Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: Mr. Electric Wizard on April 15, 2020, 01:59:02 PM
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On Part 2 of the assembly, I am supposed to use a short #8 bolt (non self tapping) but the bolt I have is a different thread pitch and the nut will not screw on.
I verified the nuts work by attaching them all to one of the longer bolts for the power supply.
Question:
I have a stainless bolt that is the same size/thread pitch as the one that came with the kit.
Generally stainless steel is not a great conductor but the way I see it the nuts and washers are what's making the connection to the chassis.
What do you think? Is it okay to use a stainless bolt for the chassis ground?
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The self tapping bolt that you use to make threads in the 6 lug terminal strips looks a lot like the short #8 bolt that you need to use for the ground lugs. A #8 nut will not thread onto the self tapping screw, so that is why I'm suggesting that you have likely mistaken that for the short 8-32 screw that needs to be used for that part of the build.
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It seems fairly obvious (or maybe not ;D ) which one the self tapping screw is.
The self tapping screw is more of a gray color (as opposed to the silver of the other) and has the cut outs by the tip with more of a taper.
Pretty sure I am using the correct machine screw unless the wrong one got packed.
The nut that I'm trying to use screws on fine to the longer ones used for the power supply.
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So, a stainless steel bolt for the chassis ground.
Acceptable or not? kit lockwashers were used on both sides of the solder piece.
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I can't see a problem with using SS. It's probably just down to cost as to not supplying them with the kit. The opposite is Doc using SS on his Bonneville salt bike to combat corrosion, and the fact that bikers like SS on their bikes. 8)
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I figured it was okay, but just wanted to double check.
I went on with the build in any case. 8)
Got everything bolted to the chassis last night. It's actually starting to look like something now.
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Sorry about the screw. It must have been misthreaded. SS is fine.
As to SS screws for bikes, yes I use them because I race on salt. The corrosion factor is insane. Check out Bumax. That's what's holding the engine in my race bike.
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No problem, I had another on hand.
My next issue is that I don't see a bare buss wire in my kit.
I have a set of white, green, red, and black each, but no bare.
The only package I haven't opened is the one for the Speedball (going to build it stock before I apply the Speedball).
What gauge and what type (stranded vs not) do I need for a buss wire?
I have lots of wire around.
I found some small rods that are used to actuate the flaps on a model airplane.
Pretty sure it's steel but it's small enough to go through the hole with some room to spare.
This should work right?
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It's a little 6" long piece of bare wire that is usually bent in a u shape and put in the bag with the other wire. Sorry if we missed it. You can just strip some of the other wire to make a bare wire. We supply about 10% more length of each type of wire than is specified in the kit build. So you could probably cut what you need from the black or red.
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The wire being gone could have very well been my fault. Who knows.
I think this piece of wire is going to work fine. It's solid core, albeit really stiff.
I made it work though. Thanks for the replies Doc!
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Dang, now the fuse is bad. I was wondering why I was getting no incoming voltage under the IEC.
Then removed the fuse and did a continuity test. No juice flowing through the fuse.
Will a generic T1L250V fuse work, or does it need to be something more specialized?
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Bump for bad fuse specs.
Where can I get a fuse?
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did you check the fuse for continuity with an Ohm meter?
You need to install the fuse in the clips of the PEM cover. If you place the fuse in the enclosed tunnel it will not work, that space is to store a spare fuse.
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Will a generic T1L250V fuse work, or does it need to be something more specialized?
Yeah. A T1AL250V is a 5mm x 20mm 1 amp fuse, so it should work perfectly. I would buy a 5 pack, just in case the fuse wasn't bad, but blew instantly b/c something is connected to ground that shouldn't be -- for example, b/c of a wiring mistake or a wire clipping stuck somewhere (giving the chassis a good shake with the electronics facing down and at different angles usually fixes the latter problem).
cheers, Derek
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Thanks so much for the reply!
I doubt it's any wiring being bad, as I have only soldered on the buss bar and the first black wire from the IEC to the switch, and the wire from the ground lug to terminal 16.
I'll go ahead and order a 5 pack.
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did you check the fuse for continuity with an Ohm meter?
You need to install the fuse in the clips of the PEM cover. If you place the fuse in the enclosed tunnel it will not work, that space is to store a spare fuse.
Yep, i checked fuse continuity with my DMM (i used the beeping function) and there is no continuity.
And yes, the fused is installed in the clip (not the tunnel). I even tried to install the fuse into the clips directly (without the cover installed) and still no voltage.
So, I'd say the fuse is bad.
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Well, I got the new fuses in the mail and built the rest of the Crack!
Now that it's built, I'm on the part where I am checking resistance values.
Some of the values didn't match but I think there might be something wrong with my DMM though.
Some of the digits looks like parts of the liquid crystal display are dead, so I ordered a new one.
