My little engine (continued)

[steve de24Participant @stevede2433577]

Garry,

Regarding your pic showing the driving dog. When the faceplate bolt is driving the dog is there direct metal to metal contact between the two or are you relying on the drive going through the tie? If it is then I would be worried that this could be a source of chatter. To my mind the tie ought to be just holding the driver and driven in metal to metal contact, but I'd be interested in the views of the more experienced on the forum.

Steve

[GarryCParticipant @garryc]

Hi Steve

Its not very clear in the photo but yes there is direct contact with the nut and leg – the dog cannot get through..

This photo is not that clear either but you can maybe see a little better (the dog's leg is oval in shape).

You are quite right to say not to rely on the tie for driving..

Thanks for continuing to follow along…

Regards

Garry

[mechman48Participant @mechman48]

Garry

Do you not have a straight leg driving dog rather that the one you have there; it looks a though there is very little contact albeit they are touching, you need a positive contact rather than the corner contact you have now…

Cheers

George

[JasonBModerator @jasonb]

Looks like you are pulling the dog round by the tie, should be on the other side of the stud so it is pushed around.

I tapped a couple of extra holes in my faceplate so a drive peg can be screwed in nearer the middle. You can also just use the spindle flange with a stud through one hole and a nut either side to drive the dog.

 

J

Edited By JasonB on 27/05/2015 18:34:07

[GarryCParticipant @garryc]

Hi George and Jason

My fault with a bad camera angle which is not helping – this is probably a better one below – but after your concerns i'm going to change it…

Thats a good idea Jason to tap the face plate, my holes always seem to be a bit further away from the centre than I need when I try to drive it, my last lathe was even worse – also a good tip driving directly off the flange. I'll remember that, think that will come in useful.

Many thanks to all of you – and its good to know someone is looking at the photo's!

Cheers

Garry

Edited By Gary on 27/05/2015 19:07:09

Edited By Gary on 27/05/2015 19:07:57

[Anonymous]

Posted by Gary on 26/05/2015 17:47:47:

I've tried to photograph the finish with the Garr Tool but I just can't do it justice. I didn't try for a finish when using just went at the same speed as with my normal cutter – but the finish was better than than anything I've had to date including on the lathe (except maybe the little holding bar I made) – it was a bit of a shock to say the least, i hadn't realised just how bad my work has been, bit embarrassed really.. I think I need to go away and practice a lot more! The Tool went through the Con Rod material like it wasn't there – normally when I mill there is some noise and vibration, just accepted it as normal I get it every time – no noise this time at all just the sound of the motor spinning – or any hint of vibration at all – and I mean none, just a nice 'hissing' noise!

I can see the Garr is maybe a high end (expensive) and industrial grade tool and need to strike a bit of a balance with cost and quality – if anyone can recommend a good make for milling cutters that are are good compromise I would be very interested to know / hear any comments. Thanks.

That's how it should be ; undue noise and vibration indicates that something is wrong with the cutting process. It's not necessarily to do with the tool, incorrect feeds and iffy workholding can also contribute.

I would regard Garr as a mid-price cutter range. I've used them extensively on aluminium, but did have some problems with wear on steel and changed to Guhring. In retrospect I was probably pushing too hard in terms of spindle speed when I first started cutting steel.

Good luck with turning SG iron. In my limited experience it creates more chatter than the Islington political 'elite'.

Andrew

[GarryCParticipant @garryc]

Hi Andrew,

No way I can go back to using cheap cutting tools after seeing the difference yesterday, it would just be impossible now – and it can't have been doing the machinery any good either.. Message has well and truly sunk in now.

and I agree the SG Iron is not nice at all..! Have to start the big end bearing shortly with the phosphor bronze – hopefully that will be a welcome change and nicer to work with..

Cheers.

Garry

[Bob Brown 1Participant @bobbrown1]

I tend to use solid carbide milling cutters on CI and steel, not so critical on speed/feed when cutting dry.

