Need to get a small tool made - Materials

partyatmygaff

A short preface... I'm currently working on my leaving cert Engineering project and am having problems bending brass bars which form an essential part to my project's structure. Our method of bending brass rods is sticking it in a vice and hammering it to the required angle. Obviously it's not particularly accurate but an even larger problem that i'm having is that the bend radius is massive and the brass becomes brittle and snaps if you try and straighten it out to rebend it. I know it can be annealed between each attempt but that's really a rubbish way of doing things.

So i've designed a fairly simple bending tool that should get me an accurate bend radius and angle. I'm fairly sure it'll work but if you'd like to have a look at it send me a PM and i'll send you images or CAD files.

What I really need to know is a place that sells and shapes metals. I can't wait until school restarts as I can't waste time making it during class. I need to get it done before the 10th of January. If anyone knows a place or any useful information let me know.

FesterBeatty

Golden Pages - Toolmakers Dublin

http://www.goldenpages.ie/category_Toolmakers_County%3ADublin-1.html

Any of them will help you

FesterBeatty

[insert small tool joke here]

DublinDilbert

Have you looked at what plumbers / electricians use for bending pipe / conduit?

Your looking to get something cnc'd up. You'll probably get some one to do it early in the new year. If you give your location, someone here will probably recommend someone local.

partyatmygaff

Dublin 15.

It doesn't really need to be CNCed as such, it's just that I don't have the required materials and don't know where to find them (Plate steel and brass rod). It's a very simple piece and in a proper workshop it could be made in less than 25 minutes. I don't really want to go the CNC toolmaker route if it'll cost me a crazy amount of money.

For example I got a quote of €210 off an online CNC machinist (And that's only for the base). I know it's my leaving cert and everything but €210 for a plate of steel with 7 holes drilled in is asking a bit too much. I'm not averse to making it myself. I've a hacksaw, a drill, files and a tap and die set. Ideally that's all that I really need to make this. My only two problems are sourcing the materials and truth be told i've never actually worked with plate steel before so amn't too sure a hacksaw will suffice.

I've made up a quick two images here to get you an idea of how it will work.

Note: Both the handle and the base are steel.


Ideally, what i'd do is the following to bend a brass rod
(Note that the handle and the base aren't permanently fixed together)
1. Cut the brass rod to size and mark where it will be bent
2. Clamp the base in a bench vice
3. Thread the rod to be bent through the base lining up the mark with the 7th pole which will serve as my bend radius
4. Insert the handle in to the base and then begin bending using a protractor to measure the angle

So in short, any ideas on where I can find plate steel? Or better yet, does anyone have any suggestions? Would a wooden base be strong enough to withstand the torsion forces?

FesterBeatty

Engineering is all about keeping things simple...

You could spend a fortune (and waste a lot of time) on this and still the examiner won't appreciate the lengths you went to simply to ensure the rods are bent at a specific angle. It's only your leaving cert - so don't worry. Either heat up the rods and bend them as required, or simplify the process using a vice, some padding and a pliars!

If you're still determined to go down the long winded, unnecessary route then contact any local toolmakers, I had similar work done (on a larger scale) for my final year thesis, and a toolmaker in Newcastle sorted it out for me. Or make it yourself - Heaton's might have some scrap plate steel which you could work with.

Theres no way I'd use timber for the base. The timber surrounding the pegs will of course be subject to local crushing forces resulting from the torsion and will naturally lead to the pegs becoming loose.

partyatmygaff

FesterBeatty wrote: »

Either heat up the rods and bend them as required, or simplify the process using a vice, some padding and a pliars!

That's what I was telling myself earlier. It's taken me 2 weeks, 5 wasted classes and many destroyed pieces trying to bend those two brass rods. I then have to cut it to size, turn it on the lathe and then drill two holes on the rod. All of that has to be done after the bend (Impossible to do it after I bend the rod). It's frustrating enough getting all of that perfect and then having it destroyed again and again.
Here's my process from start to finish

1. Cut section of brass rod to 180mm
2. Chamfer one side to cut a thread using a die
3. Centre drill the other end to cut a thread using a tap
4. Mark out small rectangle in centre of piece, file flat and then drill
5. Mark out the 2 bend lines (One 70 and one 20 degrees)
6. Anneal the brass rod
7. Stick in a vice
8. Get a hammer and a protractor and hope for the best :pac:

I either get the angle wrong and snap the piece trying to fix the damage done or the the piece ends up looking like sh1t from all the vice marks and marks from the hammer. I'll waste a lot more time if I stick to the old hammer and vice method of doing things.

