Tech Spam thread - because 1/4" BSP gets 5 hand spans to the jiggawatt

[Nominal]

Fuck pipe!

[Roman]

Nominal bore bores Nominal.

[anglia4]

I made my draughting cadet keep two labelled off cuts on his desk, one was 25mm tube, the other was 25NB pipe so he could always see that they are completely fucking different things.

Soo many ballsed up material lists...

[CorollaGT]

loled a bit at using a flowmaster to try and fix a droney exhaust

Was considering getting one of these a few months back, so glad I didn't impulse buy like normal! Yuck. Brought a MagnaFlow muffler instead, holely fuck it's quiet especially seeing as its bloody straight through. Win.

[sentra]

peters going to be mouthbreathing and salavating while he runs a 7/16 bsw tap into your japanese motor dave, burdeoning you with crappy english fastners while hes telling you "yeah yeah its M11"

hes got a whole box of them, dont trust him.

[tortron]

Looking for a very narrow and light diff.

Lsd

doesnt have to handle more than say 80hp

does such a thing exist anymore? I was thinking something like a narrowed escort diff

[sheepers]

kid up the road has a pretty impressive looking big wheel.

ill talk to him on your behalf. 

[Llama]

I have a .png of a schematic of something I'm making. There is no scale on the part. I want to be able to give it a reference scale, and then draw lines and have it show the length of the lines in mm. Any easy way to do this?

[downtrail]

Import it to a cad program draw a line of one side at x mm then scale the entire drawing to that line. then trace over the drawing and use the program to display the other values you need?

[flyingbrick]

Buy a scale rule and hold it up to computer screen

[Yowzer]

Keep answers in this thread sensible plz

[tortron]

Get out your tech drawing kit

do they still teach that in achool or is it all cad now days

i remember having to measure and draw parts of a 4K lol

[h4nd]

SCH is normally for the electrical properties, and PCB for the physical. If you're drawing a physical layout, try using using a PCB file? Most PCB editors have dimensioning functions. What package/software, BTW?

[Roman]

Easiest way is to just import the drawing into draftsight (free download)

get the picture to scale then just draw dimensions on it. Dont even worry about drawing the object. Then just select the whole lot and scale up or down and the dimensions will self adjust.

if you scale it to be 1mm long to start with then for your new scale you just type in how many mm long you want it to be

.

Solidworks is really good for this sort of thing with its 'smart dimensions' but they can screw you over if youre not mindful.

I hate any type of automatic part sizing etc though.

As an example used to have a structural steel program that could automatically plonk things together with correct plate sizes bolt grades etc.

A few times i used the auto function to add a stiffener to both sides of an i beam, but dragged the edge of one out longer to be a cleat, added some holes. Job done.

But then later the model rechecks itself and changes the cleat back to a stiffener and im getting angry phone calls from guys on site trying to hang a beam on invisible cleats haha.

[Roman]

Hey so people use fibreglass a lot for insulation (as in, pink batts etc)

 

But is the air gap between the fibres etc the main reason its a good insulator?

 

So fibreglass + epoxy or whatever, for building stuff. Is that a good insulator against heat as well?

 

Also, I'm torn between heat wrapping my exhaust manifold or not.

 

I want to lower engine bay temps but it makes such a grisly mess when it starts to come off.

 

Looks as though the 'lava rock' type stuff might be a bit more resilient than the fibreglass wrap which I've had some pretty terrible experiences with.

[Steelies]

Looking for a very narrow and light diff.

Lsd

doesnt have to handle more than say 80hp

does such a thing exist anymore? I was thinking something like a narrowed escort diff

 

a morrie guy at work who does starlet transplant yuckness to his says he's used a fiat diff of some type before, either is LSD or he was able to get the right bits for it without too much fuss.

Nominal knows him/ may know details.

 

again, someone else will know better but 411 on the street is suzuki cappuccino LSD brains go into carry housing...?

[Roman]

My stupid front seats weigh about 10 billion billion kilograms (well, about 15-20kg each)

 

I pulled one apart to see if there were any hidden gold bars, but alas.

 

There's about 4-5kg worth of complete junk in there for adjusting every little seat thing possible though.

 

Think I'll just weld the adjuster thingies all solid except for the seat angle and headrest height and biff all of the stupid shit in there.

I didnt even know some of the things in it were even adjustable.

 

Saving ~5kg per seat though is pretty swish.
 

My usual welding technique is:

 

1. Stick weld it
2. horrible failure

3. Sentra Dave tells me off
4. Drink his beer while he fixes my blunders

Oooorrr I might try get the argon bottle refilled this week so I can make blobs and holes with tig instead.

[Yowzer]

I've also looked into that lava rock stuff and it seems to be the bizz in terms of heat wrap.

It's also a heeeelllll of a lot cheaper than HPC coating

[Roman]

Yeah I can see the HPC stuff being worthwhile if you fork out for the fancy one and get it dipped or whatever so it coats the inside as well. So it reflects a fair amount of heat before it gets into the metal to start with.

 

But just spraying on the outside seems a bit meh, and as people have said it still seems to radiate heaps of heat anyway.

 

But, I've also had an engine bay full of nasty fibre stuff from crumbling wrap, which in terms of automotive horribleness is about on par with the smell of old diff oil.

[Roman]

In other news, those "Jet plane vs car quarter mile race" type things are so stupid.
 

How about a 0-600mph race instead...

 

Or race against a tomcat with an aircraft carrier style launch hook thing starting it off