Fly Press Struggles

I need to illustrate just how ineffective I am finding this fly press at what I thought it was the perfect tool for. What am I doing wrong here?

As uneven as my hammer blows were, this is barely making any impact at all.

Should I be trying to clamp down the work firmly and take multiple blows to the workpiece? At the moment I am just trying one heavy swing - the fear of doing a double blow / double print and it just looking a mess is obviously a concern.

What would you do ?

I should add, I believe it's a #2 fly press (despite having #5 painted on it). It's Sweeney and Blocksidge. It has 1 weight on the handle, which is labeled "10".

This is my attempt with the press...

This is my attempt with hand and hammer

(I thought best to make a new thread as it's got nothing to do with an arbor press anymore? https://www.model-engineer.co.uk/forums/postings.asp?th=134731)

Edited By Richard Harris 5 on 03/08/2018 12:01:52

Does your press have an iron ball on the other end of the swinging arm? This is how they work - by storing energy from the swing in the weight to release into the job. If it has the weight and doesn't provide enough force then you need a bigger press (not a bigger weight which would end up breaking something).

Hi Richard,

I am not an expert on fly presses but I think that the number represents the pressing force in tons. You said that yours is a #2 and a 2 ton press is probably not big enough for what you want to do.

Paul.

Your touch mark from the photo seems to have quite a large area requiring more force,

On my blocksidge the type number is stamped on the top of the ram ie a number 3 stamp.

I stamp when hot just before hardening and tempering,

Nice work I can see why you would want to touch mark it ,

I also visit " iforgeiron.com " for help and advice with my forging.

Regards Eric

These thoughts are offered for comment and criticism!

• The stamp needs to apply enough pressure to cause plastic deformation in the steel blade.
• The web suggests soft steel deforms at about 200Mpa (29000psi) and hard tempered steels at up to 1600MPa (232000psi)
• We don't know how hard Richard's blade is at the point the stamp is applied but let's assume it's softer than at the cutting edge and will deform at about 500Mpa (73000psi)
• Richard's flypress can apply a force of about 2 tons, 4500lbs
• Assuming the steel deforms at 73000psi, a 2 ton press can only apply enough force to deform an area of 4500/73000 square inches, ie. 0.06 square inches, which is about 1/4" square.
• Assuming the steel deforms at 29000psi, a 2 ton press could apply enough force (without breaking the frame) to deform an area of 4500/29000 square inches, ie. 0.16 square inches, which is about 2/5" square, still quite small.
• Provided the cutting part of the stamp is sharp within these limits, it should work well with a 2 ton flypress. But attempting to stamp flat areas won't.

It suggests to me that Richard should redesign the stamp so that his large initials are marked out with sharp edges rather than broadly defined by large flats. It would also be easier to stamp the metal in a soft condition. Using two stamps would help by reducing the area being deformed per strike. Perhaps one stamp to apply initials, and another to apply 'ENGLAND'.

Might be worth experimenting with the press and some smaller stamps to find what it's actual limits are.

I'm uneasy about my plastic deformation logic for several reasons! However, I hope it's more accurate than suck it and see and someone else will do better. Any suggestions?

Dave

Hi Richard, if it's a No. 2 it will be about 340 to 360 mm across the base and will weigh around 75 to 85 Kg. If however it's a No 5 it will be close on 500 mm across the base and will weigh 250 to 280 kg, this is assuming you have a standard flypress. In your thread that you were asking advice about a flypress, you said that you temporally bolted it to the floor and it ripped the bolts out and tumbled over. I'm a bit confused about that situation, as it should not have done that, unless, you have bought a bar flypress and you have left the bar out or it is missing and you are stamping metal which is sitting directly on the floor. A photo of your flypress may help us with a bit more advice.

Regards Nick.

Edited By Nicholas Farr on 03/08/2018 16:58:33

I have the ball on the end of the arm - it's labelled "10" and seems to be the original / right size for the press. It was quite an effort to find one reasonably local, then to buy it, go collect it, load it, unload it etc... I really hope I can do the job with this as we certainly don't have any use for two fly presses!

While this doesn't help with regard to the fly press would a hydraulic press be more effective. You can get 12 ton presses around £85 and 20 ton presses around £110. If the metal is near red heat then I suspect it would deform reasonably well with no risk of a double impression. The only drawback is that the stamp would be in contact with the hot metal for a little longer, whether that matters or not I don't know.

Just a thought.

Martin

Thanks Nick. If you may have read above, I've now realised it's a #1 fly press. The smallest. In my defence, the #1 marking is half an inch tall and not very deep, on the ram, covered in crud - unless you know where to look, you won't see it.

Do you have any suggestions for temporary bolting it to the floor?

It had 3 holes for mounting, but my attempt didn't work well. I drilled through the concrete floor then drove 3 threaded rods in with loads of this adhesive, and attempted to bolt them down. I think it was this stuff or similar: https://www.diy.com/departments/evo-stik-serious-stuff-solvent-free-grab-adhesive-0-29l/212376_BQ.prd

It didn't topple the press over completely when using it, but when throwing the arm around it lifted it out of the ground slightly (10 degrees or so). So rather than it coming to a dead hault and throwing all that energy into the tool, it throws a load of energy every where else.

Does that make sense?

I need to be able to lock it down completely, somehow. I don't have the time or means to fabricate an entire frame right now, I just want it locked into the floor.

I have since had a more successful experiment - this time taking more of a swing with the arm to try and generate more force, just about getting a decent print (on a very flat surface). BUT it still just lifted out of the ground, so it isn't working to it's full potential yet.

I have a photo of the press somewhere, bear with me...

Thanks Dave. I have had success using it to stamp numbers, this was my first experiment. It worked relatively well but the numbers are small and sharp, I don't have any issue doing those by hand (even cold). The stamp I've had made is definitely not a good design - I was thinking more about what I'd like it to look like, rather than how easily I can stamp it. But here we are... and I've bought the press now as well... I'd rather try and get this setup working, than go back to stage 1 and buy another touchmark.

That's okay Martin! I did think about this but preferred the idea of a fly press for it's simplicity... thinking it would work well... I am hopefully it will still work if I can get it mounted properly. The touchmark needs to be in contact for a very short period as otherwise it'll ruin the temper of the steel and it'll start to deform quicker. But I'm sure there are those who use a hydraulic press for similar things successfully.

Would bolting two large sleepers to the floor, then screwing down the press to the sleepers seem like a reasonable idea for mounting this? Need to stop it moving, somehow...