A ‘Starter Kit’ for a Stent T&C?

[IanTParticipant @iant]

In order to sharpen my lathe and shaper tools, I have made do (thus far) with an extended guide on a 6" grinder, fitted with a simple sliding table (and angle plate). I've wanted something better for a while and had considered the various options (Harold Halls 'rests' for instance).

However, I have been very fortunate this weekend to acquire a part built Stent T&C for a reasonable price. The main castings have been machined and a lot of the 'heavy lifting' work seems to have been done. I'll know more when I dissemble it and take a closer look next week. I have to decide how to mount the motor and make various small fittings/hand wheels etc, including the work-holders (I've the castings for the main work holder but no centres for instance).

I already have copies of the ME (1991) articles on the Stent build and also MEW 137 (on a "Super" Stent version) and will sit down for a good read over coffee later. I therefore have most of the available reference materials and will also re-read the various 'Brooks-Stent' material (e.g. Gadgetbuilder) available (which was another of my possible T&C options before this one came along). However, any recommendations and/or comments in this area would also be most welcome!

I will obviously need a set of grinding wheels and know that the 'white' aluminium oxide wheels used to be the norm. However, these days there are also 'diamond' wheels available (from Arc for instance).

I still expect to rough out my cutting tools on the 6" grinder by the way and I also sometimes "pre-form" them with either a Dremel or an angle grinder. So the Stent will initially just be used to maintain my existing lathe and shaper tools and hopefully thereby get better 'repeatability' and sharper tooling. However, I also want to start learning to sharpen milling cutters, as I now have quite a few that probably need it.

So my apologies for the long pre-amble but my questions are these:

What would be a good "starter" set of grinding wheels (suitable for the Stent) and what should I get – just diamond or just 'white' to begin with. What are the pros & cons of each? Should I adopt a particular "standard" for my wheels at the outset (wheel diameter, mounting holes etc?) And of course where would you suggest I buy them?

In other words, what would you recommend if you were starting over & buying these items for a Stent type T&C from scratch?

Regards,

IanT

[IanTParticipant @iant]

Advice to get going with a newly acquired Stent T&C

[egaParticipant @ega]

Bogstandard2:

I would be very interested to know where to buy one of those special oxide sticks. Are they also capable of dressing CBN wheels, I wonder?

[Roger VaneParticipant @rogervane67137]

There are dressing sticks capable of dressing diamond and cbn wheels – this Company list medium and fine…

**LINK**

Hope this helps.

Regards

[IanTParticipant @iant]

So have diamond wheels superseded the white oxide ones now then?

IanT

[Rik ShawParticipant @rikshaw]

I always think that using green on small carbide tools is brutal as they can easily get overheated and the carbide will often fracture. Much better to use a coarse diamond wheel and finish with a fine grade.

For carbide lathe tools I use a coarse then a fine diamond cup wheel.

A nice open cylindrical white will do for HSS lathe tools (don't get it brown – keep quenching). For end mills and slot drills I use a medium grade white saucer. This all applies to smaller milling cutters up to 25mm dia. Larger than this and some methods change

The chap who built the beautiful STENT exhibited at Harrogate this year may well be planning to show it again at Sandown in December. If its there I am sure it would be of interest if you could manage to get along.

Rik

[IanTParticipant @iant]

Thank you for the advice John

I had a look at the Arc site over the weekend and noted that their diamond wheels were "Recommended for grinding carbide tipped or solid carbide milling cutters and lathe tools etc. as well as glass and ceramics" – with no mention of HSS, which is my primary need. So I had kind of come to the conclusion that it was probably going to be aluminium oxide wheels for my (mainly) HSS tooling.

Does anyone have suggestions as to the best place to buy them?

I've also dissembled the machine and cleaned it up for a first look. I'm very happy with it generally but I think the spindle will need redoing. I've read all I could find about the Stent (and the Brooks) and I will change the motor to the left (as per MEW 137) and this would have required a rework of the spindle anyway. In terms of spindles (and the mounting of wheels) the Quorn seems to be well regarded in this area, so a copy of Prof. Chaddock's Quorn book is now on my required reading list.

I am going to Sandown in a few weeks time Rik and will take my camera and notebook along and see if I can find any Stent's (and perhaps some Stent builders too!)

Regards,

IanT

[Clive HartlandParticipant @clivehartland94829]

The information about Diamond wheels and HHS tooling, rough a tool out on a normal Carbide wheel on the bench grinder and the finishing on the diamond wheel taking as little off the HHS tool as possible.

The tool grinder is NOT a jobbing grinder and is only to sharpen tooling and not remove large amounts of the body of the tool. It is also used to make sure that the tool angles are correct.

When grinding tools a jig should be used to hold the tool in a fixed position, it is so easy doing it free hand to misjudge the angle and feed in and make a boo boo. I would not consider doing a milling cutter free hand and only do drills freehand if I have no other recourse.

A White Cup wheel and a flat rim diamond will in most cases suffice for precision grinding. The only other wheel to consider is a very thin diamond wheel for throating a milling cutter, that is if you can hold the cutter to do it. I find this very difficult to do on a Worden Grinder and would need to make more jigging or even make a new type of Grinder to suit. No doubt a Stent or a variation would be ideal and would look forward to buying a kit design if it were available.

Clive

[Sub MandrelParticipant @submandrel]

I use a diamond wheel to take no more than 2 thou (ideally 1) off of the end of milling cutters, following existing angles as closely as possible. I get mirror finish and sharp cutters. I used to use a little paraffin as a lubricant, but now I grind them dry.

Neil

[Rik ShawParticipant @rikshaw]

John — Good tip indeed, I had never thought of using a dremel elastic wheel to gash the end of milling cutters, thanks!

Rik

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