Nylon Washers Don't Fit

[InfinityTotality]

Hey there, I've recently gotten my Crack kit, and I'm trying to attach the transformer to the top plate, and I've noticed that my nylon washers seem to be the wrong size. Just to make sure I'm doing it right, I'm trying to put the 1/2" whiteish plastic-looking washers into the screw holes on the bottom of the transformer. They have a fairly long sheath that seems like it's supposed to go into those holes, but the ones I have are way too big to fit. Am I using the right part? Did I get some that are too big? Are my holes too small? Are they very important? Any input is appreciated!

 

[fissure]

Had the same issue with mine just took a razorblade and cut the sheaths.

 

[Grainger49]

fissure,

That all but defeats the purpose.  The black fiber shoulder washers are on three of the bolts to insulate those bolts from the top plate.  The transformer is grounded on one leg only to eliminate noise.

I wonder if the fiber washers are made wrong.  The top plates are laser cut to high tolerances, so I'll have to say the washers are wrong. 

Contact Bottlehead for replacements.  You can continue assembly but it is difficult to put them in after assembly, I know!  There are terminal strips mounted on all four bolts. 

 

[fissure]

Ah just double checked, i had the black ones confused with the white ones for the speedball kit (the ones that hold the heatsinks to the TIPs) the sleeves on those were to long.
Sorry for the bad advice !

 

[Paul Birkeland]

You need these to fit into the transformer.  Often times, they have to be pushed somewhat hard.

Cutting the tubular sleeves off is not a solution, but rather a way to roll the dice in terms of cooking your power transformer.

 

[Mike B]

I had the reverse problem, they fell out too easy.

I put a dot of super glue on the washers (both trafo & chassis) that holds them in nicely and makes for a much easier assembly.

 

[InfinityTotality]

You need these to fit into the transformer.  Often times, they have to be pushed somewhat hard.

Cutting the tubular sleeves off is not a solution, but rather a way to roll the dice in terms of cooking your power transformer.

Hmmm. I thought something like that might be the case. On the washers I have, it seems like the interior diameter is the same as the hole on the transformer. Is there usually a part on those holes that's drilled out a bit more than the rest? Unless these washers can be compressed quite a bit, there's no way they're going to be able to fit these holes currently. Would I be safe in trying to drill them out myself, or should I just try to get replacement washers?

 

[fullheadofnothing]

There can be a slight variation in size of washers and size of holes, but within each margin of error. Are you saying that you cannot fit a single washer into any hole? Try all possible combinations. The washers do have some flex, so can be pushed in with a minor amount of force if needed. Please post a picture so we can see what you are seeing.

 

[InfinityTotality]

Are you saying that you cannot fit a single washer into any hole? Try all possible combinations.

Correct. I just tried each one in all 4 holes. I measured the interior diameters, and both the washers and transformer holes seems to be almost exactly 1cm. The transformer holes may be about 1.1, but they would need to be 1.4-1.5 to fit these washers. Pictures are attached.

Edit: Sorry, those units are in half-centimeters. This ruler is a bit strange. The washers have an interior diameter of 5mm, exterior diameter of 7mm. The holes are about 5.5mm.

 

[fullheadofnothing]

I measured a handful of the nylon washers. Most are just over 5 mm. The largest I measured was 5.19 mm. The average sized washers dropped straight into the holes of 15 different PT-3 transformers. The larger ones required some effort to push in (I carefully lined them up to the hole and pushed with my thumb), but they do fit into the holes.

Due to the difficulties measuring inner diameters, I inserted a drill bit and measured its outer diameter. This bit still has a fair amount of play. I would guess the hole is still a fair amount larger than the measurement, but this definitely confirms the anecdotal data of how the washers fit into the holes.

To have an internal diameter diameter of 5mm and an outer diameter of 7mm, the walls would have to be 1mm thick. I measured between 0.36mm and 0.52mm in my samples. It's hard to get a sense of scale from the way your pictures were shot, but the wall thickness does not appear to be one-fifth the internal diameter. It's also hard to get a sense of how close in size the washer is to the hole shown as in both your pictures the washer is closer to the lens than the hole. Can you post a pic of how the washers actually seat in the holes?

We can send you replacement washers, but we would need to know who you are (see: http://www.bottlehead.com/smf/index.php/topic,3.0.html )

 

[InfinityTotality]

The top surface of the washer was actually at the same height as the hole on the transformer in that picture. I was very careful to make sure of that. I can take a picture of it on the transformer if you like, but it'll just be the washer sitting flat on the transformer surface with no view of the hole on any side. I don't have a caliper for measurement, unfortunately, but I've attached a picture of a very precise ruler resting on top of one of the washers. The units are 1/2mm. It looks like the sides are right around 0.75mm each, and the total diameter is almost exactly 6.5mm. It seems I somehow got an oversized set, so a replacement would be appreciated. I wouldn't mind paying for them and the shipping as well. I've added my name to my signature. If you need any more information, let me know.

 

[Doc B]

Not to flog this but that does not look like a metric scale. That looks like a 1/50 scale rule. We can certainly send some more washers

 

[InfinityTotality]

Ah, looks like you're right. I had made a quick comparison before, and it looked like the 2 lined up with the 1cm mark on a regular ruler, but it looks like it's ever so slightly longer. I wasn't aware of that sort of scale before, but this is in fact a mechanical drafting ruler. I suppose my measurement should more accurately be 0.26 inches. Regardless, thank you for the washers! I'm excited to get this crack put together.