What can I do with this little punch?

[fredschrom]

" So I'm going to go get an assessment locally on welding it first. See what that costs etc "

Being thats a structural weld on cast dismal is my prognosses. Make who ever says they can repair it show your some good cast welds, cause a sloppy cast weld is going to break on that.

I still think I would remake it out of dom tube and a threaded coupler.

Do you have a lathe? A piece of DOM tube and a boring bar and press fitting the bushing is going to be a better part.

[PapaLion]

I'm not clear on that really, and yes, I'll get bids from two sources for openers... both supposedly good at this kind of thing.

I'm not long on the technique you talk about Fred. Inexperienced really? some pics maybe of that thought or materials?

? Could a fella just remake the top round part, fit the brass sleeve... then make the shaft with the internal threads, both mild steel. Then with a collar cut so you can in insert the leg square and strong, MIG it Two pieces and weld them.

I feel like sending it to Zap... after all he gets all the good jobs

[Rog02]

Don't forget our very own Castweld. From some of the stuff he has shared with us here on WW I'm thinking that is right up his ally.

[forhire]

Originally Posted by PapaLion

Could a fella just remake the top round part, fit the brass sleeve... then make the shaft with the internal threads, both mild steel. Then with a collar cut so you can in insert the leg square and strong, MIG it Two pieces and weld them.

That is basically the method fredschrom is suggesting. I think a weld joint is likely asking for trouble. If you did decide to weld it... you'd weld it before finishing the bore and pressing in the bushing.

Personally, I think I'd machine the shape from solid material. Depending on the clearances... you might get by with a flame cut (or water jet) shape. It could also be milled. Basic process... bore the crank, drill and tap for the shaft, drill and tap for the keeper bolt, drill and tap for the zerk, slit the part with a saw. Massage (grind) the shape by hand for any clearance issues.

The welded version will save some on material cost but the overall process will be very similar either way. I'd plan on a new busing and hone to fit after pressing it in.

What are the dimension of the part?

[puddytat]

Hi, there's no reason to actually have this piece made in cast iron....it was made in cast iron because for production purposes it can be cast in quantity using a pattern.

The iron one would have to be made that much heavier in the thread area because cast iron is pretty brittle, and it takes a shock loading every time the press hits down.

If I had this dilemma, I would get the piece remade out of a number of steel pieces and remake it totally.....I reckon it could be fabricated in 3 pieces, allowing for the offset locking screw boss, and welded together...one piece from a round billet of hot rolled steel bar, bored for the bronze bush.

Then another piece of smaller diam hot steel bar, bored and screw cut for the thread, adding the offset lug last, and welding the lot together.

The fabrication would be stronger than the original casting.

They just don't fabricate these parts because it's labour intensive as opposed to having a casting, and a drop forging in steel would be many times the price of a casting.

If Papalion has any machining skills it will be a piece of cake, making it from solid or fabbing it, but to get it made outside as a "jobbing" type job, it would cost an arm and a couple of legs.
Ian.

[fredschrom]

A dirty little pic, drew it up a tad different after reading Forhires post. Do full penetration fillet welds down the coupler nut, on the rods on both sides, weld on the top before welding the rod plates to the DOM tube.

yolk.doc

There are a couple of ways to do this but this is strong and simple, the rod pieces I would do out of 3/8 plate cut with a torch or a plasma.

[forhire]

Originally Posted by fredschrom

A dirty little pic, drew it up a tad different after reading Forhires post. Do full penetration fillet welds down the coupler nut, on the rods on both sides, weld on the top before welding the rod plates to the DOM tube.

There are a couple of ways to do this but this is strong and simple, the rod pieces I would do out of 3/8 plate cut with a torch or a plasma.

Ineresting. If I welded the parts... I think I'd cut the yoke out of some 1 inch plate, weld it in place, then drill and tap. The trick will be to keep everything nice and square.

[tapwelder]

Any reason why the part cannot be repaired, in part or whole. It looks like it failed stress caused by clamping stress.

Or (provided you have the clearance) perhaps Machine down screw/clamp from the existing part and slide a steel sleeve over it, braze it on and add a new clamp to the sleeve.

[PapaLion]

The break is most lilely from someone tightening the clamp too tight, not from pounding stress.

Some approx sizes:

Length> 6"
Width > 4" ( and diameter of the round top)
Thickness > 2"
Bore > ~ 2 1/2"

Shank length > 2"
Width > 1 3/4"
Internal thread length > 2 1/4" (hole goes all the way through to the brass bushing.
Threaded bore .> 3/4"
Threads /inch ~ 9

Bids to make it out of mild steel? pm me.

[ZTFab]

Hey Papa...

I made a model and drawing of the original part based off of your dimensions.

Maybe that can help you get it quoted and reproduced better.

[fredschrom]

" Any reason why the part cannot be repaired, in part or whole. It looks like it failed stress caused by clamping stress "

Doubt it, the press was set up too tight on a punch operation and 5 tons happening several times a minute. A lot of damage can happen to punch press on being too tight, usually they are manually stoked without power a couple of times and feeler guages are used to set up the dies too tight on the downstoke is very destructive to both the die and the press. Remember punch presses aren't always used for just poping holes and when forming you can't squish a piece of material anymore, and it has nowhere to go except into the stoke arm.

ZTfab good job of drawing up that part.

