Denford Software & Machines

Hi to all
New to the forum, and would like some help if posible on a Starturn 4 lathe. i have bought the lathe on e-bay and as good as new, even still had the anti rust coating on. but alas no pc so now on the road to converting to mach3... but thats another story...

i have run the spindle and it gets realy hot, have pulled it appart and cleaned all the old grease out and now have it back together, but i would like to know what the pre load for the bearings should be? also i want to fit a new chuck but not sure on the spindle nose thread size, if any one can help it will be apprcated..

regards

Paul

Please bear in mind that most of us who monitor the forums have never seen a starturn 4 so it's really a case of help yourself.
What info we find or have given we put on here but we won't have all the answers.
Answers about bearing preload will probably never be found - you will need to judge that yourself depending on speed, accuracy required grease type etc...

The 2nd image in this post, entitled Starturn 4 mechanical manual shows the spindle nose as being M18
viewtopic.php?f=46&t=460

There is a lot of info hidden away on here so I've added a google search feature at the bottom.
It's not ideal, but much better at finding stuff than the forums' built in one

If it is 'good as new' - maybe it never actually got run in, and the old grease had just hardenened up, so causing a bit of heat, and just needed a few hours operation.
As Admin says, it is unlikely that pre-load figures are available - haven't found any yet for any Viceroy lathes or Senior mills.
So its a case of take up the slack, give it a 'nip-up', then run at a slow speed to start with and use your built-in temperature/vibration probes (= fingers) - if it gets too hot to touch it's probably too tight, if you can feel vibration its too loose.
If it's OK at a low speed, increase speed and repeat......


Andy

Hi Admin
Hi Andy

Well firstly thanks for the answers and where to look for info...

I have used the built in sensing system, and it tells me that not too tight and just the mild tempreture at speed is fine....and at full speed slightly warm.

just out of interest simalar to adjusting wheel bearings on a car... but a bit more refined.
after playing some more..
I now have less that 0.01mm play, and a pull on the chuck of less than 12grams, spring balance, ( no belt fitted) so all seams fine,
The test run to night will give the final answer,

Many thanks to you both, again
Paul

From my experiences of denfords the spindles always tend to run quite warm - we always used to joke at work that those canny yorkshire lads had included a tea warming facility.

Seriously though my starturn generally tends to run quite hot - just hot enough to be uncomfortable to hold. The Triac and Oracs were exactly the same.

On the retrofit front - viewtopic.php?f=46&t=452

Ok i will have to tighten up the spindle bearings now to keep my tea warm!!

Thanks for the link and i have had a read through interesting info...i have completed a conversion using the digiplanSD3 drives and used a ULN2003 darlington driver chip to pull the step / direction lines low on each axis (3 axis mill) Parallel port direct onto the transitor inputs with LEDS for indicators and also to pull the lines to 0.5v when off.

cheap option!!!

In the starturn 4 i have bought an interface of e-bay all opto isolated and that has been grafted into the original wiring for X and Z, with a tap off for the optical encoder for speed feed back. all back to Mach3.

so far working well...

I have read that the stepper motors may need upgrading but i am not sure if that will be the case on mine as the system seems not to lose steps..

time will tell!!

The only time I have an issue with mine losing steps is if I haven't used it for a couple of weeks and the slides seemed to get gummed up. Before I run the machine I always cycle it back and forth a few times the whole lenght of both axes with a drop of oil. This sorts it out and it's fine then. I did set my drivers to run a 2A instead of the 1.8A they are supplied with.

The biggest annoyance I have when using the machine is that if you are turning 'big' jobs in steel for a long period or doing lots of drilling the main fuse has a habit of blowing. I keep a good supply of them in my toolkit. It only ever happens when you are really pushing the spindle hard and I've never had the steppers stall. It is a very good idea to link an Estop to Mach in case the fuses blow!

paul hunt wrote:Ok i will have to tighten up the spindle bearings now to keep my tea warm!!

Thanks for the link and i have had a read through interesting info...i have completed a conversion using the digiplanSD3 drives and used a ULN2003 darlington driver chip to pull the step / direction lines low on each axis (3 axis mill) Parallel port direct onto the transitor inputs with LEDS for indicators and also to pull the lines to 0.5v when off.

cheap option!!!

In the starturn 4 i have bought an interface of e-bay all opto isolated and that has been grafted into the original wiring for X and Z, with a tap off for the optical encoder for speed feed back. all back to Mach3.

so far working well...

I have read that the stepper motors may need upgrading but i am not sure if that will be the case on mine as the system seems not to lose steps..

time will tell!!

Welcome to the club Paul, Denford make great machines. Bringing them back to life through Mach is great fun.

Hi All
I do agree the Denford is a great machine...and it is reasonably simple to work on..the version i have has two clips ether side to enable access to the electronics, once you lift the main bed. two parker digiplan SD2 drives i am keeping these units employed as they work perfectly well and and are very robust.

Interesting on the main fuse blowing,,,what sort off depth of cut are you using?

i normaly only run a cut of 0.1mm, good point on the slides. i have cleaned them out and there are no signs of wear, so i will keep an eye on them. good idea on the e-stop

spindle is now running warm at full speed and not to the point as it was before burning the in built sensors!! so happy with that now. next is the drive controler..and what to do.

I have been investigating the drive controler and was considering upgrading it to a sprint drive. i have used a 370 in my mill and the 340i in a lathe, boxford machines. both have given good service and are at a resonable price...the " i " version is a lot easer to interface as the speed pot input is insulated from mains potential...also you get outputs for displaying load and speed, but i will not need that as the speed feed back is interfaced with Mach 3

I have had a look through the diagrams for the Starturn and done a few measurments and it seems the spindle drive card pot is at mains potential???

so another nights work draws to an end

sprint-electric... google search

a v3 board from diycnc solves the unisolated input

Hi Angel tech

I have bought one and it is in use on the other machine...simple unit and i may even try to build one myself..only need to be opto isolated from the signals and can have its own power supply there fore will not need the DC DC converter on board....
setting should be almost the same as for the DIYCNC board in mach3..

Checked out the stepper drives this morning and will be setting them to 400 step and upping the current... I have found that the increased steps make a big differance..

run the spindle again today and all is now spot on so can now progress with the rest of the conversion.

strip out of the stepper motors/ screws for a clean and inspection...

Hi

checked out the spindle and have found the tread size for the spindle nose....
and ic ouldn't belive it but it is the same thread as an 18mm sparkplug the realy old type..
i can now make the back plate for the new chucks i have bought i will post a drawing when i have completed the back plate...