Bob

[GarryCParticipant @garryc]

Thanks Bob that's interesting to hear and something I'll remember as changing over to better cutters. The sheer number of different types is a bit of a minefield when starting I'm finding. Buying the cheap sets of drills and milling cutters that I initially did was a mistake, no way I could have known at the time had to start somewhere – I would have been better off just buying a small number of good quality ones even just one or two.. I've been way too slow releasing it and.been guilty of putting lots down to not expecting much from the small machinery – truth is its a case of bad operator great machinery!

(I've just re-done the faceplate driver and about to make todays start…)

Cheers

Garry

[GarryCParticipant @garryc]

Just a quick photo of progress this morning.

I haven't got much further, been very enjoyable (and challenging) today and to be honest I've been struggling! Biggest problem is using the round nose tool in order to get the radius's on the shoulders and to turn between them – I'm using a piece of tool steel I rounded myself and its not very good! I have got an indexable button tool that I put away somewhere after having trouble with it digging in last time I used it – can't find it now of course. I'm getting the same problem with the one I'm using as well, this one is much smaller so I thought it would be less of a problem..

I have done the Bearing register and foot and almost have the rod diameter parallel – and my compound slide does at least have enough travel so that I can use it to do the taper..

At the moment though I'm having real trouble though just getting the tool into the material to put even a tiny cut on to finish getting it parallel before starting the taper..

I hadn't released the material to come off for sizing the foot would need to be off the top otherwise I wouldn't yesterday have put in the small flat on the diameter, thinking I needed to for the fillet – should have left it alone it would have sorted itself out in sizing the foot.. So my fillet is going to be a big one I think!

Cheers.

Garry

 

Edited By Gary on 28/05/2015 14:37:36

[JasonBModerator @jasonb]

I quiet often do most of the turning with a normal tool leaving a bit in the corner that I can do back to with the round nosed tool, usually cuts quicker that way

[GarryCParticipant @garryc]

Ah very good to hear that Jason, thanks. I was in two minds this morning as to whether it was done like that but didn't try in case it was wrong and ended up making things worse – makes such a difference to hear from someone who knows! Thats what I'll do tomorrow..

Ta very much.

Garry

[Clive HartlandParticipant @clivehartland94829]

Garry, re, the milling cutters. I bought a set of 5 Carbide cutters from Cromwell for about £25 and they are superb. They are metric and very sharp and you have to be carefull when extracting them from the container in case you cut yourself. The name has, 'Swiss' in it as I would have to go out to look at it to be sure.

Clive

[steve de24Participant @stevede2433577]

Clive,

Have you got the stock control number for those cutters? I looked on the Cromwell web-site but couldn't see any that cheap. (although their site search is not the best).

Steve

[GarryCParticipant @garryc]

Thanks for that Clive, I'll have a look..

Cheers

Garry

[Clive HartlandParticipant @clivehartland94829]

S teve/Garry, it seems they have gone up in price since I bought mine, Price quoted @ £48.55 per.

2 flute SWT1614526A.. 3 flute SWT1614890A.. 4 flute SWT 1615028A Look under:- carbide milling cutter sets.

Clive

[steve de24Participant @stevede2433577]

Clive,

many thanks for the info. It looks like you got yourself a bargain. I have noticed there are some bargains at Cromwell but they more than make up for it with some price rises that are way above the rate of inflation. A case of buyer beware.

Steve

[Clive HartlandParticipant @clivehartland94829]

Steve, they put out a weekly/monthly ? paper with all the bargains in it, I collect one now and again and it looks as if they have, 'End of run' sales where they list and give the qty they have left. To save postage I always ask for delivery at the shop. Luckily i have one close where I work with ample parking. A while back they had 10mm rippa cutters at £8.00 each but only 3 or so in stock.

Clive

[Bob Unitt 1Participant @bobunitt1]

Posted by Clive Hartland on 28/05/2015 21:31:06:

S teve/Garry, it seems they have gone up in price since I bought mine, Price quoted @ £48.55 per.

2 flute SWT1614526A.. 3 flute SWT1614890A.. 4 flute SWT 1615028A Look under:- carbide milling cutter sets.

Clive

What size are the shanks on those, I'm not familiar with the 'FL' designation ?

