Member postings for mick

Quick update. I contacted Maxitrax from the list Paul supplied mainly because they are only about 30 miles away from where I live and they have been very helpful. They will either sell your model and take a commission, this would result in a higher price for the seller, or they will buy the model for half its estimated value.

I'm now at a stage in my model engineering where I need to think about selling a couple of my completed models. I've looked at the usual online auction sites but none specialise in one off handmade engines. If anyone has had experience of selling their models I would be interested to hear their experiences. Thank.

Mick.

Not the best of photo's but here is the finished cam shaft and the two cams lying in the same direction. I elected to fabricate it rather that go the turning fixture route. If you have any questions about the build email Steve Huck his address is with the drawings, he's very approachable.

We all have our own ways of doing things, for the past thirty plus years I've used a piece of paper positioned beneath the cutter face, when it just starts to grip that's the established TLO, which works for me.

If anyone's interested the problem was a 2.5 value in the gauge block window. The question still has to be how it got there as it needs to be manually entered and as its a feature of the control that I've never seen the point of and have never used in the thirteen years I've operated the machine.

Hi. Jason. Yes the zero position is always a point on the component. This is one of the conditions I was experiencing that prompted me to start this process. However today it didn't happen once, but a new condition appeared on the Z axis. The first feed depth move is always 2mm deeper than programmed, i.e. Z-0.5 is Z-2.5. No matter how many times the offset was re-established I had the same situation. The only way round it was to program the first two depth moves as + values. I can now use the machine as the problem on the X axis is resolved, but I'm just waiting for the next control problem to rear its head!

Hi. John.

Perhaps I haven't explained myself very well. At the end of a program or cycle I return the spindle to the work piece zero from where all the dimensions are programmed. The x axis returns to this position while the spindle over shoots by about 10mm in the Y- quadrant.

If anyone else experiences the problems I've been trying to get to the bottom of I would suggest the first thing to check might be the coupling clamping screw on the ball screw. Once tight full jog is restored and might also explain the program stalling when cutting in the direction of X- . But it doesn't explain why I still have the problem of the spindle over shooting absolute zero in the Y axis when go to zero is clicked.

When the gib is adjusted by means of moving the two adjusting screws in which ever direction is required to allow free travel by light hand pressure to both limits and with no side way movement, the gib is held captive by the two adjusting screws at either end and therefore cannot move as the slide passes. The gib can only be fitted in one direction, that is inserted from the right hand side. The power to the stepper is off when the I move the slide by hand, as this allows the motor to freely rotate. After too many years that I care to remember I'm reasonably confident that I can recognise and repair most mechanical problems that manifest themselves on most conventional machine tools, its the addition of the electronic dimension that clouds the issue for me. Which doesn't explain why the slide will move freely when disconnected from the ball screw, but jams and won't jog when the ball screw and stepper are connected.

With the gib adjusted to allow free travel with minimum hand pressure the ball screw is re-connected, which requires more effort to move the slide to both limits, reconnect stepper motor and its a bit stiffer again while the table won't move in either direction on jog, but I can still move the table with finger and thumb pressure on the ball screw square, which must suggest that the coupling isn't impeding the rotation of the ball screw. slacken gib by releasing tension on the right hand adjusting screw and increasing on the left, this is now pushing the tapered end of the gib back, but the slide now has sideways play and will only jog a short distance in the + quadrant but no movement back to the - quadrant. with the gib completely removed there's free jog in the + plus quadrant but again no jog movement in the -. Either jogging with the gib removed in the - quadrant is somehow introducing a slight twist to the slide which is making the rear dovetails jam or there's a electronic issue with the jog in the minus. As all this started when I removed the gib to clean the slideways the only situation I can come up with is that after thirteen years and over 2,800 hours of work there is a degree of wear to the central areas of the dovetails, which, when the gib is reinstalled and adjusted to give free movement and no sideways play is bearing on an slightly shallow area of wear and causing the gib to jam against the slightly higher areas where there is less wear, but even so I don't see why this should affect the jog function as I would have thought there would be sufficient torque to overcome this. I'm probably missing something quite fundamental but my options are rapidly running out as I think I've done everything mechanically I can think of that on a manual machine would have proved effective.

I've had a day off to do some gardening but tomorrow I'll check the coupling as its been removed a few times now and I assumed that all the time the drivers on the motor and screw hadn't been altered the plastic drive plate would have gone back in the same alignment.

First off thanks for everyone's input. I have to confess that most of the electronic stuff is way outside my comfort zone. I did say earlier on that the stepper rotated when disconnected from the machine, I tried it again this morning and I can't stop it rotating with hand pressure which would indicate that there's torque there. So with the slide moving freely with only light hand pressure without the ball screw connected, but appreciably stiffer when it is connected, although it will move with only finger and thumb pressure on the ball screw square, but the jog won't move it, could it be this torque adjuster brain cell that Adam was talking about a few posts back?

