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The mundane mechanical assembly.

Posted: Fri Jul 11, 2014 9:00 am
by RegB
A couple of things;
1) Insertion of ALL THOSE 6/32 nylock nuts.
I found this tricky to say the least and hard on the thumbs and forefingers.
They have to go in with a nut point leading (obviously).
Needle nosed pliers and hemostats denied me the "feel" to know that the axis of the nut was aligned to where the screw's axis would eventually be.
Tip;
Unpack one of the 2 in long 6/32 screws, use it as an insertion tool.
Thread each nut onto it until the nylon just grabs it.
Align the nut to the pocket, spin the screw to align the nut's flats, press it in.
Feel that the nut's points protrude the same amount on each side of the melamine.
Straighten the screw in the slot for fore/aft and side to side.
Remove screw, proceed to next nut, etc.
You should have confidence that the screw will find the nut when you do the assembly and should NOT cross thread.

2) Cheapskate bearings and bearing sleeves.
I had difficulty getting a bearing to balance evenly in a sleeve, put another sleeve on top and then press them together on a table.
Motorcycle repair experience suggested that the bearing needed to go in the freezer and the sleeve needed to go in the oven (-:

Tip;
This worked for me, it might work for others.
I held maybe 5 or 6 of the sleeves in my closed fist for 1/2 minute or so.
Picked up a bearing, selected the sleeve closest to my palm and slipped it on with forefingers and thumbs - quite a bit easier.
Selected the next sleeve deepest in my palm, snapped it onto the other side, done.
Not sure if this is due to thermal expansion and/or softening of the plastic - almost certainly not due to hand sweat, or "palm oil" (-:
Point is, it worked.

3) Assembling tower supports and Mounting the motors.
I left it too late to get Astrosyn dampers, but got some isolating gaskets.
Since I didn't know just how far these would compress I left the drive pulleys off until the assembly was almost complete.
I also put 1/8 inch rubber grommets under the heads of the motor mounting screws to isolate the screw heads from the melamine.
No idea how well this will work, but it cost me a dozen M3 x 0.5 x 16mm stainless screws - the kit ones are 10mm.
I also used M3 "fender washers" between the screw heads and grommets.

Tip;
I inserted the screws for the idler pulleys from the OPPOSITE side, not the motor mount plate.
Basically my small philips screwdrivers are too short to use that close to the motors.
I held the nuts with a hand held (I didn't want too much torque) 5/16 socket, no ratchet handle.
Since I had introduced a new variable with the vibration isolation gasket the drive pulleys could not be mounted flush at the ends of the shafts.
To get the pulleys aligned "right" I aligned them to the idler bearings once the rest of the assembly was together.

Tip;
Do this by squinting along the idler bearings in a direct line such that you can see the same amount of space between the bearing and the spacers on the left and right - align the drive pulley to the bearing.

4) Cheapskate assembly and adjustment.
As a general principle I dislike the idea of assembling or setting things up "in mid air", so I assembled and adjusted my cheapskates "on the bench", not "around the towers".
I assembled them FULLY, laid them on the side that has the fixed bearing spacers and used a tower extrusion as my "feeler gauge" to adjust the eccentrics, which were "on top".
Obviously this was out of sequence, I hadn't run wires through the tower extrusions or mounted them.
I think this has a better chance of controlling assembly errors than assembling and adjusting them "around the towers".

Re: The mundane mechanical assembly.

Posted: Sun Jul 13, 2014 1:02 am
by RegB
Threading belts;
The manual is good, VERY GOOD, but the belt threading section seemed unnecessarily complex (to me).
I also feel that it could have explained a little better how the teeth are on the inside of the belt loop, but are on the outside of the cheapskate where the clamp goes.
It wasn't obvious (to ME) at first that the ends get turned out.

Tip;
I left the cheapskates at the bottom of their travel, got a tower directly in front of me and poked the belt through the slot and down the hole.
As soon as I saw it appear below the first idler I poked at it with a screwdriver to send it behind the motor pulley.
After it was a bit past the motor pulley I trained it straight down, just before it hit bottom I pulled it out to wrap around the second idler.
All the time keeping the belt feeding straight and free to avoid any twists.
Up the outside of the extrusion, over the top, down to the cheapskate where I inserted a small screwdriver as it approached to guide it out of the cheapskate slot.
Quick test: Move cheapskate up and down with one hand, feel motor pulley turning with other hand.

Re: The mundane mechanical assembly.

