2015 POTD Thread Archive

[savarin]

I enlarged 4 holes in a circular saw blade so I could bolt it to a face plate,took a bit of time to ensure it was centred spot on.
Then bored the 19mm centre hole to fit the 25mm mandrel of my table saw.
Then used it to cut 1x60mm square and 1x90mm square from some 12mm thick aluminium plate.
I expected the saw blade to be harder than it seemed to be.
Now have the squares turned to circles ready to make into end caps for the telescope and finder end caps.

 

[bpratl]

Brian, you did a first class restoration on that transit, thanks for sharing. Bob

 

[jrstech]

Over the last week, been pretty busy in the basement putting things back together after the minor flood from the fridge filter. Finished mudding, taping, sanding and painting the old location for the bathroom door (was in workshop - now in hallway), re-plumbed the bathroom, moved 4 receptacles to a more convenient location in the workshop, (i.e. not behind a storage cabinet), installed 4 ceiling led pot lights in hallway, 1/2 the drywall was put up in bathroom, etc.. etc...
As for the machining related activities, I turned two blanks (from 1045) for a pair of helical gears - a 19 tooth and 123 tooth gear. They are presently at True Gear getting cut and should be ready for pickup today.




Drilled a couple of ball bearings and made a new handle for this small vise.





Cut and drilled a block of wood to hold all those small tools that you use repeatedly and can't find underneath the mess on the bench. Still have to mount the ruler and thread gauges.




Picked up a couple new 1" tool holders at a give-away price and machined them to fit my AXA holders.




Picked up a solidly built dividing head and matching tailstock. Unit is a Cat 50 style and he threw in a holder I can mount a chuck/faceplate to. Only identifying marks I can see so far are "Modern Toronto" . Unit feels like it is around 100 lbs. I'll clean it up this week and repost the pics.

 

[Charles Spencer]

I don't have a cannon. :-(

Well then, here you go:

http://www.instructables.com/id/Black-Power-Mortar-full-scale/

 

[road]

Over the last week, been pretty busy in the basement putting things back together after the minor flood from the fridge filter. Finished mudding, taping, sanding and painting the old location for the bathroom door (was in workshop - now in hallway), re-plumbed the bathroom, moved 4 receptacles to a more convenient location in the workshop, (i.e. not behind a storage cabinet), installed 4 ceiling led pot lights in hallway, 1/2 the drywall was put up in bathroom, etc.. etc...
As for the machining related activities, I turned two blanks (from 1045) for a pair of helical gears - a 19 tooth and 123 tooth gear. They are presently at True Gear getting cut and should be ready for pickup today.

View attachment 114588


Drilled a couple of ball bearings and made a new handle for this small vise.

View attachment 114589 View attachment 114590



Cut and drilled a block of wood to hold all those small tools that you use repeatedly and can't find underneath the mess on the bench. Still have to mount the ruler and thread gauges.

View attachment 114591


Picked up a couple new 1" tool holders at a give-away price and machined them to fit my AXA holders.

View attachment 114592 View attachment 114593


Picked up a solidly built dividing head and matching tailstock. Unit is a Cat 50 style and he threw in a holder I can mount a chuck/faceplate to. Only identifying marks I can see so far are "Modern Toronto" . Unit feels like it is around 100 lbs. I'll clean it up this week and repost the pics.

View attachment 114594 View attachment 114595 View attachment 114596 View attachment 114598

How many dividing heads is that now ? 3 or 4 ?

 

[RJSakowski]

Am starting to get the hang of drilling using the small lathe (Hercus 9") - go steady - clear the hole regularly - use cutting oil.

Needed to drill a 1/4" hole through 13.5" of black bar - had to go half way from each end and was absolutely chuffed when they met in the middle. Am able to slide a 1/4" rod all the way through and not feel any "step"

Got the rough bar between centres initially to turn it parallel and cylindrical.

Wrapped one end in kitchen paper and stuffed it through the headstock so that the loose end wouldnt rattle around inside the headstock bore - and gripped the other end in the chuck.

