Building a New Lathe

[awemawson]

Steve good to see you back casting again

You may have seen I now have my big induction furnace back in commission but can’t yet use it in earnest as I’m plagued by roof leaks where it is. (So far 5 roofers have attempted repairs plus myself. Waiting the next rain to see the latest results. Trouble is it’s the join between the roofs of three buildings). I have taken delivery of 18 meters of 6 mm x 100 mm steel to weld up some copes and drags as I seem to have given away all the commercial ones that I had!

Good luck with you next go at the brass handle.

[vtsteam]

Hi Tom, I have used pour extensions in the past, but have to admit I don't like them too much. They put a lot of hydraulic pressure on the cope when using heavier metals and can float it or blow out, unless the flask is heavily weighted or clamped. They need bigger melts, etc. Okay for aluminum on lost foam, though.  My problem was just not thinking the casting through, and lack of recent practice 

Hi Andrew, sorry I missed the induction furnace -- I'll look for it. Just starting to catch up reading here. Water/moisture/condensation and mouse damage are the bane of my existence here, so I feel your pain! Thanks for the good wishes! 

[vtsteam]

Okay, second try, fingers crossed.

This time I eliminated the riser, I bulked out the spokes by simply scooping away a little sand under them on the cope  side. And I remembered to vent both the cope and drag, right through the pattern impressions.

My guess about last time was that there was gas entrapment at the opposite end to the sprue, and brass just flowed up the stem and riser without filling the far side of the ring. And the spokes were too thin to let the brass flow  through them-- especially on the gassy side of that casting.

Hoping that by eliminating the riser, and venting everything, the metal flow will now be toward the vented far side of the ring first, and the bigger spokes will then allow easier flow up to the hub.

So far it looks better -- a neater pour, and also the shrink cavity at the top of the sprue is a good sign that a bigger (fuller) casting is drawing metal, and hot enough to remain fluid while doing so.

[vtsteam]

Breaking out, my hopes are up. It's a full ring!

But you never know until it's completely free. .......

[vtsteam]

Yessssssss! 

Sometimes less is more. No riser, better casting. It's possible to overthink stuff like this. Just sprue as normal, and remember to vent the darn thing!

[tom osselton]

That looks great!    I know what you mean I haven’t cast anything in 2 years. I use bolts instead of pins for my cope and drag and never have had a blow through.

[vtsteam]

Bolts sound like a good idea.

I built a bunch of stacking steel flasks back when I was casting iron but I used tapered pins to locate faster when closing up. I seem to have reverted to my oldest wooden flasks for this lathe.

They have quite a few burn marks now -- mainly from pouring the hotter metals. They were clean during the all-aluminum days. But I really appreciate their lightness, and they are easier to handle and pack bare handed for me.

I just like the feel. They have lasted nineteen years and through the construction of two lathes and countless castings. They were made from scrap lumber in the first place. And I could make a new set in a couple hours probably when these get beyond use. They remind me of when I first got started, and all the excitement of it, reading the Gingery books, lunch hours at work, and casting lathe parts on the weekends. It was an amazing learning experience. 

[awemawson]

As I mentioned I'm about to embark on making a range of steel copes and drags and plan to have 50 mm angle iron on each end with a pin & hole for location and a pair of holes for hold down bolts to prevent lifting on the 'keep it simple' theory!

The Induction Furnace Resurrection is here Steve but is rather lengthy :

https://madmodder.net/index.php/topic,13100.0.html

[AdeV]

Several years ago, I bought the late Rob Wilson's casting setup, complete with a bunch of steel flasks that he'd made from what looks like armco and rebar.... I can take some photos of those, if anyone's interested?

[russ57]

Yep.. (interested that is)

-russ

[vtsteam]

Me, too, Adev!   

Thanks for the link Andrew, I'll read through tonight. I like the idea of pins plus bolts. If I remember correctly my steel flasks were made of 1/8" x 2" channel iron (3mm x 50mm). The flanges faced out, and they could be stacked and bolted together into deeper drags or copes if need be. They did use tapered locating pins as well. But, oddly, I never thought to bolt cope and drag together!

I was very much influenced by Ironman's flasks -- he used amazingly (to me) shallow flasks for pouring iron. And what beautiful castings he does! His flask frames were made of thin aluminum, too, so they were nice and light. I tried casting an aluminum flask with thin walls but didn't get good results, and I hated to use up a lot of my dwindling aluminum stock, so switched to welding out of the steel channel iron.

But.......here I am using my old charred wooden flasks again.... 

