Snapped bed casting, C.I. repair advice?

MihiT · Jul 21, 2018

Hi, Sorry if this is in the wrong forum, it seemed the most apropriate.

I have unearthed another old belt drive lathe (15x63), no markings or brand, and it's in pieces.

Sorry also, no photos yet, so please bear with my 1000 words.

My query is that the headstock front way has snapped off.
In section it would be a "T" shape with the top being 40mm (1.5") thick and the stem only 15mm (5/8")

For repair my thinking would be to thoroughly clean and degrease the faces of the crack and surrounds, clamp in place and drill/counterbore pins, or even cap screws, through the ways into the bed, however there isn't much "meat" if I went with 10-12mm (3/8-1/2") screws: that's only a couple of mm (16ths) either side, of (presumably soft) Cast Iron.
I could back this up by dishing it out and arc welding it cold (stitches, well peened, alternating ends). Obviously then it needs to be scraped back into line and level.

Is there anyone with any other ideas, or a standard old-timey fix I don't know about?

thermite · Jul 22, 2018

MihiT said:
....standard old-timey fix I don't know about?

Hard to work without good pictures on situations of this sort.

For useful guidance, as well as examples of such fotos, go and have a read of John Oder's thread on his Greaves-Klusman lathe. There are several repairs to CI that may help shape your choices. PM has several more such "projects", too.

MihiT · Jul 22, 2018

thermite said:
Hard to work without good pictures on situations of this sort.

For useful guidance, as well as examples of such fotos, go and have a read of John Oder's thread on his Greaves-Klusman lathe. There are several repairs to CI that may help shape your choices. PM has several more such "projects", too.

Yes I can appreciate that, I will upload when I can.

Is that the 20" one? Looks like 13 pages of homework for me! Thanks.

thermite · Jul 22, 2018

MihiT said:
Yes I can appreciate that, I will upload when I can.

Is that the 20" one? Looks like 13 pages of homework for me! Thanks.

It is indeed a good deal of reading. OTOH, John is thorough, and he knows things most folk would need TWO lifetimes to learn, present-day absorption rates, so.

"Well worth it" if you'd like to avoid re-learning those things one-at-a-time, alone, and in the dark.

Paolo_MD · Jul 22, 2018

If I understand correctly, a chunk of the front ways is broken off. Unless we are dealing with an extremely rare example of early lathe in need to be preserved in a museum for static display, I would consider this lathe only as a donor of good vast iron for other machines, or a source of chunks that could be transformed into straightedges or other objects.

If is to be preserved for static display, I would put back together with epoxy glue. Otherwise, here are my concerns: the risk of creating hard spots on the ways by welding is significantly high. Moreover, it is unlikely that your stitching and welding approach would conserve the linear length of that side of the bed, introducing, therefore a curvature in the whole bed, which will require removing a lot of material by grinding.

Again, without pictures, I could have misinterpreted your description. But I'm really afraid that, that machine is now pure scrap.

Paolo

thermite · Jul 22, 2018

Paolo_MD said:
But I'm really afraid that, that machine is now pure scrap.

Paolo

Not in New Zealand, it ain't!

Anything a ship or aircraft can carry can be HAD there, but finding time and MONEY for that make choices nearly as challenging as boosting them into orbit.

Trust that it will be fixed "somehow" to "some level" of utility.

Fred Beier · Jul 22, 2018

MihiT said:
Hi, Sorry if this is in the wrong forum, it seemed the most apropriate.

I have unearthed another old belt drive lathe (15x63), no markings or brand, and it's in pieces.

Sorry also, no photos yet, so please bear with my 1000 words.

My query is that the headstock front way has snapped off.
In section it would be a "T" shape with the top being 40mm (1.5") thick and the stem only 15mm (5/8")

For repair my thinking would be to thoroughly clean and degrease the faces of the crack and surrounds, clamp in place and drill/counterbore pins, or even cap screws, through the ways into the bed, however there isn't much "meat" if I went with 10-12mm (3/8-1/2") screws: that's only a couple of mm (16ths) either side, of (presumably soft) Cast Iron.
I could back this up by dishing it out and arc welding it cold (stitches, well peened, alternating ends). Obviously then it needs to be scraped back into line and level.

Is there anyone with any other ideas, or a standard old-timey fix I don't know about?

How much is snaped ? Pictures please.

In general the way to fix these problematic breakages is to machine past the break and into where there is more substantial material and then you make a piece wich fits everything and anchors to solid foundation. Think of a gap bed lathe.

Richard King · Jul 22, 2018

I have done several ways on ways ( lol), welded beds, cold stitched, filled with plastic metals, machined and bolted in inserts, etc. As Paolo points out welding where the 2 materials merge will get hard even with rosebud heating and peening. The lathe bed will suck up the heat and probably fine crack When you attach some photos we can all help a lot more. If there is room you may want to consider milling out a section and making an insert and counter bore the holes and turn cast iron plugs to set in above the cap screws. :-)

MihiT · Jul 23, 2018

A couple of pictures here. One is top-down the other looking into it from the front. Damn camera phone isn't that good quality but hopefully you get the point.

