What did you do today?

[Jim Stewart]

Hadn't thought of that. Never used helicoil. How's it hold in aluminum? Thin walled stuff.

Ummm, not sure what you mean about thin walled. You said there was enough meat around the hole so you could tap it at 1/2", right? That's more than enough.

A helicoil kit comes with a drill and a tap. Once you've tapped the new hole (probably a bit smaller than 7/16"), you insert the helicoil - its OD matches the newly tapped hole, its ID is a perfect 3/8".

I've installed dozens of helicoils in aluminum motorcycle cases. Easy and long lasting.

-js

[lakeside53]

also look up Timesert... they are are my favorite.

[MrFluffy]

I think by thin walled he means the thread isn't very deep. Also controversy time, helicoils are stronger than timeserts. I didn't want to believe it ether, how could a bent wire jammed in a hole be stronger than a really nicely made machined insert. But seems each coil in the helicoil spring distorts and spreads the pull out load between coils. So a helicoil has a much higher pull out force than a timesert in formal lab testing as a result.

But... Darren can just tap it bigger and work around it with no grief, I'd take that over fiddling round with inserts any day of the week.

Today I stripped the turbo from my landrover 90's 19j turbodiesel engine, it ran away on turbo oil about 8 years back when the original turbo failed, and this unit was scarfed up out of junk in the junkbox with a mismatched core/housings/impellers. I'm surprised its lasted so long but it had started leaking oil into the intake pretty bad of late and I don't want another runaway when the bushings collapse. Especially since last time a slipping clutch meant I couldn't stall it out, so I just had to retire to a safe distance while it screamed blank smoke at insane rpm's expecting it to rain pistons and conrods until eventually it made this sad bark and shut off. Amazingly the engine survived this and with a replacement turbo core and fluids changed it passed emissions 8 times since.

So back to this turbo I cleaned it in the parts washer then took the housings off. One bolt on the hotside sheared off when disassembling but 0.25mm/0.010 of axial endplay with max play listed as 0.15mm/0.006" and a large amount of radial play, 1mm/0.04" against a book spec of 0.1mm/0.004" say its dead.
Its a oddball TB02 garret, as already the impellers aren't matched to the housings I think I want to get a whole good s/h untampered with replacement turbo from a running vehicle and rebuild the core for it with new bushings and piston seals. Fingers crossed its not something worse inside the engine also, or that will really start to suck.

[vpt]

I think by thin walled he means the thread isn't very deep. Also controversy time, helicoils are stronger than timeserts. I didn't want to believe it ether, how could a bent wire jammed in a hole be stronger than a really nicely made machined insert. But seems each coil in the helicoil spring distorts and spreads the pull out load between coils. So a helicoil has a much higher pull out force than a timesert in formal lab testing as a result.

Possibly in a one time use. But if the bolt need to be pulled and put back in numerous times over its life a simple helicoils usually don't hold up. A timesert is common in aluminum even when the part is new, to hold up to a bolt being in and out of the hole many times. I have done timeserts in aluminum engine blocks and transmissions quite a few times and they always work perfectly. I have used and watched others try to use helicoils in the same situations and the helicoil just pulls out of the aluminum.

Ford triton motors with their spark plugs failures is a good example.

[Willy]

Another vote for Timeserts. Helicoils are good, Timeserts are better.

http://www.timesert.com/

Originally Posted by MrFluffy
Today I stripped the turbo from my landrover 90's 19j turbodiesel engine, it ran away on turbo oil about 8 years back when the original turbo failed, and this unit was scarfed up out of junk in the junkbox with a mismatched core/housings/impellers. I'm surprised its lasted so long but it had started leaking oil into the intake pretty bad of late and I don't want another runaway when the bushings collapse. Especially since last time a slipping clutch meant I couldn't stall it out, so I just had to retire to a safe distance while it screamed blank smoke at insane rpm's expecting it to rain pistons and conrods until eventually it made this sad bark and shut off. Amazingly the engine survived this and with a replacement turbo core and fluids changed it passed emissions 8 times since.

.