[JasonBModerator @jasonb]

Shank sizes in their catalogue here

2FL = 2 FLute

Edited By JasonB on 29/05/2015 10:08:00

[Anonymous]

Posted by Gary on 27/05/2015 22:13:14:

Have to start the big end bearing shortly with the phosphor bronze – hopefully that will be a welcome change and nicer to work with.

In general bronzes machine beautifully, with two caveats. One, there's sometimes a tendency to chatter when boring with small depths of cut and two, it's a pig to drill; makes brass look easy! Above about 8mm I tend to use slotdrills as the helix angle is lower and therefore less tendency to snatch.

Andrew

[Clive HartlandParticipant @clivehartland94829]

Looking at the offer price on the sheet JasonB put up the 6 set is a bargain! Solid Carbide shanks the same dia. as cutter. Extremely high quality that i would buy again even at that price. Each cutter over £10 x 6 so compare.

Monday, I will call in to the local Cromwell Depot and see their latest News sheet for any more bargains, if any

Clive

Edited By Clive Hartland on 29/05/2015 14:32:16

[GarryCParticipant @garryc]

Hi Andrew

Thanks for the warning (and info), I have a few cobalt drills but i've been tending to use my cheaper ones in between those sizes [in Cobalt] when working up through to enlarge holes – I need to fill in the gaps and get some more – need to use my slot drills at the first sign of any problems by the sound of it then and be very wary of the cheap ones, thanks again Andrew… Hope I can make a better job this time of soldering the half bearings together for machining as one – I'll be glad to move on from this SG Iron thats for sure..

Hi Clive

Its been a bit of a busy one today, not much chance to be at the bench either but time to sit down and have a good look over the weekend, they do sound like a bargain. I quite like the idea as far as cutters and drills go to find a particular make and supplier and stick with them – might help to develop more of a feel for using I thought. This engine has been quite a big step up from my last one with much bigger parts and seemingly harder / difficult materials, I seem to need upgrades all over the place!

Just having a cuppa and finishing my very short (later than usual) session in the workshop and I'll put a few more photos up shortly.. Difficult time again but great learning practice – and all good fun though..!

Cheers

Garry

[GarryCParticipant @garryc]

Just a quick session today..

It was definitely much easier and quicker to use a normal tool for most of the bar and then to switch back to the round nose to sort out the rest and then with just a light cut to the entire length. I didn't have a 'straight' tool so couldn't get very close in to the shoulders.

Only had chance to do the one corner but at least the radius is beginning to show. Still finding it difficult to stop the tool digging in and so went at it very slowly and lightly. Once the other corner is done I can try the taper. My compound slide is a bit stiff to use so no idea how that will turn out yet! it felt like it was good practice today though as most of it was done manually (i.e. not auto feed).

Cheers.

Garry.

 

Edited By Gary on 29/05/2015 18:38:45

[GarryCParticipant @garryc]

Managed a bit of mess up this morning – and its been bugging me all day as I couldn't understand why, but its just sunk in now I think – or at least I hope I'm understanding correctly.

Its come down to me missing the fact that my cross slide dial is one that takes off exactly what is says on the dial 0.04mm (ie. you don't need to half it, as I did on my last lathe) – its meant that I was starting the taper too far in (25 marks on the dial instead of as it I should have 50 marks on the dial – idiot! I thought I had simply worked out the wrong angle but no I think the 1 degree on the compound slide was correct and it should have taken me from 10mm diameter down to 8mm over 2.1/4 inches – if I had realised I needed to account for the cross slide dial being as it is..

Sorry to waffle on I bet I'm not explaining that very clearly. Anyway the upshot is that my taper looks not too good, it was too late before I realised the mistake to sort out properly! I hope though that I can still use it, I've gone about 14 thou undersize on the little end (Big End is ok) – hopefully not weekend it too much, and to me the real thing still looks just about ok and again better than the photo, but thats only because I don't know what it should look like I guess. Does anyone think I need to start over with it?

The figures that I used..

The Con Rod so far 1.

The Con Rod so far 2.

Cheers

Garry

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