Making a flange

[rslaback]

Recently I picked up a snowblower project that was listed as needing some chute work.

It's a massive 32" wide cut tracked Craftsman. The chute issues is that the flange on which the chute rides has worn through and started to peel off. For those unaware, the chute sits on the horizontal section of an inverted flange that has been welded onto the circular opening. The chute is retained by clips that bolt onto the rotating section and extend underneath the flange.

I'm having a hard time determining my best method of creating the flange. It isn't a difficult part per se but I am not sure that I possess the proper equipment to make it well. I wouldn't even know what to ask in terms of having someone make it for me.

The flange is basically a revolved L with the minor diameter of 6". My original thought at first glance was to just cut a ring with my plasma cutter and ignore the vertical section but upon closer reflection I am not sure that I could weld it on tight enough that the retaining fingers wouldn't rub. I imagine this is why there is a vertical flange in the first place as it moves the welds lower and away from the retainers.

Any advice on the best way to make this flange?

 

[matt_i]

I think you want to cut the bottom flat ring out of a sheet. Then roll a ring with a 3-roll device from the same sheet (or an equivalent flat bar as its going to be long ~18-1/2") and size it to the cutout ID in the first piece. From there its tig welding or silver brazing if you ask me. Probably some hammer tweaking at the end (light taps) to restore the planarity of the bottom after the stresses especially if welding is involved.

 

[Stooge]

if im looking at it right, and the flange sits down into an opening, for the simplest way, i would cut the ring out of sheet, and then buy the smallest section of either 6 OD exhaust tubing, (you can probably thank the mall crawler lifted truck guys for that being relatively easy and cheap to get), would probably have to be a 1' length but also places like Speedy Metals, will sell 6" OD 1/8 wall tubing by the inch for $6 an inch, which could cut down another step on your end, then its just welding the ring and tubing together together
http://www.speedymetals.com/pc-3609-8242-6-od-x-125-wall-dom-steel-tube.aspx

 

[bugnut]

you might be able to use what is commonly know as an angle flange

see this http://www.nordfab.com/nordfab-products/adapters/angle-flange/

If you will pm me your address I have two 18v ryobi batteries that were ready to go into the bin at HD. I will empty them and send you the carcasses.

 

[BD1]

I would do as you say and cut the ring. Then get flat stock for the size you need and roll to fit ring. Tack and grind tacks.

 

[rslaback]

That angle flange might be the ticket if I can't find a way to make this.

I was thinking that a bead roller might be the ticket based on the first part of this video.

In terms of making the part as two and then welding them together, if I can't make it somehow from a single part I will probably just make a single ring and weld it onto the housing. The vertical section doesn't really serve a purpose other than making it so no welds exist in the corner. Making it in two pieces means that there would have to be a weld there.

I added in the pipe on which this mounts as well as the retaining finger which holds the top of the chute on. The gray portion needs to be able to rotate around the flange without snagging on any welds. I believe this is why this part is a 3 dimensional flange.

 

[ilovevocs]

This is a great application for a hammer form.


This guy is basically creating the opposite of the form your looking to achieve. Where he is shrining the flange you will need to stretch.

 

[MoonRise]

Slackers.

You need to tool up to be able to roll angle iron flange-out on a 90 deg. A nice Hossfeld with attachments should be able to do it.

Or go all billet on it and take a large thick ring and using a mill and rotary table, machine away the material that is in the way of the piece being a flange with a 90 deg 'lip'.

Or just go and cut a flat ring and then take a piece of flat bar stock and roll it into a ring and weld the two pieces together. Dress the welds as needed.

 

[rsanter]

How thick of metal are we talking?

I have a bead roller if you need that done.

Someone mentioned a hammer form, that was my first though as well.
Get some MDF, cut the hole the size you want it and round over the edge a little with a router bit.
You can harden the MDF a little with some CA glue or a smear of epoxy and some sanding to smooth it.
Cut a second piece with the same size hole or just slightly larger.
Do a large round over with the router on this one.
Cut your sheetmetal and cut the hole in the sheet metal smaller than the hole you eventually want.
Clamp the metal between the two pieces of MDF and start lightly hammering around the circle. Keep going and little by little you will have that flange formed

 

[DieselNut88]

Mcmaster carr sell duct flanges that might work. 6 1/8" i.d. 1/8" thick. For 6" duct.

