Dave Lammas tool post

Hello. I read an article in the 25-year edition about Dave's 3-way tool post. There were only dimensions for the smallest version. Does anyone have the dimensions for the larger version? I have a 9" South Bend which is similar to the Boxford. I live in the US.

Dimensions of the castings are in he Blackgates catalogue:

**LINK**

Hope that's what you need

MichaelG.

The only critical dimension is the thickness of the bottom part, this should suit your usual tool size.

Other dimensions can simply be 'in proportion'.

Neil

Thanks for the info. I will attempt to build one. Probably out of individual pieces.

JasonB. Quite some time ago,(2012 actually) you made the comment 'cannot see the point in using a casting, easier and cheaper to machine from a block of steel or CI. Did you ever make one, and if so do you have a copy of the detail drg. for the 'B' version. If yes, any chance of a copy?. Regards Lynne.

Me make tooling, well only if it's a leap year and when good Friday falls on a Thursday in the same year would you catch me doing that.

No I had no intension of making one but stand by what I said its easier and cheaper to make from solid and you can adjust any sizes to suit your particular lathe rather than be tied to what can be accomodated by the casting.

I think this is the smaller one

Could be cut out of a bit of 80mm CI bar for £12.50 or a casting for £17

If you take the differerences in length between the A @ 2.875" and B @ 3.25" then proportionally you end up with something like this assuming the drawing above is for the A type. This would just come out of a bit of 90mm bar

Edited By JasonB on 18/06/2016 14:27:23

The stock removal from a solid bar is probably going to be 2 or 3 carrier bags worth of swarf. Do you think you're up to that for the sake of a few bob? I'd rather go for machining the casting if it's still there.

Michael W

Where do you get these small carrier bags from? You could fit teh whole raw bar in a 6" zip loc bag thats the 90mm bar round the edge, 3 saw cuts and a skim won't make much swarf.

You also get 3 usefull bits of iron for another job and unlikely to bu**er a cutter on any hard spots if you start with cast bar.

Edited By JasonB on 18/06/2016 17:17:21

Agree with Micheal that stock removal when machining from solid will be wasteful and hard work for typical Home Shop machines which tend to be rather lightweight for this sort of thing. The shape isn't exactly solid bar friendly either. Especially if you have to hacksaw it out the "armstrong" way! Built up from two plates and acentre block will be bit easier but the shape is still wasteful.

As many folk here already know I'm a great advocate of multiple built-up two slot block type toolposts as being the easiest and least costly "fairly quick" toolpost system for home shop workers. You choose the plate and centre block sizes to suit your machine and simply cut the requisite lengths off. Generally there is enough variety in avalaible thickness and width combinations that you don't need to cut both length and width of top and bottom plates. Bottom needs to be at least 1/4" thick so it doesn't bend when removed, top 1/2" to give plenty of thread engagement on the clamp bolts. Centre bar can be alloy if thats what you have. Makes tapping through for the hold together screws easier. Probably tap right though. Countersink type allen heads are best screws to use. I'd back up with adhesive.

SouthBend drivers like Anthony have an advantage in that not only is the compound slide Tee slotted but said slot also corresponsd to standard bar sizes so long Tee nutd can easily be made by screwing and gluing a narrow bar on top of a wider one. With the additon of a fixed stud and locking handle to make up completed toolpost and retainer units it becomes very quick and easy to interchange multiple too posts. In my SouthBend days I usually had 3 or 4 sets on the go. Mine were 4 ways but I pretty much never used more than two slots. An indexing device to ensure toolposts went back into the same position each time would have been nice but was never quite missed enough for me to get round to figuring out and making a good one.

Clive.

I thought the idea of these toolposts was that they could be made on the lathe and only the lathe that they are going to be used on, typically a flimsy myford?

Biggest cut is the 1.25" wide by 2.25 long edge, which is going to be the same size whether you make it from a casting or solid, a few more passes or saw cut just means a bit of time not more powerful machine requirements. Easily done with a flycutter or indexable 40mm cutter up the spout. The casting if I remember rightly does not have the tool slots rough cast so in both cases you will have to mill the 1/2" x 1/2" slots.

I know my far eastern hobby machines would have no problem making one. Infact the 4-way that I made on my Unimat3 many years ago had similar areas to machine and that coped well with it from steel!

Edited By JasonB on 18/06/2016 17:44:31

.

Jason ... A reminder of the opening question ^^^

MichaelG.

Michael I was replying to Lynne's post today who specifically asked me about the B size Toolpost. not the old post where the OP who probably wants a C size for the Southbend.

"JasonB. Quite some time ago,(2012 actually) you made the comment 'cannot see the point in using a casting, easier and cheaper to machine from a block of steel or CI. Did you ever make one, and if so do you have a copy of the detail drg. for the 'B' version. If yes, any chance of a copy?. Regards Lynne."

Now as I've given some likely dimensions for a B size maybe you would like to give them for the C size, and my comment about using solid bar is even more compelling in this instance as postage to the US will make the Blackgates casting more than a few bob more than a bit of Durabar.

J

I've just noticed a bit of a down side to this design of tool post, what do you do if you want to hold say a L/H tool for facing or a boring bar? Make a second one that is the opposite hand and keep swapping them over?

There is a more economic way to overcome the above, I'll keep it to myself for now.

Have a look at my qctp in my album it is easy to make and can be made to fit any lathe .the one in the album was made for my Myford.The toolholder is clamped onto the topslide so there is no overhang,very quick in use and it dose not have the jacking screws that are often in the way on a Dickson type.

Frank

JasonB, drill the tool holding screws both sides so you can turn it over. If the bottom has to be recessed, you need to make a washer too.

Dave

That was my way of thinking too but still a bit of a faff as you would have to take all the screws out from the top for it to sit flat then pack up all the tools again when you put it back the right way up. The second opposite hand post is sounding more appealing all the time.

.

Jason,

(a) That's OK then ... It looked like you were just using the opportunity to have an unnecessary dig at the "flimsy Myford".

(b) No, not really ... I have no personal interest in the larger size, and anyway, I have already given a link to the catalogue which lists the castings.

Incidentally: My Myford already has a decent 4-way toolpost, and a Dickson, so; although I do find the Lammas design interesting, I am unlikely to make one for it. ... I may, however be tempted to make a miniature one sometime, for the little Jason lathe.

MichaelG.

Edited By Michael Gilligan on 18/06/2016 20:22:01

Yes I can see its advantage over a 4-way particularly when using tailstock support, though as I said in that old 2012 thread the extended Dickson holders do a similar job or more often than not I will now just use a DCMT tip in a reasonably thick holder to get in close.

I was Just a bit taken aback by the comment that a piece this size was considered hard work on a typical lightweight hobby machine. It's no bigger than a 3.5g inside cylinder block or mid sizes Stuart cylinder and hundreads must have been machined in the past with just a lathe which more often than not would have been the trusty Myford. I don't have the original Lammas article but would have assumed as he only detailed the small ML4 version that that was the lathe he had used to make it for, even if he had a mill it would likely have been in proporting to the lathe.

J