MihiT · Jul 23, 2018

Paolo_MD said:
If I understand correctly, a chunk of the front ways is broken off. Unless we are dealing with an extremely rare example of early lathe in need to be preserved in a museum for static display, I would consider this lathe only as a donor of good vast iron for other machines, or a source of chunks that could be transformed into straightedges or other objects.

It had crossed my mind, scrap prices are low and I don't have enough projects to melt it all down for.

If is to be preserved for static display, I would put back together with epoxy glue. Otherwise, here are my concerns: the risk of creating hard spots on the ways by welding is significantly high. Moreover, it is unlikely that your stitching and welding approach would conserve the linear length of that side of the bed, introducing, therefore a curvature in the whole bed, which will require removing a lot of material by grinding.

Again, without pictures, I could have misinterpreted your description. But I'm really afraid that, that machine is now pure scrap.

Paolo

I would like to get it running. It does have the carriage and tailstock, steadies etc, so I guess it's pretty complete.
I'd say most of the load is straight down, however it will need some resistance to shear, as there would be a bit of torque trying to fold it.

Paolo_MD · Jul 23, 2018

MihiT said:
A couple of pictures here. One is top-down the other looking into it from the front. Damn camera phone isn't that good quality but hopefully you get the point.

From the pictures I would interpret that you have a gap-bed lathe and the broken chunk is the base of the headstock and not a chunk off the ways of the bed as defined as that portion traversed by carriage and tailstock. A more general look at the machine would also be of some help.
If my interpretation is correct, the repair should be less problematic than I thought.

Paolo

ballen · Jul 23, 2018

I assume that you still have the broken-off bit. A photo or two of that would also help.

Richard King · Jul 23, 2018

It looks like to me the broken area is where the headstock bolts to? How about a picture back away from the machine so we get a better idea what is broken. Also please picture the broken piece and headstock. Did you remove the headstock after you saw the break? If your only interested in getting the machine running, you might be able to bolt on some steel and screw it together. If the crack is a non wear area as we first thought, welding and bolting in combo could also work. AS few more pictures. Plus are you familiar with welding cast Iron? There is a lot of room for you to type. The more info the better for us to advise you. Rich

M.B. Naegle · Jul 23, 2018

We've fixed lots of broken iron over the years, but haven't ever tried a lathe bed.

IMO Welding would be ideal, but presents potential issues with the heat and you may find it to be off when you are done. I'd say a bolt together solution would present the least issue. Grind a piece of angle iron to fit into (what looks like) the underside portion of the break and hand drill and tap several bolts into either side. That way you can adjust it as you go until you know it's in place. You may be able to drill a couple of dowel pins in from the top to lock it in place as well.

Keeping it square will be imperative so using lots of clamps and maybe even the headstock's footprint itself will be necessary to keep it from moving around as you locate and drill each hole. Afterwords you may still need to shim or scrape the top surface to get it square with the rest of the machine.

tdmidget · Jul 23, 2018

Looks to me like a broken bed way AND a broken headstock. The headstock is rusty and the bedway is fresh. Maybe time to "fess up?

Richard King · Jul 23, 2018

tdmidget said:
Looks to me like a broken bed way AND a broken headstock. The headstock is rusty and the bedway is fresh. Maybe time to "fess up?

Does look like a riser block or something on the back ...hmmmm...odd

Peter from Holland · Jul 23, 2018

To me it also looks like were the headstock is bolted on
Machine it square up to the cross section and bolt in a square block of CI
with a slot if need be
Then machine the top
But scrapping it wil save you some headaches

Peter

M.B. Naegle · Jul 23, 2018

tdmidget said:
Looks to me like a broken bed way AND a broken headstock. The headstock is rusty and the bedway is fresh. Maybe time to "fess up?

It's speculation on my part, but It looks to me like he flipped the broken piece over on top the the unaffected side for the sake of the photo.

If New Zealand is as wet as South Texas, that could be rust from a couple days. Especially if it's not in an AC environment.

pressbrake1 · Jul 23, 2018

I done a similar repairs with a mixture of pure nickle arc rod and braze.
Said repairs were not in high accuracy or stress areas( lathe aprons)

Tony Quiring · Jul 23, 2018

Force here is upward so it will need very good securement.

Do NOT grind or weld yet...think about did bearings that ate broken then machined as these parts have specific fit.

Need to be able to clamp in place with headstock bolted on then determine how to hold.

Possible butterfly or a strap bolted in place then cavity filled with lead or epoxy.

Heat may ruin the match fit but others much better qualified.

How much power in this breadstick as that matters too

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