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Question on motorized screw presses


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I know several people on this forum either have now or once owned motorized screw presses so I would appreciate a brief explanation of how the screw is held at either end of its travel. In other words, I can see from the various pictures and illustrations that the press is raised or lowered by friction against a driven wheel(s) but what type of clutch or other mechanism allows the machine to stop without tearing the frame to pieces? Having never seen one operate in the first person, I'm having trouble understanding that part of the process.

Thx, Hollis

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I know several people on this forum either have now or once owned motorized screw presses so I would appreciate a brief explanation of how the screw is held at either end of its travel. In other words, I can see from the various pictures and illustrations that the press is raised or lowered by friction against a driven wheel(s) but what type of clutch or other mechanism allows the machine to stop without tearing the frame to pieces? Having never seen one operate in the first person, I'm having trouble understanding that part of the process.

Thx, Hollis


At the bottom end of the travel, you know what happens. It expends its energy on the work. So I presume it's really the top of the stroke you're asking about. Usually the operating linkage is connected to the ram in some manner so that when the ram reaches the top of it's allowable stroke it shifts the drive no neutral. If the ram is going up very fast it will actually move far enough to engage the down drive to keep it from crashing.
post-8656-008695200 1281582268_thumb.jpg

Notice at the top on either side of the screw there are two knobs. Theses are nuts. On my 100 ton machine they are 4" "bolts" from top to bottom. Usual practice is to heat the bolts to 400 degrees or so, install them, run the the nuts down tight by hand and as they cool and shrink they put the frame under tremendous compression.
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OK, that makes sense but what keeps the ram held up? Seems to me with the fast, multi-start screw that the thing would tend to fall if it was simply in neutral. Does the reverse wheel maintain light contact on the flywheel to keep it at the top of the stroke?

It looks like the drive wheels run in one direction and screw vector is governed by the drive shaft toggling from side to side to touch one side of the flywheel or the other, ie, "friction press". I've used manual fly presses so have that in my head as a basis but don't quite understand all the nuances of a motorized one.

That's an interesting comment about heating the bolts and letting them shrink; it's logical to keep the frame from stretching.

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My #10 ram will fall if you manually put it in neutral, which is difficult because the spring mechanism holds it to the up position as well there is a brake shoe at the top that grabs the fly wheel until you actuate the downstroke. Also mine has a couple of safety stops that also brake the flywheel at the top of the stroke.

post-2769-099272800 1281622566_thumb.jpg

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A mechanical brake that releases the flywheel makes sense. Thanks to both of you for the explanations.

I'm seriously thinking of getting a small press after a couple of my current jobs finish up and I have some available coin. Would be a good addition to my shop and the type of work I normally do.

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At the bottom end of the travel, you know what happens. It expends its energy on the work. So I presume it's really the top of the stroke you're asking about. Usually the operating linkage is connected to the ram in some manner so that when the ram reaches the top of it's allowable stroke it shifts the drive no neutral. If the ram is going up very fast it will actually move far enough to engage the down drive to keep it from crashing.
post-8656-008695200 1281582268_thumb.jpg

Notice at the top on either side of the screw there are two knobs. Theses are nuts. On my 100 ton machine they are 4" "bolts" from top to bottom. Usual practice is to heat the bolts to 400 degrees or so, install them, run the the nuts down tight by hand and as they cool and shrink they put the frame under tremendous compression.


Grant,
Could I get you to expand (expound) a bit about these little rascals in general? I'm thinking more about 30 T. and the typical scenario goes that I'm presented with one to buy or not and I have to know enough (hopefully) to do a good job. Do you have instructions, parts callout for the pic you posted here, set-up and maintenance info? If I said "pretty please" would you share it?

I (think I) got through doing this on a No. 3 hand flypress OK but I don't have any experience with a motorized one. I took a photo down to the used machinery shops in the ship outfitting area to find the hand press. You know I'm across the pond.

