Bending cast Brass, Question - Steering Spider

[Brian S]

I have a old cast brass steering spider that I need to bend the spokes to both match shape and luckly reduce the diameter size. Before I start in bending I wondered what is the best way to bend the brass. Should I heat each spoke with a tourch and bend them, or bend them cold..or? I just don't want to risk cracking the metal. Bending techniques are welcome also. ..vise, beat, etc. - Thanks for your advice! (photo attached...may be under "Attachment" above)

[Ivan Saxton]

It helps for a start to know what alloy mixture you are dealing with, but there are general principles. Brass can be annealed byheating to a dull red, and either leaving it to cool, or by quenching. Some metal spinners, when making for example a headlight shell which work hardens so it requires several softenings, drop the hot spinning job into a bucket of dilute vinegar (acetic acid). This has the advantage of leaving it bright and clean. Brass is "hot short". this means that if you heat and try to bend it will fracture. When it is not hard it will bend ok, or can be adjusted by light tapping with a soft hammer. Why would you want to change the size? It is not a big deal making a segmented rim with overlapping upper and lower rings. You would probably use walnut. Blackwood is most convenient for me. But best and easiest might be to get the Amish to make exactly what you want. (cheapest, too)

Ivan Saxton

[Brian S]

Thanks Ivan, The spider now is about an inch too large for the 17 1/4" wood rim. Bending it would match the shape I'm looking for and make it fit the correct size wood rim. (see image) I might concider a smaller rim if there's a risk of damaging the spider...or look for bigger spider. Amish contacts welcome! ...if someone cares to visit with a wireless laptop...

If I heat up to dull red, let cool, bend. Do I need to worry about strength afterwards? Heat and dunk afterwards?

- Brian

Replies from anyone welcome also.

[1937hd45]

Do you plan to drive this vehicle after all that heating & bending?

[Brian S]

Yes...and would not think it is all that uncommon. Any blacksmiths, silversmiths out there?

[Bhigdog]

Depending on the alloy the brass could be quite brittle. If you are determined to try bending, then heat the legs to DULL red in dim light and water quench. That will anneal them and should allow bending with the emphasis on "should". One problem is that the spokes will now be quite soft and could deform with usage. If it is a rare and hard to find part I think I would make the wood fit the brass. If it's replacable, what the Hell, you learn by doing.....Bob

[Coley]

The zinc content in the alloy would determine just how easily it will break.

I would try it only as a last resort and do it cold.

Maybe find a spare first???

[Ivan Saxton]

I personally do not think strength would be an issue after annealing and adjusting. With spokes ay an angle from horizontal, once the rim is attached it and the spider become a very rigid unit. I just made a blackwood rim (total 16 segments for the 1911 Napier. The 5 spoke aluminium spider is a casting from the pattern Bob Chamberlain made for his project to build a car around the original engine of Samson that Arthur MacDonald drove at Daytona Beach in 1903. (Bob made his design calculations and drawings from A.J.Rowledge' original design notebooks on the car!) Anyway, thogh the spokes are less than 3/16" thick, and the overall diameter of the wheel is around 19 1/2", the entire wheel is very strong and rigid. Of course, it is better not to change the spidr unless you have to. Phil Irving, who designed the championship F1 Repco-Brabham engines, once advised us that most often, after you had devoted a great deal of effort and expense in altering something, that you found that the designer was right in the first place!

This evening I caught up with David Dryden to get the Amish contact for you. David says that they are excellent to deal with in every way, and that he could not commend them more highly. However they do not welcome enquiries on Sundays or days of religeous significance. You should contact Witmer Coach Shop, 1070 West Main Road, New Holland, PA 17557. Believe it or not their phone# is 717-656-3411, and fax 717-656-4311; but they do not use computers. I saw the hood bows that have just arrived for David's 1904 Ford, most beautiful steam bendings, and amazingly inexpensive.

I would ask them if they can steam-bend and figure-joint a round ring of whatever colour wood you desire. If you do no good let me know thw inside and outside diameters you need. I have to make another set of segments (8 per ring, with the joints of the two rings staggered) for the King of Coonabarabran. John Ryder gave me a dimension, and when the spider arrived, it just didn't seem to match the size I had. Maybe even the pair of rings I already made would suit what you need.

Ivan Saxton

[Brian S]

Thanks all & Ivan,

I'll give the bending a try and see how it goes. If it fails I may be searching for a brass spider to fit an outside diameter wood wheel of 17 1/4". Think the inside diameter is 14 1/4". Of couse if someone has one out there that looks simular to the images I posted under the "Attachment " link at the beginning of the tread, it will save me the hardship.

Brian, fairfaxca (add @) yahoo.com. Thanks.

[R Walling]

Steering wheel for sale Ebay # 280049572617