And the reason welding up that cast part doesn't excite me or a couple of others is getting that part welded so it structurally sound is doddgy at best. Do you weld up piston connecting rods in a motor? this part has more stress just less rpm's.

I am curious why Forhire And ZTfab don't like the welded part its simpler to make certainly and using 70 tensil strength rod that exceeds the 65-70 of the original cast? Are you worried about the weld cracking? Its a tad tricky to fixture but not outgrageous difficult. What are you guys thinking here? Something is flagging you.

[puddytat]

Hi, here's a sketch of a possible fabrication from one piece of solid hot rolled mild steel, cut off from a billet.2" X 4" X 6" long.

I''ve shown a modification where the fabrication is split across the bronze bearing hole to form a "big end" so that it can be removed without stripping the whole crank assembly.

There would be no need to round the corners off for appearance, as this just adds to the cost if made outside.

There is a split line across the face and bottom, through the 3/4" hole so that two bolts (instead of one on the original),can pinch the 3/4" threaded hole together to secure the nuckle adjuster.

The split is put in last by bandsawing across the width and face (two cuts to form a loose piece) once the hole has been tapped for the 3/4" X 9 tpi thread.

Making a loose piece across the thread ensure it will clamp the 3/4" screw without distorting the fabrication.

The only important size is the big hole for the bush and if this goes oversize in the remake, then just make a new split bush from phosphur bronze.

The bush, now in two halves ,is secured from turning by the bolt with a peg on it on the top.

I estimate this would be a 4 hour job, costing approx $160 + material etc, labour rates at $40 per hour, mostly lathe and drill work plus a bit of bandsawing..
Ian..

[fredschrom]

here are some pics of the same part on my presses. they are bigger for two reasons, more tonnage, and longer stroke. They also are faster presses. the yellow arm shown s the faster press and notice it doesn't use the split casting method to secure the secure the downstroke adjustment, it uses a concentric bolt to hold it tight.

I didn't draw it up but DOM tube was my first thoughts but I was avoiding the tap. But 1-3/8 DOM with .375 wall thickness for the stem. tapped to 3/4-9, and 3 inch .625 wall run on a lathe. bevel the stem into the top which has been countersunk, the use a full penetration weld.

Anyway here are some pictures of the same type of part: ( this will need a second post )

[ZTFab]

Originally Posted by fredschrom

ZTfab good job of drawing up that part.


I am curious why Forhire And ZTfab don't like the welded part its simpler to make certainly and using 70 tensil strength rod that exceeds the 65-70 of the original cast? Are you worried about the weld cracking? Its a tad tricky to fixture but not outgrageous difficult. What are you guys thinking here? Something is flagging you.

Thanks.

I'm not worried about making the part a weldment. I just simply provided Papa with a simple dimensioned drawing of the original part that he might be able to give to a shop or fabricator to see what they can do for him.

I think it could be fairly easily duplicated in mild steel.

[fredschrom]

And the last pic

[PapaLion]

Fantastic, I printed the drawings ZT thanks much. I did the measuring with a tape, so not very accurate but with the piece in hand they can do their own measuring. Helps a lot, and Fred I see yours, which is similar.
No reason it has to physically look like this one. So a capped top might work just as well. I have time today to see one of the better fabricator shops here so I'll get some thoughts there on cost.

These presses are worth about a grand out on the net, in excellent working order... I'm into this one abut $250 bucks... so there is some wiggle room.
.

[Joker11]

Oh, and let us know who the better fabricator shop is!!!!!!

[PapaLion]

Hey Joker, well I was kind of hoping you'd help me decide. You have way better tech skills and training and can understand choices better probably. I'm favoring FIRM myself, they are much bigger and do a lot of AG equipment fabrications. I'm open to ideas?

I figure to take it out to the Jr College, my Prof there and get his views.

[forhire]

Originally Posted by ZTFab

I made a model and drawing of the original part based off of your dimensions.

Great drawing. What program are you using?

[ZTFab]

Originally Posted by forhire

Great drawing. What program are you using?

Thanks.

I use Solidworks 2012.

[PapaLion]

I let 3 fellas/shops take a looksee. I got two ~weld it again~ and one remake. Remake was going to be $4-500 approx. Welders varied too but the average was near 1-2 hours... about $100 +/-.

So I felt the larger fabricators (FIRM) who does a lot of work for major corporations like Dole Veggies etc had the equipment, skills, and desire. They have it in hand, to be welded.

We'll see... no time given exacty, but I expect about a week.

The drawings were handy ZT... they drew all over them deciding what could and couldn't work. Again, thanks for that.

[PapaLion]

Here's a 7 ton Kenco i found pics of... the main tie rod/heim is two piece for removal without taking out the whole crankshaft.

[PapaLion]

Well Monday morning and the piece is back from the Fabricators. Both threads work fine.

Here are the pics, no comment from me yet, because I'm interested in what trained eyes see. My cost? $80.

[mechanic416]

I really don't think its going to hold. I Think this will start to crack here.

[mb_welder]

Silly question...I've built mild steel parts with a tensioner hole and a keyway for a snug fit on shafting, but why does a cast piece have a slit for tension on a threaded fitting? Could be why it broke. (tensioner overtorqued?) I dunno. maybe I'm overthinking things or looking at it wrong?

(Terminology has never been a personal trait, IMO)