Chainsaw Repair

Chain - Grinders - Filing - Wood Milling - Tools - Welding - Machinist - Mowers - Tillers => Tool Shed => Topic started by: KilliansRedLeo on April 01, 2014, 12:40:21 pm

Title: Making new ends on recoil springs
Post by: KilliansRedLeo on April 01, 2014, 12:40:21 pm
I have been using a little gizmo I found at the hobby shop that makes those little circular ends on the recoil  springs. You basically heat up the end of the spring, slip it into a slot in the tool and twist the tool round to form the rounded end. It is not in the RC stuff, it is in the clock making supplies, I believe it is really intended for large clock springs. Whatever it works great, I will post some pictures perhaps Al can figure out how to make it on the cheap.

Went looking on e-Bay and found something that may work even better:

 http://www.ebay.com/itm/Bail-Shaping-6-In-1-Bail-Making-Pliers-Multisize-Loop-2-Mm-To-9-Mm-Tool-HD-New-/331145956365?pt=LH_DefaultDomain_0&var=&hash=item4d19d64c0d  (http://www.ebay.com/itm/Bail-Shaping-6-In-1-Bail-Making-Pliers-Multisize-Loop-2-Mm-To-9-Mm-Tool-HD-New-/331145956365?pt=LH_DefaultDomain_0&var=&hash=item4d19d64c0d)
Title: Re: Mkking new ends on recoil springs
Post by: 660magnum on April 01, 2014, 12:46:34 pm
Good find.

I've been making them with regular needle nose pliers but you have to study the shape and figure just how to hold the spring to start the bend.
Title: Re: Making new ends on recoil springs
Post by: aclarke on April 01, 2014, 11:32:01 pm
Cool stuff!
Title: Re: Making new ends on recoil springs
Post by: 3000 FPS on April 02, 2014, 12:12:40 am
How about cutting the end off an old screw driver and then slotting it to fit the spring you are bending.
Title: Re: Making new ends on recoil springs
Post by: KilliansRedLeo on April 02, 2014, 05:24:54 am
That is basically what the tool I got from the hobby shop is except that it is a 'T' handle. I suppose the 'T' is to give you more leverage when bending. It does work pretty well.
Title: Re: Making new ends on recoil springs
Post by: countryhog on April 02, 2014, 07:23:49 am
i always get confused. when you heat spring steel and bend it - do you air cool it to retain its springiness or do you quench it?
Title: Re: Making new ends on recoil springs
Post by: 3000 FPS on April 02, 2014, 10:29:42 am
I might be wrong on this but in my experience once you heat the steel the spring I'd gone.   If you quench it then it can become brittle and break easy.   So I just let it air cool.   That part of the spring does not need to have any spring in it any ways.

I believe to get spring steel the conditions have to be held just right including.  The correct temp, length of time, and special quenching methods none that I am an expert in.
Title: Re: Making new ends on recoil springs
Post by: KilliansRedLeo on April 02, 2014, 10:48:01 am
You are correct Roger. Too hot and quench in water = brittle, quench in oil = softer but usually it takes two heatings and two quenches to do it correctly. A really good blacksmith can do it in one heating. Heating to correct temp is critical and IIRC is actually done by color.
Title: Re: Making new ends on recoil springs
Post by: 660magnum on April 02, 2014, 11:42:46 am
The "H" grade of steels always needed a double anneal.
Title: Re: Making new ends on recoil springs
Post by: countryhog on April 02, 2014, 04:07:17 pm
true on the no springy need thing. so hows about regular carbon, nonspringy, steel. when heating to  bend or fabricate should it air cool or quench so as to return to its preheat level of stiffness? don't want it brittle but also want it to hold shape - say its for an "L" type bracket
Title: Re: Making new ends on recoil springs
Post by: 660magnum on April 02, 2014, 04:15:09 pm
The oil is safer than water from that point of view.
Title: Re: Making new ends on recoil springs
Post by: 3000 FPS on April 02, 2014, 05:15:23 pm
With regular mild steel I do not know if I would worry about how it is cooled.
Title: Re: Making new ends on recoil springs
Post by: Al Smith on April 02, 2014, 08:06:42 pm
You cannot harden mild steel by heating and quencing .Spring steel do not heat it to the scaling point or else it will fail .A little bit past cherry red .

Oil is better for quenching because once water boils it lets in oxegon  .Sounds hard to believe but remember water is H2O .
Title: Re: Making new ends on recoil springs
Post by: countryhog on April 03, 2014, 10:20:49 am
thanks guys, nice to have some people with metallurgy backgrounds. that's one of my many weak areas

another question. i've heard of people making knives from old lawn mower blades by grinding down to a desired shape and then sharpening with a wheel before doing all the fine tuning by hand. i know there're tricks to this. after grinding do you quench it with oil or air cool. i know those blades are both springy and hardened and its not a 5-cent answer but 5-cents is all i got. thanks much, jerry
Title: Re: Making new ends on recoil springs
Post by: 660magnum on April 03, 2014, 10:45:36 am
If you don't turn them blue, you don't have to heat treat them at all.

Some steels will crack or get too hard with water so oil is a safer bet.

The true way to heat treat steels from a layman's point of view is to heat them to a cherry red (this temperature is above 1333F) then quench them in water or oil. At this point they should be full hard. This may be too brittle so you draw them back by heating to 550F and hour per inch of thickness and let them air cool.

Regular 1018 steel will not harden.

Some tool steels like A1 and D2 are air hardening. You just let them cool on their own after heating up to 1550F. Then they have to be drawn back.

Got to tell a story at this point:
A devious character that worked near my machine shop wanted to make a anvil for his log splitter. Log splitter anvils are not hard but he didn't know that. Anyway, he got a block of steel from my tool steel area marked D2. After sharpening it like he wanted in the saw, he heated it up in the heat treating furnace and when it was cherry red, he dumped it into the water tank, whereby it exploded into a thousand pieces. He didn't mess around the tool steel any more.
Title: Re: Making new ends on recoil springs
Post by: Al Smith on April 03, 2014, 09:16:44 pm
You gotta know how to read the colors to harden and read the "rainbow" to temper .It's all on the internet .A good site is anvil fire .

With me with a last name of Smith it's in my blood . ;)