steel for a project

[sean logieParticipant @seanlogie69385]

I'm looking for material suited for making a tool post . i can't find a topslide and base for love nor money so it's been suggested that i use a steel block to fill in the space the topslide and the topslide base would take … I'm going to try this and see how i get on . Would any old piece of steel made to the correct dimensions do . I'll be working out of the yard so i'll have access to their big Colchester lathe i believe it is ,it also has a vertical slide so maybe i could use that to true up two faces of the block … That's my plan anyways ,i'd appreciate any feedback on my plans ….

Sean

[sean logieParticipant @seanlogie69385]

[Thor 🇳🇴Participant @thor]

Hi Sean,

If I understand you correctly you want a tool holder that doesn't mount on the top slide, but directly on the cross slide. Some time ago I made a tool holder that mounts directly on the cross slide of my small lathe, I used mild steel, it has worked well.

Thor

[sean logieParticipant @seanlogie69385]

Ah…right ,it'll be a bit crude but i'm certainly no expert on a lathe .

 

Been trying to sort out the pulley drive system today .. didn't go too well ,bit more involved than i first thought … 

 

Thanks Thor

 

Sean

Edited By sean logie on 11/09/2016 16:59:03

[NJHParticipant @njh]

No need to limit yourself to steel Sean – you can buy pieces of cast iron too.

Norman

[sean logieParticipant @seanlogie69385]

Posted by NJH on 11/09/2016 16:58:57:

No need to limit yourself to steel Sean – you can buy pieces of cast iron too.

Norman

Would cast iron be easier Norman

Sean

[Tim StevensParticipant @timstevens64731]

Cast iron would certainly be easier to machine, as long as the material you use is of reasonable quality – otherwise it may have inclusions of casting sand etc which will do your nice sharp tool no good at all. Other than that, it is dirty stuff to work with, because of the carbon it contains, which will fly to your hands (face, shirt, etc) as though magnetised. But it washes out OK.

Of course, as soon as you have a tool holder made up, you can get on with making your own proper toolpost. Cast iron again, I suggest.

Cheers, Tim

[BazyleParticipant @bazyle]

Nope, don't use cast iron as it makes a mess of the lathes which needs taking apart to clean and they might not be so happy at work. With a big Colchester to play with it won't matter that steel is harder. You can use the clamp piece on your existing part topslide rather than cutting a tool slot in a taller piece. You can square up the piece in the 4-jaw more easily than the vertical slide and drill a hole down the middle for a clamping bolt depending on how you want to fix it.

Missing out the topslide is not unheard of. Some early lathes like the Drummond round bed never had one and some people call the post you are going to make a "Gibraltar" tool post because of its greater solidity.

[sean logieParticipant @seanlogie69385]

If the 4 chuck is on the Colchester which I hope it is that’s the way I’ll try and do it . I’m also in talks with a local smiddy just now . I’d rather it was done right than a bodge job by me .

[duncan webster 1Participant @duncanwebster1]

Posted by Bazyle on 11/09/2016 19:42:50:

Nope, don't use cast iron as it makes a mess of the lathes which needs taking apart to clean and they might not be so happy at work. With a big Colchester to play with it won't matter that steel is harder. You can use the clamp piece on your existing part topslide rather than cutting a tool slot in a taller piece. You can square up the piece in the 4-jaw more easily than the vertical slide and drill a hole down the middle for a clamping bolt depending on how you want to fix it.

Missing out the topslide is not unheard of. Some early lathes like the Drummond round bed never had one and some people call the post you are going to make a "Gibraltar" tool post because of its greater solidity.

I've machined cast iron for various projects for over 40 years and never felt the need to take the lathe apart afterwards. Machine it dry, then clean up with a hoover. You can drape sheets of paper kitchen roll etc over the bed if you feel the need, avoid rags as if they get caught up in the whirling bits they can cause all sorts of mayhem, including dragging bits of you in. Paper tears if it gets tangled up. If you're doing a lot you can rig up the hoover near the end of the tool and suck the dust away direct.

[Neil WyattModerator @neilwyatt]

I have a cast iron block i use with my t-slotted table as the topslide won't fit to it.

Don't live in fear of cast iron, it is messy but if you get the good stuff it is beautiful to machine (although it turns your snot jet black if you breath it in).

Neil

[MWParticipant @mw27036]

Posted by Neil Wyatt on 11/09/2016 21:59:32:

I have a cast iron block i use with my t-slotted table as the topslide won't fit to it.

Don't live in fear of cast iron, it is messy but if you get the good stuff it is beautiful to machine (although it turns your snot jet black if you breath it in).

Neil

I machined the hemingway pinion mill, which is mostly cast iron and breathed a good heap of it in the process and i'm not dead yet, dirty black horrid stuff.

But i wouldn't disown it, when it machines quite nicely, just remembering to easy on the depths for milling and speeds for turning (if you can guard against or tolerate the shower of grit against your skin as the indexable carbide rips through it!).

PS. Get hold of meehanite if you can, wonderful stuff. 

