2018 POTD Thread Archive

[mksj]

Finished up on my ball/radius turner which mounts in my QCTP. I switched out the cutting insert to a 32.52 CCGT insert, the softer nose radius gives a much cleaner cut, almost no ridging at all (see below). The insert holder was machined from O1 steel and fits into a Shar's 3" boring head. I machined a knob that attached to the head screw adjustment so I am not fiddling with Allen wrenches when cutting the radius. There are adjustable stops to set the degree range of the radius, and there are a few tweaks to getting the correct insert angle/geometry in the head. Overall the cutting finish is better than I expected with the new insert. I did not run any lubricant, but will do so in the future to help prevent the insert from having metal stick to it. With the insert one needs to take smaller cuts on each pass, the 3/4" bar below took about 5 passes to cut the radius.


Radius adjustment knob.

Finish after the cut.

Insert holder.

 

[Boswell]

Finished up on my ball/radius turner which mounts in my QCTP

MSJH, that is an awesome looking radius cutter. Nice work.

 

[pdentrem]

Made a folding back rest for the rider.
After installing the new Corbin seat, the OEM back rest becomes too low for the rider to use comfortably. So the necessity is the mother of invention. First weekend of May we have a large swap meet at the local arena, 37th year! I and rider went looking for a larger back rest and found a nice one for $50. With a little trial and error for height, I made up a new mounting bracket which allow the back rest to fall forward, resting on the seat when not in use. The rider simply flips it up and sits down. Some may laugh but it works. Still have to paint the metal and put a small bend in the larger section so that it sits with a small back angle.

 

[JohnG]

I found this little Yankee drill chuckless in a junk store. I liked the heft and condition of what was there. It was about the price of a cup of coffee.



I wasn't going to hang a cheap Chinese chuck on it, so I found this vintage USA made Jacobs. A little threading on 2 ends of a piece of steel, and it all fit together. It's heavy, but to my eye it doesn't look awkward.

The app for this tool is spot drilling center punched marks with a #50 or so drill. I'm finding it easier to position this drill over a mark than to get a mark right under the drill in the drill press. I like to make jigs for wet grinding out of hard plastic, but it's soft enough that the drill won't draw into a punch if the alignment is at all off.

 

[Cadillac]

I have two of those that I have set with countersink bits and I use for deburring or chamfering holes after drilling. They work great acouple spins of the wheel and you get a perfect chamfer every time. Great ways to make antique tools work for modern times.

 

[dave_r_1]

Fixed the lights & wiring on a trailer I recently bought.

I don't understand it, but this is the second thing I've bought with lighting problems, where some of the connections are just stripped wires, twisted together by hand, then with a bit of tape over it. Huge surprise when the lights don't work...

I'll have to make time to improve the exhaust system from this post (https://www.hobby-machinist.com/thr...you-make-in-your-shop-today.67833/post-584122), as, while the exhaust doesn't directly blow onto the fuel tank on the GX270, it does pass by close enough to heat up the top of the tank more than I'd like. The muffler has support for bolting on an attachment to redirect the exhaust in various directions, but I'll fashion a short, straight exhaust pipe to bolt on, to keep the exhaust contained while going over the gas tank.

 

[dulltool17]

I don't understand it, but this is the second thing I've bought with lighting problems, where some of the connections are just stripped wires, twisted together by hand, then with a bit of tape over it. Huge surprise when the lights don't work....

Unfortunately, most folks aren't familiar with Butt splices or dead-end connectors

 

[BGHansen]

POTD was making a bushing to mount Scotch-brite buffing wheels on a 6” bench grinder. Won a pile of these wheels off eBay. A lot of my work involves brass turning; polishing by hand was getting old so took a chance on some powered wheels.

The wheels have a 1” ID hole, bench grinder a ½” arbor. Pretty simple project, chucked up a 1” aluminum round, dialed it in to less than 0.001” run out with my set tru chuck. Center drilled, drilled and reamed the ½” hole. Probably overkill since the wheels are really light so not a lot of balance issues even at 3450 RPM. Parted and faced the other end.

By the way, really like those Scotch-brite wheels on a grinder. I have them in difference “grits”, the fine bring out a really nice finish in a few seconds.

Bruce

 

[BGHansen]

POTD was making a holder for small parts going to the bench grinder for deburring. I make parts from 5/16" diameter brass and parting on the lathe leaves a burr on the end of the parts. I had been deburring the ends by setting the parts on a drill bit (most have a central hole) and sanding them with a 2 x 42" sander. Then buff the end with a Scotch-brite pad.

I picked up a box full of Scotch-brite buffing wheels off eBay (see POTD above) which would do the deburring a lot quicker. Problem is how to safely hold onto the small parts without launching them across the room and smoking the ends of my fingers as the parts heat up.

Made a holder from a piece of CRS. Drilled and reamed an over-sized hole for the OD of the brass parts (5/16"). Holder has a knock-out pin made from 5/16" CRS with a shoulder for setting the parts onto.

It works really well! Set a part on the sliding pin, slip it back into the outer sleeve, deburr on the wheel and knock the part off by pushing out the center pin.

Bruce

 

[RJSakowski]

Fixed the lights & wiring on a trailer I recently bought.

I don't understand it, but this is the second thing I've bought with lighting problems, where some of the connections are just stripped wires, twisted together by hand, then with a bit of tape over it. Huge surprise when the lights don't work...

I have been wiring trailers for almost fifty years. After maybe a dozen years of dealing with the frustration of poor connections resulting from point contact connectors I began soldering all connections. IMO and backed by my experiences, mechanical connectors, water, and road salt don't play well together.

If I am splicing two wires together, I will strip about 3/4" -1" of insulation and slop a 2" length of heat shrink over one wire. I then tightly twist the two wires together with the two ends facing each other, working the twist to compact and smooth it and trimming any excess wire. I then solder the splice, tape it with electrical tap, and slide the heat shrink over the splice to lock the tape.

If it is a tee type splice into an existing wire, I cut the existing wire and lay the new wire along side of one of the existing wires. The heat shrink goes on the pair of wires.

If there is a black oxide coating on the wire, common for old wires, I dip the tip of the wire in muriatic acid. This removes the oxide coating instantly. I rinse the acid off with water and dry with some paper toweling. The heat from soldering will boil off any remaining acid. For naysayers that will quore never using an acid flux fir electrical soldering, that pertains to the zinc chloride flux commonly used for plumbing work. Zinc chloride is a salt and will not vaporize so it continues to eat away at the copper.

I have gone one step further to pulling apart the light housings and soldering the internal connections. Recently, it seems that manufacturers are using point contact connections.

In more than thirty years, I have never had a soldered trailer connection fail. This includes multiple boat trailers where the connections are immersed in water.