When you get things back together think about installing a simple cable operated air shutoff in the air intake system. These types of emergency engine shut-down systems have saved the day for me on at least two occasions. Once while pumping gasoline into a large storage facility. Gasoline fumes entered the air intake system of my truck sending engine rpm through the roof. I had 11,000 gallons of fuel onboard pumping into a 300,000 liter storage tank, I did not need a fire!

[danlb]

I had to make a part for my car.

It seems the plastic insert in the passenger door panel which has the interior handle has a flaw. It has one screw holding it to the door. The bottom of the insert has a depression the size and shape of a fingertip with a hole in the bottom for the retaining screw.

After only 16 years the bottom of that depression fractured all the way around, leaving the door handle unattached with a 1/2 inch diameter hole in the bottom.

The fix was to make a large Delrin washer with a standoff in the middle that matched the size of the hole that was left when the bottom broke out. The standoff will handle the pull of the handle as it's closed. The washer will spread out any upward forces. It works fine.


Even more impressive, for the first time since I bought the 9x20 lathe I've taken all the QCTP tools out of the chip tray and moved them to a drawer in the chest a couple feet away. That's only 7 years.

Dan

[PStechPaul]

I received some things from Banggood on Monday.

A set of miniature carbide milling bits, 0.8 to 3.0 mm, $5:


A set of five indexable boring bars with six inserts, 6, 7, 8, 10, and 12 mm, for $20. This is the smallest one:




Haven't used them yet, but they look pretty good.

I also got a mini wireless keyboard, $12, from AliExpress. It works pretty well, but difficult to type very fast. The touchpad works better than I expected.


Other than that, I tried to accept a quote for $100 to have my car towed to a junkyard, through LKQpickYourPart Auto Salvage, but the quote was good for only 1 week. I had called November 24 and called back December 3 (9 days), and they requoted it for $5! So I also had called JunkCarMedics, and they sent me a quote for $70. I called Buzzy Shamer, who said he might be able to pick up the car for $100 on Thursday, but he always seems to be really busy. He also does repos and said he was at the courthouse to deal with someone who threatened him about a tow, and he was waiting to get approval to enter with a concealed weapon. Hmmm...

Today (actually Tuesday) I got a text from someone who offered me $100 for the set of four almost new tires and wheels I've taken off the car, but he is coming from Philadelphia (~100 miles). I agreed to meet him in Aberdeen where I will also pick up a load of compressed wood blocks at Tractor Supply, and it's about 75 miles from there to Philly, right off I95. Then I got another email from peddle.com (through JunkCarMedics), for $130, so it looks like I'll go with that. I'll be glad when this rigamarole is over and done with!

[MrFluffy]

I don't really think this is machined, but I ran off some test pieces on my new toy, a chinese 40w laser cutter. After keyrings and engraved pictures etc, I thought I'd test it for the reason I wanted it, making gaskets.

Came out pretty good with no extra work. This is not a real gasket just a cad file I had lying about to save drawing one from scratch. I *could* do this with a craft knife and hours of work, but once I have a gasket drawn up, I just put some gasket paper in and press go.


New toy justified...

[Noitoen]

I got me one of those lasers a few years ago. After a few cuts it started to weaken for no apparent reason. Checked out, it was smoke from the cutting that had covered the lens. After I built the air assist, the problem went away. I also also changed the mirrors and focus lens and it turned into a new machine. Most of the power was being absorbed by their cheap optics.

[MrFluffy]

Yeah, they need a bit of tweaking for sure. I'm already going to replace the stupid clamp with a mesh bed arrangement, and I ordered a fish tank aeriation pump and some little laser lines to make a sight/air assist for it but it hasn't arrived yet. I had to seal the exit fan on with duct tape and its a pretty poor match to the port too so that might be being made betterer shortly. Its also got no laser interlock safety switch on the lid like it was supposed to have but nothing I cant add easy, and it could do with a water flow sensor. I also read they're a 35w max tube being overdriven, and if you fit a real 40 or 50w tube, they don't fit inside the cabinet and need a better psu. So that might be in its future too.
Maybe I'll get some better quality lens and mirrors for when I swap over to the bed too, I've heard mention of that before. Right now I'm just using it as it came out the box to make sure it all worked in the period where I could send it back if not. Well, apart from using k40whisperer to control it and inkscape to prepare and colorise the svg's, as I run linux, which is great software.
It is a case of "hey its $400 for a laser cutter!", no regrets with it yet, eyes wide open going into this.

