POTD- PROJECT OF THE DAY: What Did You Make In Your Shop Today?

[extropic]

You need to add some back rake to the tap . Just a little. You can grind it, sand it. 10 thou for cutting plastic should be enough.

so you are saying off center, toward the back end of where the rake would be

I think you are using the wrong terminology. I think the correct terminology is CLEARANCE, back clearance or radial clearance.
Rake is the angle of the cutting plane relative to the center axis of the tap. The slots that @WobblyHand cut provide quite a bit of positive rake.
Back clearance, or radial clearance, is created by the thread form of the tap decreasing in radius behind the cutting edge. The lathe cut, single pointed thread form creates essentially zero variation in thread form radius. The purpose of back clearance in a tap is to eliminate unnecessary friction and resultant heat. Friction and heat are not significant factors in WH's project.

 

[francist]

Nice job @WobblyHand! I can see that working very well for what you needed it for.

A while back I made a similar one although quite a bit smaller -- somewhere in the range of #7 x 40tpi -- to clean out some gunked holes in a machine casting. To cut the flute I used the corner of an endmill so I got the one leading face at about ninety to the cut and the other trailing edge quite a bit shallower. It also worked well although pound for pound there was more gunk vs flute capacity so it tends to clog easily. Still works though. I did a short post on it here...

2020 POTD Thread Archive

@GoceKU - I really have to admire the quality and thoroughness of your work. You make it both functional and good looking, and I'm sure you'll be proud of it every time you make use of it. Thanks again for showing us how it's done! Thank you for the kind words, i'm a big believer if your making...

www.hobby-machinist.com

 

[WobblyHand]

I think you are using the wrong terminology. I think the correct terminology is CLEARANCE, back clearance or radial clearance.
Rake is the angle of the cutting plane relative to the center axis of the tap. The slots that @WobblyHand cut provide quite a bit of positive rake.
Back clearance, or radial clearance, is created by the thread form of the tap decreasing in radius behind the cutting edge. The lathe cut, single pointed thread form creates essentially zero variation in thread form radius. The purpose of back clearance in a tap is to eliminate unnecessary friction and resultant heat. Friction and heat are not significant factors in WH's project.

There's no clearance behind the cutting edge, so everything behind the edge is contacting the thread, increasing friction, but the cutting edge has loads of positive rake. Hope's this makes it clearer. Edit: 14 degrees of positive rake.

 

[ggbutcher]

Just joined, second post...

Staring at that indicator I posted about on the "what did you buy" thread, needed to figure out how to use it. Gotta let the budget settle a bit before I buy something, so I thought I'd make a first project of a chuck mount for it:



Don't zoom in too close, many scratches and gouges from workholding. It's aluminum rod and bar, slotted with an end mill, drilled with a twist drill, and turned down to 1/4" for the chuck. I eyeballed a lot of it, getting the slot and screw hole at right angles was the most critical, but it threaded together with the bolt just fine.

It's snowing here, so I rummaged the BBOH (Big Box of Hardware) for nuts, bolts and washers, did find some wing nuts which are on the far side. I'll get something prettier and more grippy on the next trip to Ace...

Oh, it appears my crossslide is about 0.2mm out of kilter...

 

[woodchucker]

View attachment 465690
There's no clearance behind the cutting edge, so everything behind the edge is contacting the thread, increasing friction, but the cutting edge has loads of positive rake. Hope's this makes it clearer.

yep that made it clear as mud.

 

[woodchucker]

Just joined, second post...

Staring at that indicator I posted about on the "what did you buy" thread, needed to figure out how to use it. Gotta let the budget settle a bit before I buy something, so I thought I'd make a first project of a chuck mount for it:

View attachment 465691

Don't zoom in too close, many scratches and gouges from workholding. It's aluminum rod and bar, slotted with an end mill, drilled with a twist drill, and turned down to 1/4" for the chuck. I eyeballed a lot of it, getting the slot and screw hole at right angles was the most critical, but it threaded together with the bolt just fine.

It's snowing here, so I rummaged the BBOH (Big Box of Hardware) for nuts, bolts and washers, did find some wing nuts which are on the far side. I'll get something prettier and more grippy on the next trip to Ace...

Oh, it appears my crossslide is about 0.2mm out of kilter...

it also appears that your indicator is not 90 degrees, looks about 5-7 degrees off. while it works for just relative indicating, you want 90 for a drop indicator for measurements. I really don't use them for measuring, just for relative indicating (centered, or level ..etc) if you get a test indicator then you actually don't do 90.. But that's for another day. Nicely done.

 

[455dan]

Used the now functioning Tida 1224 Lathe and "modified" a spare head for my yz 465 to make jetting it a bit easier, but mainly reduce detonation by changing the squish angle and shaving the head to hopefully fix a small head gasket leak .

Both the lathe and MIG came in handy to make a spark plug arbor to use with the 3 jaw chuck. Also repaired the kickstand mount that recently broke off the frame.

 

[DeadGuyAle]

Had a little time for cleaning tonight.




Further disassembly is a bit of a puzzle.
Believe the bearings were installed as the last operation in assembly once the shafts had been placed.


Some light tapping on things pushed the top bearing out about 1/8" and created a bit of wiggle room.


Rotated the right side gear and got the key out. Shaft drives out to the left and bob's your uncle



Still contemplating how to remove the other gear set.

 

[eraserhd]

Put the wood vise back on the workbench I dragged up from the basement. The installation instructions had this crazy bit about insetting the bracket 1/8”, then shimming it. We did that last time and it was kinda terrible.

Then I realized the whole reason for this was because they saved money on not milling the front face of the casting flat… so my mini mill has more earned a little bit more of its keep.

Yeah I also tried hand-cut dovetails for the first time. Terrible, don’t look.

 

[DavidR8]

Reassembled the headstock of my DF-1237G.
No leftover parts