Taylor Hobson cutter grinder modificaton

[Andrew CrowParticipant @andrewcrow91475]

Hi David, I’ve been following this thread since it started and it’s looking really good.

Great to see something that originally had limited use now being given a new purpose with the ability to grind a wide range of tools.

Andy

[Martin Johnson 1Participant @martinjohnson1]

Looking good, David.

Just wondering how you are indexing the drill through 180?

Some time back Jacques Maurel described a cam system of drill & tap grinding in MEW which would be fairly easy to incorporate.  I did it on my home spun grinder and am very impressed with results and ease of use.  Sorry, I dont have the references to hand as I am away from home just now.

Martin

[BazyleParticipant @bazyle]

Cross reference in this thread https://www.model-engineer.co.uk/forums/topic/sharpening-taps-and-dies/

[David George 1Participant @davidgeorge1]

Hi Martin I have put a collar with four equal distant holes in with a grub screw to clamp it in place. These holes locate on a pin in the top slide so I can release  the side clamp lever slide the collet holder back then rotate to opposite hole, slide the collet holder forward to stop and re-clamp and grind the second edge. I can do either two or four for end mills as well and will make a collar for some three flute countersinks I would like to sharpen.

 

David

[David George 1Participant @davidgeorge1]

I decided to try drilling with the drill which I have just sharpened and it worked perfectly. I didnt even spot or center the hole  and it cut perfectly.

David

 

[David George 1Participant @davidgeorge1]

I managed to do some work on the parts for the tool holder jig. I had to machine a half circular end to the angle bracket so it can be engraved with the angle scale.

 

 

 

I used arotary table and a 6mm carbide end mill.

David

[David George 1Participant @davidgeorge1]

I Have got round to continuing with the cutter grinder mod and have made an adjustable table so I can grind flat tooling like turning tools tips etc.

Also I have engraved the dials so I can use them for seting and amount grinding angles etc. I have also started making base for the grinder as it is a bit light and wobbly.

David

 

 

 

 

[David George 1Participant @davidgeorge1]

I have mostly finnished the mods to the grinder I intend when finnished to have it chemicaly blacked and the engraving filled whith white paint to show up the lines and digits. I  thought I would actualy sharpen an end mill and after changing the adiamond wheel for a white Aloxite 100 grit wheel and stet up and easily sharpened the 20mm cutter.

David

 

 

[BazyleParticipant @bazyle]

You have graduated the horizontal axis – do you have plans for the vertical? The Worden seems to make a major feature of it.

[David George 1Participant @davidgeorge1]

I have got round to the vertical height adjustment with a serice of interlocking spacers of various thickness.  For most flat jobs the centerline is the same as the center of the grinding wheel but for some end mill cutters etc the angle needs height adjustment and I have a series to adjust that.

The spacers interlock with the bed location and the base of the angle plate holder so the radial angle can be set to suit the end of the cutter etc.

David

 

[Michael GilliganParticipant @michaelgilligan61133]

It gets better all the time, David

MichaelG.

[David George 1Participant @davidgeorge1]

I have received the parts back from blackerising and it looks great to me after filling the engraving for the dials and angle indicators.

 

 

 

[David George 1Participant @davidgeorge1]

Thats it done know I think.

David

 

[Andrew CrowParticipant @andrewcrow91475]

And very nice it is too, as well as being an excellent addition to the workshop.

Andy

[Colin TeasdaleParticipant @colinteasdale]

Hallo David,

Apologies for resurrecting this thread, no matter how interesting!

When you came to machine the dovetails, I noticed that you milled a slot and then cut the dovetails – did you cut each side in a single pass, or did you take multiple passes each with a relatively shallow depth of cut?

If the former, did you have to cut both sides at once, or did you take multiple passes using different sizes of dovetail cutter until you reached the desired width?

Reason for asking is that I have a Hemingway retracting tool holder getting to the top of the ‘projects to do’ list but I can’t work out how to actually cut the dovetails!

Thanks in advance,

Colin T

 

[bernard towersParticipant @bernardtowers37738]

for me its usual to cut a straight slot first then use dovetail cutter to run down one side in one cut and the same the other side.

[Andrew CrowParticipant @andrewcrow91475]

It is normal practice to cut a central slot first prior to cutting a dovetail, then cut one side then the other. Cutting straight through with the dovetail cutter puts lot of pressure on the cutter plus a lot of swarf to clear, high risk of breakage.

Andy

[Mark RandParticipant @markrand96270]

Basically, try to use mostly or only one face of the cutter at a time, to reduce the load on the delicate corner of the cutter.

An example:- have the cutter 10 or 20 thou above the desired ‘flat’ height. Take cuts on the taper until the calculated width is reached, reduce the height to the correct level and take a final cut.

In a perfect world, use a narrow slotting drill or (better) a slotting saw to cut a slot just past where the corner of the dovetail will be (depending on what tools and work holding are available), then cut the dovetail. This gives a clearance at the corner of the dovetail and makes it easier if you need to use a scraper to achieve a perfect finish.

[David George 1Participant @davidgeorge1]

Hi as Andy says cut a slot first to depth and then cut the angle after using a roller against the angle face as I have a drawing with the dimention to the roller to the outside face of the slide or base. II also leave aa small flat on the edge of the dovetail so you dont have a sharp edge.

David

[Colin TeasdaleParticipant @colinteasdale]

Many thanks for the replies, gentlemen.

I’ve a had a practice and it all went rather swimmingly! That said, I’ve probably cursed myself for when I come to do the real thing, but hey ho!!!

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