Messages

11

General Mach Discussion / Re: Windows 7 with 64bit

« on: November 30, 2012, 03:53:05 AM »

I use my machine as a hobby toll to make model 5" gauge steam trains so use it every other week for an hour or so don't want to have to make expensive alterations for such limited use. Jim

Its a small world...thats what mine is for!

I think, and an expert will be along sortly I'm sure, is that in the event of failure of the workshop pc, you would need to change you BOB for one that connects via USB or ethernet, thenyou'll be on the road again.

12

General Mach Discussion / Re: Windows 7 with 64bit

« on: November 30, 2012, 03:25:22 AM »

You must use a smoothstepper with a laptop I know that much.  If I understand correctly, a desktop will output the movement command until the axis is to stop, but because of its powersaving gubbins, a laptop won't.  So what the smoothstepper does is hold the signal up until the end of the move, then tells the laptop its done it whats next?  Something like that anyway.  As I say, I believe its essential with a laptop.

13

General Mach Discussion / Re: Windows 7 with 64bit

« on: November 30, 2012, 02:30:48 AM »

From what I've been reading, in the run up to ordering my pc in the January sales (!), is that Win7 64-bit is fine as long as you connect to a machine by USB or ethernet.  Seeing as you're not connecting to machine, you should be fine.

Either that, or my information is wrong, and I need to crack it before I order my pc!

14

General Mach Discussion / Boxford AUD stepper sizes

« on: November 29, 2012, 04:32:11 AM »

Hi guys,

When I've got the Bridgeport up and running my next project will be the Boxford lathe.  I've had a look in the section about 'your machines', had a look at Hood's ML10 based lathe already.  So far not found the info I'm after.  What would be a recommended size of stepper for the X and Z axis?  I'm guessing that the Nema 34 8.5Nm steppers I'm using on the mill are well overkill...especially for the X axis, not to mention the bulk, Z perhaps it would be ok, afterall thats where the majority of the cutting load would be.

Can anyone suggest suitables?  The current leadscrews are 3/4" for the Z and 7/16" for the X, (doubt they're metric) I was originally intending using them to start with, using the half nuts for the Z movement as there's next to no wear in them.  Ultimatly they would be replaced with ballscrews.

15

Show"N"Tell ( Your Machines) / Re: My Bridgeport clone project

« on: November 27, 2012, 12:08:32 PM »

Ordered two slightly different length A section belts this morning, should be here for the end of the week and we can see how things fit up.  Also ordered the belt for the Z axis, and last night I got the spindle pulley anchored down and the top housing bolted on - hopefully for the last time!

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Show"N"Tell ( Your Machines) / Re: My Bridgeport clone project

« on: November 25, 2012, 03:00:56 PM »

phew, got it right!

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Show"N"Tell ( Your Machines) / Re: My Bridgeport clone project

« on: November 25, 2012, 02:35:32 PM »

Hi Hood, I *think* I've got it worked out....please correct me if I'm wrong!

Working backwards, I've got the steppers.  They're connected to the drivers, that goes to the smoothstepper, then the breakout board, and provided I use USB connectivity, I can run to a laptop running Windoze 7 pro 64-bit....I think...  If I understand it right, I can only use the 64-bit software if I use a USB connection between laptop and BOB, and the smoothstepper will iron out the laptop's tendancy to power save

Yes?

18

Show"N"Tell ( Your Machines) / Re: My Bridgeport clone project

« on: November 25, 2012, 03:43:44 AM »

Little more progress has been made, not at lot as I've been busy making bits for my steam engine, and the workshop's cold now (must finish insulation then I can have a heater!).

I got the stepper for the Z axis at the start of the month and got that mounted, and I've now modified my SPA pulley to sit low enough to clear the top housing.  I still need to make a spacer for keeping the pulley down, and then a spacer to fix the pulley on the motor shaft in the right place.  Both easy jobs, I just need to get on and do it!





At the moment I'm trying to decided whether to buy a laptop or a desktop to run it from....sort of leaning toward laptop at the moment, then I can program in the house...

19

Show"N"Tell ( Your Machines) / Re: My Bridgeport clone project

« on: October 27, 2012, 10:39:46 AM »

The Z axis mount I got for the mill was from a servo driven Bridgeport and not exactly matched to the Lillian...not that thats a problem for me!  Minor modification to the head casting was required and that was sorted out.  Because the old servo motor had a 5/8" shaft, and the steppers I'm using have a 1/2" shaft, I had to discard the pulley....the belt appeared to be an odd pitch, and so I ditched both and got new 5mm pulleys.  The one has been fitted to the ballscrew for some time, the other is waiting payday to get another stepper. 

Another problem was the mount holes of the servo motor being different to the stepper, and the shaft on the stepper being slightly shorter.  So, yesterday afternoon I headed off to a friends to use his mill to sort that out.  An hour later and I'd thinned the plate a little to let the motor sit a touch higher, and then drilled four new M6 mounting holes...as luck would have it, they just fell outside of the old slots!



Been playing around some more this afternoon.  I've known from day 1 I could have trouble with the main spindle motor.  The original motor fretted its shaft at the bearings, with the result the stator moved and chewed out the windings.  Repais was going to be £750+VAT to have the shaft ground, plated and ground back to size, and then rewind.  Too much.  Especially with the belts we're getting at work only last 6 months and hundred squid a pop.  So to that end I got a new 3hp standard motor, and its now got a 3 stage V belt pulley, and I've stripped the old varispeed drive out.

I've always thought the motor was too long to sit on the old top casing and I'd have to fabricate or get Aubyn too.... a new top casing to hold it the other way up and down one side.....it was only when I started looking at it this afternoon......







It fits...but literally only just!

I've still got other problems to deal with....at the moment the pulleys are too high and are fouling the middle of the casing meaning I can't use top speed...i need to take it out and recess the back of it to let it sit lower on the old bottom pulley which is also the spindle brake.

20

Show"N"Tell ( Your Machines) / My Bridgeport clone project

« on: October 24, 2012, 11:53:31 AM »

Hey guys, its about time I started a thread for my project.

Its a 1991 'Lillian', a Taiwanese clone of a Bridgeport.



I bought it from work when we scrapped it.  The motor threw its bearings and chewed up the stator, with repair costs being more than we though worth, and the old 2-axis CNC system was on its last legs.

I've got it a brand new motor and a Variable Speed Drive which I'll control with a 3-step pulley setup I've made, and use Mach 3 to hopefully control the motor.  Servo drivers being expensive, and needing to add the third axis anyway, I've opted for 8.5Nm stepper motors from Zapp Automation, driving through 2:1 belt drives.  So far, I've only got the long axis set up, and I think I've got some backlash somewhere that I'm trying to trace.  I have started work on the short axis, and got a Bridgeport Z axis for it.  It may be the Z which gets done next I'm not sure, a little bit of modification is required to mount the motor as the mount holes are a different pitch to the old ones. 













More to come as work progresses