Overhaul of a 9" SB model "A"

[steamer]

Well, I started in on the CS dovetail. I checked my straight edges first and both needed tuning up . My angle straight edge is a bit short, but not enough to be a real problem as long as I am very careful....it would appear that the center of the dovetail is high....but I need to finish tuning the straight edge up first.

I did find a suitable piece of old mold plate in the lucky box that I think will make a good base for the Auxillary drive. I'll need to lay that out ...but it looks good. I may make this sooner than later just to get some stuff up off the floor in the shop! :big:

I also have the dovetail block for the high speed drilling/milling spindle roughed out and ready to bore for the watchmakers lathe bearings.
I'll then need to make the driving and driven pulley. I figuire 1725 to 4500 is plenty of range for this spindle.

I'm going to bore it on the Logan purposely high, and then machine/scrape the spindle down to the HS spindle height on the SB later.

Dave

 

[Mosey]

Are you laboring under the grave misconception that you can do this without showing us the pictures??? Get serious, man!

 

[steamer]

Don't get ya knickers in a twist!.... ;D


Sometime tonight I"ll snap a couple of shots....Trying to shoot mark ups ain't easy with a droid......but I'll try.

Dave

 

[lazylathe]

Maybe you need a proper droid Dave?

"I don't think so, sir. I'm only a droid and not very knowledgeable about such things."

LOL!!!

Andrew

 

[steamer]

Honestly....I think my droid knows WAY more than I do... :

Dave

 

[lazylathe]

Lol!!

You do know that was a quote from Star Wars!! ;D

Andrew

 

[steamer]

No, but I still think my droid knows more than I do! :big:

Dave

 

[steamer]

OK Mosey....here ya go.

Straight edge.....almost complete...needs a few more points ...it bowed high on the ends and I needed to take it down
It bowed because of stress relief.

Same thing with the angle straight edge with the same thickness of marking...though not as bad...it looks awful, but it's probably only a couple tenths....it's easy to push on this and make it bow flat....I just slightly grabbed it in the vice for the photo, but I wouldn't mark it that way...I would use the straight edge above with this in a free state. You'll notice the marks look like "bullseyes". That is a sign of true bearing. The part in the middle is where it's actually touching and then it fades away as you move off from the center

A rather scrungy looking piece of 1 3/8" plate 6 x 8" for the Aux drive base

And the 1/4 HP 1725 motor I'm going to use sitting on it....this came off a small punch press that I had to , by law mind you , scrap by destroying with a sledge hammer....but I saved the motor and flywheel.... ;D

Here's the block with the dovetail for the tool post mounted light duty milling/drilling spindle.

Along with the "donor" watchmakers lathe headstock gotten off the bay for about $20

The block needs a straight through bore so that the lathe spindle and bearings can be mounted. I'll be putting a 1.25" pulley on the end to be driven by the motor above.

Dave

 

[Mosey]

Definitely OK! Will be watching as you go forwards to completion of a unique little accessory.

 

[steamer]

I was able to get the straight edge sorted out and then I scraped in the guiding side of the dovetail on the cross slide. Interestingly, the guiding side was hour glass shaped but biased towards one end. I had to use a straight edge that was shorter than the piece, so I had to work from one side, and work my way over to the other side. but because of the hour glass shape, this wasn't so bad. I just scraped "straight down" and didn't try to steer the work in another direction.
Funny thing is the way I was scraping it , it would end up a bit hollow along the length, and I had to really concentrate on making sure I was scraping flat as the width of the dovetail is about a 1/2". In the end I had to put the handle of the scraper on my shoulder and grab the shank with both hands to "choke up" on the scraper to gain enough control to just cut the mark and nothing else.

I took some photo's but I need to get them off the camera....they're coming Mosey..... ;D

I need to scrape the gib side so I can make the gib and return the gib clamp fixture that was loaned to me.

Dave

 

[Don1966]

Heh! Dave looks like you are making some progress, but do you really want to put that 1/4HP motor on your 9 inch lathe? How about a 3/4 HP motor. I just change the motor off my vertical band saw to 3 phase and I have one laying around. PM me if you are interested.

Regards Don

 

[steamer]

Hi Don, The main lathe spindle is 1/2 HP....which is fine.

the 1/4 hp unit is for the auxillary toolpost mounted spindle.....for drilling and light milling of parts in the headstock spindle like clock wheels and small gears, and drilling small circular hole patterns


Thanks for the offer though!

Dave

 

[Mosey]

Lookin in with admiration.





Mosey

 

[steamer]

Thanks Mosey.

Dave

 

[Don1966]

That is a great idea Dave, are you going to index the headstock as well?

Don

 

[steamer]

Hi Don,

Yes

My F1 has a great dividing head attachment that clamps onto a 35mm diameter shaft. I'll make an adapter to use on the back of the SB spindle and a torque arm.
Dave

 

[steamer]

Here's a few photo's from my last session....The saddle way surfaces for the CS are next starting with the flat ways

It started with good bearing, but not all the way across, then ended up with a groove once it carried....

 

[steamer]

As you can see in the pictures...at first, there was low "strip" down the middle...and I finally figuired out it was ME!

When the blade hits the relief groove it would twist slightly, and with the curve of the blade it would cut leaving a groove.

The only way to get over that was to be very careful to cut the mark up.....I have the photo's kinda mixed up , I'll straighten them out and put them in chronological order....

Dave

 

[steamer]

Did a bit more tonight scrapping the saddle CS flat ways to the CS. Then the angle ways.

Dave

 

[Don1966]

David you have put in a lot of effort into this project. In the long run it should pay off. You lathe will almost be like new. I wish I could do that, but I am still green behind the ears still. There are a lot of mechanical things I can do, but scrapeing is not one of them. Looks like you did your homework on this one.

Don