ABOUT ME

I live in a camper van with a couple of West Highland Terriers for company.
My passion is photography but it is a work in progress.
I am always willing to share what knowledge I have and can be contacted through the comments on this post or e-mail ADRIAN
ALL IMAGES WILL ENLARGE WITH A LEFT CLICK

Tuesday, 29 May 2018

FreeCAD CAN BE FUN.

I have had a frustrating but reasonably constructive few days dreaming things steam bike. I had an hour of FreeCAD crashes whilst constructing a piston valve. I blame myself as I'd filleted and chamfered everything, there was just too much mesh in the job. I was gathering myself together when I realised the bloody engine I was contemplating would be over two feet long when the cross-slide and crank were included. I did consider an over square engine but then thought of using a car air conditioner pump as a steam engine. These pumps are a multi cylinder swash plate set up and are very compact and powerful. I googled them and found they wiz round at a fair rate of knots so a reduction box would be desirable. I remembered seeing an epicyclic gear box on a vintage lawnmower. These are great and also act as a clutch. If you drive the sun gear and take output from the planet gear carrier then have a brake band on the ring gear when the ring gear is arrested you trundle along and when it's free to rotate drive is disengaged. An open version would also be in keeping with the steam punk business. I can't describe it with any more clarity but here is an attractive animation of one doing what it does.
This chap enjoys colouring in......a man after my own heart.
I decided to do some of the bike frame work but could I get FreeCAD to join tubes to the headstock? No I couldn't, not a chance even when I resorted to using special words.
As is my want, when I get stuck I change tack, I found this gem, it's a spread sheet for calculating valve timing.
If anyone is interested then I can look the link up for you. I have saved it into EXCEL just in case I need it for a valve. Whilst trolling through Google I found a very compact square piston engine. It was invented by an American called Dake at the end of the 19th century. It is superb, cannot stop on dead centre, will reverse by switching inlet and exhaust and has only three moving parts. The chap may not have been able to spell but he certainly had all his ducks in a row. I'm going to 3D one. Here's a bit of an animation.
I have sorted the tube malarkey. I can't join anything but plain tubes but I can now start putting a frame together. The video is narrated by me. I am not a teacher so there are many Ums and pauses,the dogs add to the experience with panting and shaking; rattling their collars. It is all about pipes and cylinders so you may wish to give it a miss. I will have to start scripting these and learn the script.


The next instalment may be a week away as I'd like to show a rough concept of my dream.
Have fun.

2 comments:

  1. Sorry Adrian, I've just caught up with this one!
    It's all getting very high tech. now?
    Brings back a lot of memories of many a happy(??)day spent cutting in tubes, by eye and air grinder, for space frames and roll cages. The round tubes were relatively simple compared to the oval/aero tubes for suspensions/wishbones etc.
    Keep up the good work...[;o)

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    Replies
    1. Yes I have done a fair bit on both the Royale and bike frames after a bit of an offski.
      Should the job ever get to construction then I would like to plasma cut the tubing. I have lost the gen on the plasma tube notcher but it ought to be easily found with Google.

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