Cutting leaf spring for draw knife!!!

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rapsod · #1 Post by **rapsod** » Sun Dec 18, 2005 3:27 am

Yeah!!! Is is job for man!!!

rapsod · #2 Post by **rapsod** » Sun Dec 18, 2005 3:33 am

Job is done but not without sacrifice. My favorite worknk t-shirt almoste took fire. Now I have big air vent on my belly. After that I mont a "thermal shild" that I find on junk yard .

rapsod · #3 Post by **rapsod** » Sun Dec 18, 2005 3:38 am

It is simle piece of pine wood that in one moment took fire. It is hard steel.
That hole is long 15cm. Behind that white t-shirt is my belly. I am very attach to it so it it woud be very bed if something burn it.

rapsod · #4 Post by **rapsod** » Sun Dec 18, 2005 3:50 am

I use this cutting plate. It is for inox steel but what the hell... it is good for wood cutting also. It is 1mm thich and I must say that it cut exatly 1mm.
What means 13300 rotation in minute? It is max speed or min speed? My bosch hand grinder or how ever you call it can max rotate at 11000 rotation in minute.

rapsod · #5 Post by **rapsod** » Sun Dec 18, 2005 3:59 am

This is my leaf spreing stock. I hope that I will have enought for at least 5 draw knife. I am going to make diferent types of draw knifes and few irons for japanese plane disagned by me.

rapsod · #6 Post by **rapsod** » Sun Dec 18, 2005 4:11 am

Now, I am going to soften that piece of steel in order to make it perfectly streight. After that I will use special grinding plate for sharpening.
The main problem is how to temper steel. This type of steel. I find out that
leaf spring is tempered 2 times. Firs to mecome very hard and that in lover temperature to become spring and not to breake. You can find this on www.eatonsprings.com in section about reacting or something like that. (I hate english. I don't know how you write it. I think that it is easier to learn writing chinese that to write english. Why don't you take our serbian metod of writing.)

#7 Post by **Stickbow Hunter** » Sun Dec 18, 2005 12:07 pm

Rapsod,

Looking good so far. It is interesting that you are making your own draw knives. Please keep us up to date with your progress.

What country are you from?

It would seem that you are going to use the draw knives for making bows. What woods do you use for making your bows and have you any photos of your bows?

Thanks

Jeff

jindydiver · #8 Post by **jindydiver** » Sun Dec 18, 2005 5:49 pm

I also use that type of cutoff wheel. It makes the job 10 times easier when it only has to cut such a thin slice. The revs written on the side are the MAX revs the wheel should be used at.

You will find that when you use the springs at the temper they are now they will sharpen OK but will not hold an edge. You can reharden your steel if you have access to a forge or you can build a big enough fire.

Get your fire raging and build up a good bed of bright orange coals, as hot as you can get it and put your knife in the coals. You will need to move it around a fair bit to get the temp even and when the steel is bright orange you take it out and let it cool in the air. This part is called Ã¢â‚¬Å“normalizingÃ¢â‚¬Â and is to relieve the stresses in the steel from your grinding.
Next you need a big flat tray with vegetable oil in it. The tray needs to be big enough that you can easily fit the blade into the oil. Get your blade very hot again (you can check that it is hot enough by getting a magnet and seeing if the magnet will stick to the hot steel, if it doesnÃ¢â‚¬â„¢t then it is hot enough). When it is hot enough, pull it from the fire and place it in the tray edge down in the oil. It will smoke and sizzle and maybe catch on fire if some of the blade is exposed, and leave it in there until the blade has lost most of itÃ¢â‚¬â„¢s heat.
Take it from the oil and give it a good clean, being careful to not drop it and then place it in your preheated oven set at around 140 degrees Celsius. After an hour you can turn the oven off and leave your blade in there over night. In the morning you will have a blade that will be well tempered for your use.

Here is a web page showing the basics
http://www.engnath.com/public/harden.htm
It is in degrees F so you need to convert the temps.

Your steel is 5160.

rapsod · #9 Post by **rapsod** » Mon Dec 19, 2005 6:37 am

I am from serbia and montenegro. That montenegro part to be precise. I make my own draw knife because I don't know where to buy it. And because I love metal work. I realy love metal work.
I didn't made nither one bow. I am going to make a english longbow. I need draw knife for rough work and than spokeshave for rest of it. You can find project of spokeshave at http://rapsod.altervista.org/spokeshave.pdf because I can't post pdf file. It is based on Veritas spokeshave kit for DoItYourself. You can't print file and there is no dimension. I don't want Veritas accuse me of stealing their project. I just use their instruction how to build it and that can bi found on http://www.leevalley.com In that help you can find every dimension of spokeshave.
I am probably going to use combination of ash and maple or juniper. Yew grow but it is rare and protected tree. People say that it keep away evil so
thay cut it often so...

I find another "recepie" for hardening. A forget what site was but was about one man who use this steel for plane iron. I softened one little piece of steel
and than try to cut it with metal saw. Soft as cheese. Then I warm it until magnet coudn't atract it. I put it in kitchen oil and become very hard. But
not as hard as it was before my intervention.

#10 Post by **Stickbow Hunter** » Mon Dec 19, 2005 8:49 pm

Thanks for that information rapsod. It is interesting hearing of things from your part of the world. It would seem that Ash of some sort is used right around the world for making bows. Keep us up to date with how the draw knives are coming along and post some more photos as you progress more.

Jeff