 

[rslaback]

I have a 20 ton press. Would it work to try to form it by making a couple ring forms with a hole around 6.125" in diameter from MDF or similar and then try to push a 6" plug through the middle with my press? Essentially hammer forming in a single smooth motion with the press.

The existing ring is probably between 14 and 16 gauge steel. I haven't measured it yet.

 

[matt_i]

I think trying to stamp/draw the ring is probably the cheapest way to make hundreds but amongst the hardest to just make one.

Here's why. First you have to machine a 6" OD punch, then you have to machine a 6-1/8" die. I don't think MDF is going to cut it here, you need 1018/A36 at minimum so the workpiece doesn't smash the punch or die.

Next, the classic ironworker equation is LTS/2000 which is length 6* pi * thickness (0.062") x Strength 36,000 psi/ 2000 = 21 tons. Now you aren't trying to fail the material in shear but you have to get it bending and the inner flange stretching which is taking tonnage.

The part you wish to remain flat has to be thoroughly clamped so the material doesn't pull out so another exercise in making a thick flange to transfer the loads plus a bolt pattern, drilled one side and tapped on the other to hold the workpiece.

As you see a lot of machine work involved. It would eventually work (given the proper tonnage...I can't say with 100% accuracy) but you'd have to be prepared to blow thru a fair number of workpieces before you got the first dimensionally correct part. But then you'd be prepared to make hundreds

 

[rsanter]

I have a 20 ton press. Would it work to try to form it by making a couple ring forms with a hole around 6.125" in diameter from MDF or similar and then try to push a 6" plug through the middle with my press? Essentially hammer forming in a single smooth motion with the press.

The existing ring is probably between 14 and 16 gauge steel. I haven't measured it yet.

Odds are no, I’m thinking that press as well as wood for the center form will not be stout enough for the 16 or 14 ga
Give it a try and you can always use a hammer as a backup

 

[kkroger]

With 20 Ton you MIGHT get away with some zero condition Aluminum with good dies... Maybe. you COULD bend a piece of 16 into angle then stretch it with a stretcher on the outside fin... but it would be touchy and you really need to sneak up on it.

 

[kkroger]

This was a 2"x2" 18Ga "Angle" stretched into a circle

 

[rslaback]

I've spent enough time moving this project around. Time to get back on it. I actually machined out a mold to press out he flange from a flat ring but I had a change of heart. I think rolling it might work better.

First step: Buy one of these jobbers.



Second step: Turn up some custom roller dies.

 

[thunderalley3]

Hit craigslist and find a snow blower that has severe issues but a good chute. Cut it out and adapt it to your unit.

I know it is not as much fun but it is much easier!!

 

[MP&C]

For a one piece solution, starting with a formed ring (so you know the size is correct) you’ll need to stretch to get the flange to lay over. A tipping die on a bead roller will start the process of the bend but won’t provide stretch. Would be quite a bit of hammering for a manual operation.

If you started From a flat sheet, you would need to stretch the inside, but maintaining accuracy of the hole diameter is more of a challenge.

What gauge metal are you working with?

 

[rslaback]

It is probably 16 ga or so.

Tonight was time to cut a piece out of a scrap molding I had...




Take the top wheel off and go for broke.




So far so good. Time to cut the old flange off the blower so I can sneak up on the perfect size.

 

[rslaback]

For a one piece solution, starting with a formed ring (so you know the size is correct) you’ll need to stretch to get the flange to lay over. A tipping die on a bead roller will start the process of the bend but won’t provide stretch. Would be quite a bit of hammering for a manual operation.

That looks pretty slick. The only problem is that I am a Fuckwit so I am not allowed to use equipment like that.

 

[rslaback]

It's not perfect but few things I create are.