Thanks, life begins at sixty
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A mechanical brake that releases the flywheel makes sense. Thanks to both of you for the explanations.

I'm seriously thinking of getting a small press after a couple of my current jobs finish up and I have some available coin. Would be a good addition to my shop and the type of work I normally do.


I have two small flypresses for sale posted in the Houston Area Blacksmiths Assoc. website www.habairon.org. I am in Bellville, TX. You are not too far from me. Tommy 979-830-3578.
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Grant, thanks for posting that video - it explains a lot (that old "a picture is worth a thousand words" thing). How big is your press on tonnage? The induction heater is pretty impressive too; looks like you are doing reins in one heat...I reckon you can work as hard as you want to with that thing in the shop. :P

Tom, I looked at your presses; thanks for the HABA link. I should have said small motorized press in my previous post. After I finish the next couple of jobs, I am going to start hunting a 10-30 ton unit.

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Here's a quick video that shows the workings pretty well:

FRICTION SCREW PRESS



Grant, thanks for the posting(s). My end prevents me from viewing most videos and these are no exception. Is a direct link for downloading possible? My old eyes like big videos and downloading several gigs at a time is usually no problem.

Thanks,
life begins at sixty
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Good video Grant,
It is interesting seeing all the wiggle parts in the machine.



How many more inches of throw do you have if you removed the bottom block? It appears that you have a raised block under the bottom die so as not to get a full 100 ton blow.

Ric
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Hey, thats me in the video about five posts up!!! Was not aware that existed. And those are my wedding clothes!!! Looks like I got some squishing in on the big day. Makes sense I don't remember, we had some kegs of Sierra Nevada on hand. Wow, thats just great.

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Hey, thats me in the video about five posts up!!! Was not aware that existed. And those are my wedding clothes!!! Looks like I got some squishing in on the big day. Makes sense I don't remember, we had some kegs of Sierra Nevada on hand. Wow, thats just great.


Hey Nuge that real cool, you were "at it" on your wedding day.

That video and a few others on Youtube were what convinced me I HAD to get and induction heater. Finally got it yesterday, it's the next one up (25KVA) and boy oh boy does it rock. More info here
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Finally got it yesterday, it's the next one up (25KVA) and boy oh boy does it rock.


Three phase? I would love a bigger one. I'm giggling like a little kid in that vid and I owned it for two years!! I am so psyched for you man. Induction changes the game.
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Three phase? I would love a bigger one. I'm giggling like a little kid in that vid and I owned it for two years!! I am so psyched for you man. Induction changes the game.


Yeah, I think 3 phase 415 Volts is much more common over here. It's kinda the "expected thing" with a lot of industrial units. Don't you have three phase? I'm sure the "non pink" Anyang of yours (in the picture on Sams 33lb thread) is an 88lb. I've got one myself and over here they come with 3 phase motor. Those Anyangs sure do rock don't they.

I've taken a video showing the induction heater doing it's magic on a bit of 40mm round, it heats it from cold to where it starts to spark and burn in about 60 seconds !!!!!!!!!!!!!!! When I've sussed the Youtube thing I'll post a video. 40mm square or 50mm round wouldn't fit in the coils supplied. I'll make up some new ones over the weekend and see how far I can push it.

Have you got any advice on coil geometry, number of turns, dimension etc etc ???

Yeah it's a game changer isn't it.

Seemed to work pretty good with stainless, okay with silicon bronze, sort of worked on brass but struggled with copper. I'll tell you what Nuge, I'm gonna love being able to see the colour of the bronze/brass directly. No more puddles of molten metal on the gas forge floor.
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The bigger hammer is single phase as well. Hopefully the next shop has three phase, the equipment is sooo much cheaper cause not many folks can run it.

I'll get some shots of my coils soon. Plenty of failures there, but its real pleasant when you make a good one. I want to try some claw shapes to isolate the heat on the edges of big flat bar. It would be cool to be able to work the edge without any warping.

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