[Zahnrad Kopf]

Yeah, they need a bit of tweaking for sure. I'm already going to replace the stupid clamp with a mesh bed arrangement, and I ordered a fish tank aeriation pump and some little laser lines to make a sight/air assist for it but it hasn't arrived yet. I had to seal the exit fan on with duct tape and its a pretty poor match to the port too so that might be being made betterer shortly. Its also got no laser interlock safety switch on the lid like it was supposed to have but nothing I cant add easy, and it could do with a water flow sensor. I also read they're a 35w max tube being overdriven, and if you fit a real 40 or 50w tube, they don't fit inside the cabinet and need a better psu. So that might be in its future too.
Maybe I'll get some better quality lens and mirrors for when I swap over to the bed too, I've heard mention of that before. Right now I'm just using it as it came out the box to make sure it all worked in the period where I could send it back if not. Well, apart from using k40whisperer to control it and inkscape to prepare and colorise the svg's, as I run linux, which is great software. It is a case of "hey its $400 for a laser cutter!", no regrets with it yet, eyes wide open going into this.

Just amazing where our industry has gone. I started out in the waning era of Cincinnati & Kearney & Trecker Horizontal Mills, Warner & Swasey lathes, Acme Gridley, Davenport, & Brown & Sharpe screw machines and am now in an era of multiaxis as standard milling, turn/mill machines as standard, and 3D printing and laser as common. CAD/CAM has gone from $100K to free. I wish they could do as much with lasers for marking steels. If I could find a laser to mark our parts for any kind of money like that, I'd buy it post haste!

[MrFluffy]

Maybe you should look at Cermark paste Zahnrad. They claim really nice consistent results at 60w. Although being a complete cheapskate and with only 40 chinese watts* at my disposal, I've ordered some dry moly d spray, as you can get similar effects at certain combinations.
Spraying the part with moly/cermark puts a surface coating that the laser embeds into the steel, rather than cutting into the steel itself properly. They have nowhere near enough power for that.
Someone doing comparison runs... :-

https://youtu.be/5ziyB9EEnL8?t=351

Its something I'll be experimenting with when my spray can turns up


* chinese watts are as we all know smaller than everyone elses.

[Zahnrad Kopf]

Maybe you should look at Cermark paste Zahnrad. They claim really nice consistent results at 60w. Although being a complete cheapskate and with only 40 chinese watts* at my disposal, I've ordered some dry moly d spray, as you can get similar effects at certain combinations.
Spraying the part with moly/cermark puts a surface coating that the laser embeds into the steel, rather than cutting into the steel itself properly. They have nowhere near enough power for that.
Someone doing comparison runs... :-

https://youtu.be/5ziyB9EEnL8?t=351

Its something I'll be experimenting with when my spray can turns up
* chinese watts are as we all know smaller than everyone elses.

I am VERY interested in hearing about your results, Sir. Even offline. You have my personal email. Thanks.

[Noitoen]

* chinese watts are as we all know smaller than everyone elses.

I'm very surprised with it. I can cut 10mm acrylic and 12mm plywood (depending on the glue) in 3 passes.

[RichR]

... I wish they could do as much with lasers for marking steels. If I could find a laser to mark our parts for any kind of money like that, I'd buy it post haste!

I remember Sir John posting about laser marking steel. Here are 2 of his posts. There may be more useful information elsewhere in those threads:

http://bbs.homeshopmachinist.net/threads/65526-Laser-engravers-cutters-aka-china-variety?p=957221#post957221

http://bbs.homeshopmachinist.net/threads/65555-Laser-head-to-mount-on-mill-for-engraving-etc?p=957907#post957907