Ruggedising a Type 17 Stepper motor electrical connection

[GreensandsParticipant @greensands]

[GreensandsParticipant @greensands]

Can anyone suggest a means of ruggedising the electrical connection to the Type 17 stepper motor as illustrated in the photo as the 4 lead connection provided with the motor is far from being workshop proof. One problem is that I do not know the correct term or type reference for this type of cable connection or whether or not more purposeful plugs exist which can mate directly with the socket which is a 6-way, the cable connection being 4-way. Any ideas or suggestions as to how to go about making the assembly more workshop proof would be much appreciated.

[DC31kParticipant @dc31k]

Plenty for 23 and 34, so they may be a starting point for inspiration, search terms or suppliers:

https://www.soigeneris.com/stepper-motors

https://www.thingiverse.com/thing:2481149

https://www.cnccookbook.com/gorgeous-nema23-stepper-motor-back-covers/

https://cnc4pc.com/3d-printed-back-motor-cover-kit-for-nema-23-60mm-570oz-in.html

[duncan webster 1Participant @duncanwebster1]

What I did was make up some longer bolts to replace those which hold the whole thing together and use them to hold a plate to the end. This plate protruded beyond the connector and supported a plastic box, in the side of which I had a grommet to support the 4 core cable. My motor didn't have a plug socket arrangement, so soldered connection inside the box

Not a brilliant photo, but it might help. I'll take a better one if it would help

[GreensandsParticipant @greensands]

Hi Duncan Yes, another pic would be helpful

[JourneymanParticipant @journeyman]

There are a number of 3D printed covers / caps designed to provide cable restraint such as this one on Thingiverse. This particular example is for NEMA 23 size motor but could be re-drawn to suit, the right size cover is probably somewhere on the interweb! Found this one for NEMA 17.

John

Edit: Add link for 17 size

Edited By Journeyman on 19/08/2021 10:08:00

[Dave SParticipant @daves59043]

The 'quick and dirty' way I have often employed is to turn the motor so the wires are at the bottom, secure to the motor body with a cable tie and 'pot' the whole connector and tie in hot melt glue.

Dave

[noel shelleyParticipant @noelshelley55608]

Like Dave, Fit a strip connector to the motor and continue to the controller in much thicker wire and pot the lot ! Noel.

[John HaineParticipant @johnhaine32865]

Sugru is excellent for "potting" since you can mould it round the item and it supports itself.

Another method I used on the steppers on my lathe and dividing head, which have flying leads emerging from the motor, is to drill a hole at one end of a small plastic project box, pass the wires through the hole into the box, and glue it down on the side of the motor with Araldite.  Then terminate the flying leads with terminal strip inside the box on to multicore cable run through a grommet, screw on the box lid, and if necessary use a tie wrap round the flying lead for strain relief.  Will post a photo if I can find one.

This is the X axis drive on my VMB mill.  It uses a Type 23 stepper so a bit bigger, you would need a smaller box.  In this case the 8 flying leads from the motor needed some interconnect to put the windings in series, so they are soldered and heat-shrink sleeved, then the non-commoned ends connected to the choc bloc segments to connect to the leads to the driver – this could have also been soldered to save space.  The leads were actually led in from the end of the box, and protected by moulding Sugru around them.  At the other end the cable I made up has a spiral nylon binding, fixed at the otor end with heat shrink, and again moulded in Sugru.  Box lid has been unscrewed to get this shot.

Edited By John Haine on 19/08/2021 12:00:28

Edited By John Haine on 19/08/2021 12:23:42

[Tony Pratt 1Participant @tonypratt1]

Obvious answer is turn the motor 180 degrees so the connector is at the bottom.

Tony

[Oven ManParticipant @ovenman]

I don't think there is much demand for end covers on NEMA 17 steppers as they are mainly used on 3D printers that don't operate in a particularly harsh environment. This is where the ability to design and 3D print something really comes into its own. I can't find any size 17 designs on the web that would fit to a motor that has a built in connector.

Peter

[duncan webster 1Participant @duncanwebster1]

photo below, but mine is a much bigger motor. There is a slight bend in the plate to accomodate the draft angle on the plastic box, and 2 of the motor securing screws have been replaced with longer. Mine were tapped into the outer end plate, not recessed like the OP's. It's not the easiest place to take photos, can't get camera far enough away really

[Neil WyattModerator @neilwyatt]

Be wary of enclosing a stepper, as used in a high power application they can get quite hot.

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