OzVMX Forum
Clubroom => Tech Talk => Topic started by: TT5 Matt on February 05, 2014, 11:38:58 pm
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gunna buy or make a press and need to know what size press in tons and width of table etc I need for doing crankshafts with? spoke to some car mechanic mates and they say 10 ton is good for doing axle bearings with. ive got a 19 foot lump of 8 inch c section that I could use for the uprights and top section and got plenty of other bits of angle iron etc so other then a suitable jack there wouldn't be much to buy and my fitting tafe teacher likes it when I make things for home instead of the fixed/set jobs the apprentices have to do.
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20 ton is better than a 10, but to cranks and not make it an all day job there are a few other bits of tooling you will need , like a $100 copper hammer, 2 dial indicators ,press jigs, web holders and centres. All for a job that you can get completed to a very high standard for $50. Press is a worthwhile item to make you would need some 20/25mm plate for the bed and best to have some mechanical means of lifting that bed up and down.
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10 and 20 ton presses are great for doing general "light" fitting, transmission bearings etc. One of the most important skill requirements for a fitter to develop is what is known as a "feel".
10 to 20ton presses give a great feedback feel to the operator, imperative to instantly recognize if there is adequate "interference" between the two components, nine out of ten times, the preferred quickest path to getting a job done.
But if no resistance (interference) is felt, one must then disassemble, and precision measure to identify the offending component which has caused the lack of interference.
When it comes to presses for crankshaft pins, bigger is better. When a small inadequate press struggles, it spring loads the frame of the press instead and when the energy does lets go, it moves with a jump and a cracking bang. Definitely not preferred for a quick stress-free precision crankshaft outcome.
A twenty tonner will get most 125 crankshafts done reasonably OK without too much stress, but for a quality outcome of bigger more stubborn Maico's cranks etc, a 50tonner makes it a stress free walk in the park.
If you are building a press for heavier cranks? then the more rigid the frame, the better.
If the C section you have is heavy thick flanged cold rolled channel? then you can give the first step a tick.
Good luck Matt.
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waited 6mths for a 20tonner at toolies in gateshead,every 2nd man & his dog must have a press in their shed in the Newie locale,always sold out their 10/20T press shipments soon as they hit the floor, :P
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I can probably get exactly the same one for you much cheaper at cost Mick.
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30 ton air over oil does it for me.
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I made a 10 tonne and its done me fine for my small cranks built so far CT YZ etc i made a copy of a clarke 10 tonne Bench Press i use a porta power etc
My oil / pump cylinder sits on the front of the bench and i pass fork tubes through the frame
Piccy
http://www.machinemart.co.uk/shop/product/details/clarke-csa10bb-10-tonne-hydraulic-bench-press
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I don't want to get into a mines bigger than yours game but my 100 tonner handles just about anything.
Zane
(http://i907.photobucket.com/albums/ac276/zane255/Othersidewithhoistpresssteelrackandlathe-1_zps7f690934.jpg) (http://s907.photobucket.com/user/zane255/media/Othersidewithhoistpresssteelrackandlathe-1_zps7f690934.jpg.html)
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Good on ya, now I've got hydraulic press envy :-\
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That's a nice set up you have there Zane.
Do you use a ladder to get the ladder down :o
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Mick those long ladders come in handy sometimes but it's hard to find a place for them to live in between jobs
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Nice press Zane.
I have been doing cranks for the last 40 odd years and I reckon you need a 30 ton plus press to enable you to rebuild a variety of size cranks. I currently have cheap Chinese 30t with a 50t jack turned upside down and revalved to run that way. This press works great for cranks. I have just bought a 63t electric over hydraulic to do some bending work but will eventually set it up to do cranks also.
Stan.
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thanks fella's for your replies and words of wisdom that ill make a 50 tonner up and copy the 60 tonner at tafe where I can and im sure my teacher can give me plenty of advise when im making it. ive also got a geared boat winch/inch and 3/4 nch plate and made pressing plates so major costs will be the 50t jack which will be cheaper then a made up 20t press I saw on epay and will be a useful addition to my lathe an drill press ive had for years. im sure once ive got it ill find a lot of uses for it other then doing cranks and car axle bearings with it
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Matt once you have one you can find a 100 uses for it. If you make up a blade and vee block they make a great metal folder and plate or flat bar bender, I also use mine to hold jobs while I work on them.
