View Full Version : bending cast iron


Goofour
01-29-2005, 05:38 PM
I need to bend the arm on a auto spindle about 1 inch. can this be heated and bent?

HuFlungDung
01-29-2005, 07:31 PM
Its most likely not cast iron, but steel. If its cast, it will let you know right away by cracking off :D

sendkeys
01-29-2005, 08:27 PM
I think HuFlungDung is right and it's steel. Almost all that i seen are even very old stuff. So i dont think you will have a problem. Just remember to let it cool slow as it can. dont dump water on it :) Would suck to harden it and have it break running down the road. Much better for them to bend if they get overload :)

JEFFY
01-29-2005, 09:03 PM
Most spindels are steel, heat it up and bend and let it cool slowly, don't qwench it!
I have done it several times in the past for race car projects, all where GM products.
An inch is a lot to bend on a arm thats only a few inches in lenght, we would weld extra mounts in the spot we needed. Also note that you may be able to find a spindel that has a bolt on arm, these arms are a lot easier to work with somtimes.

ViperTX
01-29-2005, 11:46 PM
Come on....you need a matched pair....buy some dropped spindles...much cheaper and safer.

Hobbiest
01-30-2005, 03:47 AM
Come on....you need a matched pair....buy some dropped spindles...much cheaper and safer.
Usually this kind of a modification (in my hot rod experience at least)has more to do with steering interference. As stated above, heat the arm cherry red with a rosebud, bend slowly, air cool. For best performance, try to match the origional orientation between the hole and spindle shaft. As also stated above, dropping the arm will shorten it, relative to the amount of drop, and may change steering geometry. Be sure to keep your ackerman geometry (type into search engine), and if safety is a concern to you, have the spindles magnfluxed afterword. BTW...what kind of a spindle is it? My experience is with early Ford parts. Good luck.

Goofour
01-30-2005, 09:06 AM
Thanks for your responces I am trying to use S10 spindles and brakes on a Triumph Spitfire that I installed a 350 chevy motor in. I modified the controll arms to hold ball joints but I was having trouble with the bump steer because the tie rod arms had to be shorter. Bending the spindle arms outward should fix that.

JEFFY
01-30-2005, 09:22 AM
HE DID NOT SAY HE WAS DROPPING IT! Just for your info, he said he was wanting to bend or adjust the arm. Its not uncommon to have to adjust the arm postition after some form or another when you modify for racing or off road, also for your info on oval track in not uncommon to have differant spindels on the left and right sides. For off road where a higher ground clearance is needed and done with a lift kit, the steering gear is stiil on the frame and now with the height differance sometimes you have to adjust your arms and linkage to get the wheels to turn in there proper arcs(ackerman effect)
FYI: never broke a spindel after any of the mods that where done to several differant spindels use in dirt track racing in 25 years

Goofour
01-30-2005, 09:42 AM
Here is one more question I was thinking of using a larger tie rod end but the arms on the rack are 1/2" Would it be safe to weld a thicker bolt on the arms that will fit the stronger tie rod?

JEFFY
01-30-2005, 10:06 AM
having trouble with the bump steer because the tie rod arms had to be shorter. Bending the spindle arms outward should fix that.
Take a look at the pivot points first, a general run of thumb is the top ball joint and bottom ball joint, draw a line between pivots and the ball of the tie rod should fall in this line. The inner pivots should be the same, then try to get the tie rod linkage level with the control arm it close to. The lemght of the tie rod assembly should be at the two lines, GM generaly has there point match the lower control arm, take a look under a S10.
You should also look at you old spindel arm height, as bump is more tied to a differance in arc pivot heights.
Try the arm as is but with some washer on fitted to the taper of the rod end to raise the pivot and check for bump, if the bump decreases thats the way you move it(the washers are for bump test only)

Goofour
01-31-2005, 09:48 AM
First try failled. The arm is about 2" wide and 1" thick after heating it didn't stay red very long but it did bend. After the second try it cracked. Am i not getting it hot enough or did I bent it to far? (1" was easy I was going for 2")

HuFlungDung
01-31-2005, 12:32 PM
You may have not had it hot enough, over a wide enough area. You don't want to force all the elongation to occur over a 1" width. If it is a severe bend, you might want to hammer it firmly (only while it is still red hot) to improve the grain of the stretched area. Then, bend it a bit more, if necessary. Use a good sized hammer, you want to dent it to show some indication that you are moving a few molecules around. :D

Maybe it is cast iron, or malleable iron, which resembles steel up until the time you heat it, after which it reverts to cast iron again. There's no cure if that is the case.

Did you try a spark test? Just grind a little bit of the part's corner on a grinding wheel to find out if it is cast iron: dull red sparks, low in number, indicate cast iron. Compare that to a known piece of steel, which sparks quite bright orange, large volume of sparks.

Hobbiest
01-31-2005, 11:24 PM
Thanks for your responces I am trying to use S10 spindles and brakes on a Triumph Spitfire that I installed a 350 chevy motor in. I modified the controll arms to hold ball joints but I was having trouble with the bump steer because the tie rod arms had to be shorter. Bending the spindle arms outward should fix that.

Is the height of the spindle the same? If the S-10 are taller, then the arms will be in a different arc. The wheelbase on the S-10 should be longer than that of the Spit, so yes it would make sense to ben the arms outward. If there are any attachment points on the spindle which would accept longer bolts, you may be able to make new steering arms out of steel plate. Just some thoughts...hope they help.

BTW...JEFFY? Take a pill daddy-o...we're all just trying to help, including (I assume) you.

pbhayes
10-08-2006, 06:05 PM
Hey Guys,
I found this thread and have the same problem as Goofour had when he started this thread. I need to bend a Saab steering arm 1" out-wards to adjust the Ackerman. I see that it has been over a year from the start of this thread so I wonder if Goofour had any luck.
Or for that matter does anyone have any advice especially with regards to cooling the part. or past success / failures

To give you an idea what I am doing:
I am building a 3 wheeler, 2 front wheels for steering (and front wheel drive),
1 rear motorcycle wheel just to hold up the rear.
I have mounted a Saab front end to a 2" square steel tube frame. I used a BMW posi diff. inner C/V joints are BMW outer C/Vs are Saab. (I re-splined the axle shafts) and a custom built centered Mavel rack and pinion.
It is to be powered by an 8" ADC electric motor @ 96 volts.
I mounted the right side spindles on the left side to make it a front steer rig. and to give clearance for the electric motor.
this led to a reverse in the Ackerman angles. (big Bummer) but I can fix it.
(I hope)

Thanks Paul

Goofour
10-19-2006, 06:58 AM
I tried heating a spindle from a S10 pick up. I could get it red under the torch but I could not get enough heet into it to stay red for long. So when I bent the steering arm it cracked. I tried twice and failed so I went a different route.

Switcher
10-19-2006, 07:47 AM
Maybe this site will help you?

www.blazinlow.com

.

pbhayes
10-21-2006, 12:38 PM
Thanks for the reply,
As they say timing is everything. Had I read your reply day before yesterday I may not have tried it, but I made the bends yesterday with no problems. I made a 1" bend in the two arms and got them within .004 of each other. I took the advice of just to let them air cool rather than to insulate them to slow the cool down time. This seems to have worked OK, but I have not load tested them yet to see if they are too soft now. I won't know how close the Ackerman will be untill I replace the bearings and reinstall everything.
($105.00 each) I think it will be about 12" in front of the center line of the rear wheel. but this is as far as I could bend them before they would rub the brake roters.

Thanks
Paul