Anyone doing any actual metalwork?

Last night I made a couple of inserts and did some machining on some suspension parts for a 'vintage' bike. The inserts were made to allow a crude external adjustment to low speed compression damping on a set of forks which originally had no adjustment.

Pete

in the garden.

welding to stabilize

I got with my

window awnings, and

on, you can't hear

I've been doing some cylinder sleeve jobs for snowmobile engines lately. Does that count? phil

Lately, I've been putting fine 60 degree points on 1/4 in. carbide threading tools. This done with the AccuFinish diamond sharpening system by Glendo (US made just across the river from KCMO) With AccuFinish1200 grit diamond you can get a 60 degree point that is is invisible to the naked eye looking straight in at the tip. Proof of the pudding done with my Sherline lathe threading attachment. Various pitches cut on 1/16 in. drill rod turned down to requisite diameter. Ultimate goal is to make some small taps and dies. I practiced cutting a lot of 0-80s and 00-90s. The finest Ilve done so far is a 00-350. That is 350 tpi on 0.034 diameter. Don't ask.

Bob Swinney

in the garden.

welding to stabilize

I got with my

window awnings, and

on, you can't hear

I've been doing some cylinder sleeve jobs for snowmobile engines lately. Does that count? phil

That would work. Don't have any chainmail in the closet, maybe a form-fitting grounded shield made of thin copper. It's just a matter of getting around to it.

Yes. My study concerned fields which are relevant to pacemakers as well as cardioverters.

Pacemakers and cardioverters seem to be rated to withstand AC B-field of 1 gauss and AC E-field of 1 kilovolt/meter. These ratings are probably quite conservative.

I found that E-field was not an issue in my shop with MIG (GMAW) and it wouldn't be with stick (SMAW) either. It can be with TIG (GTAW) using HF HV start.

I found the B-field in my situation to be well below 1 gauss at currents up to about 180 amps. A key parameter is how the leads are arranged. To minimize magnetic field the ground lead and "stinger" lead should be close together, even twisted, as much as possible. You want to avoid loops in the stinger lead, particularly close to your body and particularly in a plane where the axis of the loop goes thru your body.

I don't know what would happen if fields from a welder (or anything else) did interfere with operation of your pacemaker. That question would be best dealt with by your electrophysiologist. I did find the folks at Boston Scientific incredibly helpful. 1-800-CARDIAC

--Still getting Calliopus Minimus ready for 'prime time'; i.e. I'll be showing it off at the upcoming Makers Faire in San Mateo, CA. Working on tidy method of mounting electronics. Trying to figure out who makes a portable air compressor that isn't louder than my calliope!

Its cheaper to just have a photo of a good looking naked woman in front of you. It doesn't matter if the pacemaker stops, your heart will take care of itself.

Getting an education on lousy machining by using an optical comparator to look at and measure the fillet radiuses on a transmission shaft. Also learned to calculate the resultant stress concentration factors. Also learned that in some cases the Machinist was not the culprit. He did what the designer said via the drawings. Also Qualtiy Control, or lack thereof, let some dangerous botched machine operations slip thru. There are some good reasons for having time life limits on parts used in critical mechanical components. I'm searching for anyone who understands not just how, but also the why of the "4 pass graphic single plane balancing method". I'm surprised by the number of people who know how to use it but not the why the various parts are done. Finished construction of my steel racks for the storing of a bunch of steel angle, strap and tubes that I picked up for a song at a yard sale. Won't need to go to the steel supplier for a while.

Stu Fields

Been working rather furiously on a turned five part enclosure for an electronic instrument I'm designing. Got a proof of concept unit and a

3d modeled proto turned on my Jet lathe and had a real machinist make me 4 more preproduction units. Played around with Alodining the parts and painting them with bake-on phenolic resin paint.

Right now I have to work on finalizing the cad dwgs into a bid package and send it out. Anyone out there have a CNC lathe and want to bid?

Took time out Saturday to go to the Bay Area Model Engine club meeting...

Every time I want to get inspired to do good machining, I see what those guys are up to.

Looking at some old sheet metal designs that can be redesigned in 3D CAD and simplified.

Get one that's big enough, then make a sound-proofing box around it.

3/4" plywood, acoustic tile lining, and leave a labyrinth at both ends for cool air in and warm air out. And a box fan to ensure flow. And then park it outside and bring a few hundred feet of 3/4" air hose, because you can /still/ only muffle the sound so much.

An accumulator tank inside*right* before the calliope too. You need to recreate the big wind chest right below the pipes in a pipe organ.

-->--

Would metal window screen work? Make a denim/screen/denim sandwich and then sew up a jacket. I have a freind with an upholstry business that would do this very cheap if I tell her its for a freind.

Karl

Well there is two threads that if you marked ignore would kill 800 posts.

Outside of Cliffh and TMT, most of the people that post often not only have a point of view but know what they speak of. Not to single them out but JC and EH are a valuable resource. Gunner also has answered a number of metalworking questions and helped to connect various members of this usenet group with items they seeked.

Kill file the cross posters that get linked from the troll posts, mark ignore the threads that have devolved and your view of rcm will be will be though a fairly clean window.

I did touch my lathe (Clausing 6903)

as a witches tit. Felt good to touch the girl. Someday the grass will be green and the snow will be gone.

Wes

If MIG doesn't bother it, then TIG shouldn't, either. The electric field from the HF won't penetrate the body, as you are essentially a bag of salt water. The magnetic field of the main arc and cables does penetrate, but you have already shown that is not a problem. TIG generally has a pretty steady current on DC, but of course pulses on AC. MIG is just pulsing continuously as each bit of filler wire explodes. So, if a high-current MIG doesn't bother the gadget, I wouldn't expect much different.

I'd keep the TIG electrode and cable away from the chest area, but you probably already do that. I did manage to let a filler wire touch my shoulder once, and was surprised at how little of a bite it had. The sparks in the Argon shield gas look totally awesome, like a little plasma globe, so I expected it would have much more of a jolt.

Jon

Hey, it's metal.

On Wed, 25 Mar 2009 11:02:10 -0500, the infamous Don Foreman scrawled the following:

So just machine up a chain-mail-making-machine tomorrow morning, wot? Be sure to ground the arms together to avoid any nasty loops.

Hi Steve, I bit the bullet and bought a cheap stick/TIG welder/plasma cutter and am learning to weld. Well...that may be an exaggeration. I'm learning to make very bad seams, that's what I'm doing.

Also bought nomex coveralls to wear while welding. Only partly for fire safety. When I bought a VW bus many years ago, my friend Jeff gave me a pair of coveralls and insisted that I wear them while working on the bus. It seems that a pair of dirty coveralls intimidates the vehicle into thinking that a proper mechanic is working on it. I'm using the same kind of logic to improve the welds.

It's not working...

Best -- Terry

Hi Jim, where do you get bake-on phenolic resin paint? I have an application not at all related to painting...

Best -- Terry

I have not tried it with curves but I have made straight line transitions by cutting cardboard patterns for each side and cutting the metal oversize for laps. I bend the laps and screw or rivet together. If your patterns get cut undersize you can just tape another piece on where needed until you get it all how you want it. You can also make each pattern in more than one piece and tape together. I first did that to make a pattern for cutting flooring to go in a small bathroom.

I know there are more elegant methods.

Don Young