Zane
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Here are a couple of photos of the press brake attachment I made. I got the urethane press block at what I thought was a reasonable price off of eBay. I have enough fingers to go the whole width, from about 1" to 6-8" wide.
(http://www.eurospares.com/graphics/metalwork/PressBrake04.jpg)
(http://www.eurospares.com/graphics/metalwork/PressBrake05.jpg)
cheers,
Michael
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that press brake attachment would be very handy and doable at tafe since I don't do the set course the kids get landed with. the scrapy here get a lot of steel off cuts and a good source of cheap steel and a lot of other stuff, I often walk around the paddock and find gear there and get it for cap city scrap price.so what other attachments have you guys made for doing stuff with?
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I admire what you are doing Matt.
I went down the fitting and machining apprenticeship line for no other reason then to learn how motorcycle parts are made. Which I still get excited about.
Encouraging to see you have a great teacher that knows the importance of assisting you to think for yourself, by developing your education out of the square.
Although you can do a lot of cranks with the smaller presses, there are some stubborn ones. Maico run a heavy interference for example. You wouldn't attempt to use a tack hammer on a six inch nail, unless it was all you had.
What you have chosen will serve you well for life, and do a lot more than cranks, as Zane and others have suggested.
looking forward to seeing your success.
PS; no doub you can always upgrade this through its life as opportunity for the right price knocks
EG; when you trip over an old air or electric over/hydraulic pack.
Good luck ;)
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Matt if you build a press make sure your bed and top are strong enough, quite often you see where they have bent while pressing and that can cause the job to spit out and be dangerous. You can weld plate on the outside of the bed etc this adds strength and helps to stop bending and also the bed collapsing and spreading.
It is also a good idea to use flat bar for the uprights, this allows you to bend longer lengths in between them where if you use channel you are limited to the width of the press. I machine pressing blocks from dumps of steel and try to keep them if I can to use again later, if you use them once then you will likely use them again.
Try to position the press where you can get to both sides or it it is not to big and heavy then some fit wheels so they can be moved a bit to make this possible. But a warning moving heavy presses can also be dangerous (photo below).
These 1 inch bars bent like they were made of solder when the sling broke while moving it.
(http://i907.photobucket.com/albums/ac276/zane255/Pressplatesetc007_zps8a9f6796.jpg) (http://s907.photobucket.com/user/zane255/media/Pressplatesetc007_zps8a9f6796.jpg.html)
A couple of bits that are handy to have around your press.
I have 3 plates for pushing cranks apart they are made from Bisloy steel and are in 3 different thicknesses for small to large cranks.
(http://i907.photobucket.com/albums/ac276/zane255/Pressplatesetc002_zps66799160.jpg) (http://s907.photobucket.com/user/zane255/media/Pressplatesetc002_zps66799160.jpg.html)
Its handy to have a light, a knife blade for heavy flatbar etc, a light weight knife for folding sheet metal etc, I also made a simple base plate from a bit of flat bar and 2 bits of pipe welded onto it for doing those slow rounded bends.
(http://i907.photobucket.com/albums/ac276/zane255/Pressplatesetc010_zps140f9882.jpg) (http://s907.photobucket.com/user/zane255/media/Pressplatesetc010_zps140f9882.jpg.html)
(http://i907.photobucket.com/albums/ac276/zane255/Pressplatesetc005_zpsff01870b.jpg) (http://s907.photobucket.com/user/zane255/media/Pressplatesetc005_zpsff01870b.jpg.html)
(http://i907.photobucket.com/albums/ac276/zane255/Pressplatesetc006_zps4037f0fa.jpg) (http://s907.photobucket.com/user/zane255/media/Pressplatesetc006_zps4037f0fa.jpg.html)
Zane
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if your going this far better look at some crank pots too