Thread: Your latest project

Originally Posted by SurfinNev

Never try to burn powder coat of alloy with a gas torch. The alloy melts before the powder coat burns. Don't ask how I know that.

Even the fast forming oxide on Aluminium melts at a higher temp than the base metal - hence the need for aggressive flux, or “AC” on TIG/MIG.

"Even the fast forming oxide on Aluminium melts at a higher temp than the base metal - hence the need for aggressive flux, or “AC” on TIG/MIG."

Think you might have missed the point SurfinNev was trying to make. We were talking about using Oxy. Tig certainly makes ali welding much easier, much more control over all the variables.
If the stainless is going gray using the tig then its too hot or your not moving fast enough. With the mig it never looks as good, usually dull silver.

Cam.

Originally Posted by Bigcam

"Even the fast forming oxide on Aluminium melts at a higher temp than the base metal - hence the need for aggressive flux, or “AC” on TIG/MIG."

Think you might have missed the point SurfinNev was trying to make. We were talking about using Oxy. Tig certainly makes ali welding much easier, much more control over all the variables.
If the stainless is going gray using the tig then its too hot or your not moving fast enough. With the mig it never looks as good, usually dull silver.

Cam.

Thanks.
I understood the point. I’ve tried to weld ally with a Dillion Oxy/Acetylene rig, and aggressive flux. Never had much success. The TIG is certainly easier.

I’ve read the “grey” on Stainless is too much heat. I’ve been experimenting, and if I turn the current down any more it won’t form a pool. I’ve tried turning it up, and traveling as fast as possible - still looks like I’m burning it. The only time I’ve managed the rainbow colouring is with “pulse”, no filler, shallow penetration and pretty fast travel. More practice/experimentation.

Used a divider between the jaws to scribe the mid points, then drilled four 8mm-ish holes in the chuck:
IMG_1633.jpg

Then started machining some spacers. About 15mm long:
IMG_1634.jpg

Had lots of problems parting these off. The steel is tough - forged 4140, so I was taking my time and being careful.

However, my little MGEHR1212-2 parting insert holder was just twisting, vibrating, and generally killing inserts. The outside of the steel stock was hard, but after the first mm or two, progress varied. It would cut OK in places, making nice tight little snails, until it would often jam or sieze the spindle.

Generally, the only way to keep cutting was to pull back and machine extra side clearance.

In the end, after killing 3 inserts, I used a hacksaw to cut the majority of the diameters.
IMG_1651.jpg


Instead of drilling the centre of the spacers out to clear 8mm bolts, I actually tapped them to M8 coarse, so they could be bolted to the faceplate for easier assembly:
IMG_1654.jpg


Was considering seperate bolts front and back, but decided long bolts would help me mount the chuck on. Only hard part was finding socket screws that were all thread.


Here I am, about to torture test the chuck with a nasty interrupted cut:
IMG_1655.jpg


It survived - still bolted securely to the face plate

This is basically a copy of the one Joe Pie made in one of his videos. I made some Sketchup drawings if you want to make one the same. I made mine from 10mm W1. Only because I have 5m of it! I didn't harden it. Do you think I should?

Picked these up at the op shop recently , metal cabinet/drawers and the lockers . The price was too good to leave them there !

I will make some shelving for the lockers . Reminds me of the lockers we had at High School.

Dropped my plunge DI a few months ago. The plunger binds badly. Finally worked up the courage to open it up and try to repair.

Assuming the shaft is bent, first thing is to see by how much.


1. Open it up, bolt to the mill, and use a different DI to align it:
IMG_1672.jpg

to dial in the inside of the plunge shaft, and then to check the protruding bit:
IMG_1675.jpg

Left to right was good, but the shaft kicks up about a thou.



2. Applied some finger pressure to bend, but that was worse when sliding in the sleeve,
so I tried tapping the end of the sleeve to straighten it.

Basically, inconsistent improvements, so out the shaft came:
IMG_1677.jpg

I was rotating to find the high spots, but it was very hard to find straight bits to locate in the V block.
(middle section has a flat ground either side of the teeth)


After a while doing this, I thought of the lathe. Between centres should be easier, right?
WRONG. After putting shaft b'twixt centres, there was over 3 thou of wobble!

Here is why:
IMG_1676.jpg

Looks like a new MT3 centre, locates like a new MT3 centre, wobbles like a banana


3. Back to the V blocks. Half an hour later, I deduce 1.5thou total wobble, and decide that isn't enough to really jam the shaft.


4. Spend another hour manipulating the sleeve. Stainless tube with brass/bronze is hard to bend straight. To get it sliding smoothly, I had to drill out the outside few mm of the sleeve from 4.5mm to 4.6mm, and "file" some of the step using the teeth on the shaft. A cordless drill turning the shaft helped
(The horror )


5. Assemble the gears back together, have to re-do that a few times to get the starting points and needle spring tension correct, spend a while sliding in and out a few hundred times, re-assemble fully.



Anyway, after spending half a day repairing a $20 DI,
it is now useable, but will slightly jam if there is too much sideways load on the tip.


Luckily, a new one arrived in the mail:
IMG_1658.jpg
along with a HSS spot drill set

Someone gave me a little machined MT2 arbor thingy:
IMG_1659.jpg

It has a 1/4" hole at the front. Just the thing for holding a spot drill !
(without having to put it in a chuck each time)


The hole is only about 3/8" deep, so I drill it through with a 6mm drill:
IMG_1660.jpg

then attempt to use the 1/4 spot drill to finish it to size:
IMG_1661.jpg


Sadly, that was too much material to remove. It started jamming, so drill through using a worn out (undersize) 1/4":
IMG_1662.jpg


It didn't quite drill on-centre:
IMG_1663.jpg


but that doesn't matter. Mount the spot drill in it, and test alignment:
IMG_1665.jpg


Seems OK. Only problem now is getting it out of the tailstock. It needs to be longer.