Hi. John.

With the stepper removed the slide does move with hand pressure but not as freely as when the ball screw isn't connected to the slide, I can however move the slide quite freely with just finger and thumb by rotating the square on the ball screw which would suggest that the gib is correctly adjusted. With the stepper reconnected there's no jog just a slight jerking movement. Everything should be in line as the ball screw mounts are doweled to the ends of the slide and no matter where ever the gib is situated the rear dovetail will align the slide.

Hello again. This morning I removed the stepper motor when it became clear how to remove the slide, which I did and totally cleaned all slideways and the ball screw. I coated the ball screw in Moly lub and worked the screw back and forth to get all the balls coated, at this point the ball screw moved freely. With all the slide ways coated with slide way lub I re-assembled the slide, introduced the gib and adjusted until the slide moved freely to both limits with only light hand pressure. When the ball screw was re-introduced the slide became stiff and would even jog across the 100mm area it did before. the stepper works when away from the machine. Options are narrowing.

Thanks Ketan. Plenty to think about there, I'll start by disconnecting the stepper from the ball screw. The one thing that stopped me from completely removing the X axis slide for checking and cleaning was the prospect of loosing all the balls! Judging by the machine serial number mine is a 2009 machine. As I said its got over 2,800 hours on the clock and I'm completely lost without it as its become an integral part of my workshop. Thanks. Mick.

Edited By mick on 30/01/2022 17:05:14

Good morning all. Haven't posted for a couple of days as we've had visitors! Update. I've tried swapping over the X & Y steppers, as the Y stepper wiring is part of a loom I could only swap the X (which maybe the problem) and connect to the Y stepper, there's no movement at all not even a slight stutter, swap them back over and all's fine. I've been through every page of my manual and there's no reference to any stepper motor torque. As I've said before I can only adjust the gib with the table centrally positioned and then I can only find one sweet spot that allows 50mm or so jog in both directions until the slide jams. I can move the slide to both limits by spinning a small BA spanner attached to the square on the ball screw using only one finger, so it would seem like the X stepper only needs a bit more umph to drive the slide to its limits. With 2,800 hours on the clock the limited movement may be due to wear as most machining is done with the table centrally positioned, but until I removed the gib and cleaned the slides the table could be jogged to limits, it was only the situation of programs stalling and the control loosing its zero home position that prompted me to clean the gib and slideways. As I've said, when it comes to electronics I'm a bit at sea, so would the consensus be that I try a new stepper motor and as there are no markings on the X stepper what torque would be the one to go for. Thanks.

Hi. John.

Thanks for your input, electronics is a bit of a closed book to me, if I can't solve a problem mechanically I'm lost, so with this in mind how would you suggest I go about tweaking the current settings? Thanks.

I posted a few days ago about my problem with the control of my KX1 stalling and loosing its reference position. One suggestion was that the slide ways could be sticking, which after some 2800 running hours was a distinct possibility. After removing the X axis gib, a complete clean and applying copious amounts of ptfe slide way spray I put it all back together and after several hours of fine adjustment achieved about 50mm of smooth jog in both the + & - directions when the cross slide is centrally positioned after which the slides jammed, this is quite possibly due to thirteen years of wear, however the slide moves smoothly to the limits when rotating the ball screw via the square on the end. I can only think the main problem might be the stepper motor not being man enough to drive the slide after the re-assembly. Another stepper motor would not be that expensive but I can't find anything on the cross slide stepper that tells me its torque as I would want to get a slightly more powerful one as a replacement, so I'm sure someone out there will be able tell me what the torque of the current motor is and maybe be able to suggest what sort of torque I should be thinking about as a replacement. Thanks.

Not having one shot lub I tend to use an spray lubricant on all the slides before I start machining, but I've never stripped down and cleaned the slides, so now could be as good a time as any. Thanks for that bit of advice. Do you speak from experience?!!!

I've had my KX1 for thirteen years now, it was one of the early imports as the serial No. is 1/09/0044 I've always been okay with machining and programming but when it comes to the control Its been a bit of a closed book. I'm pleasantly surprised that I've come this far without any serious issues, but over the past couple of weeks proven programms have either stalled or the control looses its bearings and sends the cutter on a walkabout. I have also had the cutter over shoot its home position when returned to zero. I expect that perhaps thirteen years of use is about as good as it was intended, but now buying a new machine (even if I could afford it) would mean an import from The People's Republic. So, my question is: are there any fairly straight forward diagnostic steps I could undertake to establish the source of the problem and if mechanical or electronic is there are source of replacement parts. Thanks in advance.

Edited By mick on 22/01/2022 17:10:06