Tooling Choices, identification & WM290 Feed Question

Hi All, new to the forum and indeed the world of turning & Milling.

Entering retirement after a lifetime of electrical engineering I decided to get myself a lathe to pass the time and give me something to learn. Being a keen Car mechanic I think if Id had one 30 years ago it may have paid for itself by now, but as it is it's early days to say how much use it will be. Ive been holding out for second hand unit for over a year but with a lack of anything that fitted expectations, but more importantly my shed, I bit the bullet and bought a new Warco WM290V and have had it a month now.

Had a few teething issues with it which I'll probably cover in detail in a different review for the benefit of others either thinking of getting one or having similar issues but in short, the change gear table on the machine was different to that in the manual in several areas, there is a reference line missing from the cross slide and it quickly developed a fault where the drive would stop and start in both fwd and reverse. I fixed that myself and advised Warco of a design weakness which they are feeding back to the manufacturer. Drives and control was my field. Warco have been very supportive of my findings but with the Coronavirus prevalent in China, getting answers back may be protracted.

Let's get to the point of this post though.

Along with the Lathe I ordered a milling slide, collet chuck/adapter plate, and several indexable tools. (some were thrown in as a sweetener)

Being an oaf and learning at a rate of knots I've managed to blunt or chip some of the inserts. Feeling that Warco have had enough of my pension I thought I'd look elsewhere to replace the tips and therein lies my question. The tools have numbers marked on them and I had hoped that there would be an easy way to match tips to the tool but no so. Not that I can't find anyhow. There are some guides on t'internet but they don't seem to correspond with my markings. Is this something that is easily navigated or am I tied to Warco as a tip supplier? Not that I have too much of a problem with that but it would be nice to a) have options, and b) to understand how it all works.

Hope someone can guide me.

There are a few odd sets that have unusual inserts but in the majority of cases most holders are generic and take commonly available inserts. If you can post a link to which Warco ones you have, the holder numbers or a photo then we should be able to come up with something suitable.

How to post photos

Welcome to the forum Dave.

If you can't find a picture, at least share the serial numbers on the tools.

You might find some HSS tools are more forgiving for the 'learning' phase.

Neil

Thanks for the quick replies gents.

I’ve created an album with some pics in there per Jason’s suggestion.

All the inserts in the set of 5 are interchangeable. In the set of nine two there are 5 different tips, ie some share. I’ve captured all the numbers on the tools.

if anyone could explain how to translate these numbers into tools I’d appreciate that so I can self service in future.

I tried making some tiny brass parts and failed miserably with the indexable tools. In fact they don’t even feel that sharp in the finger tip. I used an old hss tool I came across and it cut so much better. Big learning curve to conquer, but I’ll get there, especially with the help of guys like you. So thank you.

dave

I wonder if we are related ....................

If you’re an anal retentive when it comes to detail and quality we might be Colin.

Seriously though we could be though it’s a bit off topic! My family moved to Wales in 1961. I was added in 1963. Father from a little place called Milltown near Newcastle SE of Belfast. There aren’t too many about, especially with the double n in the middle. If you would like to pursue the theory further we should take it offline. PM me if that’s allowed on the forum...

cheers,

Dave

Welcome to the wonderful and deeply confusing world of carbide inserts! Good news, you're not trapped with Warco. Bad news, I've not found an easy way to navigate inserts from first principles.

I may have the same set as you, and somewhere wrote down what the inserts are. Guess what I can't find!

Anyway, try searching for the first 4 or 5 letters of the holder id. For example SWUCR is a right-handed SWUC, which is a boring bar, and a search shows they take WCGT inserts, of which there are many variants depending on the type of cutting to be done. Carbide inserts are bewildering because industry select them from catalogues to maximise productivity, and there are hundreds of variations - various shapes, point angles, chip-breakers, positive, negative & neutral rake etc. Because industry like to remove metal quickly for minimum electricity bills, inserts tend to be blunter than is ideal for amateur use, so it pays to look for sharper types.

Assuming the inserts in your Warco are the same as mine, they perform best on chunky steel parts, not delicate items. They work best at high-rpm, deep cuts, and fast feed-rate. They don't work particularly well on brass or aluminium. Other insert types are better for non-ferrous. Also, the holder and insert should be sized to the job - giant inserts not good for fine work.

Warco don't carry a wide range of inserts; have a look at ArcEuroTrade - the range they sell is better suited to 'our' machines. I've found buying the smaller inserts and holders advertised for sale to hobbyists by ArcEuro & others removes a lot of confusion. Nothing wrong with the Warco set if big lumps of steel are your thing.