 

Michael W

Edited By Michael Walters on 11/09/2016 23:34:40

[Ian S CParticipant @iansc]

I,v been machining a cylinder for a IC engine today from some cast iron obtained by another ME in Christchurch a few years ago, I'm not sure of the grade, it machines more like mild steel, and reasonably clean, which is more than can be said for the next job which will be making the piston, which will be the cast iron from an old window weight.

Cast iron when used on machinery has the advantage of dulling vibration.

Ian S C

[Martin KyteParticipant @martinkyte99762]

Does anyone have any definitive evidence of harm (to machinery) from cast iron dust. To my non metallugists mind it's going to be small particles of carbon dust from the free carbon nodules and larger Iron Carbide particles which should not be too detrimental and reasonable easy to clean up. Graphite is a fairly good lubricant. OK if you are machining a chilled casting some of the iron lumps are going to be hard and sharp which you would not really want under your tailstock for example but using emery cloth on the lathe or a toolpost grinder is potentially more likely to cause longer term issues. Maybe its a case of because its messy it must be doing damage.

I would value other opinions, preferably informed ones.

regards Martin

[Neil WyattModerator @neilwyatt]

> Iron Carbide particles which should not be too detrimental and reasonable easy to clean up. Graphite is a fairly good lubricant.

Graphite is a lubricant, but carbides are abrasive.

Neil

[JasonBModerator @jasonb]

I think any risk is more likely to come from residual casting sand that may be on the surface or in the odd pocket rather than the iron itself so no real problem if using bar or block but give any actual castings a good check before machining. Chilled spots will also produce hard swarf but again more likely on cast items than bar & block.

Apart from the black bogies I don't have a problem with machining it and certainly don't strip and clean the machine after cutting it. Also if you are getting a lot of fine dust take a look at your cutting tools as when right you get chips with minimal dust.

Edited By JasonB on 12/09/2016 16:10:15

[Roderick JenkinsParticipant @roderickjenkins93242]

Iron castings tend to have a "skin" which consists of sand and chilled cast iron, both of which are hard, granular and therefore abrasive which tends to both blunt HSS tools and cause an increased rate of wear if left on machine slides. Sections of cast iron as bought from the trade (such as meehanite) have had the skin removed and are pretty benign to machine, if somewhat messy since the iron and carbon tend to come off the tool as powder rather than curly swarf. For what it's worth, my view is that a machine is made for cutting metal and I'm happy to machine anything that comes along, cleaning up as necessary afterwards. There is an argument that cast iron, since it has very little coherent crystal structure, is better at absorbing vibration than steel and is therefore better for the manufacture of machine tool components.

Cheers,

Rod

[sean logieParticipant @seanlogie69385]

Check out my folder,I have a picture of a damaged topslide, do you guys think this is repairable.

Sean

[HopperParticipant @hopper]

Work lathes are like rental cars, they will do things that your own won't – like machine cast iron without a worry.

I made my "semi-Gibraltar cum rear toolpost" out of pieces of black mild steel bar welded together and machined in the lathe to suit the existing four-way toolpost I scrounged up for nothing in a box of junk at a garage sale. I very rarely use the topslide these days. Pretty much only for screwcutting.

So yes, any old block of mild steel you find lying around the yard of suitable size should do the job, or a stack of pieces of flat plate or flat bar welded together also. Just make it good and solid, so 3" or 4" square is ideal. The clamping bolt down through the middle of mine is from memory 7/16 UNF high tensile, machined to fit the T slot at the bottom and  to fit the 3/8" T slot. Tool clamping screws are 5/16" but 1/4" will do the job if you are using 5/16 or 1/4" square HSS blanks instead of the 3/8 tool bits I use.

If you just make a big square block with one slot milled in it for the tool bit, you can mill it in your own lathe by setting the block in its operating position, but packed up with spacers as needed and hold the milling cutter in the lathe chuck and away you go. I made another four way toolpost  that way. The whole thing was milled from solid like this:

Edited By Hopper on 13/09/2016 08:54:57

[sean logieParticipant @seanlogie69385]

Would a two flute be capable of this type of work using my little myford ml3. Might be better using the Colchester at work ,which I may add that I found out today the later £500 for 😥 , thanks for the photos ….food for thought 😀

[Howard LewisParticipant @howardlewis46836]

Some years ago, I made a four way Rear Toolpost for my lathe. The raw material was a 3 foot length of 3" x 1" BMS, (declared scrap by R & D). It was made to match the four way front toolpost.

Each of the five laminations was machined differently, and clamped together, internally, by three long Allen capscrews. The fourth position was used for a dowel to locate each orientation. It carries a parting tool and two chamfering tools (front and back chamfer).

1/2" bar was ideal for making the M10 Tool clamp screws.

The base is clamped onto the rear T slot of the Cross Slide, with two small dowels to locate it against the back of the Cross Slide.

Have also made two other 4 way toolposts, for friends from lumps of mild steel. One is on a Little John, the other on a Chester Cub.

As far as I know,like me, they have had no problems. So Mild Steel will do the job.

When machining cast Iron, I position a magnet under newspaper beneath the chuck. Aftrerwards, removing the newspaper allows the dust to be disposed off quite easily, and the lathe needs almost no cleaning up.

Howard

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