Author Topic: A fix for the shakes.  (Read 6342 times)

Offline Bluechip

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Re: A fix for the shakes.
« Reply #45 on: September 29, 2018, 02:09:55 PM »
I know them as 'Japan Solderless Terminals' . ( Manufacturer )

Dave

CPC-Farnell search for 'JST'

https://cpc.farnell.com/w/search/prl/results?brand=jst-japan-solderless-terminals
« Last Edit: September 29, 2018, 02:13:52 PM by Bluechip »

Online zeeprogrammer

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Re: A fix for the shakes.
« Reply #46 on: September 29, 2018, 04:13:24 PM »
Congrats Don. That's some fine progress.  :ThumbsUp:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline Mosey

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Re: A fix for the shakes.
« Reply #47 on: September 29, 2018, 10:35:40 PM »
I know them as 'Japan Solderless Terminals' . ( Manufacturer )

Dave

CPC-Farnell search for 'JST'

https://cpc.farnell.com/w/search/prl/results?brand=jst-japan-solderless-terminals
I'm corrected, TY.

Offline Mosey

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Re: A fix for the shakes.
« Reply #48 on: October 01, 2018, 01:24:23 PM »
BTW, I noticed the crimping tool at that source for only 300Euros. Better get a couple at that price. Or go to the local auto parts store and get one for $12.00.

Offline ddmckee54

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Re: A fix for the shakes.
« Reply #49 on: October 02, 2018, 02:46:28 PM »
Awhile back reference was made to JST Connectors. It is my understanding this means "Japanese Standard Terminal, and does not specify one particular size of terminal, rather a whole set of them. Am I correct?

Mosey:

That's right.  The pitch that seems to be most widely used is the 2.54mm pitch, or 0.1".  That's one of the reasons that it took me 3 tries to get a crimper that would properly crimp the 2.54mm pitch terminals without requiring multiple crimps or mangling the terminal.

My crimper is a Chinese clone at $39.95.  If I was doing this professionally maybe I could justify the cost of the real live 300Euro crimper, but not for strictly hobby purposes.

Don

Offline Bluechip

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Re: A fix for the shakes.
« Reply #50 on: October 02, 2018, 03:37:36 PM »
BTW, I noticed the crimping tool at that source for only 300Euros. Better get a couple at that price. Or go to the local auto parts store and get one for $12.00.

Don makes a valid point.

Depends on how much use it's going to get. If you only do 100 terminations a year in your shed then the £12 item is the one to go for. You might have to return the first two to get one that works ( sort of ) OK but then you're in business. If, as I did, you're doing 300+ crimps a day then the reason for the price difference will not escape your attention. At the end of the working day you will probably still have the use of your hand  ;D

Been there, done it. Yes, I DO have some 'professional' crimping tools and some 'budget' end  items.

I had one budget tool from a reputable source that was faulty. After crimping it was possible to pull the wire out with not too much effort. It's replacement was just the same. The third one DID actually do the job. Not the sort of thing to discover 200 miles from base at 3AM on a Sunday morning  :cussing:

The old saying 'You get what you pay for' is usually true.

Dave
« Last Edit: October 02, 2018, 03:46:38 PM by Bluechip »

Offline ddmckee54

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Re: A fix for the shakes.
« Reply #51 on: October 02, 2018, 05:30:55 PM »
Bluechip:

I know what you mean about those little surprises when you're far from home.  I was working on a project about 300 miles from home in an industrial system where we had to make up a bunch of custom Ethernet cables.  Not a single one of those cables would work.

Turns out the installer had borrowed a crimper from a friend that told him it should work for what he needed to do.  On close examination, really close examination using 10X magnification, we found that the crimper had shaved a tiny curl of plastic and left that curl of plastic on top of one of the contact pins in the connector.  It was late in the project and we wanted to get it over with, so after a little minor surgery to remove the curls of plastic everything was talking just fine.

Don

Offline ddmckee54

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Re: A fix for the shakes.
« Reply #52 on: October 02, 2018, 06:50:03 PM »
OK, the trip down memory lane has been fun but back to the topic at hand - a fix for the shakes, crimper version.

I got a few things printed out over the weekend, but yesterday was busy and I didn't get a chance to post any pictures.  The attachments are a couple of views of what this crimping station will sort of look like when it's set up for operation.  I probably should have tried a shot or two without the flash, then maybe things wouldn't have washed out so badly.

Anyway, what you are seeing is about my third or fourth attempt with minor tweaks between each attempt.  In the process I found out a couple of things:

1) I was right when I suspected that things might "sag" a bit.  That's why the 90° bracket that the X and Y racks are bolted to now has a "foot" under it and didn't in the original design.

2) My Z axis really flopped around when the X axis was moved.  Hence the sliding foot under the Z axis.  Because of this I could probably eliminate the foot under the X-Y connecting bracket but it was already printed, so....

3) What little playing that I did with this thing, moving the various axis around, I have discovered that while the rack and pinion allows very rapid movement, a 3D printed rack and pinion really sucks for the small movement required for the final positioning. 