Dave

PS As the inserts in my 6 year old set have 3 or 4 sturdy points each, I've not had to buy any replacements yet. But It's not the set I use most of the time.

Well if nothing else I’m pleased that it appears I’ve not been a total numpty and missed something. There is obviously a bit more to the tools than meets the eye.

I went with indexable tools as I thought it would remove a variable from my results in the form of my ability to grind a good hss tool.

My brass experience has made me question my choices but I’ll persevere with them on larger mild steel jobs and will invest in a few hss tools to have a play with. Would still be worth finding an alternate source for the warco tools though. If you can find your data I’d love a share of it.

I did find that the lead screw clutch on the lathe appeared to jump with fairly low cut depths and the slowest feed rate whilst using the inserts too which made we wonder whether the clutch is just very weak or the inserts are really dull. Not enough experience to be able to tell but I guess operator error is more likely on a new lathe.

cheers,

dave

Dave

Have a look at these insert shapes to determine the type of insert your holders use, then measure the cutting edges to confirm which size. The first 2 letters show which shape and the last 2 numbers state tip radius.

Emgee

http://www.jbcuttingtools.com/epages/es461493.sf/en_GB/?ObjectPath=/Shops/es461493/Categories/%22Turning%20inserts%22/General_Purpose_Inserts

Edited By Emgee on 01/03/2020 22:04:51

This is the sort of finish you ought to be able to get on brass with insert tooling:

The part was turned with ordinary CCMT inserts, not the ground and polished ones intended for aluminium. The threads were screwcut using inserts too.

I'd say there's something wrong with the leadscrew clutch if it jumped out when turning brass. I'd expect the clutch to be set to drop out just before the spindle motor is overloaded. Otherwise there's not much point in having the extra motor power if you can't use it.

Andrew

Dave,

Welcome to the forum. Hope you enjoy it as much as I do.

I found this chart online some while ago. It'll give you an insight into the variety of inserts out there and how to de-cypher their codes. Prepare to boggle your mind ..........

It's not very clear as is, but you should be able to zoom in to read it by double-clicking it.

John

Edited By John Hinkley on 01/03/2020 22:33:59

I’m really enjoying a new facet to engineering that I’ve not explored yet. Lots to learn but I’m realistic about my limitations and goals. I’m never going to be able to mass produce but if I can make small quantities of things with reasonable accuracy and finish I’ll be a happy bunny.

the link provided by Emgee certainly appears to have some inserts that I haven’t seen elsewhere and look like good candidates. Will check further tomorrow. Haven’t had chance to check John Hinckley’s offering yet.

Maybe I wasn’t clear regarding the feed clutch. That wasn’t happening on the brass cut, but when cutting steel using inserts. Anything over about 0.4mm and it started jumping. 200 rpm and the slowest feed rate x whatever that was. As I said the change gear chart was all wrong but it was pretty slow.

I’ll reserve judgement until I’ve tried some nice sharp hss bits on steel and see how that copes.

cheers

Dave

Definitely not right; to be technical it's chocolate teapot territory! Looking at the lathe specs it has a 2hp motor, so as a rough rule you ought to be able to remove about 2 cubic inches of mild steel per minute. Would I be correct in assuming that the lathe has an induction motor and VFD? If so I suspect you need to up the speed, you might have full torque at 200rpm but the power will be well down, irrespective of the feedscrew clutch tripping. We don't know what diameter the work is, but 200rpm seems very slow for steel and insert tooling.

Andrew

As I said at the start some sets can have unusual inserts and you have just such a set, the parting and threading inserts are not common so you will have to stick with getting them from Warco or a few other hobby suppliers that do them. Or just get holders for the commonly available inserts to replace these tools.

The ones that are interchangable will have a code beginning with "W" but would need sizes and a closer photo to have a stab at the rest. Possibly a WNMG but there are other similar inserts, WCMT would be a similar shape but better for non ferrous but I suspect your issue is quality of teh carbide insert not it's specific shape with these ones..

