Lathe solid tool post mount thoughts

[RaisedByWolves]

They are too small to be Blanchard ground - unless these are Blanchard ground flat, then sawn to size.... (possible, but a costly way to do it)

Do you have a piece of float glass or surface plate (countertop granite won't do). Then put a sheet of 2000 wet and dry on the flat surface and lightly take off the saw/grinding marks. This will improve your contact significantly. Only take a tiny bit off the tops of the marks until you see a new surface over most (75-80%) of the surface.

When/if you learn scraping, the same principle applies.

That is exactly the way they do it.

Small billets of oversize material ganged in rows and ground to size, then run through an automatic saw.

I do agree grinding and cutting these out of a large sheet of billet would be expensive, but these can be cut and put on a shelf ready to be shipped.

Making them in batches for ready use offsets the cost of paying the bank for having it sitting on the shelf.

Then you only need a guy to run the saw all day and others to pick/pack.

Materials cut to order will call out a lead time in the description.

 

[dml66]

Have the float glass ordered, thank you!

A question about where to mount the QCTP with respect to X and Z axes: I'm assuming the best spot is to have the center of the QCTP right over the center of the cross-slide mount?

 

[savarin]

Just a thought, I made mine so the tool holder could be lowered below the top of the plinth so I could use larger tool bits. Its only been a couple of times I've needed it but it was well worth it.

 

[epanzella]

When I made my tool block I didn't have any stock tall enough to match the compound so I made a spacer for the difference. I put a short pin in it to keep it aligned with the tool block when making angle changes.

 

[SouthernChap]

or surface plate

I knew it!

All this talk about never using your surface plate to do sanding/lapping on; about that being one of the cardinal sins that will get you sent to the 7th level of machinist's hell; where you forever have to make a truly squared cube to sub-micron precision using only a cheap, blunt Chinese manufacturered needle file and a woodworkers vice, was all just bluster.

Still and all, not sure I want to take the chance; Pascal's Wager and all that. Think I'll stick to the 'lapping glass' plate I have.



(Actually this has brought a genuinely sensible question to mind, which I'll create another thread about, so as not to hi-jack this one)

 

[ddickey]

Ideally for maximum rigidity the TOOL should be in the center of the cross slide. If you can get away with it this is the best option.
Start at 1:30

 

[dml66]

Ideally for maximum rigidity the TOOL should be in the center of the cross slide. If you can get away with it this is the best option.
Start at 1:30

I've contemplated eschewing the swivel 2-bolt mount in favor of a 4-bolt mount directly to the cross-slide. The video shows the 4-bolt direct mount is at the edges of the cross-slide, and into the dovetails. In may case, drilling and tapping the dovetail areas would constrain bolt diameter, probably to M4, while doing the same outside the dovetails constrains bolt length to 5mm or so, and would probably require custom facing/parting the bolts so they don't protrude past the bottom of the cross-slide.

My instinct tells me bolting through the dovetail area is the better choice, I can always add another bolt making it a 6-bolt mount if needed.

 

[Dabbler]

All this talk about never using your surface plate to do sanding/lapping on; about that being one of the cardinal sins that will get you sent to the 7th level of machinist's hell; where you forever have to make a truly squared cube to sub-micron precision using only a cheap, blunt Chinese manufacturered needle file and a woodworkers vice, was all just bluster.

I have a 20$ surface plate I use for lapping.

 

[SouthernChap]

I have a 20$ surface plate I use for lapping.

So if I buy one of these:



I can use one of these



as a kitchen chopping board and not be eternally damned then?

Phew...that's a relief!

 

[Dabbler]

I love it!!

My lapping plate is an old Lee Valley surface plate 9" X 12", sourced from offshore. It isn't very accurate and very small. I paid about 29$ for it, but didn't realize it was useless for machining. It is perfect for a single sheet of wet and dry.

I've used float glass for lapping as well..