Hendey T&G Lathe

[a smile]

My tool in that photo is patterned after a tool that machine tool rebuilders have used for a long time.

@Mcgyver has a good write up on his version on his site. It’s much better than mine.

Versatility of the Alignment Tool - Metallum

the Versatility of the Alginment Tool I know, its rather unbecoming to toot ones own horn, however when an idea works out this well I just have to tell someone! The main ‘foot’ of the alignment differs greatly from the Kingway Alignment tool. Its a 90 degree arrangement with two positions for...

www.metallum.shop

I wonder if adding an elastic rubber band between the two supports can increase the balance and stability of the contact between the cylinder and the dovetail.


I think the stability of the support and the contact pressure with the left and right dovetails will affect the accuracy of the measurement, so I hope a professional engineer can help me answer the question.

 

[Rauce]

I wonder if adding an elastic rubber band between the two supports can increase the balance and stability of the contact between the cylinder and the dovetail.


I think the stability of the support and the contact pressure with the left and right dovetails will affect the accuracy of the measurement, so I hope a professional engineer can help me answer the question.

In the arrangement I showed I’m only measuring against one dovetail. The rear support only rests on a brass pad. As I moved the tool I gently pulled the front support against the one dovetail.

When I have time I would like to remake the tool with more rigid clamps and larger diameter rods so it is a bit more stable.

 

[Rauce]

Well it looks like I’ve learned another lesson! Or at least I’ve learned it in practice (again?)

Everything is rubber!

I did some additional checks on the saddle ways today with an indicator mounted like this in each corner and pushing and pulling to see what kind of movement I got. My thought process is that this would confirm the blue contact I saw after my last scraping pass.

I was surprised to see indicator movement of nearly a thou with the indicator mounted on the front corners. This indicates that at the ends of those ways I don’t have the contact I thought I did. I believe this is because of the saddle confirming against the ways when I was doing my blue check. Clearly I was putting too much downward pressure on the saddle.

So it seems I will be back scraping again for a little while longer.

 

[Susquatch]

Everything is rubber!

Couldn't agree more. Absolutely everything deforms when subjected to a force. Doesn't matter how big. It isn't if, it's only how much.

You are doing amazing work! I'm continually impressed and jealous!

 

[Mcgyver]

Scraping in the saddle ways has been a long process. I think I’ve been at it for at least 3 weeks.

Really glad at the thorough approach you've taken. At the beginning I was thinking maybe this is going to be a grind the bed and apply lots of lipstick, but nope, you've made the Herculean effort to do it all properly....I bet you will be happy with it, well, forever.

Today I popped the granite square up on the ways and aligned one edge with the carriage travel.

That is one massive square! For those lacking the biggest granite square north of the 49th, another way is to sweep a pin laying in the dovetail. I requires the head stock to be aligned first (a bit chicken and egg as without an alignment tool you kind of need the carriage to get the headstock right...one way is to get the carriage to bed, then headstock to bed, then the cross feed ways on the carriage). A ground pin is in the dovetail and is swept with indicator held on a bar in the spindle. The sweep comes from rotating the HS. Sweep at one end, move the pin and sweep the other