Parting tool is possibly a CK3

Threading tools possibly JCL-15-120

Also have a read of this old thread ignoring Neil's (stub mandrels) answer

Edited By JasonB on 02/03/2020 07:29:35

There's a lot to learn, but don't worry it comes. Do you have any books yet? A few hints:

1. Don't assume the lathe or inserts will cut any old metal you have lying around. I wasted a lot of time as a raw beginner because my scrapbox happened to be full of obnoxious alloys. It's worth buying new metal where the spec specifically mentions it's suitable for machining or 'free-cutting'. (Easier to spot difficulties due to awkward materials when you know how a good one cuts.) Buy some EN1A - it machines much better than ordinary mild-steel.
2. Carbide inserts remove the need to learn how to sharpen HSS, which is handy, but they are a little harder to select and use. Carbide likes to cut at about 5 to 10 times faster than HSS, so generally run it fast and hard. Hobby lathes aren't generally fast or powerful enough to get the best out of carbide, but a WM290 gets into the zone (2HP at 2500rpm). Actually inserts do work well at lower speeds, but look for the sharper type,
3. RPM, depth and cut, and feed rate depend on the metal being cut and its diameter. Aluminium alloys, Brass, and Steel all behave differently. RPM and diameter determine the surface speed, so a large diameter object is spun slow, and a small object is spun fast. Rule of thumb for steel: rpm = 10000 divided by diameter in mm. Experiment with DOC and Feed Rate; results depend on the tool-shape and characteristics of the metal. Another rule of thumb, slow down if getting poor results with HSS, speed up if getting poor results from Carbide.

I use carbide inserts at least 80% of the time because they're more convenient than HSS. Apart from threading and turning large diameters, I run the lathe at high-speed, mostly 1200 to 2000 rpm. I switch to HSS mainly for fine delicate work, but also when I need a specially shaped tool, or can't get a good finish from carbide (rarely). For amateur use, HSS is fairly tolerant provided it's sharp. Works well at slower speeds and low depth of cut. The main disadvantage is keeping it sharp for which a grinding wheel and certain amount of skill are needed. Not everyone is good at grinding. (Blush!)

If lathes were easy, we'd soon get bored! Be prepared to experiment; at the moment sounds like you're running the machine too slowly.

What are the wrong gear ratios? Not come up before as a problem, but these things happen. I expect a 290 owner can help.

Dave

Lots of great info to digest here. The Table John H posted looks great but it's in French. Some I can work out... others not.

As for Andrew J's comments on speed, don't blame the machine. I'm just scared to wind it up but it sounds like I need to. I'll go digging for inserts given the detail supplied and if I need more I'll come back. Unless someone has a turnkey solution to these specific Warco tools that wish to share. It'd be a bit cheeky to ask Warco for the part numbers

Dave

In the meantime I just dropped another photo in an album showing the dimensions. The inserts are inverted to better align with the ruler edge. They each have a 4.5mm hole with a taper seat and are 4.1mm thick..

In answer to Sillyoldduffer' I've also uploaded some pics of the machine change gear plate and the manual which I printed and have taped it to the machine for now. Not great but hopefully better than what was there where data accuracy is concerned?

Note that in the imperial threading table the gear selector rows reads BAC where all the other tables read CAB. By chance the first thread I tried cutting was 11tpi and it just want working out. I explained to warco who said the gear selector should be set to C not B as per the manual. Sure enough that fixed it but why then does the plate on the machine say B. That led me to want to check all the data on the plate and all those with a bit of black electrical tape above them show different gears to those in the manual too. Compare the photos!

Rather than have me install all the ratios and check them for accuracy I asked Warco to tell me what is right and to supply a new plate with the corrections incorporated. They in turn referred it back to the Chinese manufacturers. Could be a long wait. If anyone else has one maybe you could lean on them. I wonder how many other models suffer this. The manual is a copy paste of the 280 in the most part.

Had I not tried cutting an 11TPI thread as my first one I may never have discovered this error!

To: Dave B.

Should you wish to add to any confusion you still have after your original posting , there were a number of opinions on this website a couple or so years ago. (I'd hesitate to write "all relevant opinons":-

https://www.model-engineer.co.uk/forums/postings.asp?th=130308&p=2

Dave B there is no clutch for feed son the 280/290 so can't help with that unless you can point to what part you are referring.

Simple way to check the gears is that A is 1:1 straight through the front gear box, C is 1:2 so half the rate and B is 2:1 so double. When doing the maths for any screw pitch work it out in A and then you can half or double it.

You don't say what pitch leadscrew you have so the table may only affect on of the two options.

Unless it is very large diameter brass then use the higher of the two speed ratios and save the lower one for very heavy cuts, large diameters and screwcutting where you will welcome the time to react.

Edited By JasonB on 02/03/2020 16:09:39