theblindwoodturner
Established Member
This is out of the realms of the other sectors of the board, so I'll post this bit here.
I've had folks ask over time, how I go about designing my custom tools and design for new products. I apologise for lack of photos.
I've replied to a topic on firmer chisels hence this post and it's been something I've meant to write for a while.
Tool making is one of the largest yet least used by "the average folk on the street" approach.
There are many myths and legends about various steels, suitabilities and methods of toolmaking and yes most are true. The question you have to ask yourself is....
What tool will solve the problem"
Tool designers and manufacturers design products which are there to make our lives easy and the trend these days is.... Why make life harder? make it easy on yourself......
What I'm going to write here is a background in my own approach to turning tool designs and adaptations. There are some areas I won't cover as they are processes closely guarded which make my own custom tools perform how I want them to perform.
First let's start off with the initial concept...
A sighted toolmaker can sketch up a plan in autocad or on paper and take measurements, etc to work out the best approach.
My method relies on scribe marking and working from a sensory level to work out what my custom tools will do and how they will achieve the end result.
The tools I use are pretty much standard. A 4-1/2" grinder with different abrasives, a bench grinder with aggressive wheels (change with fine wheels for finer finish), engineers files, a lapping plate, blow torch with mapp gas for higher temperature delivery. The crucial parts are also a quenching area. using water with a derusting agent and stabiliser and also an oil trough.
Depending on the weight of the tool needed and the profile needed, the steels I will often work with are M2, HCS or HSS standard. I have experimented with HSS Cobalt and found it very good for profile scrapers but the forming process is much longer and expensive.
Grinding....
Unlike a sighted person who sees where the blade is and where the sparks end up, I first position the wheel to the are in need of cutting, remove my hand and start, letting my body work as a kind of feeler gauge so to speak. relying on what the grinder is doing and dictating where I take off material. Each process and pass then is accompanied by quenching for as long as it takes to cool the metal to a suitable temperature. Each cut, scrape or polish achieves a different result and merging the overall shape to the relation of the cutter head is relevant. Where creating the cutter head, the steel is moved to a comfortable angle facing away from me, so that I am in a comfortable position to grind away from me and also let the grinder rock where necessary.
Creating the cutting tip / head...
What we ask ourselves is.. What will the tool be used for and its objectives required from it?
Take as an example a scraper as a pretty simple approach. The only areas of the steel which need to be formed are the tip and the tang so the blade can have it's handle of choice.n The cutting tip for a scraper foesn't have too great a detail. So the average profiles are:
Square,
Domed,
Round,
Right and left curve,
undersweep (creating lip and neck profiles)
V scrapers.
In this example, a domed scraper is created either on the bench grinder or angle grinder. My preference is with both tools. first off with the angle grinder to start the initial process. Then to create the balance on the bench grinder. Again as above, I grind away from me with the blade set so the final surface is relative to a 90 degree point. What I mean is, the steel will be positioned at a 30 degree or relative point to encourage an easier grind, I use a jig to set up the angle according to my grind preference. Each time, I feel the edge to keep myself in check. The grind continues on the bench grinder with a rest system set up to support the largest portion of the blade for better control. This prevents me accidentally lifting or lowering the angle needed. Slow and careful sweeps are used. Depending on a full round curve, I will use a rounding jig (initially used for the bandsaw methods). After all aggressive / stock removal methods are done, time to use finer wheels to create a fine profile. It's at this time I move from oil to water quenching as finer wheels remove less stock and impart a polish finish.
Finishing the scraper...
After the grinding has taken effect, it's time to give the tool some preparation in the form of lapping and polishing and the final hone.
a scraper benefits from lapping on all sides to create a flat surface which helps with harmonics generated by the tool against the spinning workpiece. It's a good idea after lapping to apply a light coat of tool protect or something like this so that when you have completed the honing process, you're ready to go. I'm always mindful of feeling each change I make in relation to the finished product and it's worth bearing in mind that the slightest of changes in the final form can make interesting differences.
Handles:
Always consider the blade length, width and thickness, to the proportion of the handle. my general rule of thumb is 2:1 (handle twice length of cutter bar) and in some cases 3:1. The handle is the most important part. Ergonomics play a large factor in the quality of your turning. For me, my handles take on a difference.
