DVR warning and upgrade

[duncanh]

I thought this might be of interest for all those with NOVA DVR lathes...

when carrying out a cleaning procedure to remove dust from the DVR sensors make sure that you switch off power to the lathe and wait 30 seconds or so.
A couple of months ago whilst trying to remove some persistent dust (after RPS Error state 0 on the display) I needed several attempts including removing the sensor board. On my final attempt I forgot to switch the power off and I inadvertently touched the sensor board against the inside of the headstock, causing a short circuit which blew something on the main board :-( Yikes!

After some communication with Teknatool and instructions to take some meter measurements I had to send the board, controls and sensor back to Record UK. Unfortunately they weren't fixable but Record confirmed that I could replace them with the ones for the DVR XP (which I've asked Teknatool about several times but never had an answer).

After a wait of 6 weeks I received my new board at the weekend and I can confirm that they do work with the DVR3000 but need a bit of filing to fit. I now have all the DVRXP functionality and I really like it. The 5 stored speeds work well and are easy and fast to access as well as program. In addition, the up and down speed control work faster (or at least that's how it feels).

I had a couple of problems with the upgrade...
1) the instruction sheet was for a different version of the board and there weren't updates on the Teknatool website. Teknatool did send an update when asked though
2) the earthing wires on the DVR3000 attach to the headstock in a different location to the DVRXP and I had to grind some of the heatsink away so that I screw in the attaching screw.

Now to the question of cost. The whole replacement including delivery and tax was £287.
If I hadn't needed the replacement then I probably wouldn't at that price, but I guess I'm just lucky that the new board works with my older lathe.

Now I just need to think about fitting my remote box - is the wiring inside the control box the same on the 2 lathes? I wouldn't want to blow up the new one!!


Duncan

 

[CHJ]

Glad you got it fixed Duncan, must have been quite a relief.

Surprised to hear that the sensors are in a position to be contaminated by dust, not exactly an unknown substance on a wood lathe.
Also disappointed at the design concept if this is a regular 'maintenance requirement' that you are able to access with circuitry still live.

Mind you there are very few lathes that have sensible safety switches fitted to adjustable drive belt or control covers, like most bandsaws have.

 

[big soft moose]

personally i cant think of anything worse than having to "program" speeds into a lathe or "access stored speeds" - I supose it has its uses but to me it seems totally over engineered - on my lathe , which has electronic variable speed, you just turn a knob right for faster , left for slower.

 

[duncanh]

Glad you got it fixed Duncan, must have been quite a relief.

Surprised to hear that the sensors are in a position to be contaminated by dust, not exactly an unknown substance on a wood lathe.
Also disappointed at the design concept if this is a regular 'maintenance requirement' that you are able to access with circuitry still live.

The sensors have a notched metal disc running through them which is attached to the main shaft.
The headstock has ventilation slots to cool the interior and these let in dust.
The manual recommends regularly vacuuming through these holes and holes in the rear and also blowing air through the holes. I do tend to leave it a little too long before doing this and sometimes have to clean the sensors. This happens about twice a year.

It's one of the few down sides to the lathe

 

[duncanh]

personally i cant think of anything worse than having to "program" speeds into a lathe or "access stored speeds" - I supose it has its uses but to me it seems totally over engineered - on my lathe , which has electronic variable speed, you just turn a knob right for faster , left for slower.

The speed input system is the major draw back to the lathe. I guess there must be some reason for keeping this method as they kept it when they released the updated XP model of the lathe.

The method to access stored speed if surprisingly fast and takes just a couple of seconds. Storing new speeds takes maybe 10 seconds. You can only store 5 speeds.

 

[dickm]

er.... why would you want to store speeds??

 

[cornucopia]

er.... why would you want to store speeds??

it would be very helpfull when thread chasing- you go from turning speed to chasing speed allot- other than that i cant think of another reason.

 

[duncanh]

er.... why would you want to store speeds??

Because for some reason when they designed it they chose to make the speed control up and down buttons rather than a dial. If you want to go from 500 (speed at startup) to 3500 then you have to keep your finger on the up button. I've just timed it and it takes 13 seconds.

 

[dickm]

Because for some reason when they designed it they chose to make the speed control up and down buttons rather than a dial. If you want to go from 500 (speed at startup) to 3500 then you have to keep your finger on the up button. I've just timed it and it takes 13 seconds.

Brilliant :?

 

[stevebuk]

what on earth would you turn at 3500rpm anyway, i haven't had mine above 1100 yet.

