Member postings for Ian P

Sid

I think the example you gave us is not a deliberate trick. The only thing wrong with the listing is that it does not say 'From' with the pricing. I would happily accept that in the seller just forgot to put the word.

It is always worth while looking at the feedback ratings. If it not 100% it does not mean the seller is a rougue. I have looked at the last 500 feedbacks for this one and the negatives that are there are ALL from inexperienced buyers.

When I first started buying and selling on eBay I put on some brand new Jeans that were given to my wife. I gave a full and proper description and then got a Negative, which at the time I found very depressing.

The reason given.... 'Because they did not fit'!!!!

Every retailer and seller in the world highlights or promotes the lowest price, nothing new in this case.

Ian

I've seen the Diamond supplies advert (how could one miss it when it overlays the forum text!) but I wonder why they are the only company selling metal 'Rods'?

I'm just being pedant really but on their website they call the material 'Bar Rod'.

Ian

Michael

Welding is not an option as these parts are going into a piece of bespoke furniture and need assembling in stages. The structure is to keep two separate ends of a table surface the right distance apart, and level with each other. Most of the time the whole structure will be stagnant and only come under any strain when in in transit, or being moved around a room.

My aim when I started the thread was to establish how I could make the best use of what I had. My first design (after I eliminated splines etc) did have two bolts on the centreline but I then thought that the cross drilling for a M10 or M12 bolt would remove too much of the shafts cross section.

If I use M6 bolts 6mm each side of the centreline I get nearly 10mm of thread engagement on each bolt, which should allow the bolts to be pretty tight.

Ian

Mike

Do you mean Classic Bike, the magazine, or real old motorbikes?

Ian

Michael

Thanks for your advice. The material and sizes of the two parts, and the positional relationship between then is already defined, The only thing I can vary is how they are bolted together and the main requirement is to resist torsional movement of the 20mm diameter 'axle'.

The bolts (12.9) have to go into tapped holes in the round bar, I like to have about 2xdia thread length which is easy in 20mm thick material, in fact I could put the bolts past the width of the flat if I spotface where I have to drill.

The width of the flats is about 18mm so the furthest away from the centreline would put M6 bolts 11mm apart. I could use 6 M5 bolts and get those even further apart. Its only a one-off job so cost is not an issue, 4 or 6 takes longer to do than just 2 but time is not too critical.

I wonder whether two small fixings in conjunction with a 'large as possible' tight fitting dowel might be a better approach?

Ian

Steve

The tapered boss mentioned (Para 7 of the Plymouth document) seems to infer that the bolt thread stretch effect can be correctly countered over the whole length of the engaged thread,

So manufacturers have been selling us less than ideal nuts by the million for hundreds of years, palming us off with substandard products. Maybe nuts would be better if the hexagon was tapered, another big advantage would be that any size spanner would be a perfect fit!

I have read para 7 several times and I still dont understand it.

Ian

My money is on DCs interpretation.

Its a bit like when my wife and I were invited to a neghbours house for dinner and finding out how warm the hosts house is heated to. I later discovered that normally they are miserly (economically sensible) with the central heating unless guests are present.

Ian

A bit OT but this is the first time in in 6 months that I am seeing the 'adverts over text' effect here. I have CHANGED NOTHING today or in the last few days so I'm stumped as to why I should suddenly be aflicted.

Thanks for the links, I don't understand the bit about having tapered bosses (near the end of the first article) to even out the thread loading.

Ian

I never thought of it like that, but it does make sense. (refering to the combined cross sectional area of all the fixings)

But you have made me ponder more, Its the root diameter that matters but my gut feeling is that the proportion of 'root area to overall diameter area' gets worse as the bolt diameter gets smaller so creating a law of diminishing returns.

All else being equal a thread with finer pitch is better, at least thats a fact.

Ian

Given a fixed amount of overlap of two steel parts that have to be fastened together as strongly as possible, how does one decide on the best number and size of bolts?

I have a long (1.5m) length of 20mm diameter EN1A that will have flats at either end to which cross pieces of 16mm thick steel bar will be fastened (forming a wide 'H' shape). The flats on the round bar are 18mm wide and 50 long to match the width of cross bars. In use the theoretical external load will tend to twist the round steel bar.

Because of access reasons the bolts have to pass through the rectangular bars into tapped holes in the 'D' shaped section of the bar. Given the limited area should I use two 8mm bolts (staggered) or 4 M6 as far apart as possible. I will use HT fixings, maybe metric fine if it helps.

Other than FEA how is one supposed to work out this sort of thing?

Ian

I have had consistently excellent service for several years now, from 'Noggin End'

No connection etc, just a satisfied customer

Ian

Jim

Quite so!

How on earth were ordinary mortals supposed to know that was what the thread was about though?

Ian

Jason

The editor DID contribute, in fact he was the first to do so, unfortunately not in a positive manner.

Bikes, mopeds, unicycles etc, whether full size or models, I dont care they are all valid on this forum as long as there is some engineering content.

Ian

John

Thats an uncharacteristcally caustic comment from you! Its my own fault because I my opening remark was meant to be a bit sarcastic. My point was that the OP posted a somewhat obscure topic title, and the first few following posts did nothing to clarify, even the magazine author brought no clarification.

Ian

I know some thereads go OT, but now we are getting threads that start off topic!

Not quite an oxymoron, but 'Jim' started a thread today on 'Classic bike'. Does this have any connection with MEW? If it an article in ME then it would be better to have said so. Not all users of this website get both mags.

The 1st, 2nd and 3rd replies make no sense to me, they just add to the confusion.

I will bookmark the thread and maybe it will get to the beef eventually.

Ian

Update

For fun, I have just tested the unsubscribe function.

It unsubscribes me from email notifications. I then went into manage subscriptions and ticked the box again so it does do what it says.

Ian

I have just had a nice personalised email from the editor of MEW which is a sort of newsletter. It gives (and links to) a preview of the next MEW issue.

I get many email newsletters and notifications from many sources, these usually have an 'Unsubscribe' option (I have a feeling its s mandatory requirement) at the bottom of the page. The MEW news email has this as well but it also has a 'Manage subscriptions' link.

Out of interest I clicked on the manage subs link and it takes me to my magazine subscription page, fair enough. However, I did not try the unsubscribe because I don't actually want to stop the newsletters and I was wary that it might unsubscribe me from the paper magazine.

So, does 'unsubsribe' stop the newletter only, or does it just take me to the manage subscription page?

Ian

PS

The image in the email is blank, although clicking on the placeholder works.

Has geriatric been regraded?

It used to refer to old people, 50 is very young

Ian

David

I must be thick! I don't understand your answer.

'Thread Information'. Not sure what that is.

'Links'. I understand and know all about.

'Links to the pages'???

As it appears to me. You create some copy for the website (which then sits on one page.) you than post 'one' link to a new thread on the forum.

Is my question clear?

Ian

OK David, now please can I ask a question... and I hope I can understand your answer.

WHY can't you post to the forum (create the thread) AFTER uploading the new issue announcement?

Ian