Posted: Thu Jul 17, 2014 3:43 pm
by RegB
Crimping sub D

Anyone ELSE have problems with this part ?
I got the pins and housings from Hansen hobbies as suggested, also a Radio Shack crimper, followed the toots on Hansen's web site, etc.
The hardest thing for me is getting the pins into the housing. It seems I have to pinch the pin with pliers in EVERY ONE of the 360 degrees to make it perfectly round. Maybe only 180 (-:

Would a megabuck crimper help ?
OK, I don't have "Mega", but could spare a hundred or so to get out of this aggravation.

Re: The mundane mechanical assembly.

Posted: Thu Jul 17, 2014 4:09 pm
by geneb
Don't scrimp on crimp tools. :D

g.

Re: The mundane mechanical assembly.

Posted: Thu Jul 17, 2014 5:18 pm
by Eric
Don't have to pay a fortune either.

This is the one I got a while back, and it's been doing a fine job: http://www.ebay.com/sch/i.html?_sop=15& ... c&LH_BIN=1

Re: The mundane mechanical assembly.

Posted: Fri Jul 18, 2014 9:03 am
by RegB
Thanks guys.
Today I had intended to drop by You Do It Electronics in Needham, Mass. with the intention of SPLURGING on a Paladin PA 8000 crimper frame and PA 2097 die set - about $85 plus 6.25% sales tax.
Quite a drive, but I will be passing close to there anyway.

Ummm, ...something about a poor workman blaming their tools ? something like that (-:

I think the problem is most likely ME.
I just found a video from Hansen Hobbies and ...this may have been too subtle for me;
The pin is inserted in the crimper with the pin's open "wings" in the female half of the die, then the crimper is closed just a little bit, enough to see that the pin's "wings" just start to fold around.
Then the wire is inserted and the (dirty talk alert) male member comes in from "behind" the pin's body to apply force.

Hmmm; I just tried that technique with my Radio Shack quality ~$10 crimper - MUCH BETTER and it fits into the housing a lot easier.

Now I have a ~$90 quandary hovering over me )-;

Re: The mundane mechanical assembly.

Posted: Fri Jul 18, 2014 10:28 am
by Eaglezsoar
RegB wrote:Thanks guys.
Today I had intended to drop by You Do It Electronics in Needham, Mass. with the intention of SPLURGING on a Paladin PA 8000 crimper frame and PA 2097 die set - about $85 plus 6.25% sales tax.
Quite a drive, but I will be passing close to there anyway.

Ummm, ...something about a poor workman blaming their tools ? something like that (-:

I think the problem is most likely ME.
I just found a video from Hansen Hobbies and ...this may have been too subtle for me;
The pin is inserted in the crimper with the pin's open "wings" in the female half of the die, then the crimper is closed just a little bit, enough to see that the pin's "wings" just start to fold around.
Then the wire is inserted and the (dirty talk alert) male member comes in from "behind" the pin's body to apply force.

Hmmm; I just tried that technique with my Radio Shack quality ~$10 crimper - MUCH BETTER and it fits into the housing a lot easier.

Now I have a ~$90 quandary hovering over me )-;
If the Radio Shack style crimper works good then I would use that. The advantage of the higher price crimpers is that they can handle a lot of different crimp pins.

Re: The mundane mechanical assembly.

Posted: Fri Jul 18, 2014 11:37 am
by geneb
The crimper I use is the same that Hansen sells for $35.

g.

Re: The mundane mechanical assembly.

Posted: Fri Jul 18, 2014 2:18 pm
by Polygonhell
I think I paid $35 for mine from pololu, and if you shop around you can probably get cheaper than that.

Re: The mundane mechanical assembly.

Posted: Fri Jul 18, 2014 8:55 pm
by RegB
I backed off from the $60 crimper frame, went for the $39 one instead.
The die set was $24.50, most on line stores ask closer to $30.
So, ~$65 - which I know is a LOT more than most of you have paid, but I have been SUFFERING (albeit my own fault for not paying attention).
I know, good technique with cheap tools beats poor technique with expensive tools.

BTW Paladin was merged with Green Lee, so I got Green Lee packaging with Paladin model numbers.
I couldn't resist the little helping hand vise with magnifying glass and soldering iron holder with sponge well, $13.

Since this is Tips 'N Tricks.

Tip;
DO pay attention to the Hansen tutorials on crimping.
In particular put the pin into the crimper with the "wings" (or "ears") into the female half of the die - as shown.
This makes the wings/ears wrap around the wire, then it all gets crushed together when the male half of the die is pressed in.