TBW
I've had folks ask over time, how I go about designing my custom tools and design for new products. I apologise for lack of photos.
I've replied to a topic on firmer chisels hence this post and it's been something I've meant to write for a while.
Tool making is one of the largest yet least used by "the average folk on the street" approach.
There are many myths and legends about various steels, suitabilities and methods of toolmaking and yes most are true. The question you have to ask yourself is....
What tool will solve the problem"
Tool designers and manufacturers design products which are there to make our lives easy and the trend these days is.... Why make life harder? make it easy on yourself......
What I'm going to write here is a background in my own approach to turning tool designs and adaptations. There are some areas I won't cover as they are processes closely guarded which make my own custom tools perform how I want them to perform.
First let's start off with the initial concept...
A sighted toolmaker can sketch up a plan in autocad or on paper and take measurements, etc to work out the best approach.
My method relies on scribe marking and working from a sensory level to work out what my custom tools will do and how they will achieve the end result.
The tools I use are pretty much standard. A 4-1/2" grinder with different abrasives, a bench grinder with aggressive wheels (change with fine wheels for finer finish), engineers files, a lapping plate, blow torch with mapp gas for higher temperature delivery. The crucial parts are also a quenching area. using water with a derusting agent and stabiliser and also an oil trough.
Depending on the weight of the tool needed and the profile needed, the steels I will often work with are M2, HCS or HSS standard. I have experimented with HSS Cobalt and found it very good for profile scrapers but the forming process is much longer and expensive.
Grinding....
Unlike a sighted person who sees where the blade is and where the sparks end up, I first position the wheel to the are in need of cutting, remove my hand and start, letting my body work as a kind of feeler gauge so to speak. relying on what the grinder is doing and dictating where I take off material. Each process and pass then is accompanied by quenching for as long as it takes to cool the metal to a suitable temperature. Each cut, scrape or polish achieves a different result and merging the overall shape to the relation of the cutter head is relevant. Where creating the cutter head, the steel is moved to a comfortable angle facing away from me, so that I am in a comfortable position to grind away from me and also let the grinder rock where necessary.
Creating the cutting tip / head...
What we ask ourselves is.. What will the tool be used for and its objectives required from it?
Take as an example a scraper as a pretty simple approach. The only areas of the steel which need to be formed are the tip and the tang so the blade can have it's handle of choice.n The cutting tip for a scraper foesn't have too great a detail. So the average profiles are:
Square,
Domed,
Round,
Right and left curve,
undersweep (creating lip and neck profiles)
V scrapers.
In this example, a domed scraper is created either on the bench grinder or angle grinder. My preference is with both tools. first off with the angle grinder to start the initial process. Then to create the balance on the bench grinder. Again as above, I grind away from me with the blade set so the final surface is relative to a 90 degree point. What I mean is, the steel will be positioned at a 30 degree or relative point to encourage an easier grind, I use a jig to set up the angle according to my grind preference. Each time, I feel the edge to keep myself in check. The grind continues on the bench grinder with a rest system set up to support the largest portion of the blade for better control. This prevents me accidentally lifting or lowering the angle needed. Slow and careful sweeps are used. Depending on a full round curve, I will use a rounding jig (initially used for the bandsaw methods). After all aggressive / stock removal methods are done, time to use finer wheels to create a fine profile. It's at this time I move from oil to water quenching as finer wheels remove less stock and impart a polish finish.
Finishing the scraper...
After the grinding has taken effect, it's time to give the tool some preparation in the form of lapping and polishing and the final hone.
a scraper benefits from lapping on all sides to create a flat surface which helps with harmonics generated by the tool against the spinning workpiece. It's a good idea after lapping to apply a light coat of tool protect or something like this so that when you have completed the honing process, you're ready to go. I'm always mindful of feeling each change I make in relation to the finished product and it's worth bearing in mind that the slightest of changes in the final form can make interesting differences.
Handles:
Always consider the blade length, width and thickness, to the proportion of the handle. my general rule of thumb is 2:1 (handle twice length of cutter bar) and in some cases 3:1. The handle is the most important part. Ergonomics play a large factor in the quality of your turning. For me, my handles take on a difference.
TBW
)