Centre drill - then 1/8" x 2"- then 3/16" x 2"- then 1/4" x 6 3/4" - lucky I happened to have an extra long 1/4" drill - approx 1/4" "pecks" and clear the flutes each time - didnt take very long - was quite surprised.

After a few inches of drilling, loosened the chuck and advanced the workpiece so that the drill was always drilling through the part gripped in the chuck jaws.

After 6 3/4" turn the workpiece end for end.

Gently honed the 1/4" drill by hand with a diamond plate before using it.

Am truly astonished that it was possible to do this - I guess in 5 years time I will take it for granted, I dont think I could have done that with a piece of wood when I was interested in woodwork.

Is it simply the nature of the lathe that the holes drill straight down the middle without deviating ?


Bill

It has long been my feeling (nothing to support it) that drilling a hole with a stationary drill and rotating workpiece was more accurate than the alternative. If you notice, a center drill which makes first contact slightly off center will find the center.

Drill wandering on a lathe does occur and once it starts, it tends to get worse. Uneven cutting edges on the drill can cause it, as can coming in at an angle. Basically, unbalanced forces.

 

[RJSakowski]

All I know, it's a magic box. I just know that all the LED lamps I've seen have some sort of circuitry that filters or conditions the power to them.

LED's (and all other solid state diodes) have a property where the voltage drop across them will decrease with increasing temperature. If some sort of current control is not use, they go into a thermal runaway mode and self destruct. The simplest way of controlling the current is to put a resistance in series. When the current starts to increase, the voltage drop across the resistance increases, reducing the amount of voltage available to the LED.

The strip lighting which is becoming commonplace of late uses this technique. Typically, three LED's are connected in series and in series with the resistor. White LED's have an operating voltage window of about 3.0 to 3.5 volts so three in series gives a nominal voltage of about 10 volts. The resistance drops any remaining voltage. The strips that I have used will operate from about 11 volts to 14 or so with increasing current and brightness as the voltage increases. Somewhere above 14 volts, the LED's are being over driven, shortening their life.

LED's can also be operated on ac current, using their property as a diode rectifier. The now ubiquitous LED Christmas lights will series wire some thirty or so (for 120v.ac) without any additional circuitry.

Another method of driving LED's is using and active driver which contains electronic circuitry to set the drive current. This type of driver can typically operate over a large input voltage range. Some that I have used can have a 25 volt operating swing. Active drivers are also available in a boost configuration, where they increase the output voltage, and for operation on ac power, in which case the module has a built-in rectifier. Many of them also have provision for dimming, either internally or externally.

Bob

 

[jrstech]

How many dividing heads is that now ? 3 or 4 ?

New (to me) dividing head , two indexing heads, rotary table, small collet indexer, all different and provide similar yet different functionality. Can't ever have enough tools. Might need to build an extension "tool shed" for the garage just to store tools.

 

[Franko]

LED's (and all other solid state diodes) have a property where the voltage drop across them will decrease with increasing temperature. If some sort of current control is not use, they go into a thermal runaway mode and self destruct. The simplest way of controlling the current is to put a resistance in series. When the current starts to increase, the voltage drop across the resistance increases, reducing the amount of voltage available to the LED. ...
Bob

Thanks, Bob. It is all perfectly clear to me now.

 

[zmotorsports]

Last night I got the Jeep ready for our monthly Jeep club trail run. I pulled the Jeep in the shop and checked the fluids and ran a vacuum through it.


I then put it on the lift and gave the undercarriage a good once over.


A few months ago I machined a base plate to mount a 3-jaw chuck to my 8" Vertex rotary table for a project. I had to improvise to mount the chuck as I didn't have any T-nuts that were the correct size. I didn't want to place an order for only four T-nuts so I just decided to machine them.

I had some time left over last night before the wife got home so I grabbed a piece of bar stock from my scrap pile and clamped it in the mill vise.


Taking it down to size.


Now that it is to size I can drill/tap the threads and take the two sides down.


Hopefully tonight I can take a half our or so and finish them up.

Mike.