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Trim wiring frustration

J

JurgenRoeland

Well Known Member
Hi all, I'm in the process of wiring the elevator pitch trim servo. It's the standard ray allen motor. I read in the vpx manual and saw an illustration video how people crimp dsub pins on the wires that come out of the motor and then connect the dsub pins one by one. Then putting heatshrink over each pin to secure the connection.

I tried multiple times and the crimped pins keep moving or coming of of the stripped wire after crimping. I guess the AWG size is just too small. After trying normal dsubs, I switched to high density pins and using the steinair High Density Positioner for SAT-004 crimp tool.

an illustration can be seen in the images.

I tried again by winding up the wires (thinking this would increase the gauge a bit) but even then, with high density pins, I can pull the pin of by applying little force on a pull test.
I'm using the high quality stripper SAT-005 of steinair on the 26 awg size wire and can not see any strands cut off.

scratching my hear on what I'm doing wrong and getting worried I won't have any wire left on the motor.

Anybody any suggestion or any other good method to connect the wires to the connecting cable ?

dsubhd1.jpg

dsubhd2.jpg
 
Double your strip length then fold the exposed wire over on itself. You can even triple it if needed.
 
I tried doubling up but then it's too thick for the regular DSub pin. Is it ok to cut of a few strands on the doubled part ? (only bending 3/4 or 1/2 of them over) I guessing yes but just want to make sure. i'm a complete newbie to the electrics work.
 
JurgenRoeland said:
I tried doubling up but then it's too thick for the regular DSub pin. Is it ok to cut of a few strands on the doubled part ? (only bending 3/4 or 1/2 of them over) I guessing yes but just want to make sure. i'm a complete newbie to the electrics work.
Click to expand...

I can't see where the crimp is located in the pictures. Is it high by the top blue color band? This might be catching just enough at the top of the wire to hold it but failing the pull test. If so you need to adjust the crimp position to be between the blue/orange. I do mine just above the orange. Which brand crimper are you using? Maybe it isn't crimping fully onto the wire when the squeeze is finished? Ask someone close to try their crimper as a comparison?
 
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It’s coming out because you don’t have a good crimp. I used pins and have no issues.

I built my harnesses for the avionics so I invested in a DNC crimper and bought a set of inexpensive positioners. Even used, the crimper was still expensive and will resell later and break even.

If you don’t have a proper crimper, then solder and heat shrink.
 
This is from my can bus. Although fuzzy, you can seen the crimps on the pins.
 

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Webb said:
This is from my can bus. Although fuzzy, you can seen the crimps on the pins.
Click to expand...

24 ga wire I assume? Make sure you get em in the right hole as impossible to remove without cutting the wires off.
 
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I can't tell from the fuzzy picture, but can you see the wires through the little hole above the wire entry into the pin? If not, then you aren't getting the wire deep enough into the pin before crimping. This may require stripping a bit more wire before inserting so it goes deep enough.

I would also question if you have the right crimper, or have the right positioner for the wire size, and have set the crimper settings to the correct ones for the wire size. (Assuming you are using a DNC crimper, Can't help you if you are using a different lower price crimper. With crimpers, like most tools, you get what you pay for.)

Best of luck
 
Ray Allen wire

I had some issues with the first few crimps but subsequent were good. I have a DMC though. I set it at #5.
Ray Allen wire is really small stuff. Almost wished I had just pulled 5 conductor 22AWG shielded.
I did use heavier for the flap motor. Two conductor 18AWG and three conductor 22 AWG.
 
JurgenRoeland said:
Hi all, I'm in the process of wiring the elevator pitch trim servo. It's the standard ray allen motor. I read in the vpx manual and saw an illustration video how people crimp dsub pins on the wires that come out of the motor and then connect the dsub pins one by one. Then putting heatshrink over each pin to secure the connection.

I tried multiple times and the crimped pins keep moving or coming of of the stripped wire after crimping. I guess the AWG size is just too small. After trying normal dsubs, I switched to high density pins and using the steinair High Density Positioner for SAT-004 crimp tool.

an illustration can be seen in the images.

I tried again by winding up the wires (thinking this would increase the gauge a bit) but even then, with high density pins, I can pull the pin of by applying little force on a pull test.
I'm using the high quality stripper SAT-005 of steinair on the 26 awg size wire and can not see any strands cut off.

scratching my hear on what I'm doing wrong and getting worried I won't have any wire left on the motor.

