Can a Dremel Tool Cut a Cross Section for an Engineering Project Lock?

[patrick101]

Heya, just a quick question...

http://img88.imageshack.us/img88/9140/yaleeurocylinderkitemardv0.th.jpg http://g.imageshack.us/thpix.php

Would I be able to cut out this cross section (I know, very poorly drawn in paint) with a dremel tool? I need to create a lock where I can see the pins working for an engineering project. I'm told this sort of thing is usually done with a milling machine, however they're ridiculously expensive.


Also, if a dremel tool was used, what fitting would I put on the end of it?


Thanks in advance,


Patrick

 

[berkeman]

Don't think a standard Dremmel tool would work, but I could be wrong.

Also, are you planning on taking the lock apart first? And you shouldn't plan on cutting down the mid-line of the pin chambers -- the pins and springs will fall out. An alternate plan might be to take the lock apart, remove the pins and springs from the upper chambers (remember which ones go where, or you will have to make a new key!), and then use a tabletop grinder to grind the side wall down until you expose about 20% of the pin chambers. Clean up the pin chambers if they're burred, and re-assemble the lock. You should be able to see the pins moving up and down as the key is inserted into the lock.

 

[Danger]

You should be able to see the pins moving up and down as the key is inserted into the lock.

Make that keys, plural. That's an IC core lock, so there's one key to unlock it and another to remove the core from the housing. There are also 2 top pins in each chamber (more if it's on a masterkey system).
You're definitely right about having to remove less than 50% of the chamber wall.
Another possible approach would be to cast a duplicate of the core body in acrylic and load the internals into that.

 

[Topher925]

A dremel should work fine. This is of course assuming you take the lock apart first. You will probably go through a dozen cutting wheels but I see no reason why a dremel and a little bit of skillz wouldn't do it.

 

[Danger]

You will probably go through a dozen cutting wheels

I shouldn't expect so. Those things are made out of brass. With a bit of persistence, you could cut one in half with a bread knife.

 

[patrick101]

Hi folks, thanks for all of your suggestions.

Ok, I have been looking at this for some time now, and having thought of all the advice I have been given, I am around 50/50 on whether it is going to work...

My main problem is actually the nature of a dremel tool, it's hand held obviously, so it isn't going to give me a very acurate or nice finish (asuming it orks at all).

I have instead started looking at small milling machines, which seem to be more suited for the job I'm trying to do. The one I have in mind at the moment is this one

http://www.powertooldirect.co.uk/proxxon-micro-miller-mf70-p-78630.html"

However, I have no idea if this is actually suitbale or not. Would you kind folks tell me if I am onto the right thing here, nad indeed if this particular model is any good.


Oh and I know I have to remove the pins, and obviously not cut more than 50% of the lock.


Thanks again :)

 

[Claws]

IMO it is a bit exaggerated to spend £2-300 on a mill for just this job - are you certain that you can''t find a shop that owns a mill - I would be surprised if they would charge you for milling an inch off a *brass* part ;)

But hey, having your own mini-mill would be really nice.

 

[Danger]

Oh, man... sweet little machine. I want one!
It certainly looks like it will do the job, but you don't really need to go to that expense. A Dremel will do the job as long as you take a couple of precautions.
First, clamp the lock body in a solid vise. Hold the Dremel with both hands, preferably using a padded wrist-rest, and work slowly. While I haven't actually tried it, I suspect that a regular steel cutter, which is intended mostly for plastic, will work fine on brass or aluminum as long as you take it easy. If not, the fibreglas cut-off wheels will definitely do it.
Whatever irregularities remain after the cutting can easily be touched up with a very fine file or even an emery board.

 

[patrick101]

Heya, thanks again I like all of your suggestions.


I would like to make a good few of these things (upwards of 10), with half an eye on making more in the future, so at the uttermost importance is getting something which consistently performs well, giving a nice neat finish. I also can think of many other engineering projects where a milling machine would come in useful, so it would be a bit of an investment rather than a one off use.

Obviously a milling machine works more like a sideways drill rather than a "cutter" which the dremel would use. This is more appealing to me as it would provide a lot more control etc. I would be a bit worried of cutting in too far and screwing the lock up (considering I am making so many, using something like a hand held dremel something is going to go wrong).

Any other thought people? :P

I seem to always gravitate towards the more expensive option :)

I really don't know a great deal about these "mini milling machines" though. Can anyone provide some insight into what price has to be payed for a reasonably good one etc.

Thanks again folks :)

 

[Danger]

Well, it's a whole 'nother matter if you're going for bulk production.
I would recommend that you seriously consider making moulds and casting your own pre-cutaway shells out of molten brass.

 

[patrick101]

Right ok...

Where would I be able to find more information about this, how much would it cost, and what is the benefits of using this kind of system?

I'm going to read up on it :P

Thanks

 

[Danger]

I can't say about the cost. Most artists, for instance, supply the original shape to a foundry for production. Setting up your own shouldn't be too expensive, but might be on a par with the milling machine.
The prime advantage is repeatability. You have to make only one original, then you can clone it as often as you want to.
There are lots of videos and descriptions on various sites such as U-Tube. Discovery Channel's How It's Made had a good segment on it; it might be available on their site. Google for bronze casting, rather than brass, because that's what's most often used. The process would be identical.

 

[patrick101]

Heya, thanks for the response, I'll have a think about it.


But just to confirm, this milling machine would definitely be able to do the job of cutting away the cross section of the lock?

http://www.diytools.co.uk/diy/Main/sp-45-7078-37689-proxxon-27110-micro-miller-mf-70.asp

Thanks again, your advice is really invaluable.

 

[Danger]

I'm pretty confident that it would work just fine. Work slowly, though, since I can see a potential for 'chattering' of the toolbit when you break through into the pin cells. Really shallow cuts should eliminate that.

 

[Redbelly98]

Why not visit a local machine shop, and talk to them about what you need done? See what they would charge for doing 1, 5, and 10 of these. Even if you end up getting your own mini-mill, it may still make sense to have a professional shop do the first ones.

 

[kv_home]

Best bet is definitely to go to a machine shop -
That milling machine is a cute tool, and cheap, but the machine is only the first expense, you need cutting tools, clamps, fixtures, etc - and you will need different ones for every job you do. Until you have experience machining, and defining what you need, it is best to use the pros, tell them what you want done, and they can help. It will be cheaper in terms of effort, if not actual out of pocket expenses.

If you still want a milling machine after dealing with machine shops, you will probably want something bigger - used equipment is available for low cost