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Hello,
I am looking to get made some simple brass handle fixings for a handbag. The drawings can be see here:
Attachment 5282
I need them to have a nice clean finish to them, suitable for electroplating afterwards. I'm hoping someone can help me out with these as I've had no luck when contacting manufacturers. I'm looking initially for 20 to be made, and if things go according to plan then more would follow.
Thanks,
Barry
Looking at that profile view making a gustimate on the hole depth then you would only be looking at 2ish mm deep hole? that would not be enough to make a thread without drilling all the way through? It would be better to go through completely and look at pins with a peened over head instead maybe? it would keep costs down for you as well because you could do the peening yourself with a one off tool made for you?
Just a thought
Thanks for the feedback, drilling right through is not an option as that top face is the cosmetic part that needs to have the clean finish.
I've modified the drawing to use two threaded pillars instead, does this seem workable?
Attachment 5284
Yes and no? this is where design clashes with manufacture and i am a fan of both. You need to think about how it would be accomplished and will those pins need to be fitted into the sockets or machined as 1? plus the threading? gluing? what are the downsides? etc
Assuming these are for fixing the fabric handles to the bag then a single pin across the maybe more acceptable (think watch strap). A hole can go straight through and a pin which could be polished or ground down to meet the surface afterwards. Yes the fabric would need to be folded and stitched maybe? This would be less noticeable?
I think it will need to be a single piece, although I'm not sure. Essentially the outer faces need to be clean and crisp, the inside of the 'U' doesn't feature cosmetically. I see what you mean by the 'watch strap' approach, unfortunately that wouldn't work with the design of the handles. I've attached a crude picture that might help clarify things:
Attachment 5285
The brass part needs to be fully outside of the face of the bag, and the backplate goes behind - only the screws pass through the bag facing, otherwise the leather will be weakened too much.
Would it be technically possible to make these as a single piece do you think?
(duplicate removed)
Seeing as these are brass and will be plated how about drilling through and braze,solder in two studs, Buff and plate it should not be noticeable.
Just a thought
Bruce
So basicly you want this.!! (See pic)
The machining in it's self aint a big deal but one off's are not cheap to make, even 20 would be not be enough to make them at low cost. Expect to pay a premium price. How much was you expecting to pay.?
EDIT: Why not have it this why regards bolt hole,would mean having the side piece's slightly wider but easier and better looking IMO.
you could make a short hole and solder or braze threaded rod into the block.
Are the threads for clamping bolts that come from the back plate through a strap to the block.
Great minds think alike Jazz, i was going to suggest threaded holes on the risers of the block.
I hate sensor ship!! . . .:redface: :redface: :redface: :redface: :redface: :redface: :redface: :redface: :redface: :redface:
Thanks for the feedback everyone - I have been trying to reply but I think because I only just joined my messages are sitting waiting for moderator approval.
JAZZCNC - that model you have done is pretty much spot on what I am after, just the pillars need to come flush with the outer sides, and be a bit smaller in diameter. Would you be able to make a sample for me? I need to check the fitment with the bag manufacturer, if they give it the ok then I'd be ready to order the 20 to start (obviously price permitting, if you can give a rough quote that would be very helpful - I know they won't fall into the 'cheap' category, but the lower the better :) ).
penny washers could be an alternative to the backplate
Thanks again to all for the feedback!
i2i - I think you are right about using washers instead of the backplate, originally it was bigger to spread the weight and ensure the bag kept it's shape, but having reduced the size probably washers will suffice.
The screws have to pass through the handle strap in order to secure it, so they cannot go into the sidewalls of the part. Plus I need to keep the same 3mm wall thickness all round for cosmetic reasons.
Would it be helpful if I made up a 3D model of the exact size / shape? If so what kind of format would you guys require?
I'd love to hear from anyone who would like to take this job, I'm keen to get started on it.
looking at the threaded spigots, they would need to be 4 - 5mm diameter, and i would expect they would need to be 5mm to have enough strength. Which will leave a thin edge on the strap.
I could bring the spigots inwards to give more of an edge to the the strap. I did have a thought - do you think using blind rivets would be ok instead of screws? That way the need for tapping the threads would be removed, which would make it simpler to make, and I assume a fair bit cheaper too.
Barry Replyed to your PM.
There are still some fundamental flaws with the design. The spigots needs to go through the handle so there needs to be support sown into the handle (plastic strip) or this thing is just going to pull apart very quickly. if you were going to market these with a chain they would be putting samples you put in front of them through the ringer. Barry you also need to think about the material supply cost as well, Like jazz has said the first outlay could be expensive.
Look at what others do, generally they rivet or sow the handles to the bag then put a decorative cover over the top (these could be similar to what you want in looks). These covers are normally pressed parts (looks cheap), i don't know what your retail cost of this bag is but the cost can spiral quite high if you do not understand a bit more with the manufacture costs (this is not a dig just an enlightenment call).
It would be interesting to see what your alternatives are?
do you need two spigots, one would be a better solution all round.
does the block physically clamp the strap, or just cover it?
Thanks for all the input, I am reading it all and taking it onboard, replying is hard because it takes a while for the mod to ok my posts (any idea how I can get approved to post straight away?)
2e0 - thanks for the tip of using plastic in the strap, I will do that. The bag manufacturer has told me that screws or rivets would be best for securing it. I did think of making this piece just cosmetic, but then I can't see how to fix it securely in that case. Any suggestions are welcome.
I2i - one spigot would help keep more strength in the strap, do you think the rivet would hold it tight enough not to rotate though? It is going to clamp the strap in place.
Cheers
I think I got a picture now? This is for the handle? Why not stitch the handle and then cover it with a brass trim, no screws, just decorative? (Unless the screws are a feature for adjustment or something?) Make a model (cnc) then lost wax and polish. Sorry if I have the wrong end of the stick! If it needs to be pins I'd think about pressing them in, interference fit?
Tom
Hi Tom, this is for fixing the handle to the body of the bag - it has to have the screws, stitching isn't strong enough on such a small section (it is leather, and the stitch apparently makes a cut rather than a hole like in textiles, so it ends up weak from the perforation).
Can I ask what you mean by 'lost wax and polish'? I'm not up on the terminology of metalworking I'm afraid. Do you mean the cnc part could just be polished and not require plating for a nice finish?
Hi Mate
What a busy thread! Lost wax can be a good way producing small brass parts but I've had a rethink (based on the assumption of no machine tools at home!).
You could have them cnc'd. Or, fabricate, I've looked around for channel that size, not there. Get some one to mill out the channel from bar the right size, easy job = cheap. Those little posts? drill through, countersink and rivet, just a hammer and drill required and a little patience. Or, drill a blind hole and solder them in (make them from 3mm bar). You could silver solder but if they are a tight fit, regular soft solder would hold.
Brass works well and easily with simple hand tools, rivets can be filed and polished flat so you cant even see them.
Then I thought, through to the back plate? I make the odd knife, check out these knifemaking supplies, they have lots of rivets for fixing the scale, and also a lot of leather working tools a well .. nice!
http://www.attacc.com/itemslist.aspx?listid=11
http://www.english-handmade-knives.c...of_scales.html
They are all designed to be fixed/tightened and filed flat. Brass polishes rather well but tarnishes and marks easily (see knife!). Generally you would plate or at least lacquar. A brush matt finish would last longer.
This is a recent knife I made, just utility and scratched. the brass ends are riveted on with two rivets (on the left one, one of teh rivets is a tube). Yes you can see one but I wanted it quick for a fishing trip and inherently lazy. The rest are invisible.
http://www.flickr.com/photos/4933236...in/photostream
Re stiching you are sort of right, but there is stitching and stitching. Some needles have cutting edges some are round, for a light leather a round needle would be better and the stitch density and thread tightness makes a huge difference to the strength. You could back the leather with something (could be more leather) and scive the edges, you would never know it was there. If I were to be critical of the design I would say that with the pegs attached only to the channel, it will want to twist and the holes in the strap will stretch spoliing the neatness of the strap just above the brass. Just some stiching will help some of the stress to be relieved and give a better look for longer. With a hook shaped needle you could run the stitch up above the brass for a small distance and it would be invisable, just stiched through the fold. (Im in the footwear industry). But I;m also assuming you don't want to scour the planet for machines that will do this!
Option 3 (I think) .... slot the bag face, strap through slot, through backing plate, back on its self and firmly fixed. Brass channel hides joint, where you have stitched a dummy strap end?
Just thinking aloud.
Tom
Thanks for all the info Tom, it seems you are a mine of information!
I'm new to both the leather and the metal side of things so it's a very steep learning curve for me here. The help is very much appreciated.
I've got neither the tools nor the skill to make these things myself, thankfully one of the members on here has offered to make a sample for me. I think the design will work, not sure exactly on how to attach it yet though.
The leather of the bag is quite heavy nubuck, and the handle is actually going to loop back so it's doubled as it goes through this metal piece. Plan b if I can't get these metal parts was to slot cut the bag face like you suggested and just use stitching. I imagine the solution will be doing the same but with the screws giving the main support.
I seem to be waffling with no real point here... My head is spinning from all the options :)
Where have all the good old fashioned machinists gone? :whistling:
Can no-one thread a blind hole in a piece of 3mm plate anymore?
Take a strip of 5/16" brass.
Blind drill the holes.
Grind your tapping drill tip down to square so it can't cut in the middle.
Dip it into all the blind holes, you cannot overshoot.
Thread the holes, (take the tip off you bottoming tap).
Saw to oversize
Screw onto a jig plate from below to cut the sides.
Nip in a milling vice while you cut to height and cut the channel removing your pilot threads.
Quick rub on emery, buff off the sharp corners.
Send them to the customer, knowing full well the threads aren't deep enough.
When he comes back with the improved design, suck air through your teeth and shake your head.
Overcharge him, he is yours forever :beer:
Good one Robin :lol:
Thats one way to screwed right
When you get a sample in your hand you'll get a much better perspective on the design. Hand bags can be difficult because girly's tend to fill em up, so they look good empty but bad when full. Nubuck should be quite tough but just think a little about taking the stresses out of that handle/bag joint, you could run it inside around the base for some extra strength and the actual joint becomes almost cosmetic. Learning is good! And there's lots of help available.Quote:
Originally Posted by barryg
Tom