Motor-Manufaktur: Shop:Shop Press and Press Brake

Note: I haven't found yet the time to translate my home page. If you want, you can use Google's translation service to look at the rest of my Home Page in English. But be aware that their translation is even worse than mine (would be). Sorry for the inconvenience, I'll fix that.

Shop Press in normal operation:

General view of the press. Set up for normal pressing work. You will note, that one expansion spring is missing (on the upper left). It broke once and when I wanted to buy a new one recently, the shop was closed due to illness. Went there again, now closed for holidays.
The hydraulic cylinder is just kept in place with the allen screw. It only stops it from falling out, it would never hold the 10 tons!
The whole thing is about 950mm high (including cylinder), 420mm wide. The lower bridge is 70mm high and 10mm thick. Of course, there is another one behind the bridge in the front.
The side flats are about 35 * 20 mm and are at their very limit! Make them thicker. When I built it, it was the stock at hand. The screws sticking in from the side and holding the bridge are M14 12.9 (high tension screws). Make them bigger. They withstand the stress, but you can't overdimension there either.

A side view of the press. You see that it is basically symmetric. I have built a stand out of OSB.
The dial indicator is normally not installed. I just have put it in there to show that it can be installed if you have to check the travel.
The two blocks between the middle bridge act as a guide. I should have made them longer, but they work good enough.

Shop press for bending bars straight:

These are the accessories for bending bar straight again. On the top is a holder for a copper prism that presses against the bar in work.
Next row on the left a rest that can slide along on the lower bridge and the bar is laid in. Next is a holder for a dial indicator. With it you can see how much you have bent the bar. It takes some trials to find the exact point beyond yield strength. But when you have found it, you can bend within 1/100 mm.

Here you see the accessories for straightening installed in the press. They jjust sit between the two flats forming the bridge. The upper holder for pressure piece should be secured with another screw. But when I made the pictures I had to discover that I obviously needed that screw in another place.

Here is a bar installed for straightening. See the dial indicator touching the bar from down under. It takes some experience to adjust the two rest (with the copper prism). The sharper the bend, the closer they have to go to the center. If one side of the bent is soft and the other is sharp you have a setup that looks like this.

Press Brake with Veith Eladur

This is the punch for bending sheet metal.
On the top you see the holder for the punches.
Below is a set of punches cut to different lengths. That's useful when bending boxes.
The punches were milled as one piece and then cut to length. After cutting, the area of the edge was casehardened and not tempered. Believe it or not, they were made out of simple CRS (cold rolled steel) and hardened with casenite. I have bent 5mm thick strips without harming them.

The rightmost punch is laying on it's side so you can see how it is held in the holder by its tang.

The punch holder from the side. You can see how the punch's tang sits in it.
The three holes (two can be seen) are for fixing the holder in the bridge.
The strip with the screews through it (M6) has a recess on the back and thus clamps and presses the dies into the holder.

These are the mysterious rubber bars.
They are from Veith and are called "Veith Eladur". They are available in different hardnesses. The softer ones for smaller bends. They are made out of Polyurethane and are very tough! You can bend 5mm steel and punch in them with the corners of the punch without hurting them. Their length is 250mm, cross section 25 * 25mm. The bore is 10mm diameter. If you need longer ones, you just put them side by side.
The huge advantages of them are:

No scratches at all on the outside
No need for a minimum stickout to bridge the gap in a conventional vee die.

Veith is giving sizes for the bar the rubber rests in (next picture). They have an informational brochure that is very interesting.

Here is the rubber bar with its "bed" and on the left of it the two back gauges. These can be adjusted in length and be swiveled out of the working area.
Don't look at the welds. Even my mother complained about them, but I didn't want to grind them off and reweld. But they hold more than they promise.

Another view of the rubber bars and their bed and the gauges.

Here you see the accessories for bending installed in the press. This is the front view, from where you operate the press.
The punch holder goes between the two flats of the bridge and is kept there with the 3 pins (bored and reamed).
The bed is just stuck between the two flats of the bridge. Then the two screws (left / right front) are tightened and stop the bed from tilting out.

Side view of the press brake.

Back view of the press brake with the back gauges.

Here is a picture while bending 0.5mm brass. It is bent on the soft stick and you can see how deep the punch goes into the rubber bar.

Quite an abuse, I think. Showing what happens to the rubber when bending 2.5mm steel on the medium stick. For clarity, I have moved the whole setup to the left. This is the reason why the bridges are no longer parallel. Normaly, the die has to be more or less in the middle of the die holder.
Note:
I could have put a stop between the two bridges on the other side to keep them parallel, but I forgot to.

Here a 3mm hot rolled steel (60mm wide) gets bent. This is near the limit of the 10 tons. The bar really looks abused, but after releasing the force just minor dents are in the rubber bar. They will disapear after some hours. Veith recommends harder and thicker sticks for that, but I have just the two. I don't do such heavy bends normally. I just wanted to demonstrate what can be done.

This is the 3mm by 60mm HRS. Bending radius was about 1mm (also an abuse).

Outside view of the same 3mm bend.

Other Tools:

Here are two more accessories I made for bending.
On top is the holder you already know from the bar straightening attachment. Below it is the punch. It was used for bending Us (I think it was for a flat 5 * 30). The bend was 180°.
Right of it is another tool (punch and die) for bending a 5*30 by 90°

Both tools are quite crude, but it was crude work anyhow.

Veith Eladur:

That stuff is really indestructible. You might have success with other products, but the trick is the hole in the bar. Unfortunately, Veith has no English home page. But if you google for "Veith Eladur" you should find dealers. If you have found some or are one, you can mail me their links and I'll add them here.

Improvements:

There are some minor points I should have made better:

10 tons sound a lot, but they are not, depending on what you do. When bending sheet metal with the rubber bars, it requires more power than with conventional press brakes with a vee die. For what I did with bending, it was enough. But for pressing crank shafts or ball bearings (of your car), 10 tons are the lower limit.

I should have made the two vertical columns stronger. They are at their limit. I don't remember how I messed up my math, but when I recalculated what I have halfway built it showed up.

The two thick square sectioned bars on the middle bridge that act as a guide should be longer. Maybe 200 mm.

The distance between the two horizontal flats building the bridges could be bigger. Now it is 35mm, but there is always need for more.

From the Shop: A flexible shop press and press brake

Introduction:

The Pictures:

Veith Eladur:

Improvements: