Author Topic: Small (broach) press. Hydraulic or mechanical?  (Read 8934 times)

Offline PekkaNF

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #25 on: March 26, 2015, 03:52:25 PM »
Got hydraulic cylinder with front flange, but there is some junk on front of the flange, have to design over it.

Hope that I will get some garage time this weekend. Bought bolts and nuts.

Cylinder has 500 mm of stroke and I will need about 350 mm of it....can loose some.

Pekka

Offline PekkaNF

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #26 on: April 19, 2015, 02:56:39 PM »
Little progress here. I have been bying every nut and bolt only as I need and not rushed oout all that I think I might need :D

Good news: Less money spent.

Bad news: Everytime I start working on it I figure that I need one extra dimension on part I don't have and tools I though I had or have capacity falling just 1-2mm short...therefore, most of stuff is being made with plan B!

80*20 mm HRS does to fit into 80 mm vise.
My trusty russian boring head stops to 47 mm, just short of 50+ needed, I'll try holesaw to it, because not that good accuracy is needed, just clearance.

I have idea how to put three holes (each part) on same line on four parts. Only two parts are same size, other two are unique. I'm thinkking of using the largest piece as a jig and finishing it last.

Pekka

Offline Lew_Merrick_PE

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #27 on: April 19, 2015, 07:10:14 PM »
Little progress here. I have been bying every nut and bolt only as I need and not rushed oout all that I think I might need

My trusty russian boring head stops to 47 mm, just short of 50+ needed, I'll try holesaw to it, because not that good accuracy is needed, just clearance.

I have idea how to put three holes (each part) on same line on four parts. Only two parts are same size, other two are unique. I'm thinkking of using the largest piece as a jig and finishing it last.
Hi Pekka,

I don't know about Finland, but here in the U.S. it is usually less expensive to buy a box of 100 screws, dowel pins, etc. than it is to buy 10-20 a piece at a time.  Then you have the extras the next time you want some...

You could make an boring bar insert that is (say) 2mm broader than the ones that came with your boring head.  ???

As to the last, you can line bore the two that are the same size and then use them to dial in hole locations on your other two odd parts.  The other way to accomplish this is with tooling buttons that are positioned using parallels and gauge blocks to assure accuracy of position.  In essence, a tooling button is a piece of round steel that is drilled out to be somewhat larger than a (relatively) small screw.  You then drill and tap for the screw, insert it through the (now tubular) round bar, and adjust the position using parallels and gauge blocks before the final tightening of the screw.  [Button Head Socket Cap Screws tend to work the best.]  You then dial in on each button in turn.

Hopefully, some of this will help you...

Offline PekkaNF

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #28 on: April 20, 2015, 03:51:29 AM »
Thanks,

It is pretty much same here and I normally just do that. But sometimes I'll get lazy and figure that since I'm turning some bars with 1,5 mm lead I'll do the M16*1,5 and buy the four nuts I only, because I'm not convinced if can find the remaining nuts ever after.

I need to get somewhere box of 4/5/6/8 mm dia dowel pins, those I would need often. Yesterday I cut two dowels out of silver steel (that was closer to 4,9 mm than nominal 5,0 mm).

It's the eternal balance to have enough stuff to keep you going and not accumulating all the stuff that might come handy one of these days.

I considered line boring, but these will not fit into my small lathe and my big lathe (old junk revolver missing the capstan assy and tail stock) would need some little additions. Two pieces are 240*80*30 mm, one 25,00 hole in the middle and two 16H7 holes on both sides. All on on the central line. I'll give some more consideration to your text. Buttons....maybe this is the time to make some, so far I have used bearing rings. I think I don't actually need that accurate here, but it might be a good excercise.

I was thinking of drilling them individually way undersize, drill central hole tight for a dowel that will align them all centrally. Stack three critical ones together, dowel pin on the centre should keep them aligned. Mark orientation on each piece. Drill the whole stack a little undersize and then use hand reamer on critical holes (on the sides). Then take that stack apart, use two holes to align the pieces and bore the central hole clearance.

Would this work?

The Boring bar has enclosed cylindrical slide and boring bar moves in a slot milled to boring head. This slot limits the movement and should make a cranked boring bar to it....I rather build or buy different design for another boring head, but that will "some day" project.