 

[penman]

Steve

I turn my pens at 2500-3000 rpm
:lol: :lol:
It's much easier at that speed


Malcolm

 

[wizer]

yes I've always like the look of those lathes but, even tho I'm a self confessed nerd, I can't work out why you need a computer to run a lathe ? Also, if I'd bought it, that bl**dy start up jingle would have seen me taking a hammer to it. :lol:

 

[duncanh]

what on earth would you turn at 3500rpm anyway, i haven't had mine above 1100 yet.

As Malcolm says pens, and anything that sort of size, are easier at high speed. I don't go there very often but it's useful when I do.

I can't work out why you need a computer to run a lathe ? Also, if I'd bought it, that bl**dy start up jingle would have seen me taking a hammer to it.

They do seem to be overly complex. I can't really compare them to other lathes as it's only the second one I've used - I bought it when I was very inexperienced and the main reason was it's quietness (and that it was a disounted ex display model ). If I was to buy again I'd investigate other lathes further.
One feature is that it tries to maintain constant speed whilst you turn, so when you apply the tool the lathe uses more torque to make it spin at the required speed. There are 3 fixed settings for how forcibly it maintains speed for if you intend to apply more pressure with the tool - eg for when hacking down a wide, wet log when you want to remove a lot of material fast. If you apply too much force in normal mode this may stall the lathe, but in high mode it'll happily continue.
This is one of the claimed advantages, but I could probably live without it.
Maybe I'm just a sucker for shiny, high tech gadgets!

 

[bobham]

Part of the reason for the computer is that the motor is not a normal, run of the mill electric motor. The rotor, which is attached to the spindle, has no wire windings on it but is solid metal. The rotor is surrounded by coils that generate a magnetic field when energized. In order to make it go around the coils are energized sequentially and are constantly cycling on and off as the lathe runs. The computer controls the orderly cycling of the coils to maintain the desired speed.

While the up/down arrows for speed control are a bit of an irritant, I consider the biggest fault the lack of a big red "panic button" type of shut off. A membrane keyboard really doesn't cut it as far as tactile feedback of whether you actually hit the button or not, and something that can be activated by a flat palmed slap without looking would make me feel a lot better. It would be even better if it was remote so you could position it near where you were working rather than having to reach across the line of fire to hit it.

Take care
Bob

 

[duncanh]

While the up/down arrows for speed control are a bit of an irritant, I consider the biggest fault the lack of a big red "panic button" type of shut off. A membrane keyboard really doesn't cut it as far as tactile feedback of whether you actually hit the button or not, and something that can be activated by a flat palmed slap without looking would make me feel a lot better. It would be even better if it was remote so you could position it near where you were working rather than having to reach across the line of fire to hit it.

Take care
Bob

How could I have forgotten that as the main drawback with the lathe. I've asked Teknatool about making one several times and was once told that a remote box was in testing and almost ready for production. This was several years ago and nothing has appeared.

Bob - are you aware of the circuit design that was worked out by Walt Ahlgrim and which can be seen in his photo folder in the Yahoo group? I made one for my original DVR and it worked really well. I had a homemade wired remote box that had a secondary, large emergency stop box daisy chained off it.

I've made a second, improved version but have yet to test it with the new board. Total price for components was probably £20-£30, so hardly expensive compared to the price of the lathe.

Duncan

 

[pete honeyman]

Must say I'm very happy with the DVR - my five preset speeds are pretty much all I ever use, and the 3000 rpm is great for small items like pens, gives very clean cuts and is super quick, you have to remember to clean it out occasionally to keep the sensors clean, but that's a five-minute job once you've done it a couple of times. I must agree though that the off switch is annoying - as I've pointed out before, when turning outboard, the switch is actually behind the work, so those invisible corners on square pieces are very easy to catch. I will probably fit a footswitch in the power line when I get round to it.

Pete H

 

[CHJ]

My controls are in similar position on the headstock but I have programmed in a soft slow start into the invertor to give time to stand clear of chuck etc. at startup.
I fitted a heavy duty micro switch and a large red mushroom button to the right hand side of my lathe bench, (it kills all NVR's in the shop) I have conditioned myself to step away and hit that to stop when ever I have anything objectionable spinning or the headstock swung round.

 

[bobham]

Hi, Duncan:
I did see an article recently that was about making a remote set of controls for the DVR and it looked like a pretty slick modification. Unfortunately I got bogged down after about the 5th paragraph in the instructions when it got into Cat 5 cables (?) and muti pin computer connectors....

http://woodcentral.com.ldh0138.uslec.ne ... _824.shtml

I'm afraid that when it gets beyond basic household wiring I am out of my depth.


Bob

 

[duncanh]

That's pretty much the same as mine. The only difficult part is making the connector, and it took me a few attempts to get it right.
If this is beyond you could I suggest that you contact Teknatool and your country's distributor and ask for one - the more requests they get the more chance there is that they'll make one.