Thread: Hafco 3-in-1 Pressbrake, Guillotine & Rolls 300 x 1mm

Should the shears handle 1mm brass plate.

Stewie;

http://www.machineryhouse.com.au/S648#tabs

If you have some spare brass around, I'd take it in and try it. You are up against the upper limit of the machine and I doubt there is much margin left to play with so it really comes down to how much force you can exert and how the machine stands up to it. Personally if I was in the market for one of these machines I'd try to find something with a little better margin on capacity (1.2mm or 1.6mm).
If H&F won't let you try the machine out, I think there's your answer.

Michael

Originally Posted by Michael G

If you have some spare brass around, I'd take it in and try it. You are up against the upper limit of the machine and I doubt there is much margin left to play with so it really comes down to how much force you can exert and how the machine stands up to it. Personally if I was in the market for one of these machines I'd try to find something with a little better margin on capacity (1.2mm or 1.6mm).
If H&F won't let you try the machine out, I think there's your answer.

Michael

Hi Michael. I already jumped the gun on this one and purchased the machine. I tried the brass plate (likely 1.2mm gauge than 1.0mm) in the shears and the best result I could get was an indent across the brass showing the shear jaw line. I did assume that being rated okay for 1mm mild steel it should handle the brass okay. I had the clearance set pretty tight between both jaws. I later did a quick search on the net and found a recommendation of 10% plate thickness between the 2 jaws for this type of machine. I will try again when time permits using that clearance gap outlined, but have some major doubts it will make enough difference on the brass.

Stewie;

Can someone explain why brass sheet of 1.2mm should be more difficult to shear than 1mm mild steel that is rated okay to cut on this machine.

Stewie;

Originally Posted by planemaker

Can someone explain why brass sheet of 1.2mm should be more difficult to shear than 1mm mild steel that is rated okay to cut on this machine.

The shear tonnage is about the same "with the correct clearance"
If you machine is set for 1mm its going to be tight for 1.2mm. But I would guess that the machine is set even tighter than that. Does it cut printer paper?
Have you tried cutting 1mm MS?

Stuart

I guess there are a couple of things here.
Firstly, to shear material you are basically pushing one piece of material past another, so your shear area is thickness x width.
For the same thickness material you are talking 20% extra shear area.
Next there is material. Steel comes in a range of grades and I suspect that they use the lowest, softest grade they can when making these claims (the web page is saying hot rolled 250Mpa). You don't say what grade of brass but it could be quite hard and some brasses can work harden as well. One of my books gives brass strengths higher than 300Mpa for some grades. Shear strength is not a constant proportion of either, so for steel it may be say 50% of yield but brass may be 70% (WAG). so - you could have a material that is stronger and takes a greater amount of force to shear.
The last thing I would suggest is that there is no standard test for the capacity of these machines, so you don't know whether the 1mm steel was 300mm wide or 100mm wide. Similarly, does "capacity" mean that it can handle the same size sheet in all three operations (rolling, shearing and bending) or is it a last process standing thing? How much force was used to operate the machine? A moderate amount or an amount just under something that would cause permanent distortion? It would be interesting to get some hot rolled 250mpa steel 1mm thick and see how much force is required to bend/ shear/ roll.

Michael
(Of course, no machine manufacturer would dream of exaggerating their claims either)

Originally Posted by Stustoys

The shear tonnage is about the same "with the correct clearance"
If you machine is set for 1mm its going to be tight for 1.2mm. But I would guess that the machine is set even tighter than that. Does it cut printer paper?
Have you tried cutting 1mm MS?

Stuart

Hi Stuart. The clearance set is adjustable on this machine. I dont have any 1mm MS to try out. Will try it out on the printer paper with zero clearance as a trial. Before doing so I will go ahead and stone the edges of the shear blade.

Thanks for the feedback.

Stewie;

Originally Posted by Michael G

I guess there are a couple of things here.
Firstly, to shear material you are basically pushing one piece of material past another, so your shear area is thickness x width.
For the same thickness material you are talking 20% extra shear area.
Next there is material. Steel comes in a range of grades and I suspect that they use the lowest, softest grade they can when making these claims (the web page is saying hot rolled 250Mpa). You don't say what grade of brass but it could be quite hard and some brasses can work harden as well. One of my books gives brass strengths higher than 300Mpa for some grades. Shear strength is not a constant proportion of either, so for steel it may be say 50% of yield but brass may be 70% (WAG). so - you could have a material that is stronger and takes a greater amount of force to shear.
The last thing I would suggest is that there is no standard test for the capacity of these machines, so you don't know whether the 1mm steel was 300mm wide or 100mm wide. Similarly, does "capacity" mean that it can handle the same size sheet in all three operations (rolling, shearing and bending) or is it a last process standing thing? How much force was used to operate the machine? A moderate amount or an amount just under something that would cause permanent distortion? It would be interesting to get some hot rolled 250mpa steel 1mm thick and see how much force is required to bend/ shear/ roll.

Michael
(Of course, no machine manufacturer would dream of exaggerating their claims either)

Thanks Michael. A lot of good info. Well appreciated.

Stewie;

sorry didnt explain myself. Was trying to do two three things at once.
It if cuts paper its to tight for 1mm. It should fold paper. I just meant for it to be a rough clearance check to see how tight it is set.

Is it adjustable easily? I guessed it wouldn't be that easy to adjust.

Stuart

Originally Posted by Stustoys

sorry didnt explain myself. Was trying to do two three things at once.
It if cuts paper its to tight for 1mm. It should folder paper. I just meant for it to be a rough clearance check to see how tight it is set.

Is it adjustable easily? I guessed it wouldn't be that easy to adjust.

Stuart

Thanks Stuart. That makes better sense. Yes its quite easy and quick to change the clearance set.

I have been fairly busy of late building 4 more of these traditional box chamfer planes.



Stewie;

Lovely workmanship on that Stewie What sort of money do you sell them for please, as I would love to have a plane of that quality.
Kryn

Hi Kryn. Thanks for your inquiry.I will send you a pm nearer the completion date.

regards; Stewie.

planemaker,
How did you fare with the 3 in 1 Guillotine function ?.

Were you able to adjust it enough to cut your 1 mm brass sheet. There was a middle sized unit of the same make at a school I taught at. No one was ever able to get it to cut cleanly.

It was a real pain to use .A friend has hopes of buying one and I really can't advise him to, as I think its a common fault with them.

Hoping you have had success?

Grahame

Hi Grahame. I haven't had the time of late to focus on fine tuning the new Guillotine Shears. I would need to allow a couple of days within my schedule to do it properly. At the moment I am still focused on a 4 to 6 week completion date with the new box chamfer planes, so that's my current priority.

I do have another back up shear which I have used in the past to cut my brass. (See attach; similar type). It cuts through the 1.2mm brass plate very easily, but you do end up with some distortion to the surface flatness, requiring later straightening out. Getting rid of that distortion was the real impetus for me purchasing this new Guillotine Shears.

http://www.ebay.com.au/itm/3S-5R-SEA...item540b5a7df8

Even after I complete the fine tuning, I would not be surprised if I still have to rely on the old shears to apply a starting nick before the new shears will cut right all the way through the brass plate.

Time will tell.

I would recommend your friend looks for another machine with a bit more grunt.

regards Stewie;

If your looking to cut saw plate steel, the old shears I use do a very good job.

In the USA they do have access to the better designed Beverly Throatless Shears for cutting saw plate.

https://www.tinmantech.com/html/beverly_shears.php


Here is a Tenon Saw I made about 12 months ago.



Stewie;