Pekka

Offline Bluechip

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #29 on: April 20, 2015, 05:02:23 AM »
Thanks,


I need to get somewhere box of 4/5/6/8 mm dia dowel pins, those I would need often. Yesterday I cut two dowels out of silver steel (that was closer to 4,9 mm than nominal 5,0 mm).

Pekka


I know where to get 'em in UK. But they come in boxes of 100 and I don't know if Cromwell ship out of UK ???

https://www.cromwell.co.uk/index.php?q=2dd54819-466f-4b2e-abf6-05b33aa84e58&p=advancedsearch&action=advancedsearch&search=1&search_all=dowel+pins&search_any=&search_phrase=&search_none=&search_brand=&search_price_from=&search_price_to=&search_sort=&search_limit=10&search_offset=50

Here you go anyway ...  :thumbup:

You're on the right page, just scroll down past the 20mm to get to the 2mm and then page on for the rest ...
Dave
I have a few modest talents. Knowing what I'm doing isn't one of them.

Offline Lew_Merrick_PE

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #30 on: April 20, 2015, 11:59:01 AM »
Pekka,

Not knowing your shop, I would have assumed that such work would be done on a milling machine.

One thing to keep in mind is that a drill will follow an existing hole.  A boring end mill (an end mill that has been ground to dull the circumferential edges) will generally allow you to move a hole a bit without the following effect.

With respect to the boring head, what I am talking about is the insert boring bar.  They usually have a slip-fit cylindrical end that fits into the boring head, an offset taper between the fit cylinder, and a circular cutting end that extends out beyond the tapered leg.  It is the circular cutting end that can be increased in size to gain you some throw to enlarge your range.

With respect to tooling buttons, the first set I made as an apprentice were made from .500 inch drill rod (silver steel).  Five of the button bodies were made to be .500 inch long and one was made to be .875 inch long.  The .875 inch long one was my zero basis (so I would always know which button represented my zero position).  The buttons were drilled & reamed to .250.  I then used #10 (.190 inch major diameter) Button Head Socket Cap Screws as the clamps.  I mounted them all on a piece of (drilled & tapped) steel bar to keep them together.

Over the years I have made sets of tooling buttons with clamp screws ranging from #0 (.060 inch major diameter) up to .375 inch major diameter.  My more recent sets were made from A1 (air quench) tool steel bar to reduce post heat-treat warpage.  I have an appropriately ground boring end mill with each set.

Offline PekkaNF

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #31 on: April 20, 2015, 03:23:14 PM »
You are right on that. Drills tend to folow previous hole and reamer follows the hole.

I have to rethink this. I have milling machine and I have history of getting holes skewed even though I think I have trammed head.

I was cutting 100*100*12 mm angle iron, about 700 mm long and managed to drop it to my toe. I had been wearing steel tip shoes for 20 years and they go old. Transhed them and didn't got round buying new one. I can tell running soes offer very little protection.

Pekka

Offline Sid_Vicious

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #32 on: April 20, 2015, 03:29:20 PM »
I can tell running shoes offer very little protection.

Pekka
I know, Bin there done that :beer:
Nothing is impossible, it just take more time to figure out.

Offline RodW

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #33 on: April 20, 2015, 04:44:33 PM »

I have idea how to put three holes (each part) on same line on four parts. Only two parts are same size, other two are unique. I'm thinkking of using the largest piece as a jig and finishing it last.

Pekka

After experiencing the same problem, I went looking for Transfer screws and transfer punches. The transfer screws are very cool but hard to find. You can get both from here

http://littlemachineshop.com/products/product_category.php?category=1438824943&First=T&Last=U
RodW
Brisbane, Australia

Offline PekkaNF

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Re: Small (broach) press. Hydraulic or mechanical?
« Reply #34 on: April 21, 2015, 09:39:44 AM »
My toe is very purple and swollen all over. They said it should be better in 3/4 weeks.

Thanks for the transfer punch idea, I'll have to consider that.

I always though that transfer punches are accepted marking out clearance hole / thread holes and such, I'm such a kloz that I probably would bugger something and would add too much error.

Pekka