counter shaft not running true

[sean logieParticipant @seanlogie69385]

Good new year to everyone .

 

Have had plenty of time in the workshop lately and I'm admitting to myself I have three problems with the Fortis .

#1

I need to get the lathe sitting better on the concrete floor(any suggestions welcome ) .I'm toying with the idea of making a plinth for the lathe to sit on using self level cement or something the same .Possibly using rubber matting strips (4mm thick) between the bottom of the pedestals and the floor then bolting down firmly not super tight (again I'm open to any ideas ) . .The cast iron pedestals the lathe sits on only have 3 bolt holes ,2 in the head stock end (front and back) and one on the tail stock end . My first thoughts were to turn a set adjustable feet, but I'm not sure if it would work with just the 3 mounting points .I've read in a few places the reason for only the 3 mounting points is so the lathe can find it's own footing so to speak .

http://s1259.photobucket.com/user/Fortis64/media/20161106_111752-800x450_zpsdhqdvhn4.jpg.html?sort=3&o=0

Anyways that's my dilemma regarding the mounting/fixing of the lathe .

#2

The counter shaft/pulley is not running as true as i would like ,it's causing a slight vibration and because the lathe is not sitting perfect it's effecting the finish on the parts I'm turning ,more so on longer parts when using the tailstock .

#3

Tail stock is out of alignment ,I'll need to sort #1 & #2 before i can adjust it ?.

 

Other than that I've been having a great time messing about with the settings/speed feeds,big cuts ,very light cuts (dusting) ,using the 4 jaw more and more (great bit of kit ) really well made also . Anyone made an adaptor to use their cordless drill on the top slide for cutting tapers . I made one yesterday ,the improvement on finish is well worth the effort to make it .

 

Sean

Edited By sean logie on 04/01/2017 10:08:25

[sean logieParticipant @seanlogie69385]

[mechman48Participant @mechman48]

Take a look at Double boost video for taper turning adaptor…

https://www.youtube.com/watch?v=qKj9_nPcVgk

​#1… I laid a self levelling concrete pad for my lathe, sat the cabinets on 2 – 1/4" rubber mats, so far not had any major issues, having said that the supplied cabinets are very flimsy sheet metal design so I fastened them to the wall with large shelf brackets which improves rigidity much more.

George.

[sean logieParticipant @seanlogie69385]

Posted by mechman48 on 04/01/2017 10:01:45:

Take a look at Double boost video for taper turning adaptor…

https://www.youtube.com/watch?v=qKj9_nPcVgk

​#1… I laid a self levelling concrete pad for my lathe, sat the cabinets on 2 – 1/4" rubber mats, so far not had any major issues, having said that the supplied cabinets are very flimsy sheet metal design so I fastened them to the wall with large shelf brackets which improves rigidity much more.

George.

Thanks George ,one thing that can't be said about the pedestals i have is that they are not flimsy. The base (top of the pedestals are 3/4" thick and the sides are 1/2" cast iron .Johns adaptor is the same style as the one I made ,except i didn't have a mill to cut the slots . 

Photo of the fortis and the Pedestals 

These photobucket links don't seem to be working ,either that or I'm not linking them properly ?

 

Sean

Edited By sean logie on 04/01/2017 10:18:40

Edited By sean logie on 04/01/2017 10:22:07

Edited By sean logie on 04/01/2017 10:23:57

Edited By sean logie on 04/01/2017 10:31:43

[Michael GilliganParticipant @michaelgilligan61133]

Posted by sean logie on 04/01/2017 09:48:10:

. .The cast iron pedestals the lathe sits on only have 3 bolt holes ,2 in the head stock end (front and back) and one on the tail stock end . My first thoughts were to turn a set adjustable feet, but I'm not sure if it would work with just the 3 mounting points .I've read in a few places the reason for only the 3 mounting points is so the lathe can find it's own footing so to speak .

http://s1259.photobucket.com/user/Fortis64/media/20161106_111752-800x450_zpsdhqdvhn4.jpg.html?sort=3&o=0

.

In theory [kinematics] a 3 point mounting should be ideal

… What's the approximate spacing of the bolt holes ?

MichaelG.

[Clive FosterParticipant @clivefoster55965]

Had a similar floor problem with my SouthBend Heavy 10 in my old shed workshop due to the concrete pad sloping away at one corner. As the lathe was to sit in the corner my solution was to fix 1/2" (ish) rough battens to the floor in an L shape defining an area large enough for the late to stand on. Mixed up one of the thinner self levelling compounds with as much water as I dared and slurried it in. Rough leveled with a trowel and left for about week to harden off. Being over thin it took much longer than it should to go off but it was able to flow to near enough level. In retrospect I was lucky that it went off at all! Worked a treat tho'.

Self levelling compounds are really for achieving a good surface finish. Their flow is to take out trowel, tamping et al marks not to take up a truly level surface as a proper liquid will. Right way to do the job would have been to make 4 sides with the battens and set tops to level with wedges et al. Then use the battens as guide to tamp the self levelling compound flat.

Clive.

[sean logieParticipant @seanlogie69385]

Posted by Michael Gilligan on 04/01/2017 10:19:36:

Posted by sean logie on 04/01/2017 09:48:10:

. .The cast iron pedestals the lathe sits on only have 3 bolt holes ,2 in the head stock end (front and back) and one on the tail stock end . My first thoughts were to turn a set adjustable feet, but I'm not sure if it would work with just the 3 mounting points .I've read in a few places the reason for only the 3 mounting points is so the lathe can find it's own footing so to speak .

http://s1259.photobucket.com/user/Fortis64/media/20161106_111752-800x450_zpsdhqdvhn4.jpg.html?sort=3&o=0

.

In theory [kinematics] a 3 point mounting should be ideal

… What's the approximate spacing of the bolt holes ?

MichaelG.

On the head stock end the mounting holes are 400mm front to back as I'm looking straight on at the lathe ,the tailstock end is in the extreme right hand side of the pedestal .The distance between the headstock mounting holes and tailstock holes is 110mm .

Sean

[Michael GilliganParticipant @michaelgilligan61133]

Posted by sean logie on 04/01/2017 10:52:01:

On the head stock end the mounting holes are 400mm front to back as I'm looking straight on at the lathe ,the tailstock end is in the extreme right hand side of the pedestal .The distance between the headstock mounting holes and tailstock holes is 110mm .

.

On the assumption that 110mm should read 1100mm … That sounds an excellent arrangement, to me.

I would bed the two pedestals down solidly to the concrete floor [using an aligmnent template to maintain the hole centres … i.e. a sheet of ply with three holes!], and then use levelling feet on the lathe fixings.

MichaelG.

[sean logieParticipant @seanlogie69385]

Apologies ….the measurements is 1100 mm . Would i use anything between the lathe base and the concrete ..ie.. rubber strips ?

Sean

[Ian PParticipant @ianp]

Posted by sean logie on 04/01/2017 10:52:01:

In theory [kinematics] a 3 point mounting should be ideal

MichaelG.

Michael

You might have set the cat amongst the pigeons now!

There is a band of brethren that can only sleep when they have spent many hours 'levelling' the bed. How on earth are they going to untwist (maybe its 'twist' in reality) when they dont have two fixings at both ends?

Ian P

[Ian PParticipant @ianp]

Posted by Clive Foster on 04/01/2017 10:45:40:

Self levelling compounds are really for achieving a good surface finish. Their flow is to take out trowel, tamping et al marks not to take up a truly level surface as a proper liquid will. Right way to do the job would have been to make 4 sides with the battens and set tops to level with wedges et al. Then use the battens as guide to tamp the self levelling compound flat.

Clive.

Clive

There are self levelling compounds and there are self levelling compounds! Some of the chemistry and technology is clever. I used one on my garage floor that I fitted a temporary 'dam' for. It was poured in as a runny liquid and not touched until walked on a few hours later. Amazingly it varies in thickness (5 to 50mm) over the rough floor and after 8 years does not have even a crack visible. (it 'glues' itself to the substrate)

I understand the same type of product is used in very large areas like supermarket floors.

Ian P

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Ian Phillips on 04/01/2017 11:39:00:

Posted by sean logie on 04/01/2017 10:52:01:

In theory [kinematics] a 3 point mounting should be ideal

MichaelG.

Michael

You might have set the cat amongst the pigeons now!

.

Ian,

Excellent ! … My day has not been wasted.

Opinions will be expressed, and couter-arguments made … and maybe Sean will be in a position to make a 'better-informed' decision.

Sorta like a 'forum' I suppose

MichaelG.

[Ian PParticipant @ianp]

Posted by Michael Gilligan on 04/01/2017 12:04:27:

Opinions will be expressed, and couter-arguments made … and maybe Sean will be in a position to make a 'better-informed' decision.

Sorta like a 'forum' I suppose

MichaelG.

I'd better set my stall out then!

I am in the three point camp.

Ian P

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Ian Phillips on 04/01/2017 12:11:29:

I'd better set my stall out then!

I am in the three point camp.

Ian P

.

Good man

… I presumed you were.

MichaelG.

[mark smith 20Participant @marksmith20]

Is 3 point fixing being discussed about the base to the floor or the lathe bed to the pedestal base?? What advantage does a 3 point fixing to the floor have??

[sean logieParticipant @seanlogie69385]

Posted by mark smith 20 on 04/01/2017 12:34:21:

Is 3 point fixing being discussed about the base to the floor or the lathe bed to the pedestal base?? What advantage does a 3 point fixing to the floor have??

That's what the lathe has … 3 mounting points on the pedestal 2 at the head stock end and 1 at the tail stock . There are 4 mounting points on the actual lathe itself ,this is what I'll be making the adjustable feet for

Sean .

[Michael GilliganParticipant @michaelgilligan61133]

Posted by mark smith 20 on 04/01/2017 12:34:21:

Is 3 point fixing being discussed about the base to the floor or the lathe bed to the pedestal base?? What advantage does a 3 point fixing to the floor have??

.

Mark … I'm just off for a walk, but please re-read my posts

Pedestals bedded firmly to the floor … three points on the lathe mounting to the pedestal.

The idea being to carry the mechanical Earth/Ground up to the top of the pedestals, and then have 3 point mounting of the lathe.

MichaelG.

.

P.S. … it would, of course, be possible to put each pedestal on its own three point support, instead of bedding them onto/into the concrete floor.

Edited By Michael Gilligan on 04/01/2017 12:54:33

[Howard LewisParticipant @howardlewis46836]

To my mind, (having a bit of a thing about twist in the lathe bed), three point mounting should minimise twist.

However mounted, I would still check for twist, and use shims under the feet, or levelling screws, to remove it. That should ensure that the lathe does not turn tapers, based on the assumtions that the Tailstock is not off centre, or the Headstock out of line, and that Headstock and Tailstock centre heights coincide.

In the end it depends upon just how exact you want to be.

Howard

[Russell EberhardtParticipant @russelleberhardt48058]

I'll put another cat amongst the pigeons; the lathe bed doesn't need to be level, just straight.

Russell

[Ian PParticipant @ianp]

Posted by Howard Lewis on 04/01/2017 16:27:51:

To my mind, (having a bit of a thing about twist in the lathe bed), three point mounting should minimise twist.

However mounted, I would still check for twist, and use shims under the feet, or levelling screws, to remove it. That should ensure that the lathe does not turn tapers, based on the assumtions that the Tailstock is not off centre, or the Headstock out of line, and that Headstock and Tailstock centre heights coincide.

In the end it depends upon just how exact you want to be.

Howard

Howard

Point is, with three point mounting no amount of packing under each point will affect the twist.

Ian P

[clogsParticipant @clogs]

Hi all, prob to late to comment

all my machines except the Bridgeport are mounted to heavy gauge 4"x2" box, welded as a frame with 12mm adjustment bolts…….these bolts have 10mm thick washer cut from 50mm stock welded on the head and a nut welded inside the box before the frame was welded……cheap simple and effective……so with a lock nut u can take care of any discrepancies with the floor……..

hope this helps…….

Clogs………

[AjohnwParticipant @ajohnw51620]

Posted by Ian Phillips on 04/01/2017 17:01:23:

Posted by Howard Lewis on 04/01/2017 16:27:51:

To my mind, (having a bit of a thing about twist in the lathe bed), three point mounting should minimise twist.

However mounted, I would still check for twist, and use shims under the feet, or levelling screws, to remove it. That should ensure that the lathe does not turn tapers, based on the assumtions that the Tailstock is not off centre, or the Headstock out of line, and that Headstock and Tailstock centre heights coincide.

In the end it depends upon just how exact you want to be.

Howard

Howard

Point is, with three point mounting no amount of packing under each point will affect the twist.

Ian P

And Neil still hasn't put a huge link up that explains what levelling means in lathe terms.

I just don't mount them firmly just finger tight and set the jack screws by hand so I can be pretty sure that all 4 are just supporting the bed. I've added rubber washers on some lathes – no point. All the fixing need do is prevent the lathe from tipping over and also from vibrating too much.

Most lathes could be changed to 3 point mounting. Couple of spacers the same thickness as a plate to fix to the feet with a hole to provide the 3rd point.

John

–

[mark smith 20Participant @marksmith20]

Posted by Michael Gilligan on 04/01/2017 12:43:00:

Posted by mark smith 20 on 04/01/2017 12:34:21:

Is 3 point fixing being discussed about the base to the floor or the lathe bed to the pedestal base?? What advantage does a 3 point fixing to the floor have??

.

Mark … I'm just off for a walk, but please re-read my posts

Pedestals bedded firmly to the floor … three points on the lathe mounting to the pedestal.

The idea being to carry the mechanical Earth/Ground up to the top of the pedestals, and then have 3 point mounting of the lathe.

MichaelG.

.

P.S. … it would, of course, be possible to put each pedestal on its own three point support, instead of bedding them onto/into the concrete floor.

Edited By Michael Gilligan on 04/01/2017 12:54:33

Understood now. How important would it have to be to get both pedestals into the same planes?

Ive resisted so far fiddling about with my Southbend 9A which is just sitting on a wooden suspended floor on a steel one piece cabinet stand(not fixed down). The lathe is fixed to this via four mounting bolts (two either side of each foot.)

My lathe has a nasty habit of turning a slight taper despite aligning the tailstock the best i can.

Ive never attempted removing twist ,the right bed foot is adjustable . How is twist ascertained,by simply placing a good level across the ways at several points or what???

How common is bed twist? Ive read that many just fix down the left headstock foot and leave the right foot only lightly bolted down.

[Mark CParticipant @markc]

Mark, I don't know if you are aware of this or not, but there is a really useful text box at the top of the page. You can use it for searching information out – typing the word levelling brings up a spread of results from 2010 all the way to date. I expect a little more time and effort would bring up a substantial number of results so you could spend hours trying to de-bunk all the tosh spoken on this subject, and there certainly is some.

Mark

[Michael GilliganParticipant @michaelgilligan61133]

Posted by sean logie on 04/01/2017 12:38:48:

Posted by mark smith 20 on 04/01/2017 12:34:21:

Is 3 point fixing being discussed about the base to the floor or the lathe bed to the pedestal base?? What advantage does a 3 point fixing to the floor have??

That's what the lathe has … 3 mounting points on the pedestal 2 at the head stock end and 1 at the tail stock . There are 4 mounting points on the actual lathe itself ,this is what I'll be making the adjustable feet for

Sean .

.

Sorry, only just seen this ^^^

… Now I am confused.

MichaelG.

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