Anybody any suggestion or any other good method to connect the wires to the connecting cable ?

dsubhd1.jpg

dsubhd2.jpg
Click to expand...

It looks like those are high density contacts, or even maybe the smaller sized cannon plug contacts. If you are using the SAT-04 crimper we sell I would recommend doing this connection with SA-1018 and SA-1017 standard density contacts. The SAT-004 is primarily set up to be used with these contacts. we also sell a HD contact die for this, but it is only designed to set the crimp depth for HD male contacts - that could be the source of the problem here?

Small gauge wire cal also be tricky with the SAT-004 since there is only one crimp strength and it's not adjustable like the DMC tools are. if you tried the above method and still have issues you could try gently folding the wire over to give a more robust connection, if that fits in the contact. Usually I have only ever seen people need to do that on the super small config module wires for Garmin equipment.

As other people have also suggested, another path would be to use some solder sleeves to splice these together. We sell these on our website, as well as a small butane heat gun (SAT-040 if I remember correctly) that you can use to melt them.

I hope this helps!
 
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Thank you all for the various remarks.

I checked the crimp again and it looked like the crimp was in between the marker lines on the pins.

@Joshua: I am indeed using the high density contacts and crimped them with the "SAT-004 Crimper, 4 way indent" and replaced the inset with the "SAT-004HDINSERT High Density Positioner for SAT-004".
The result in the pictures was using these tools. The wires on the elevator trim look like AWG26.

Folding the wire over seemed bit too thick for the hd pins and I was afraid that the normal dsubs would then again have the same issue. I'm running short on wire on the motor and afraid of trying again.

I think I'll go with the advice of using the solder sleeve technique and use the .125 solder sleeves to join the AWG26 wire of the motor with the AWG 24 of my connecting cable.
I'm anyway planning on having a dsub connector in one of the lightning holes of the F714 fuselage aft deck so that the elevator can get removed for painting or any other reason later on. So a permanent connection on the motor to this first short cable to the dsub connector is not an issue.
 
You will still have to crimp pins for the connector.

It’s too fuzzy to really tell but best I can tell the crimp is in the wrong position. Would you send a clear close up picture please.

From what I can see, the crimp is only on the tip of the wire (red arrow). It should be more at the end of the pin (green arrow) so the whole wire is crimped. Not just the tip.
 

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JurgenRoeland said:
I tried doubling up but then it's too thick for the regular DSub pin. Is it ok to cut of a few strands on the doubled part ? (only bending 3/4 or 1/2 of them over) I guessing yes but just want to make sure. i'm a complete newbie to the electrics work.
Click to expand...

Not ok. That is very thin wire IIRC, so you want every strand. The pins won't work, as they are not designed for 26 ga wire. Just solder on a short piece of 22 ga wire to them and put the pins on them. Be sure to use heat shrink and tie wrap the bundle of solder joints together and one tie wrap on the bundle of wires on both sides of the joints as strain relief. Solder sleeves are easier if you have them.

If you leave a service loop you can just solder it all up and forget the pins. It's not like this part is removed often.
 
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Solder sleeves work good for shields, not so much for wire splicing.
Hand solder and cover with adhesive thick wall shrink tube if you must solder.
 
lr172 said:
Not ok. That is very thin wire IIRC, so you want every strand. The pins won't work, as they are not designed for 26 ga wire. Just solder on a short piece of 22 ga wire to them and put the pins on them. Be sure to use heat shrink and tie wrap the bundle of solder joints together and one tie wrap on the bundle of wires on both sides of the joints as strain relief. Solder sleeves are easier if you have them.
Click to expand...

I wasn't planning on cutting any wires at the root. What I meant was cutting it on the second part that I'm bending over. that would still leave the entire bundle exposed and only some cut strands on the part folding back.
But still I think it's too much of a hustle and I will go the soldering way as it seems the more easy way to go.
I'll probably hand solder as Walt suggested. solder sleeve seems easier but I consider this as a critical connection and if solder sleeve is less fit for splicing, I'll go for the real thing. Not my favorite thing to do, but what has to be done, has to be done :)

On the side where I will have the dsub connector on the aft deck, I'll have 24ga. That fits in a standard dsub when fully bended over


I will make another close up picture of the initial pin crimp for Webb.
 
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