[vtsteam]

Found old pic of making them. Weld beads inside to help lock in greensand:



Full thread here:

https://madmodder.net/index.php/topic,8860.0.html

[vtsteam]

Using the new lathe to reduce the stub end of the handwheel finger knob:

[vtsteam]

Center drilling the handwheel:

[awemawson]

Excellent - coming along nicely 

Ironman always seems to get good fluidity in his pours, or maybe his venting is especially good as I've noticed that he avoids high 'heads' of metals that us lesser mortals resort to !

[Pete.]

NICE job of casting there Steve.

[vtsteam]

The castings, so far:

[vtsteam]

Thanks Pete! Good to see familiar people here again! 

Thanks Andrew! Yes, Ironman uses some kind of magic that I believe in, but don't understand. 

[RotarySMP]

Nice casting.
Mark

[tom osselton]

Nice casting.
Mark

I think that is part of the magic of Fero Silicon.

[vtsteam]

Thanks Mark. 

Well, Tom, I've got ferro silicon, but I ain't Ironman! I'd say it's his long experience, skill, and knowing his materials, his craft, and his own built tools so well. Plus a willingness to go against commonly held casting axioms. I see all of that in his videos, and the now lost website of his work that I came across nearly 20 years ago.

Today I concentrated on finishing all the little bits and fittings that the tailstock needs for completion. They were: turn, face and bore two brass thrust bearings, make two sliding ram clamp pieces (aluminum), add a stem to the cast brass oil dipper, and drill and tap the cast brass ram clamp handle. Everything complete today but not assembled yet, and no photos ready because parents in law came over at 5 for supper. Sorry!

[vtsteam]

Well, today I figured I'd easily finish the tailstock assembly, and even tried using some of the new parts to drill a hole in a piece of stock held in the three jaw. But the hole came out angled. Something was off..... what could it be?

Turns out that back when I bored the Morse taper in the tailstock ram, I had used a Morse lathe center as a test gauge. Nothing wrong with that. But it was of the short tail, mill style tools. When I tried to drill a hole today I used my Jacobs chuck mounted on a drill-press style Morse taper adapter. The type with a long flat tang at the far end.

Turns out that this tang interfered at the back of the relieved portion of the tailstock ram. But only by a tiny amount, otherwise I would have noticed it. The interference was enough to prevent full seating of the shank in the taper, and so though I used a center drill to start the workpiece, the hole started at a slight angle and continued when I switched to a regular drill bit.

Took a few minutes to discover the cause. Now I have to reassemble the old tailstock and then mount and bore out the back portion of the new ram. I can't just use a drill bit to do that because the diameter needs to be .525" and I don't have anything close to that. A wider bit would cut away a lot of the back of the Morse taper, and I'd prefer not to do that.

I could simply grind off some of the tang of the Jacobs adapter. But then I'd always have to remember to do that for any other morse attachment --  and accept the likelihood that I'd forget and spoil some work down the road. Better to do it right.....

[awemawson]

Can you cross drill the ram to form a morse taper ejection slot which also give space for the tang to fully seat?

[vtsteam]

Can you cross drill the ram to form a morse taper ejection slot which also give space for the tang to fully seat?

No need Andrew, The ram screw ejects the taper shank when the ram retracts. I just bored the ram clearance a little further in today with a bar, and that solved it. Actually only took a few minutes.

Here are all of the pieces made for the tailstock -- completing that job today:

[vtsteam]

The ram clamp pieces presented a slight problem but a little thought solved it with an easy solution

The original two part clamp was tightened with a 1/4" dia. through bolt. The original bolt head must have been square, because there was a square recess in the bottom clamp piece to fit. This would have held the bolt against turning when the clamp lever-nut is turned at the top of the tailstock.

However, somewhere in the life of my Craftsman lathe, someone must have replaced the original bolt with a hex head version, and that just barely caught on the edge of the square hole - still adequate for tightening the clamp, but not ideal.

Thinking about it, I could probably have cast a hex head recess into a similar clamp piece using a bolt as a core (smoked to allow release), but that seemed like a lot of work for just one tiny item.

Thinking around that problem I realized that I could just clamp the bolt head in my vise, and then saw off pieces parallel with the bolt. This would yield a Tee headed bolt. Then I could slot the clamp piece to fit. I thought about milling that slot, but that would require going down to the other storage shed, and setting up the mill (the mill vise had been removed for the las operation).

But I realized I had hanging up in front of me a big coarse file, about a quarter inch thick, and the piece I needed to work on was aluminum. So a simple clamp-up in the bench vise, and a minute of vertical filing later, I had my slot, fitting the new Tee bolt, and I was done. Fun to make a complicated-looking machining job simple and solved in a few minutes by hand tools! I enjoy that kind of thing.