Search found 147 matches

by mrfoo
Fri Feb 21, 2020 12:48 pm
Forum: General How-To & Discussion
Topic: JSR's workshop chronicles
Replies: 1
Views: 245

Re: JSR's workshop chronicles

was pleasantly surprised to find it very clean. That's good news. the deals online were just so much better if one is prepared to wait a little. Personally, I'd rather have second hand quality gear than brand new chinesium, even if it comes in more expensive. But usually, it doesn't, even if it doe...
by mrfoo
Wed Feb 19, 2020 3:52 am
Forum: Off-Topic Hobbies
Topic: "Offtopic-posts-topic" NSFW
Replies: 6603
Views: 234819

Re: "Offtopic-posts-topic" NSFW

indigoer wrote:
Mon Feb 17, 2020 9:13 am
Why this topic is marked as NSFW :D
Does the post just previous to yours look like a safe place to work?
by mrfoo
Sun Feb 16, 2020 1:40 am
Forum: Ammo & Parts
Topic: Low-friction/Specialty Ball Valves?
Replies: 11
Views: 503

Re: Low-friction/Specialty Ball Valves?

Here's one, for example : https://www.valvesonline.co.uk/manual-v ... l-bkh.html

Relatively cheap, pom / molybdenum disulphide seals, rated for 500 bar.
by mrfoo
Sat Feb 15, 2020 1:43 am
Forum: Ammo & Parts
Topic: Low-friction/Specialty Ball Valves?
Replies: 11
Views: 503

Re: Low-friction/Specialty Ball Valves?

The problem with teflon is that it's soft, it deforms. So although its coefficient of friction is low, it's on a relatively huge area, you're gonna get a lot of stiction as pressures increase. I believe the seals in high-pressure ball valves (400 bar and up) are made from POM rather than teflon.
by mrfoo
Wed Feb 12, 2020 11:04 am
Forum: Ammo & Parts
Topic: Ideas for biodegradable cannon-balls
Replies: 9
Views: 982

Re: Ideas for biodegradable cannon-balls

Surely used cat litter comes with inbuilt "clumps" :)
by mrfoo
Wed Feb 12, 2020 2:03 am
Forum: Ammo & Parts
Topic: Airsoft/ 1/4 ball bearings
Replies: 4
Views: 1626

Re: Airsoft/ 1/4 ball bearings

I'm currently on the hunt for a good barrel for the 1/4" slingshot ball bearings. I'm looking for air tight interference fit. Assuming your bearings are really 1/4", you can make your own using a 1/4" reamer and maybe a 6mm. Start with some 6mm ID thick wall tubing, if it's the welded crap with a s...
by mrfoo
Tue Feb 04, 2020 12:09 pm
Forum: General How-To & Discussion
Topic: Taking examples from nature: hydropneumatic spuds
Replies: 3
Views: 239

Re: Taking examples from nature: hydropneumatic spuds

Nah. The big issue is compressibility. Water, in particular, can pretty much be considered incompressible at realisable pressures. So we put some water behind a projectile, somehow holding that in place, and raise the pressure of the water to 10, 20, 100, 400 bars, it pretty much doesn't matter. The...
by mrfoo
Mon Feb 03, 2020 3:08 am
Forum: General How-To & Discussion
Topic: Taking examples from nature: hydropneumatic spuds
Replies: 3
Views: 239

Re: Taking examples from nature: hydropneumatic spuds

Viscosity is going to be the killer in this. You'd need something far less viscous - liquid butane or isopropanol are probably the most easily accessible low-viscosity fluids, not to mention that they are *ahem* flammable. The other option would be to vapourise a quantity of fluid, in the same way t...
by mrfoo
Fri Jan 24, 2020 3:08 am
Forum: General How-To & Discussion
Topic: "In the world of spuds today"
Replies: 2403
Views: 126208

Re: "In the world of spuds today"

Oil changes in the headstock , check. I wouldn't try tearing the headstock down unless you're replacing the bearings, which will be el-cheapo versions. Replacing them with "good" bearings is almost certainly not cost-effective. Change the oil regularly, flush out all the crap. What I'd be more worri...
by mrfoo
Mon Jan 20, 2020 2:26 pm
Forum: General How-To & Discussion
Topic: "In the world of spuds today"
Replies: 2403
Views: 126208

Re: "In the world of spuds today"

The reason for doing that rather than modding digital calipers is because I'm going to need real time feed, the main reason is to feed an electronic leadscrew setup. Neither of my lathes have threading capability... As for stripdowns, I've never had a piece of chinese gear that wasn't chock full of ...
by mrfoo
Mon Jan 20, 2020 2:14 pm
Forum: General How-To & Discussion
Topic: "In the world of spuds today"
Replies: 2403
Views: 126208

Re: "In the world of spuds today"

Could also mod a cheap digital vernier caliper into a small dro... Very interesting! Cheers. One of my ongoing projects is to try modding the linear scale from an inkjet printer. "Stock", they are generally good for 600dpi, which is just over 0.04mm in scientific measures. My plan is to try and sin...
by mrfoo
Sun Jan 19, 2020 1:31 pm
Forum: General How-To & Discussion
Topic: "In the world of spuds today"
Replies: 2403
Views: 126208

Re: "In the world of spuds today"

Yep, that looks about right as far as lever indicators go. You'll probably want a plunge indicator as well, though. And a couple of mag bases. Then you can make up some indicator holders for the lathe toolpost, and maybe one to clamp to the ways. For tramming the mill, all you really need is a piece...
by mrfoo
Sat Jan 18, 2020 7:22 am
Forum: General How-To & Discussion
Topic: "In the world of spuds today"
Replies: 2403
Views: 126208

Re: "In the world of spuds today"

The one I linked to has the benefit of the vise screw claming downwards, preventing the jaw from tilting when it is tightened. It's rather small though, 4"or 6" would be better. I do all my milling on the lathe, which means it's all a bit restricted in terms of space, I clamp onto a plate on the mi...
by mrfoo
Wed Jan 15, 2020 11:49 am
Forum: General How-To & Discussion
Topic: "In the world of spuds today"
Replies: 2403
Views: 126208

Re: "In the world of spuds today"

Nice. What's the milling machine?
by mrfoo
Fri Jan 10, 2020 10:34 am
Forum: SpudFiles Discussion
Topic: I see we have a new skin …
Replies: 25
Views: 1175

Re: I see we have a new skin …

So, to follow up on my previous "nitpicking". Here's screenshot of the "latest posts" display of a french-language machinists forum I'm on, with the screen shrunk down to about the 700px horizontal space the content gets here Screen Shot 2020-01-10 at 16.09.59.png And the latest posts here. Screen S...