Crossing my fingers that everything is hooked up correctly.
When I do the resistance checks again and see some differing values, I'll post some pictures.
The manual shows examples of bad solder joints.
I'm pretty sure some of my joints have too much solder, but hopefully they don't mess up my resistance values.
Will go through the resistance checks again when I get my new DMM.
I did double check the wiring based on the completed photo in the manual and everything looks like it's hooked up correctly.
I was VERY careful making sure that each part was connected as per the manual.
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You could try fresh batteries in your existing meter. Weak batteries can produce weird readings.
cheers, Derek
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Here's some photos of my [poor] execution of the kit if anybody cares to look and tell me if anything looks amiss.
My incoming line voltage is 122V.
Thanks!
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You could try fresh batteries in your existing meter. Weak batteries can produce weird readings.
cheers, Derek
Used the batteries that came with the DMM, but I guess that doesn't mean that they're necessarily good.
Will try some different "new" ones.
Thanks for the suggestion.
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If your soldering iron has a heat adjustment, I would turn it up as high as it would go and reflow a fair number of the joints. In particular, B7/B8 look like they could use some extra heat, as do some of the joints where the UF4007s mount.
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If your soldering iron has a heat adjustment, I would turn it up as high as it would go and reflow a fair number of the joints. In particular, B7/B8 look like they could use some extra heat, as do some of the joints where the UF4007s mount.
Thanks for much for taking the time to look at my wiring.
I went ahead and reflowed all the joints. Will check resistance again when my new DMM shows up (the new batteries yielded the same LCD issues).
One more question though: When resistance is checked the black lead on the DMM is supposed to be connected the ground bus, is that the 12U on the terminal strip? It seems like a better place to put the black lead is on the chassis ground? I guess my more pointed question is the 12U tab the ground bus?
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So here's my preliminary resistance numbers.
I hope I didn't screw the pooch when it cam to putting the kit together.
These don't loo
1. * - mine -> infinity
2. * - mine -> infinity
3. 0 - mine -> 0
4. * - mine -> infinity
5. * - mine -> infinity
6. 0 - mine -> 2.49
7. 2.9 - mine -> 2.92
8. 0 - mine -> 0
9. 2.9 - mine -> 2.93
10. 0 - mine -> 2.48
12. 0 - mine -> 0
13. * - mine -> 0
14. 0 - mine -> 0
20. 0 - mine -> 0
22. 0 - mine -> 0
B3 2.9 - mine -> 2.92
B6 2.9 - mine -> 2.93
RCA Jacks
Center Pin 90-115 - mine -> infinity
Ground tab 0 - mine -> 0
Some of these seem way off. This is with the old multi-meter. I can get a the digit before the decimal point to show if I put some pressure on the LCD with my screen. Also, I am using the 20K range on the Ohm meter. And lastly, the alligator clips are the press in kind that fit over the top of the pointy lead (which may just be a bad connection).
When I say infinity, it's the reading that you get when the red lead is not connected to anything.
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Can you post some photos of your build? Specifically I am very interested in the wiring around your headphone jack.
Absolutely to not attempt to power up this Crack just yet.
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Hey absolutely Paul! I am actually scared to apply power to it, especially until I get my new DMM.
Here's a photo. Let me know if it's not good enough and I will try to get a better one.
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Wow that photo shows how terrible my solder joints actually are.
Whoa :o
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Can you check the DC resistance between terminal 12 and all the lugs on the headphone jack? Also, you didn't have anything plugged into the 1/4" jack when you did your resistance measurements, right?
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Doh! I did have a 1/4" to 1/8" adapter plugged in. I forgot it was there.
After removing the adapter, all looks good except for the center pins of the RCA's.
Both are showing infinity.
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Wait, when I change the scale on the DMM to 200K (all other measures were done with the 2K scale) I get 98K on both RCA barrels.
You think i'm good?
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Yup.
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Doh! I did have a 1/4" to 1/8" adapter plugged in. I forgot it was there.
OK, good, I'm not crazy! (today...)
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No you are not. I am going to double check tomorrow when I get my new DMM but yay, I'm happy!
This was a fun little build.
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Yes he is.
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Just wanted to let you guys know that I received my new DMM this morning and re-did the resistance checks again, and we're all good!
This new one is auto ranging which helps a lot!
Also, I wanted to thank you both for your support and troubleshooting help!
Thank you!
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Voltages check out too!
I did hear a pop when I connected the ground clip to the 12 terminal but I never saw any smoke or anything, and the voltages all check out.
Will connect the inputs and headphones soon and try it out.
Thanks again!
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She lives!
Now I just have to figure out the routing in my MiniDSP unit to get it all perfect.
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Sounds pretty dang awesome pre-Speedball!
I'm loving it. ;D