Another Hemmingway Quick Set Keats

[redhouseluv]

After seeing a post on this subject from over 10 years ago and while waiting, waiting and waiting for deliveries to arrive I decided to make a start on the Quick Set Keats which has been sat under my bench.

I'm starting to appreciate there's a difference in casting quality or may be it's the materials used? The base casting machines wonderfully and leaves a really good finish.

One problem I realised early on, how will this fix to my faceplate as the mounting holes are not remotely near the faceplate slots. The simplest solution I could think of was to bolt the Keats onto a nice solid piece of flat bar which extends to where the faceplate slots are, then bolt this to the faceplate.......I'll have to make sure everything is machined accurately

[Dave Otto]

Could you drill and tap a pair of mounting holes in your face plate?
Nice start, I will be following along.

Dave

[crueby]

Could you drill and tap a pair of mounting holes in your face plate?
Nice start, I will be following along.

Dave

Thats something I do a lot - though its because I have found inexpensive faceplates made for woodworking lathes that have the same thread as the headstock on my lathe. I drill/tap holes as needed, then when the faceplate is resembling old swiss cheese too much it gets replaced.

[redhouseluv]

That was my initial thought too, however, my concern is where the potential new mouting holes need to be drilled, on the reverse side of the faceplate, there is a 'crown' or the part which locates onto the headstock (see pic).

1. I couldn't see how to place a nut at that position if I drilled through it and used a bolt
2. I was worried about damaging that section of the faceplate rendering it unusable

I did a search for faceplates with 70mm registers to see if I could find one which I would fit, but couldn't find anything and I imagine I would still have the same issue.

I guess drilling and tapping would be an option, rather than using a nut & bolt? I'm guessing there also needs to be a degree of freedom to position the Keats correctly, centralise accurately it before undertaking any offset machining? e.g. when machining a crankshaft

[propforward]

Bolt a piece of aluminium to the face plate. Skim it flat, then drill and tap that as a tool plate.

[Jasonb]

If I were making it for my similar faceplate then I would ditch that casting and replace it with a longer bar which can be machined to suit the other casting and also your faceplate slots. This will also reduce overhang by keeping the work closer to the spindle.

Clamp plates off the mill are another option but a right pain to set up when gravity is working against you and also always a worry that they may fly out at speed.

This is the problem with building old designes which were invariably meant to fit a Myford and expecting them to fit a larger machine or the typical type faceplate found on most imported machines that don't have a threaded spindle so you can't get the faceplate slots as close to ctr.

[redhouseluv]

Hmmm.......lots of food for thought there

I think I'm sold on the idea of making the equivalent of the casting; I guess the less components being bolted together on top of each will improve the accuracy too.

I have the mild steel flat bar which I was going to bolt the casting to (see pic), its right length and about 16mm thick OR - would it be better to use aluminium

- Starting point as described by Propforward, would be to clamp it to the faceplate and skim it?
- Reduce the thickness of each end, leaving the same contact area for the other castings as per the original base casting?
- Cut some slots in the ends similar to the castings?

One question I have is around usage of this tool and this in turn has a bearing on how it is made. As this is being clamped onto the faceplate, I still have to clock it using a DTI to get the start position - I'm presuming the answer is a yes, but feel I need to ask 

[Dave Otto]

The answer to your question is yes, you will need to indicate the shaft or stock so that it is running true to the spindle.
Be aware that if you skim that piece of steel it may warp do to the stress relief. You can advert some of this by taking equal amounts off of each side.

Dave

[Jasonb]

At 16mm thick I would drill and counterbore for a couple of say large say M10 cap heads or whatever size your mill clamps are then you can use the tee nuts from that which won't rotate in the faceplate slots as you tighten them. Which will mean you can skim right across.

Might even consider a few other changes. A hole in the middle of the bar will allow for longer items to be held and also allow the bar to be clocked true then you bolt it on, would need that flat strip moving to one side.

[Roger B]

The basic idea of this tool was that you would clock the shaft true and then be able to offset by a measurable amount as the V block slides along the flat bar to set crankshaft or eccentric throws. The V block can also be turned across the axis of the lathe which would allow cross drilling/boring of round bars.

I drilled and reamed a 6mm hole in the centre of the base plate which allows me to move from the lathe to the RT without losing the centre. The lathe operations are centred with a piece of 6mm ground stock held in an MT collet in the headstock.

[john mills]

when you mount that bar on the face plate to machine before clamping se that it is sitting flat then cut the same off each side before clamping see that it is sitting flat pack with shim if it is not.dont leave long between machining both sides.after machining leave for as long as you can then check if it is still flat
often steel or aluminium is worse depending how it is made once you cut the surface it will move.
you can use the lathe or milling machine to get it flat first.
john

[redhouseluv]

At 16mm thick I would drill and counterbore for a couple of say large say M10 cap heads or whatever size your mill clamps are then you can use the tee nuts from that which won't rotate in the faceplate slots as you tighten them. Which will mean you can skim right across.

I wish I had 1 of the following, either would have done 

1. Had the foresight to have thought of that
2. Read your message before I started

I cut the slots without thinking ahead, so left myself with the problem of how to mount it on the faceplate. I made 'alternate' arrangements' for mounting and have ended up with what can be seen it picture below.....

Note to self: THINK AHEAD!   

[redhouseluv]

I drilled and reamed a 6mm hole in the centre of the base plate which allows me to move from the lathe to the RT without losing the centre. The lathe operations are centred with a piece of 6mm ground stock held in an MT collet in the headstock.

Sorry I'm being dim, what's the RT? I like the idea of the hole in the centre for centering, that makes sense and makes things easier

[crueby]

Rotary table, on the mill.

[redhouseluv]

Ah ......okay, I'll remember RT for future 

when you mount that bar on the face plate to machine before clamping se that it is sitting flat then cut the same off each side before clamping see that it is sitting flat pack with shim if it is not.dont leave long between machining both sides.after machining leave for as long as you can then check if it is still flat often steel or aluminium is worse depending how it is made once you cut the surface it will move you can use the lathe or milling machine to get it flat first.

John I didn't skim the bottom surface so went back skimmed the bottom and then flipped it over and reskimmed the top. If you look at the new pic I have 4 holes with countersinks on opposite sides and diagonals which enabled me to hold the piece in order to skim the bottom.

I've mic'd it all the way along and on each side and am astonished to say the variance is 0.0005" - I'm good with that!