Page 3 of 4 FirstFirst 1234 LastLast
  1. #21
    Quote Originally Posted by charlieuk View Post
    soldering it sounds like a good move I will be sure to do that, did you take the 4 pins out and then modify it so the wires went through the top? along with the earth?
    I don't think that soldering directly is a good idea at all. It makes removal complicated, cleaning servicing difficult. Also you still need strain relief, even if you solder the wires. There is really no advantage, only disadvantage compared to using aviation plugs.

  2. #22
    Quote Originally Posted by Doddy View Post
    I was looking at the picture on page 1, but now having seen your reply I've noticed the second image. Not keen - I'd be concerned that such thin-walled printed structure certainly will be porous and provide little to no mechanical relief. I'd agree with Clive's suggestion - get some saddle clips (or similar rigid mount) on the plate and tie-wrap the cable-form to these. It works on fast-jets, should be fine on a milling machine.

    I am far less concerned about the printed part failing now than the plug they come with. I can apply all the force I want with my hands to the spare I printed and could not any signs of movement or cracking between the print layers, its got a 3mm wall that tapers up and solid infill, the layers are extremely well fused together, I have been so impressed with the strength of parts that come of my prusa! The only thing that may destroy it would be a few hefty blows from a hammer. Now I have the printer I will also re do the cable support that was bolted to the main frame above the old plug. The wire will never move in the blue tubing ( it was a sod to get on) and that is permanently fixed to the printed part so should never move and have taken any chance of stress going onto the motor wires inside.

    The plug witch now is obvious was the failure point on the system and considering the plug was still locked down when I removed it after it failing shows it is a weak point and when you look at them the fitment and would assume the contact of the pins to be fairly poor and im not going to risk it again, In the past I have noticed the locking collar has managed to loosen its self over time although that wasn't the case when it blew and was the first thing I checked. remove the fault and remove the problem.

  3. #23
    Quote Originally Posted by charlieuk View Post
    3mm wall that tapers up and solid infill, the layers are extremely well fused together, I have been so impressed with the strength of parts that come of my prusa! .
    What material?
    You think that's too expensive? You're not a Model Engineer are you? :D

  4. #24
    Just pla I have done stacks of stuf with it now and have been so impressed. I have stronger filaments but not yet found the limits of pla easpesialy when it comes to small things like this I would be very sure the cable would give way before the printed part ever gets close. If you have that sort of load going on the cable you have something very wrong!

  5. #25
    That'll be fun if the motor gets warm, within spec, just fairly warm for a motor ;-)

    Check out the glass transition temperature of PLA, that's why it's not suitable for stuff on your car dash ;-)
    You think that's too expensive? You're not a Model Engineer are you? :D

  6. #26
    Quote Originally Posted by magicniner View Post
    That'll be fun if the motor gets warm, within spec, just fairly warm for a motor ;-)

    Check out the glass transition temperature of PLA, that's why it's not suitable for stuff on your car dash ;-)
    After 3 year I have never had the spindle get even remotely warm even when I once found the water pump to have stoped, it hardly rises above ambient temperature and im quite often doing 8h tool paths however it no suprise as it only cutting polystyrene so not exactly working hard. Should it ever become a problem I'll just print it from something else. I have actually thought of a new idea to improve it and to work with the cable support so I will probably swap this one over but I will still just use pla it's more than adequate for the job on this machine

  7. #27
    To keep all thouse happy I put a extra clamp on the cable tower and then I re made the cable support now that I have the printer and swapped it over quickly this eve.

    I have allso switched on and all seams ok other than the control not working from Mach3. I have a signal going to the motion controller but the vfd doesn't respond so I'm guessing there it's in the programming which I will look for tomorow.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMG_5127.jpg 
Views:	20 
Size:	226.3 KB 
ID:	22689  
    Last edited by charlieuk; 28-08-2017 at 08:09 PM.

  8. #28
    Ok all up and running now and I have control from Mach 3 ( I set 001 to no.1) however if I want to bump the spindle speed up with the up arrow nothing happens. I'm assuming 002 needs to be allso changed to the same ie no.1 set by external terminals?

  9. #29
    Quote Originally Posted by charlieuk View Post
    Ok all up and running now and I have control from Mach 3 ( I set 001 to no.1) however if I want to bump the spindle speed up with the up arrow nothing happens. I'm assuming 002 needs to be allso changed to the same ie no.1 set by external terminals?
    It's been a long time since I set mine. Away from machine so will need to check later.

    On the strain relief grommet - can the cable move about independent of the spindle? If it can it really needs to give a gentle flexible support to the cable so it does not flex in the same place. Instead the cable should curve gradually to spread the stress out. Otherwise with repeated movement the cable itself may break where it exits the support bracket. You can either design a new grommet (mk3 !) with some gradual flex element as you move away from the spindle, or buy one of these:

    Click image for larger version. 

Name:	s-l500.jpg 
Views:	18 
Size:	12.2 KB 
ID:	22691

    Top right end clamps either side of the spindle end plate
    Bottom left end is the spring element providing graduated support

    But if it exits the spindle and goes into an energy chain (which is also supported at the spindle end) then I think you are OK as you are as this will act as the spring flex element.
    Building a CNC machine to make a better one since 2010 . . .
    MK1 (1st photo), MK2, MK3, MK4

  10. #30
    The cable runs up and through the inside of my z axis And every axis has cable chain. The cable comeing from the spindle does not ever move other than vibrations, the blue tube is silicone so that should take the point load of the joint and dampen vibrations. I would have thought if I were to get a failure now it would be in the cable in the chain that is constantly moving,how long are cables expected to last? I agree if the wire was just going straight up to were ever and no chain it would need more but I'm not sure why anyone would do that.

Page 3 of 4 FirstFirst 1234 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •