General advice needed

[nathan talbotParticipant @nathantalbot71483]

Hi everyone

Let me say first that I am a complete novice and after a long time gazing and wondering at some of the items you guys have made i have finally managed to secure myself a milling machine and a good lathe

My first question is do you guys know of any courses that i could attend on an evening within the Bristol Area, or are there any guys here who would be willing to give up a bit of free time on a Saturday morning, paid of course to just teach a few basics??? I am Currently in the process of joing BSMEE.

Ive tried reading from books but i do struggle i think i may be more of a hands on type

Second of all the milling machine i have purchased is a Dore Westbury MK2 although it seems to be in good condition there is allot of backlash within the X axis of the machine ( parallel with the drill) i can nearly turn the handle a full 180 degrees before the bed begins to move. Can i remove this easily or if i use a DRO will this matter?

Or am i going to grow out of this machine quite quick is it worth saving the pennies and get something a bit more robust like a Boxford VM30?? (Bridgeport is out of my range and wont fit in the space allocated)

As of yet im not sure what my full intentions are in terms of what i want to make i just want to get started, i would like to get into clocks tractions engines,etc even make the odd item for my kit car

As i have stated before I am a complete novice Im not even sure if ive installed it all correctly???

Any advice you guys can give will be great

Nathan

[nathan talbotParticipant @nathantalbot71483]

[David Clark 13Participant @davidclark13]

Sound like you will have to improve the backlash problem. Might jut be something loose. Easy to fit readout. Did it myself in an afternoon. Bit of weight lifting involved though. If you don't find the reading helpful, get an online subscription to Model Engineers Workhop and jut look at the photos and drawings.

Edited By David Clark 1 on 07/12/2015 15:38:28

[julian atkinsParticipant @julianatkins58923]

hi nathan,

the bristol lads are a great crowd and it is an excellent club.

i have a Mk1 Dore Westbury which has 60 thou play on the 'Y' axis, and 20 thou play on the 'X' axis. on my 'Y' axis the securing of the lead screw bronze bush to the base casting regularly works loose. i really ought to do something about it after 20 years. the 'X' axis has a much better arrangement for fixing it's bronze bush and is easily accessible.

cheers,

julian

[Swarf, Mostly!Participant @swarfmostly]

Hi there, Nathan,

Welcome to this site.

I am not familiar with the Dore-Westbury mill but I expect lots of the other folks here are and will be able to advise you about the back-lash you mention. What I will say is this: don't be too hasty in dismantling your mill (or your lathe, for that matter). Diagnosis should ALWAYS be performed before treatment! There are, I'm sure, a few simple but fruitful tests you can run before you need to dismantle. Sometimes machines prove harder to reassemble than they did to dismantle!!!!

My second advice would be to practice turning and/or milling on raw material of known properties – we've had forum members who've had difficulties machining and it's turned out, on enquiry, that they were trying to machine ex-scrap or cast-off material that could have been anything (aka 'mysterium' ! ).

My third advice is to devote adequate time and effort to tool grinding, persevere until you get the hang of it.

Again I say 'welcome' and I hope you will enjoy your new hobby.

Best regards,

Swarf, Mostly!

[AjohnwParticipant @ajohnw51620]

My Mk1 DW is ok too. 0.010 one way and around 0.015 with a slight clunk at the moment the other way. If you look under the table on the left side you will see the nut and it's retaining screws hence my clunk, they have worked loose some how.

When you check for back lash make sure that the handles plus dials are not moving and causing most of it. I've never had to look at them but assume that this is adjustable It might also be a good idea to check for loose lead screw nuts.

I haven't much space so the ability to machine over most of a 6 1/2" by 14" surface is ideal for me. Even further by moving the head around. The column in my view lacks rigidity but it gets away with it by the shear weight of the other parts.

I bought mine of some one that didn't rate it at all. End milling with a small blunt 2 flute slot drill and worse still with the work held in a vice that just wasn't rigid enough. The slides were also way too loose and I suspect didn't have a sensible grade of oil on them. I need to set mine up and give it a thorough oil again so I will undo the feed handle carriers and wind out the lead screws. Then lubricate well by pushing the slides by hand and adjusting the gibs so that I can feel a slight resistance to movement and no binding. Sometime they can be marginally tight and suddenly go very stiff as they are slid about. It isn't a 5min job and can take longer but is well worth doing especially on smaller machines.

John

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[Brian WoodParticipant @brianwood45127]

Hello Nathan,

As A DW Mk 2 owner owner of nearly 25 years now, I think you will find it a worthy little mill, don't be in too much of a rush to replace it. I have made a few modifications to mine which you might care to consider, the first was to replace the column key with something more robust. The original cracked and I only found it by accident when adding power lift.

The back lash you mention is excessive, mostly I suspect from sloppy setting of the cone nuts that the axis handles run off. Remove the handle, hex wrench countersunk screw on the end, pull off the handle from the steel taper cone and screw it in towards the support for the leadscrew to take up the slack, leave a little for free running and refit the handle

Other work of the type I mentioned is rather more involved.

Regards

Brian

Edited By Brian Wood on 07/12/2015 18:28:35

[Neil WyattModerator @neilwyatt]

If backlash is more than a quarter turn of the

[J HancockParticipant @jhancock95746]

It is essential to 'lock' at least two of the axis' on a milling machine ( like the DW ) and only leave the one you want to 'twiddle' with ' loose'. Don't even think about anything but 'undercutting'.

[julian atkinsParticipant @julianatkins58923]

i must say, and to echo Brian's comment's, that the Dore Westbury mill is a wonderful machine and well loved by it's many admirers who are lucky enough to have one. i have really pressed mine to it's limits and beyond over the years, and it has a lot to recommend it. ive used much bigger stuff, but i wouldnt part with mine at all.

i am grateful to John W1 for his comments and to know that with Nathan mine isnt the only Dore Westbury with backlash. it requires a certain modis operandi when milling with backlash, that J Hancock alludes to!

must admit ive never used the rotating gearbox so the pin has always stayed locked in.

Brian's advice re adjusting the tapered cones is very good, though takes a bit of practice to get right. i must re-adjust both on mine, and sort out that loose feed screw bearing.

cheers,

julian

[AjohnwParticipant @ajohnw51620]

Posted by Brian Wood on 07/12/2015 18:27:09:

Hello Nathan,

As A DW Mk 2 owner owner of nearly 25 years now, I think you will find it a worthy little mill, don't be in too much of a rush to replace it. I have made a few modifications to mine which you might care to consider, the first was to replace the column key with something more robust. The original cracked and I only found it by accident when adding power lift.

The back lash you mention is excessive, mostly I suspect from sloppy setting of the cone nuts that the axis handles run off. Remove the handle, hex wrench countersunk screw on the end, pull off the handle from the steel taper cone and screw it in towards the support for the leadscrew to take up the slack, leave a little for free running and refit the handle

Other work of the type I mentioned is rather more involved.

Regards

Brian

Edited By Brian Wood on 07/12/2015 18:28:35

How powerful a motor and what gearing, rpm etc Brian. I have often thought about doing that as it's half done on mine. There is a hand wheel sticking out of the side. It drives a screw jack via a bevel gear.

John

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[Brian WoodParticipant @brianwood45127]

Hello John,

Briefly if I may. The motor information is 240 volt AC reversible induction, input 65 W output 25 W via an internal gearbox of 1:26.3 ratio. Service duty is continuous. Shaft speed out is 60 rpm which is further geared down to the column capstan nut by about 34/110 with open spur gearing I just happened to have available.

The motor is made by Japan Servo Co model US2345A5

I also built in a thrust bearing under the capstan nut which more than halves the effort it used to take to wind the thing by hand. There were also several safeguards to operation built in.

If there is enough demand I could write up an article for MEW if Neil thinks that would be of interest

Supply from Motors Direct, Keepers Cottage, Home Farm, Iwerne Minster, Blandford, Dorset.Phone 01747 812440

Cost at the time was £25, I bought two and they are very well made indeed.

Regards

Brian

Edited By Brian Wood on 08/12/2015 10:04:06

[AjohnwParticipant @ajohnw51620]

Thanks Brian. It gives me some idea of the power needed. Maybe a mod could edit Dore Westbury into the tittle of this thread.

This is how the column lift is handled on mine. 7" dia hand wheel on the side.

As shown there is around 5" table to spindle. I'd guess I can increase that to a foot or more. I'd say about 15".

When I bought the machine it was on a floor mounted cabinet that was in any case a bit too low for me. I set to with the angle grinder and just kept the 2 drawers. The above is the view drawers removed. I had great fun getting the machine 4ft up from the floor to sit on top of them. Lifting bits wasn't a problem but reaching out with some of them really was.

John

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[nathan talbotParticipant @nathantalbot71483]

Thank you for all the info guys will have a go at that hopefully tonight thanks brian

I had a very small window of opertunity to have another look last night whilst the misses was out

My machine in particular has a power feed unit within the Y axis 90 degrees to drill) this leadscrew has a small amount of backlash an upon closer inspection it looks as though the lead screw has been extended and there are a few washers either side of the table mounting casting which then appers to be attached to the power feed drive , there seems to be some slack in the washers as i alternate the direction i can see one bunch of washers closing up and another opening, so there may some adjustment to be found there.

In the X direction (parallel with the drill) the lead screw looks as though it operates through two bronze bushes which in turn i think are fixed to the table the backlash appears to be the bronze guides moving along the leadscrew until the are stoped in the machine casting they apper to move a few mm in either direction.

Can i cure the x direction with Brians meathod or do i need to take the table away, i did this once by unbolting the 15mm bolts on the underside of the gibs ??? to my horror is saw a series of brass packers which stayed in placed by the amount of oil there so i quickly put it back before i assume made things worse??

[Brian WoodParticipant @brianwood45127]

Hello again Nathan,

I'm afraid you confuse me by talking about the drill as a direction indicator and having a power feed to the table traverse will add new possibilities to places where slop and clearance have become excessive.

Perhaps a picture or two would add some clarity. If I lived any where near Bristol I would be glad to visit but it is too far I'm afraid from Thirsk in North Yorkshire

I don't think taking the table off will help in the slightest, nor should it be necessary

Regards

Brian

[nathan talbotParticipant @nathantalbot71483]

Hi again guys

Brian i have some pictures and a little video which shows i think the problem can i email it to you?

Last night i was able to sneak into the garage and had another go at looking at the mill

I removed the machine screw which holds the handle on and tried to adjust the cone nut this did remove a bit of slack but made the leadscrew so tight that as sonn as i turned the nadle the machine scre came loose and th handle was turning and not the leadscrew, i had a more detailed view of the bronze guides and it looks as though the amchine screws that hold it to the table ahve come loose these bronze guies are moving until they hit either edges of the casting then the table finally moves please have a look at the photos below i have made a video but i dont know if i can post it

For some reason phots wont upload aggggghhhhhhhhh

[nathan talbotParticipant @nathantalbot71483]

Managed to upload a phot into an album hope this helps

Nathan

[Brian WoodParticipant @brianwood45127]

Hello Nathan,

The secret to getting the cone nut to take up slack without then binding the feedscrew is to back it off a trifle after you have set it, then push the handle back onto the cone without moving it appreciably before securing the handle to the shaft with the hexagon headed screw. When that hex screw is tightened it also tends to take up clearances in the fine thread between the cone nut and leadscrew and it may take a number of trials to set it nicely.

For another attempt, try the following method.

As you did before, screw the cone nut up to just take out the slack on the leadscrew. You should still be able to turn the leadscrew by gripping the bare shaft by hand at this stage; if not ease the cone nut back a little until you can. Then back it off by 1/4 turn before refitting the handle again. You should now have some running clearance without excessive slop

Regards

Brian

[Howard LewisParticipant @howardlewis46836]

Nathan,

I am a little more than normally confused !

You say X axis parallel to the drill. To me, vertical travel means Z axis, with X axis being Left/Right, and Y Front/Back.

The pictures look as if you are dealing with the vertical feed for the table (Z axis in my speak).

Bevel gearing will introduce additional backlash to that already present in the Leadscrew / Nut.

Also, the gears each need to be fixed firmly to their respective shaft, not only to reduce overall backlash, but to prevent damage to both shaft and gear. (End float on the driving gear shaft will also increase backlash)

From what others have already said, the carrier for the nut can become loose, so that will increase backlash even more, and cause wear of the holes and securing hardware.

Once correctly positioned, would it be possible to dowel / rollpin through the frame and into the nut carrier?

If you are desperate to eliminate backlash, if there is enough material in the nut, it could be partially slit, and then one end tapped for a screw to force the two sections apart. This will reduce backlash; although not as elegant a solution as having the ability have a second nut rotatable relative to the main one, to act as sort of locknut

In my experience, it is not too uncommon to have about 0.020" backlash in a drive. You need to be aware of, and allow for it, if reversing the direction of travel. My method is to lock the travel, reverse to take up the backlash, set the dial to Zero, and then unlock before traversing.

Howard

[Brian WoodParticipant @brianwood45127]

Howard,

You are confused! The picture with bevel gearing was from John W1 to show what arrangement he has for raising the column bodily rather than use the capstan ring working off the coarse pitch thread around the column which I have motorised.

I still, like you, don't know what Nathan means by reference to directions parallel to and across the drill, I think he means table motions laft/right and towards/away from the operator. The pictute Nathan posted was of one of the feedscrews running into a bronze nut; if the nut is loose he will see lots of backlash and it will mean winding it free and sliding the table on its guides until the securing screws are exposed enough to tighten them up. I don't think he needs to take the table off to do that

Brian

[julian atkinsParticipant @julianatkins58923]

i understood perfectly what nathan meant as his pic today is exactly as mine as described above on 7th december for the Y axis. unless those 2 cheesehead screws are really tight on the feedscrew nut the nut works loose as the holes are too big for the screws. the solution is to alter the feedscrew nut to how it fits onto the X axis.

cheers,

julian

[nathan talbotParticipant @nathantalbot71483]

Hi guys

Yes julian that is exactly what i meant,

I have managed to repair this by removing the handwheel and conical nut and also the small aliminum chip gaurd from there i was able to push the table back as it was no longer connected to the leadscrew, and there is was the screws on the bush were loose so re-tightened them with some loctite and a spring washer, then had to mill out a bit of the bottom of the chip gaurd

I put everything back together and adjusted the cone nut as you guys have suggested and it a great deal better so hopefully be able to starting to use it soon

The next thing i was maybe going to look at would be how to make the central column a bit stiffer, i have a bit of vibration was thinking of clamping it back to the wall?

[Anonymous]

It's probably better to try and locate the source of vibration and cure it rather than simply mask it. As a starter does it occur when the mill is runninh but not cutting, or only when the mill is cutting?

Andrew

[nathan talbotParticipant @nathantalbot71483]

Andrew

the vibration seems to be comming when im cutting, i can feel it throughthe leadscrews?

[Anonymous]

Posted by nathan talbot on 17/12/2015 15:43:45:

the vibration seems to be comming when im cutting, i can feel it throughthe leadscrews?

Ok, so we've established that the vibration is to do with the cutting process. The next step is to see if it is correlated with anything in particular. Say a specific spindle speed, cutter size or type, feedrate and so on? Is anything loose, like the gibs?

Andrew

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