How not to use a clamp

Hi Ramon, the set-up was a vice, as I said. Not unusual to want to leave a vice in situ for six weeks, surely.

The oiled paper didn't appear to noticeably reduce the clamping action. I didn't expect it to; like millions of cyclists worldwide, for very practical reasons I always grease seatposts before insertion into the seat-tube. Once I've done up the seatpost clamp to the specified torque I've never experienced downwards creep of the seatpost into the frame after even the longest, bumpiest rides.

I think a few folk have got the wrong end of the stick. Ade is using pieces of Alpha leather to stop marking his aluminium plate. He uses it too to not dig the clamp into a raw casting , which could fracture it. Have a look yourself. It also helps to watch the whole video & not pick bits out of it.  Building a S50 by Ade

Steve.

Edited By Steviegtr on 23/01/2021 14:23:19

Edited By Steviegtr on 23/01/2021 14:26:48

I've never heard the paper on a milling table before, can't remember where I read that machinists in the navy would make paper gaskets to fit behind screw on lathe chucks to stop them seizing on.

They would/should have been using shim gasket material for maximum precision (if that was necessary). Ordinary gasket material can compress unevenly. I use the stuff for precision jobs, such as setting the clearance on gear oil-pumps, after cleaning up any wear on the side plate.

I mentioned that once, never again

Rob

Hello Nicholas,

When I bought my first mill it only had one tee slot down the centre of the table so I had someone mill two more the same size as the tee nuts for the Myford cross slide. At first it was all a mish mash of BSF and BSW bolts and studding but when I made a new, longer, table for the mill it was time to 'standardise'. Slightly larger tee slots than Myford were milled in and 6mm bolts settled on - 8mm looked too big. Even with the new Amadeal mill with much larger tee slots it's still the same clamping arrangement for as said there's more than sufficient clamping force for anything that I am likely to machine.

Passing info on can be a double edged sword for some can and do see it as preaching where as for many it's helpful and useful. To me though to have that info and not pass it on for others is not an acceptable attribute, even worse is to carp at those that do and yes, unfortunately, there are some who do.

For my sins I'm not an academic, I'm not even time served, but I have spent an awful lot of time machining since my mid thirties and am happy to share the info acquired over that time with any who is interested.

Bill,

my apologies - I missed the significance of the 'vise' so yes, agreed, that could be in situ for a long time without being moved.

Personally though I can't see the need to place a piece of paper under a milling vice - usually it's a workpiece that that serves best but if the surfaces of mill or vise base are less than ideal then yes it would help. I would think though that the corrosion you describe would be a price to pay over long periods of time

Stevegtr - I assure you this is not a criticism of 'Ade' - I've never seen any of his videos - but more as a result of an observation of the image in the original post.

Peter - why not give it a go, you'll be quite surprised at it's benefit - just one piece of copy paper under an item will considerably improve the grip of a workpiece using the same clamping pressure.

Tug

I see nothing wrong in this setup, especially to generate 3 pages of comments!

2 clamps on the ally plate plus 2 holding the casting down onto the plate onto the bed. He's drilling a 3mm hole! If it grabs what will fail first, the clamps or the 3mm drill bit? I see no rotational forces there that would creates a catastrophic fail.

I've watched most of Ades' videos and he knows what he is doing unlike some others on youtube.

Roger

I totally agree Roger. Exactly what I said in my 1st post. No problems here that I can see for the job it is doing. regards

I think they were using printing paper to make the gaskets, that's why I mentioned it, I'm no authority on whether this is considered right or wrong, I just remembered it with the mention on paper being used on a milling table.

I will give it a try, although I'll try and keep it under 6 weeks

No apology needed, Tug.

You're right about not really needing paper under a milling vice; my main milling vice, an Arc type 2, is fixed straight on to the table. However the angle vice I was using isn't a milling vice but the four inch version of this:

https://www.warco.co.uk/machine-vices-vice-jaws/123-tilting-drill-vice.html

I was sceptical about whether it would serve for milling work at all, but so far it has been remarkably useful and much stiffer under loads than I expected. The base of the vice, however, isn't faultlessly flat, hence the paper.

keep sharing your info ramon i have picked up a lot of good tips from you over the years the yarn for packing rings being the latest. got it today.

Hi Rockindodge and Old Iron -

I did stress that I was not criticising anyone and certainly not 'Ade' whoever Ade is. I do not watch his videos nor anyone else's but like him and others have done I've done my own fair sharing of information accrued over years but mainly forum based. I have also always stressed when doing that that whatever I have posted is not the way but the way I chose to go about it.

My comments here were made based on the initial image which is now seen as s a snapshot close up and my own views on using that type of clamp it that fashion - you may recall I said the clamp on the left was correct in my book. My point was poor clamping can lead to disaster - not worth the risk of ignoring if you value the time and energy put into a workpiece.

So, it's three pages of comment - does that really matter - is that a problem here? Lets face it if you can't comment on model engineering matters on a model engineering forum there's not much point in being here - if there is I guess I'm in the wrong place

Tug

Sometimes I despair at this forum. Undoubtably there is a lot of good stuff but equally there is a lot of pointless bitching, point scoring and willy waving! Ramon, sadly you were lead into a trap here by not having the advantage of knowing what was being done or the purpose of the clamp. I don't see there is critiscm of your postings for actual machining set ups where higher forces are involved but for drilling a 3mm hole if he could have held it steady enough in the right place he could have held it with his hand! Now wait for the rush of critiscm on that last statement!

Clearly I am not alone in thinking the OP posted an extract picture with commentary that was completely out of context to the operation being carried out. For the purpose of what he was doing only a very light clamping force was required and to horse a heavy clamp down hard would have been detrimental to the casting! By all means use a valid example such as where someone is milling something held to the table with chewing gum and sellotape with a 4" face mill that clearly presents a danger to operator and machine but this example does not fit that category!

This whole thread is pointless, the video maker wasn't giving any instruction on how to use a milling machine he was merely showing how he was intending to hold an irregular shaped casting to a plate which could hold it for future ops. At no point did he advise or infer anyone else should follow his approach that I heard and I did go and watch the whole video.

Too many people on here ready to throw bricks when I am sure they probably live in glass houses.

Paul.

Sorry Tug, my comment wasn't targeted at you, I have a great respect for your work and your productive comments. I think you brought up a different scenario concerning faceplate clamping which wasn't the OPs original criticism, I totally agree with you about the correct clamping for the job in hand which Ade had done in his setup but then we had all manner of ex purts stating it was all wrong, the heel of the support would damage the table or twist itself out with all the machining forces when all he is doing is drilling a small hole.

This was a case of a snapshot being taken that put the process completely out of context and after a lifetime of troubleshooting of one type or another I learnt to not make statements without knowing all the facts.

Roger

Just watched Ade's S50 build part 3, now the poor guy feels he has to explain himself because of the comments on here. Give it a rest please, there was nothing wrong with his set up.

IanJ

I am terrible at doing that!....I mean I don't bang them down hard enough to dink the table!

So today i am going to make one....thanks for the reminder

Back to the topic, David Colwill a great post, it is easy to sit back and criticise based on one photo and limited description of the task being undertaken.

There seem to be some on here who based on that photo, will now spend all day using stress analysis calculations to work out the amount of torque to tighten the clamps and to try and analyse the metallurgy of the steel clamps as well as how much the clamping bolts stretch and the component being compressed.

Come on everyone let's take a step back from this nit picking. The photo in my view (47 years engineering experience), does not demonstrate poor practice based on the job being done.

Best wishes to you all

Derek

Hello Derek

From my perspective I have to say I don't see any of the comment as 'nit picking'.

The original poster made comment on what he considered to be bad practice in using step clamps. I supported that comment based on my view of the original image because of my experience at work with them. It's been said "He's only drilling a 3mm hole but that image does not convey that indeed it appears he is using an edge finder but it doesn't take away the fact that the clamping is unsafe - use as such for drilling but what if the next time one is using an end mill

No one - certainly not me - is 'having a go' at Ade whoever he is. No doubt he is doing a good service to the model engineering community as a whole and all power to his elbow if so. He should perhaps take stead in the fact that something he has done has promoted this discussion in the interests of safety - and not just to an operator but, as said, to the workpiece - with your 47 years experience I'm sure you'll know only too well what the latter feels like and especially for a beginner perhaps on an expensive to replace casting.

So no, no one is criticising Ade per se just making comments on what is after all - or what should be treated as such - an important part of basic machining techniques but if you put yourself (oneself) on a stage one has to accept that not all will agree with your performance.

Yes perhaps we should leave this now - it's now no longer about a subject useful to early stage model engineers but more questioning its reasoning of posting

Regards - Tug

BTW I give you two years of experience but if you haven't cured the habit of banging tools on the mill table as yet - well ......

I watched the video. I thought it entirely unnecessary, and complicated, to do it that way.

I would have drilled the first lug on the casting (likely with a pillar drill if I had one), THEN placed the casting on the aluminium plate, adjusted for a suitable position and marked the spot to drill and tap WITHOUT the casting in place. I have a set of transfer punches but they would not even need to be pressed into service for that operation. Likely a drill point or a scriber would have been used to mark the spot for drilling - or even a maker pen around the outside of the lug - which was not critical anyway.

But using clamps in that way can easily be copied by those that know no better (and there are a lot out there). Seen it all before - youtube videos with bare mains connections being enclosed in a sandwich box, is just one that sticks in my memory. If you do it, edit it it out from the video!

Following the thread, I was almost thinking old iron had another nom de plume....🙂

Edited By not done it yet on 24/01/2021 10:22:46

Lol I rest my case. Now not only is the bloke being lambasted for poor practice and leading novices astray but now his motives are being questioned as to why he decided to do the job that way in the first place! I am surprised this has not been closed down by the "authorities" early on as it potentially encourages viewing of associated content with reviews of equipment from banned (on this forum) suppliers!

Paul.