Said I might, Pantograph

[AdrianH]

I blame this purely on eSCHEn . If it was not for his plasma cut Belted cow, and then the thread going on to someone with a pantograph I would not have started it, honest!



Still a lot to do with it and not a perfect design. There are two 21 mm by 12 mm internal hole bearings in each of the four pivots. Still have to get two thrust bearings for the central fixed pint. The maximum reach is 550 mm or thereabouts. It will not open any more then in the top picture due to a design feature. I should be able to change that a bit. Plan to have two plasma holders on one leg and two pointers/follower positions on the other, idea being I could either due 2:1 reduction, 1:1 copy or 1:2 enlargement if it all works.

That's the plan anyway.

Adrian

 

[eSCHEn]

What, me?

Looks kicking Adrian, I've not even had a chance to have another go with the cutter since due to other stuff Just in case that makes it more even lol

Really looks the part man, should be a canny bit of kit when it's done. I'm working on a wee addition to my cutter this week which you might find useful. Shall post it up when I'm done.

 

[AdrianH]

It one of those things, I can do stright lines by use of a guide piece of wood, I am also ordering a circle cutter guide from china. I want to use the plasma for a bit more then straight lines and want to do some arty stuff, but free hand will be horrendous so doing this should enable me to draw, then if happy, try and trace. Going CNC will have to wait.

Adrian

 

[eSCHEn]

It one of those things, I can do stright lines by use of a guide piece of wood, I am also ordering a circle cutter guide from china. I want to use the plasma for a bit more then straight lines and want to do some arty stuff, but free hand will be horrendous so doing this should enable me to draw, then if happy, try and trace. Going CNC will have to wait.

Adrian

CNC looks really fun but there's a lot more soul in something hand cut

 

[CRB]

It will not open any more then in the top picture due to a design feature.

Most of my jobs have design traumas built in.

 

[chunkolini]

I just use an OHP to scale things up, and have to live with any operator error.

 

[500e]

Noted an add for Plasma Cam came up on this site is there a UK supplier of that size cost machine Emailed PC 18 months ago twice no reply, it was just an idea then but we have had quite a few parts cut since then 7 it is getting to a point where we may find in house is cost effective.
The feed back from someone who uses this type of equipment would be helpful.

 

[AdrianH]

Was in the garage last night until 10:45, naughty lad I am, so had to keep it short tonight otherwise I would have been in the dog house again (no dog).



I had thought about having fixed locations but after a bit more thought decided to try an adjustable holder, that way I can adjust for to correct unwanted scaling. Still have to get the extra bearings, just work is now getting in the way. Tomorrow night I will try to make a stylus of sorts again probably a U shaped bent flat bar with 2 holes in it for some steel bar to go through and another M6 locking bolt holding it against one face. I am having fun if nothing else.

Adrian

 

[doubleboost]

You have my full attention
This is something I have wanted to do for some time

 

[Norm]

that looks to be taking shape nicely Adrian, great idea on the adjustable holder, will be watching this closely.

 

[AdrianH]

The problem I have is that I do not sit down and plan it out on paper, I build, then think either Bo****ks got it wrong or Eureka can do it better! Also limited to what I have around to use. Even when the arms are finished I will still have to make a tray and holder/clamp for the bench. With a shortage of space it will all have to be demountable.

But I have had a thought. My small cnc milling has around 7 inch by 14 inch of travel on the table, with the stylus end on the table the cutter would be able to cut steel from the cnc program to repeat items as required (small items that is) That is a long way off. Hand drawn sketches and copies in steel like the old Sketch A Graph and I will be happy.

Adrian

 

[eSCHEn]

Fantastic stuff Adrian, really enjoying seeing this come into shape

 

[AdrianH]

eSCHEn Was think of you before when I saw this on ebay: -
http://www.ebay.co.uk/itm/weather-v...Garden_GardenOrnaments_JN&hash=item339bc33e5b

 

[eSCHEn]

Hah, just what we were thinking of making first! Think a wee trivet might be more along my current skill level

Bookmarked and will show the missus tomorrow.

What did you use for bearings Adrian? Are you going to weight the torch end to keep it from bouncing?

 

[AdrianH]

The bearings are 12 mm internal by 21 mm external ball races, top and bottom of each pivot point. They are fastened in a turned bit of 24 mm'ish bar at just under an inch tall. Not sure what will be needed to stop bouncing or if it will be an issue. I have very little flexing of the assembly, but then again not being used in anger with 55 psi of air flowing out of the end of the torch, so need to wait and see what problems arise. The bolts going through are M12, and when not nipped up can have some play in them, if an issue I will actually turn 12mm bolts to get rid of the play. I did take a video with my phone but it is 90 degrees out so useless.

Adrian

 

[eSCHEn]

I think you should be able to rotate it round with handbrake.

 

[AdrianH]

OK simple video link here

Adrian

 

[echosierra3]

I wish someone would sell a decent pantograph, been looking for a long time.

 

[eSCHEn]

That is a really sweet movement on the joints there Adrian, so smooth and zero flex. Absolute top job mate

 

[AdrianH]

Another quick update, done my stylus and again just a simple thing that means I can adjust it's position.



The stylus is a nail about 4 inch long with the end turned down to 1mm'ish. And then dare I say it cleaned with emery tape in the lathe (see another post on lathe accident..

The locking piece is a cap head screw with the cap turned off to give a flat face, could have used a normal bolt but this was stainless and then a M6 nut welded on the end of the thread dead easy.

Still need thrust bearings and tray yet before I can play.

Adrian