Drill a little of the tail out for M8. 17/64 is close enough:
IMG_1666.jpg


Tap it. Was a bit hard going. Should have used lubricant:
IMG_1667.jpg


Finished hacky tool:
IMG_1668.jpg IMG_1671.jpg

Originally Posted by morrisman

Reminds me of the lockers we had at High School.

Wow, that must have been a pretty flash high school. No such luxury at the school I went to. Had to carry everything with you in your school 'Port" No backpacks then either.
Peter

This is my latest project, waiting for your comments! thanks

DSC03862.jpgcraft channel out2.00_02_27_07.Still038.jpgcraft channel out2.00_02_29_34.Still039.jpgcraft channel out2.00_02_07_11.Still033.jpgcraft channel out2.00_00_55_33.Still012.jpgcraft channel out2.00_00_18_19.Still004.jpg

Wow. Nice work Scooby!

Did you hammer parts into wooden moulds or bucks?

Originally Posted by scoobyz

This is my latest project, waiting for your comments! thanks

DSC03862.jpgcraft channel out2.00_02_27_07.Still038.jpgcraft channel out2.00_02_29_34.Still039.jpgcraft channel out2.00_02_07_11.Still033.jpgcraft channel out2.00_00_55_33.Still012.jpgcraft channel out2.00_00_18_19.Still004.jpg

Beautiful work mate

Sent from my 5007U using Tapatalk

An old drawer has a lot of damaged old drill bits. Mostly reduced shank ones that have spun badly in many chucks over the years. These are all way too bad for dressing with a stone, but I hate grinding the dags off these (always seems to make a big flat spot, no matter how careful I am). So, 'twas time to try turning down in a lathe:
IMG_1688.jpg
that one had a weird groove in it - no idea why someone put that in it. Here is a more normal one:
IMG_1691.jpg

Started in the Hercus (to use its crappy old chuck, that is OK to clamp down on rough drill spiral flutes), but the rigidity wasn't there. I could either have deep inaccurate cuts, or shallow rubbing "cuts" that started to dig in and cut properly when getting closer to the chuck.

The hardest part about this was centering the drill accurately in a 3 jaw chuck. Some of the larger diameter shanks were still long enough to have the original centre drilled in them, but most didn't, and some shanks were bent so much that the drilled centre was worse than just machining it hanging out of the chuck!

Also, one had over 1/16" of circular wear in the reduced shank! It got slightly reduced in diameter, and then the damage was lopped off with diamond cutoff wheel in angle grinder.


This was my first experience machining HSS. It was a bit rough on my Carbides. Interestingly, my "roughing" TNMG 160402 inserts (positive rake) did better than anything else - in terms of surface finish and machining accuracy - but each fresh tip corner only lasted for 2 or 3 reduced shanks.



Note that one of these drills is a real antique:
IMG_1692.jpg

The inscription reads: 3/4 High XtX Speed Openshank Sir V? O? Armstrong Whitworth & Co. Ltd. Manchester





Other task was to true up a Quick Change Tool holder. When parting some hard steel a few weeks back, I noticed that my toy parting insert holder was twisted in the cut. Looking closer at the holders:

IMG_1689.jpg
1. Vs to slot is parallel, but:


IMG_1690.jpg
2. When a tool is tightened in the slot, it kicks over a little. 5 thou for 1/2" tool, maybe 1 degree of rotation?


These holders' tool grooves look like they are just milled out. The bottom (in this view, which becomes the side when slid into the tool post block) is parallel, but the left (which becomes the bottom) is not square.

I spent some time filing the corner out with a triangular file, which helped a little, then trying to file the left side square. Only got part way. Thought about surface grinding, but I have never side ground anything before.


In the end, decided to just shim the outer edge. Two layers of 0.05mm shim stock got it mostly correct.

This won't eliminate twisting under load, but it least it will start on a more solid footing?

Hi Nigel, Guys,

Re the parting blade canting issue. This is probably because the blade is tapered and the top edge probably has a slope on it. In which case it is going to be difficult to hold and keep the blade square and secure. You might recall I suggested modifying a tool holder by putting in a slot that the blade could be slid into that would ensure that the blade was held square whilst being clamped.

Since the tool holder is likely to be hardened, it might be better to make a dedicated holder from MS and clamp the blade from the top or side.

Originally Posted by BaronJ

parting blade canting issue. This is probably because the blade is tapered and the top edge probably has a slope on it

Images above were just me using 1/2" square HSS in QCTP holder to test alignment.
I don't actually have a parting "blade", or holder, though if I ever do a rear toolpost, that is what would go there.


i.e. I was measuring the flat steel side of the holder, not the blade/insert it holds.
(Unless its a bad day, Baron. I have been known to do stupid things like that )




This is the toy - a tiny moulded carbide insert. MGMN200. Insert is 2mm wide at top edge, holder nominally 1.5mm wide underneath it:
9568255E-BAFC-4560-87C9-67285F03A335.jpg
When I was having problems parting, one of the edges on the right side of this holder was scraping* in the parted material. Can't remember now if it was the top or bottom edge, but that prompted me to look into the squareness of the QCTP holder that was clamping this holder in place.


Basically, insert has very little steel under it, so twisting under heavy load is definitely going to occur in several axes.

I'm assuming that when the QCTP holder was starting it off twisted by 1°, it would have less chance of cutting well?



(* unless the scraping was from the swarf, and I am wrong about 1° making any difference whatsoever over 12mm height in the cut)