Taylor Hobson cutter grinder modificaton

[David George 1Participant @davidgeorge1]

Taylor hobson tool and cutter grinder modification.

I have a cutter grinder which I did asimple modification by putting on a table which i used to sharpen turning tools and sharpen inserts.  Recently I started to think it could be also be used to sharpen cutters.

I started by Looking for a table and found a Myford 7 cross slide at the Midlands show and set about making a support bse to bolt on to the side of the grinder. I bought a chunk of cast iron and milled it square and flat before milling in a dovetail for the top slide to slide on. I have a spare 3/8″ leadscrew, handwheel and a collet set with a 1/2″ shank to hold the cutters.

I used a piece of sijversteel to hold the jig strip i place to cut the angles on the side to match the dovetail 60 degree.

there is a slight damage to the top slide but it is only on one area which will not be used for the tool holder.

 

 

 

 

 

[Michael GilliganParticipant @michaelgilligan61133]

Thanks for sharing this, David

… as you might see I made a [now superfluous] comment on the duplicate post:

https://www.model-engineer.co.uk/forums/topic/taylor-hobson-cutter-grinder-modificaton-2/#post-767580

 

MichaelG.

[David George 1Participant @davidgeorge1]

Video of slide  first fitt.    https://youtube.com/shorts/kxMBlnEumWQ?feature=share

David

[David George 1Participant @davidgeorge1]

I have drilled the first holes to mount the slide to the grinder.

I have put the leadscrew and handle in place to see how it looks.

David

[David George 1Participant @davidgeorge1]

I started to make the leadsrew nut from Phosphor bronze. It started ok in my self centering chuck with the fourth jar swapped for the fourth jaw external jaw which worked perfect to cut the square thread.

 

It went well at first screw cutting but when i tried the leadscrew in it was a bit tight and decided to use my home made tap!

The tap worked fairly well but cutting phosphor bronze was a bit tight and was better but still tight and decided to re tap and the tap broke and scraped the thread in the nut.

Start again!

David

[noel shelleyParticipant @noelshelley55608]

OH DEAR ! David save the nut, I have a good spark eroder and that would make a good test piece. The machine and all it’s bits are in the shed – I need to find/get them out. It may take a while. Noel.

[David George 1Participant @davidgeorge1]

Remade the Leadscrew nut. New piece of Phos Bronze and only used the form boring bar as Tap smashed.

It took a while to cut the thread as I didn’t have a tap anymore.

David

 

 

 

[Nigel Graham 2Participant @nigelgraham2]

Interesting work!

Neat tip on how to machine the gib strip bevels.

A shame about the broken tap. Is it alum solution that, if I remember rightly, will slowly corrode the tap away? I have used it once, and it is a slow process.

 

[bernard towersParticipant @bernardtowers37738]

Keep the alum solution warm to hot this speeds things up as well as regular flushing

[David George 1Participant @davidgeorge1]

finnished the nut.

David

 

[Michael GilliganParticipant @michaelgilligan61133]

Big sigh of relief from the audience !

… Well done, David

MichaelG.

[David George 1Participant @davidgeorge1]

Got a while spare from Christmas and other duties and started the end plate for the slide except for machining the counterbores which takes the thrust bearings.

David

 

 

[David George 1Participant @davidgeorge1]

I have finnished the end plate for the slide.

I put it on the lathe and bored the recesses for the thrust bearings to prevent any backlash.

Two needle roller bearings and washers.

The next thing is to drill tap and bore the holes to mount the end plate screws, the hole for the end of the bronze nut and the support to go under the table to prevent tiping with more weight on.

David

[Taf_PembsParticipant @taf_pembs]

Excellent David, as someone has said, I like the machining of the gib strips.

As for the tap, one of those moments of the realisation pause on it happening while the colour slowly drains from you, top down, just before the expletives begin!

Look forward to more 👍🍻

[David George 1Participant @davidgeorge1]

Made the washer to hold the bronze nut in place, Drilled the the Tapped holes in the end of the slide to attach the end plate and assembled the slide which workes well with no play or backlash.  Whilst drilling the end of the casting I struggled to get a drill on to the end of the casting but remembered that I had an 8mm collet to fit the spindle and also a 8mm to 5mm bush which will hold the tapping drill.

All I have to do now is to make a holder for the long stem collet set which is adjustable to hold the cutters to sharpen or make cutters.

David

 

 

[David George 1Participant @davidgeorge1]

I have started to make the top slide. Blocked up the first part and cut the dovetail firstly. Next cut the hole for the clamp for the tool holder clam so that the hole bored for the collet holder will match the clamp radious.

Dave

 

 

 

 

[David George 1Participant @davidgeorge1]

I have been playing with Alibre Atom to do a bit of design on the slide parts but it takes time and at least I have done apart assembly which has shown me a couple of problems which I have, I think, overcome.

 

 

 

David

 

[David George 1Participant @davidgeorge1]

I have Fitted the clamp and lever to the top slide body so time to drill and bore the hole for the ER25 collet chuck.

it slides with less than a thou clearance and the clamp works great.

A bit of chamfering and this part is finnished.

David

 

 

[David George 1Participant @davidgeorge1]

I have been drawing a few more bits for the cutter drill grinder but as it has been a bit cold it has restricted the time in the garage and so have been learning a bit more about Alibre and assembling the models as an assembly.

Also I needed some more steel and after geting a quote from a local supplier of around £100.0 plus Vat for a meter of 1″dia 1/2″ dia 3/4″ dia at 1 meter long ms as well as a 18″ length of 2″ x 1/2″ ms . I went to Better Metals for same as well as a 12″ longth of 2″dia ms for £62.30  Total.  Much better.

David

 

[David George 1Participant @davidgeorge1]

I have managed to get into the garage for a few hours today. I managed to finnish machine the bottom piece of the collet holder. I drilled the hole centers on the mil for the two tapped holes and then mounted it in the four jaw chuck and firstly turn the side diamiter and the location for the angle plate. The counterbore for the feed screw was similar turned using the four jaw chuck.

Next To start the angle plate parts to hold this.

David

[David George 1Participant @davidgeorge1]

I have had a little time to start to make the angle plate holder and a few other bits.

the side of the angle plate was finnished except for machining the top radius and degree markings. The top sllde fitted to the angle plate well and machined the base plate with no problems.

next to start making the top slide screw and plate.

David

 

 

[David George 1Participant @davidgeorge1]

First assembly of two parts for a try out. I tryed a drill in to the collet holder and it looks good.

I have drawn up lots of small parts so I hope the wether isn’t to cold.

David

 

 

[David George 1Participant @davidgeorge1]

Drawing of assembly with collet set.

 

 

David

[David George 1Participant @davidgeorge1]

Made a few more bits like thr top slide adjusting screw and holding plate etc to make the top slide fine adjustable.

I also made the dial for the base slide leadscrew which just needs engraving degrees and stamp numbers. will engrave all the degree parts together when i get out the dividing head.

David

 

[David George 1Participant @davidgeorge1]

The Mod isn’t finnished yet but I have enough done to give it a try out sharpening a drill. just set the angles roughly and it seems to work very well to grind a slit point on to a 12mm drill.

 

Back clearance angle

front cutting edge looks ok.

The drill looks very good and sharp.

David

 

 

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