You might be able to help me

This topic has 15 replies, 9 voices, and was last updated 5 November 2012 at 16:40 by Springbok.

Viewing 16 posts - 1 through 16 (of 16 total)

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13 October 2009 at 15:00 #21636
Alex
Participant
@alex
I need this part
Advert

13 October 2009 at 15:00 #44149
Alex
Participant
@alex
Hi everybody

Firstly i am not a model engineer (or an engineer of any kind for that matter)

i am a designer. I am trying to make a modification to a plotter head – a drawing machine,

I think the model engineering community might be able to help me.

Can anyone make this part?

There will never be enough needed to interest commercial companies – but I would be happy to cover the costs.
13 October 2009 at 15:07 #44150
Rob Manley
Participant
@robmanley79788
Im sure there are people around who would have a go for you. Where are you based exactly because it might be better for someone local to help. Otherwise I would make one – as long as you don’t mind waiting a fortnight. I would be worried about making it in two parts because of concentricity issues – how important is this? Rob.

Edited By Rob Manley on 13/10/2009 15:09:10
13 October 2009 at 16:07 #44152
David Clark 13
Participant
@davidclark13
Hi There

I would suggest using a hypodermic needle for the tube bit.

I doubt you could easily drill 0.5 through a length of 10mm.

regards David
13 October 2009 at 18:29 #44154
Circlip
Participant
@circlip
You’re basically trying to re-invent the “Rotring” drawing tip then ???

Regards Ian.
13 October 2009 at 19:18 #44158
Ian Abbott
Participant
@ianabbott31222
I picked some of the Rotring tips from a yard sale a while back, though you can still probably buy them. A cheap alternative would be the Stadler draughting pens, you can use them without the body and Stadler compasses sometimes come with screwed adaptor rings. It would be possible to shorten the reservoir to keep the hight down.

Even cheaper would be a spacer to fit a “V5 Hi-Techpoint” pen from any stationary shop.

All this assumes that there is enough space.

Also, the Summa plotter that we sold before we came back from Canada had little fibre tip marker dealies. Boy, they were expensive though.

Ian
13 October 2009 at 23:21 #44168
Alex
Participant
@alex
Thanks guys

Rob

locality, good point – I am in Sunderland England so probably best if I could get help from someone in the UK,

I am not too worried about the time scale It would probably take a few goes to get it right, iron out any problems etc. might turn into a bit of a development project.

David

Thats just the kind of thing I wouldn’t know about – why I need help!

Ian (circlip)

Pretty much but for an automatic pencil – more modify than re invent so it works properly in my application. (I wouldn’t presume to try and re invent a Rotring)

Ian (Abbott)

I’v tried quite a few pens and pencils, the problem is they don’t fit well and end up as a bodge. I think if it can be done properly I will get something that works well is convenient to use and would be repeatable.
14 October 2009 at 00:29 #44170
LionelGedling Goodwin
Participant
@lionelgedlinggoodwin18953
Hi Alex,

I also am not an engineer (yet) but it looks to me remarkably like the end of a Pentel P205 0.5mm clutch pencil. The overall length is only 21mm and the outer body shape is two tapers totalling 16.1mm in place of the 8mm and 12 mm length sections. The 4mm section is an exact match with 0.8mm outside diameter and 0.5 mm inside diameter.

No doubt the cone could be turned down to your specification if necessary.If the overall length is not critical and if the internal thread is a match, then this may be your answer.

Regards, Lionel
14 October 2009 at 11:42 #44175
Circlip
Participant
@circlip
Ahhhh, the Thotter plickens, as you’ve now mentioned plotter and pencil, as someone wi a bit of drawing office experience and an ingineer to boot (Although a paid up member of the FW society), main problem with graphite is you have to mechanically feed it through the “Nib”, so to ensure that there is always some between the paper and the tip of the hypo you must have devised a fantastish feedback system??

Due to the flooding problem of the tube feed systems and ending up with ink all owert place despite years of developement, this is where the rollerball and felt tip systems score on plotters. O I, forgot the ink jet ones.

Regards Ian.
14 October 2009 at 15:07 #44179
Alex
Participant
@alex
Hi Lionel

As you rightly surmise the innards of the nozzle are pretty much standard technical pencil (although German-rather than Japanese) except a bit longer than usual – it’s the dims of the outside that need to be different.

Hi Ian (Circlip)

You are giving me far too much credit with the “fantastish feedback system??” I have just heard of one that might work!

The main problem is getting the head/nozzle/nib thing in my sketch to fit. if that doesn’t work then I consign the whole thing to the “well that didn’t work bin”

The other thing to mention is…

In this day and age, (when ink jets are cheap and available). Who in their right mind would want a pencil to work in a plotter. Probably just me. There’s just something about a pencil line. I even do drawings for the ink jet and try to make them look like pencil.

cheers Alex
14 October 2009 at 19:08 #44187
Ian Abbott
Participant
@ianabbott31222
Dare I suggest grey ink?

Otherwise, what exactly is the mounting like. Ours was a plastic circular clamp about 3/8″ i.d., with a pinch screw and no clearance issues above it.

One potential problem is that the pen or cutter, whichever is installed, lifts between marks, so whatever is used must have a retaining system for the graphite powder or lead for whilst the plotter lifts as well as the feed.

If your plotter works like this, a ratchet could be incorporated between the pen holder and the body, using the lift to operate it.

Ian
15 October 2009 at 15:39 #44218
Alex
Participant
@alex
Thanks for all the help and suggestions – BUT

I have just heard that the auto advancing mech I was planning to use does not work very well! – So I am going to have to review the design of the little part i need making to suit an alternative – I am going to try one from Faber Castell in Germany

.”The Faber-Castell features a feed mechanism which advances the lead automatically as you write. No shaking or button-pressing required! “ “

I am going to check this out and make a new drawing – So project on hold for now.

Thanks for all the suggestions. I would like to enlist help again in the near future if it’s not a bother to you guys.

cheers

Alex
5 November 2012 at 14:22 #102858
alex bonnar
Participant
@alexbonnar26874
just recently joined so uncertian as to correct forum, i am building model aroplanre engine 1st one steel quoted for crankshaft is en30b uanble to source ssmall quantity can any one suggext alternative

thanks

alex
5 November 2012 at 15:50 #102866
JasonB
Moderator
@jasonb
EN24 will probably do. M-machine sell small amounts

Whats the engine you are making as someone who may have made it could give a better answer.

Also best in future to create a new topic rather than tag it onto an unrelated post.

J

Edited By JasonB on 05/11/2012 15:52:12
5 November 2012 at 15:57 #102867
alex bonnar
Participant
@alexbonnar26874
thanks jason should have posted more details, have posted website sent nice gentleman e-mail for further info but as usual they got you money and they dont want know. the one im working on is wt1620

**LINK**
5 November 2012 at 16:40 #102873
Springbok
Participant
@springbok
Hi have still got a few of these rotaring bits if you want them

bob
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