At work we had a modified battery drill driven din rail cropper. It used a straight guillotine type shearing action.

Martin C

On 31 July 2024 at 12:37 bernard towers Said:

…or find a friendly laser cutting company

Please have a look at part numbers 8 and 9f here:

https://www.meccanospares.com/mid-green-angle-girders/page/1/

Please suggest how a part 8 might be cut into a number of parts 9f using a laser cutter that generally only cuts contours on the XY plane.

Please suggest how you would arrange and secure the parts on the bed of the machine so that the cuts are square to the axis of the part.

Please advise effect on the multi-thousand pound laser apparatus from cutting a painted (or zinc plated) item.

I am quite sure that being a mature and sensible poster here you would not just blurt out ‘laser cutting’ without having considered these issues in some detail, so please share your wisdom with us.

How many is “a lot” ?   Unless you are talking hundreds, it is not worth making a special cutting tool. Instead use a simple guide and hack saw as already suggested. Clean up the ends with a file or belt grinder.

On 1 August 2024 at 08:05 Martin Connelly Said:

My personal method would be to fit a fine tooth belt on my bandsaw and batch cut a nested horizontal stack of them to length because I have a bandsaw with controllable rate of decent and some fine tooth blades.

Martin C

Well, try it and see!   Difficult to stop delamination and other unwanted nastiness as the teeth break through each piece.   A jig that grips a stack of angles firmly on both sides of the cut comes to mind.

I  think Bob is very much on the right track with a die, but quite a lot of Gauge Block needed!

Bob having a fly-cutter suggests he has experience in sheet metal work, where shearing is often the best way of cutting it.    Word of warning to Model Engineers – the metal-working techniques most of us have available are extremely limited compared to what a manufacturer can deploy.   Meccano would never have used a saw, laser cutter, water-jet, lathe, milling machine or grinder to make ½” angle.   They’d have a line of shearing, pressing and stamping machines churning them out very quickly by the thousand.

Much depends on how many Part 9fs Bob needs to make.   Less than 20 could be done tediously using ordinary techniques, junior hacksaw etc.   Making more than 50 definitely calls for a production method : saw or shear jigs etc.

I have some experience modifying Meccano strip by sawing and milling, and it didn’t go particularly well. Needed several Part 6a (flat strip with 3-holes), and have plenty of mangled long strips to recycle.   Hacksawed them to length and made a fixture to hold them in a rotary table to mill the rounded ends.  Left me convinced there must be a better way!

I don’t know where Meccano got their steel from, but I found it to be gritty soft stuff that didn’t machine well.   My guess is Meccano strip was manufactured from a roll of dead mild-steel plate normally used to press parts.  No problem for making models from stampings, but the steel isn’t structurally strong and is more than obviously less machinable than EN1a!

What are you making Bob?   Do I detect a proper grown-up Meccano modeller aiming to win prizes at Skegness?

Dave

On 1 August 2024 at 17:34 Bob Said:

Dave

I am working on a model of the Fishguard Titan Blocksetting crane …

 

Excellent.   I’d have to buy a bigger house!

Dave