With this in mind I think I will re-design the Y and Z axis scrapping the rack and pinion and going to a feed screw.  Those axis will only need to be set up once for each crimping position so speed of movement is the secondary consideration, accurate positioning is primary. (Axii?? Not sure what the plural of axis is.)  In all reality, the Y and Z axis only need a few mm of travel, 10-15mm max.  The Dupont style crimper might require more travel since it has more crimping positions on the jaws, but it's still within the length of the 3mm bolts that I have in stock and will use for the feed screws.

The X axis will also get re-designed, keeping the rack and pinion for rapid movement.  But it will also get a feed screw for the final fine tuning of position.

If I do this right, I will be able to keep the majority of what I have designed and built and just change/add a couple of parts to each axis.

Don

Offline ddmckee54

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Re: A fix for the shakes.
« Reply #53 on: October 04, 2018, 07:43:30 PM »
I crimped up a set of servo cables last night, they use 3 pin Dupont connectors.  I couldn't use the crimping station as it's not finished yet.  I did realize something of importance.  The way the crimper is oriented in the cradle, fixed handle down, I will not be able to verify that the wire is fully inserted into the terminal, the open part of the terminal will be facing down.

It looks like I've got a few options here, the first option is it's dental mirror time.  The problem with this option is that everything is going to be in shadow and thus harder to see. 

The second option would be to measure how deep the wire needs to go into the terminal and then measure to determine when the wire is fully inserted into the terminal.

The third option would be to rotate the crimper 180° back into it's normal hand-held position.  This would probably be the "best" option as it gets the terminal back into a position where it's easier to see what's going on with the wire.  The problem here is that I REALLY have no idea how to support the crimper in this position, everything on the bottom side of the crimper moves.  That's why I flipped it over in the first place.

Forth, I could install a CCTV camera and monitor the position of the wire/terminal - but now I'm just being silly?

Don

Offline Admiral_dk

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Re: A fix for the shakes.
« Reply #54 on: October 04, 2018, 09:57:31 PM »
Quote
If you look at the cross section drawing, you will see the rotor arm receives sparks from two different sources.

Well that depends on your eyes - how well are they doing ...?....
I can still see very small things when I remove my glasses - especially when light and contrast is good, but in other situations, when working on very small SMD components I do sometimes wish for just your fourth option ....

Offline ddmckee54

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Re: A fix for the shakes.
« Reply #55 on: October 05, 2018, 04:08:20 PM »
I reach for the Opti-visor any time that I need to do ANY small-ish work anymore.  It's HELL to get older isn't it?

If I get this and/or the soldering station working well enough, MAYBE I'll be able to work on SMD.  Right now that's just a pipe dream.  Any time I see electronics offered in kit form my first thought is "Yeah right, like that'll happen!"  And I used to love electronics kits.

Don

Offline Admiral_dk

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Re: A fix for the shakes.
« Reply #56 on: October 05, 2018, 08:24:58 PM »
Well I do prefer to get old - I just wish we wouldn't be granted so many "old age medals" (problems and wrinkles) - the alternative is permanent  :zap:

Offline ddmckee54

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Re: A fix for the shakes.
« Reply #57 on: October 11, 2018, 02:24:03 PM »
While we're sort of on the subject of JST terminals, anybody know if there is a tool for extracting the terminals from an already built block?  If there is have you got a link to it?

Don

Offline ddmckee54

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Re: A fix for the shakes.
« Reply #58 on: October 15, 2018, 10:26:43 PM »

Offline ddmckee54

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Re: A fix for the shakes.
« Reply #59 on: October 18, 2018, 07:04:10 PM »
I've got the "Y" and "Z" axis modified with a feed screw for fine adjustment.  I used an M3 button head screw 35mm long, it gives me about a 20mm range of adjustment.  I'm using a sliding clamp for coarse adjustment,  I'm still working on the "X" axis.  I'm trying to keep the rack and pinion on this axis because it needs to move in and out with every terminal crimped.  The "Y" and "Z" axis SHOULD only have to be moved when a different type of terminal is crimped.  I think I have something figured out that will allow me to use the rack for coarse adjustment and also use a feed screw for fine adjustment.  I printed out some parts last night, tonight I'll get the rest printed and see if my idea worked.  I'll take some pictures when I've got something that works.

I managed to  lose my 3D CAD work for the "Y" and "Z" axis fine adjustment that I did over the weekend.  I was routinely saving my work while doing it, but the version of DesignSpark that I am using, version 2.1, has this nasty habit.  Unless you specifically tell it to save in the RSDOC format the 3D CAD requires, it will save in whatever format was used last.  Since I was saving STL files to print the parts, my CAD work was saved in STL format.  DesignSpark WILL import an STL file, but I don't know what it uses to scale the objects from STL to CAD.  An object that measured 8mm in real life, indicated it was 382mm when imported from STL.  Between the scaling issues and the number of facets that I would have to correct, I just gave up on that idea and re-created my CAD work.  3D CAD goes SOOO much faster when you can measure an actual size part that you know works and then just draw that.

Don