >>
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