Or make it yourself - Heaton's might have some scrap plate steel which you could work with.

Heaton's? The clothes shop?

davey101

http://www.heitonsteel.ie/

http://www.impactirl.ie/


why not try one of these,
http://www.handyhardware.ie/product/22115/CM35-Copper-Tube-Bender-15-28mm
there are hydraulic versions too!

same principle as your design, without all the extra uncredited work. you could get one from a local hire shop or any plumbers you may know

slickmcvic

...what diameter brass are you using?,the 5 and 6mm stuff from MIKO is cast and as a result fairly brittle,if its for the frame of your ski-doo I'd use steel rod which is a lot better at bending sharp angles and can be easily tacked together with a mig welder.
Alternatively get your hands on a scroll set which should have a strip metal bender it'll do the job for ya
...heres mine (betwen the brushes)

suppliers here.....
http://www.metal-craft.co.uk/riveting-bending.asp

DublinDilbert

If your only bending very thin steel you might be able to make the base from ply wood. A piece of aliminium would be good also.

If your stuck and want to get something over the holidays b&q and homebase both sell metal stock.

kirving

Have you put the bar in a vice with a steel bar, and bent it around the bar to give a nice radius? If you dont know what I mean, reply here and I'll do a quick drawing - it always seemed to work for me. Soemtimes, we heated the rod as we bent it. Your teacher should really be guiding you on this.

You really shouln't have to pay for it yourself, but at the same time, if it's proving too difficult to do with the avilaibaly tools, find another way to do it(quickly) or give up on that route. It's really not worth wasting that much of your time.


My LC project in 2008 was a complicated design, but you have to remember to make it easy to build too - nothing was over over designed. Could you ring aroun anyother schhols localy to see if they have the strip metal bender? Would it fit in a sheet bender?

Once you sand it down, you can prettty much remove 99% of the vice / too marks.


As the others have said, look in B&Q or Woodies, or even a local hire shop for pipe benders too, might be worth a shot.

partyatmygaff

Kevin Irving wrote: »

Have you put the bar in a vice with a steel bar, and bent it around the bar to give a nice radius? If you dont know what I mean, reply here and I'll do a quick drawing - it always seemed to work for me. Soemtimes, we heated the rod as we bent it. Your teacher should really be guiding you on this.
.

The thing is that both me and my teacher have been trying (Without much success) to bend the brass rod. If it was steel or any other metal I wouldn't be having any problems. The problem is that the brass can only be bent once and in the direction of the bend only. I have to get the bend angles spot on the first try or it will crack and break from work hardening. The reason i'm having so much difficulty is that both angles need to be pinpoint accurate as either end of the brass rod is a threaded hole. If one angle is off by even a single degree they won't line up or if they will they'll put undue stress on the pieces they're connected to. Getting something to that degree of accuracy is hard enough with proper tools let alone with a hammer and vice. I've tried sticking another bar to between the vice and the rod to control the bend radius. It does help but there still is the issue of accuracy of the angles.

Turbulent Bill

partyatmygaff wrote: »

The thing is that both me and my teacher have been trying (Without much success) to bend the brass rod. If it was steel or any other metal I wouldn't be having any problems. The problem is that the brass can only be bent once and in the direction of the bend only. I have to get the bend angles spot on the first try or it will crack and break from work hardening. The reason i'm having so much difficulty is that both angles need to be pinpoint accurate as either end of the brass rod is a threaded hole. If one angle is off by even a single degree they won't line up or if they will they'll put undue stress on the pieces they're connected to. Getting something to that degree of accuracy is hard enough with proper tools let alone with a hammer and vice. I've tried sticking another bar to between the vice and the rod to control the bend radius. It does help but there still is the issue of accuracy of the angles.

I know nothing about your overall design, but it sounds like you have both a material and design problem here. The brass is seems to be too brittle for this type of fabrication - can you substitute with something else instead?

The bigger problem though is that both ends are threaded, so the dimensional tolerances of the ends of the bent rod are tiny (equal to the thread tolerances). Even with the most careful jig-based bending it mightn't be possible to assemble the parts together, and getting single-degree tolerances with hand bending isn't a runner. I'd strongly consider revising the design to have larger hole sizes in the mating parts so it's actually manufacturable.

Try not to get too engrossed in this and waste time - it's a small part of one project of one subject in the LC, and you need to use your study time wisely.