Gantry type milling attachment.

[olderdan]

I had at some point made raising blocks for my SB for a one off job but had not used them for years so I found another use for them.
They formed the basis for a rigid milling attachment together with some thick walled tubing, some ½ inch steel plate and a surplus topslide with 2 ½ inch travel for use with my light milling spindle.
All parts were made on the lathe paying great attention to squareness of all milled parts which are pinned and bolted together, any welded parts were machined afterwards to maintain accuracy.
By raising the head on the pillars the range is from zero to 7 inches from the table although limited to the topslide travel for any given setup.
Two ¾ inch brass cotters clamp to the columns and these maintain alignment quite well.
I have found this attachment very useful but being limited to ¼ inch cutters is not fulfilling its potential so a ½ inch capacity 3 speed geared cutter spindle is in the making, this device has helped a lot in making that in accurate hole spacing.
Future mods will be an acme thread raising adjustment to the whole gantry, in the meantime I have a stop clamp which enables me to raise or lower the head by using gauge blocks and also stops it from dropping while adjusting.
The fact that the head will travel the full length of the pillars without binding proves that attention to machining has paid of.
With my extended crosslide I have 8 inches of travel and 6 inches of saddle movement between the pillars.
The whole assembly is mounted by two ½ inch cap screws with clamp plates tailstock style and can be fitted in a few minutes.

[Toolmaker51]

abbreviated.

...raising blocks for my SB, but I found another use for them.
They formed the basis for a rigid milling attachment together with some thick walled tubing, some ½ inch steel plate and a surplus topslide with 2 ½ inch travel for use with my light milling spindle.

Prolific, rather astounding. First the original project, recognizing potential for re-use, with procedures and solid techniques to assure stability.
A salute to olderdan!
ACME threaded posts would certainly function, but initial thought seems a fine thread desirable to tune parallel to bed. Perhaps a differential nut version; ACME internally and fine pitch outside.

[Frank S]

I especially like the use fo twin posts to form a gantry this places the work piece within the confines to the columns thereby greatly reducing stresses on the parent machine
The one issue that I see and this may be a product of intended design or the viewing direction of the photo, is To me it seems with the mill attachment mounted use of the carriage in normal lathe turning would be restricted if not close to impossible Though as said I can't really tell from the pictures

[DIYer]

Thanks olderdan! We've added your Gantry Type Milling Attachment to our Milling category,
as well as to your builder page: olderdan's Homemade Tools. Your receipt:

Gantry Type Milling Attachment by olderdan

tags: milling

[olderdan]

I especially like the use fo twin posts to form a gantry this places the work piece within the confines to the columns thereby greatly reducing stresses on the parent machine
The one issue that I see and this may be a product of intended design or the viewing direction of the photo, is To me it seems with the mill attachment mounted use of the carriage in normal lathe turning would be restricted if not close to impossible Though as said I can't really tell from the pictures

Thanks Frank
This is a set up for milling only, unable to turn while in place but only takes a few minuets to change modes.
I to thought about the stresses on a bench lathe bed and decided to place directly over the bed instead of mounting over the rear, I have noticed some recent posts about rigidity issues with some commercial attachments mounted this way. You have to work with what you have with consideration.
Regards
Olderdan

[olderdan]

abbreviated.

Prolific, rather astounding. First the original project, recognizing potential for re-use, with procedures and solid techniques to assure stability.
A salute to olderdan!
ACME threaded posts would certainly function, but initial thought seems a fine thread desirable to tune parallel to bed. Perhaps a differential nut version; ACME internally and fine pitch outside.

Thanks Toolmaker51
You have given me food for thought on adding threads to the pillars.
I must admit I would struggle to make the raising blocks now as I no longer have access to a surface grinder (just a couple of lunch hours at the time).

[Jon]

Congratulations olderdan - your Gantry Type Milling Attachment is the Homemade Tool of the Week!

Strong week! Some nice picks: a Self-Aligning Clamp Pad by Toolmaker51, a Finger Plate by jjr2001, a CNC Tubing Bender by jofriedl, a Compound Rest Adjustment Adaptor by hemmjo, an Annular Cutter Holder by bstanga, a Hydroboost Nut Socket by Frank S, a Small Mandrel by astroracer, a Valve Removal Tool by sossol, and a $5 LED Light Panel by adachsoft_com.

You'll be receiving a $25 online gift card, in your choice of Amazon, PayPal, Giftrocket, or bitcoin. Please PM me your current email address and gift card choice and I'll get it sent over right away.

One more win and you'll earn the 5-Time Tool of the Week award. Here are all of your Homemade Tool of the Week winning tools:

Tool Sharpener by olderdan

tags: grinder, sharpening, dial indicator

Lathe Milling Table by olderdan

tags: milling, lathe, table

Dividing Indent Tool by olderdan

tags: measurement, divider

Gantry Type Milling Attachment by olderdan

tags: milling

[tonyfoale]

Good one, Alan.

[Toolmaker51]

Thanks Toolmaker51
You have given me food for thought on adding threads to the pillars.
I must admit I would struggle to make the raising blocks now as I no longer have access to a surface grinder (just a couple of lunch hours at the time).

Is surface grinding to square the riser block pads to centerline of post and/or threaded portions? Dissecting the photo hinted slight design alterations to work around that. I'd turn, bore, face to .0002 perpendicular, and recess additional blocks in diameter equivalent to square size you already have. Drill + tap matching 4-hole patterns in new pads and existing pads, also tap new pads adjacent to clearance holes for jack screws. Could assemble and set up with surface plate and cylinder square every bit as accurately that grinding might produce.
Or I completely misinterpreted details in said photo...At any rate, despite having enough mills and a great lathe, I'm considering your modification. Vertical for sure, maybe horizontal spindle for weird work like Higbee thread starts. Still use rotary table and mill now, additional setups. But then most have only CNC programming solutions, or have to ask what are the cuts for?
Phffft.

[olderdan]

Is surface grinding to square the riser block pads to centerline of post and/or threaded portions? Dissecting the photo hinted slight design alterations to work around that.

Sorry for the minimal post, I have been busy of late.
To explain a little further, the raising blocks were ground to the same dimensions as the tailstock base until a DTI mounted on the boring table clocked zero over the over the width of the blocks, this would also also take into account any wear in the bed, saddle and slide ways on a very old lathe and would match the way the lathe is.
The blocks were not milled but the V was plunge ground from solid with a form wheel, this was the start point for further work.
The base of the pillars were faced after welding using a 3 point steady and the pillars running true, the top clamp faces were trued in the same manner using a service mandrel. Using this method it was at least possible to ensure correct tramming in one direction, the other could be adjusted on the verticle slide.
As this is an attachment and not a milling machine some compromise must be accepted but it has turned out better than I had hoped for, and the blocks are still able to be used for their original purpose if the need arises.
I know where your coming from regards CNC and I have used it a lot before I retired and the results are unquestionable but these days I enjoy just winding handles.
Thanks for the interest.