I guess nobody has any ideas
I've landed a small reacurring job of cutting out various sizes and thickness of sprockets\gears out of UHMW.
I'll be cutting the profile and shaft profile of the gears with a router.
I've done some broaching before, but not this many.
I'm open for any ideas how to automate the broaching process.
Any ideas of a simple fixture?
Using a fixture and jig with a electric motor and allthread to push the broach through?
Hydraulic press or jack?
Broach the keyway before I cut the shaft hole?
Any Ideas will be greatly appreciated on this.
I'll be doing 70 - 100 of these a month.
Thanks in advance
I guess nobody has any ideas
Is this a type of plastic?When you say "automate" Do you mean placing the part broaching and removing then starting over or simply broaching the part withough using human power?Also will this material handle the forces envolved or will it crack?
I cut keyways with my Drill/Mill by fixing the spindle and broaching with single toothed cutter by racking up and down.
This is manual but cutting UHMW should be like cutting cheese.
I think your best bet is with a manual press. you will need a stroke length of about 300mm. you have to bore hole first to put the guide for broach in.In uhmw it should take you only about 2 mins, a keyway so I do not see the need to automate the process
Is it possible to push the guide and the broach together.
Stack a number together. Start pressing, then lift off the top the ones broached and add more to the bottom.
the material will handle the forces, as they will be between 2" and 4" thick. When I mean automate, I mean to take the time out of this, to make fool proof as I may want to have the 18 year neighbor kid do the broaching for me and not get hurt.
I like your idea of putting a single tooth cutter and running the quill or in my case the spindle up and down, But I'll need to figure out how to lock the spindle. And yes I suppose its possible to push the guide and broach.... maybe I'll make a long guide... Thanks for your thoughts guys... guess i'll get started on something here this weekend.
I wasn't imagining they were 2-4" thick..perhaps my suggestions weren't so good.
To hold the spindle I just have a bolt through the belt cover and screw the head against the belt and pulley. This is one of the popular cheap Drill/Mills. Doesn't take a lot to hold.
I'm cutting these sprockets\gears out with a table router. And I don't have a milling machine that I can push the broach through with the knee or head.
I could just use a hydraulic jack to push the broach through, But since this is going to be a regular thing, I might as well make some sort of jig with a press.
I'm finding out that there will be at leat 4 different diameters, and 2 different size shaft holes. So I think I'm going to attempt to make a stand alone fixture\jig\machine for this deal.
Hi Don, You can buy a small hand press on EBAY for about A$50 and This will handle up to 1 ton (2000 lb) of force. Looks like a small drill press without the table. Had one for years and it works well. It' called an Arbour press in the trade.
Enco has arbor presses that are quiet inexpensive. Get one that is small enough to ship UPS and buy it with one of their free shipping offers.
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I have broached many keyways in the past. I like the single pass keyway braches made by Hassey Savage. Ream bore push broach through and all chamfers and key forms done in one pass. You do have to hold the bore size very close. +.001 - 0. We used a manual arbor press. With plastic you will get 1000's of parts on one grind and it won't take a much power to push it. Broach can be resharpened several times. They have standards and make specials. Best and most economical way for the quantity.
To automate you can build a table with an air cylinder. Two inch bore should be good. Use flow controls to set speed.