Building a bigger Easton & Anderson Grasshopper

[Jasonb]

The price is really based on machine time which is affected in several ways

1. The quality of the cut, I had the rings and spokes cut to the Q3 finish which is middle of the road and the teeth with a better Q2 on the advice of the cutters rather than the Q3 I had asked on for all the job.

2. Cut outs, each time the jet has to cut into the metal it takes longer to pierce a hole than cut.

3. Length of cut and changes of direction, the teeth cost a lot more to do than the plain rings, radiusing all the internals also helps as their are no stop/starts caused by sudden changes of direction.

4. Thickness, not only the cost of material but it takes longer to cut thicker material.

The cutters just load the file into their estimating software and it will spit out the costings.

The two rings were approx £20GBP each, the metal would have cost me just under half that.

The spoked cog at 8mm would have cost about £15 if I had bought the metal but supply and cut was a little over £60 GBP so a similar sized but more complex item cost around four times as much

[pgp001]

Jason

I am well impressed with that flywheel, well done.

How would the end results and the prices compare with laser cutting ?

Phil

[zeeprogrammer]

I saw the flywheel post at work and couldn't wait to get home so I could see the pictures.
Awesome!

[Dave Otto]

Beautiful work Jason.

Thanks for sharing.

Dave

[ref1ection]

That's some amazing work. Lots of tips and tricks to be learned in every post. I must start making more time to keep up on these builds.

Ray

[ths]

Really nice work, as well as concept, with the flywheel. I really like the riveting of the spoke webs. Were they countersunk at all?

Hugh.

[Jasonb]

I think lazer cutting would come in a bit cheaper but with the disadvantage of hardening of the cut edges

Yes the holes in the webs were lightly countersunk with a 60deg bit rather than the normal 90deg as they were not really taking any strain and its easier to expand the rod into the CSK so less risk of swelling the web.

J

[steamer]

Nice bit of fabrication there Jason!  All duly filed away for another day!

Dave

[Ramon Wilson]

Excellent work Jason - who needs castings when you can come up with something as convincing as that - looking forward to seeing more in due course.

Ramon

[Jasonb]

Next on the agenda are the "A" frame supports that the beam tie bars fix to. I started out by marking the shape onto an odd bit of 1.5mm plate, clamped it to a second piece, rough sawed the two out and then filed to the final shape.



Next a couple of strips of the same material were cut off, I find the easiest way to cut thin sheet is to place it between two scraps of MDF as this stops it flapping about and jamming the saw blade.



These were then just bent by hand and tweaked until they followed the shape of the "A" I also machined up a bit of 3/8x 5/16 with a slot in the top to form the feet.



Some slightly thinner material was cut & bent to form the inner flanges and then the lot silver soldered together along with a flat piece of plate for the cross tie. After that I soft soldered in a piece of copper to complete the flanges as it was getting hard to hold any more pieces together for silver soldering.



Finally some brass disks were soft soldered on to form the bosses where the rods and tie bar fix



The flanges and bosses were then all milled back to the correct widths, the outside one is narrower than the feet and the inner ones narrower still. Fillets added with Miliput, primed and a few simple turned parts from steel and another part can be crossed off the list.



J

[zeeprogrammer]

Always interesting to see your fabrication of parts.
It goes beyond the turning and milling most of us do.

Question: At the top of the stands...the pre-finished parts shows the brass disks and empty space to either side. The finished parts appear to have some of the top filled in on either side of the disk. How was that done?

[tvoght]

I know it's not as easy as you make it look, Jason, but I really yearn to do this kind of fabrication. I rub my hands in anticipation every time I see a new installment to this build. Thanks.

--Tim

[Jasonb]

Zee, a little JB Weld found its way in there.

J

[ths]

Jason, this sort of fabricated casting has always impressed me. a couple of questions:

1. You have the A shape, around which is formed another piece (does it have a name?), does it want to deform during the soldering process?

2. How did you then attach the other section once the A was complete?

Hugh.

[Jasonb]

I used three pieces of steel tying wire, one at the top and one on each lower leg of the "A" and  a few stratigically placed blocks so the silver soldering could all be done in one heat. The small piece of copper was the next heat but at a lower temp and being it was a tight fit there was no risk of it moving when the final heat to fix the brass was done.

The small bosses for the tie rod have spigots on them to locate in a hole in the steel The top ones were just held in place with blocks with the "A" inverted.