Shop press bottle jack size?????

[powderblast]

That sir is a very nice press, have you considered using a ram and hydraulic powerpack? Can all be had secondhand and probably for less than the cost of a jack, also no need for return spring if you fit a spool valve. Just thoughts.



Bob

I have gonna build a safety guide for the front but waiting untill the jack is installed and I'm gonna lathe some differnt size pins for it to

 

[God mode restorations]

Are the main uprights 6mm wall thickness where the pins go.

 

[balmerchris]

I've never used an inverter mig before. The murex is transformer based but it's three phase which from my experience makes for a much smoother weld.

 

[WorkshopChris]

This thread has spurred me on to start my build i have been considering a 20t bottle jack inverted was also looking at the air assisted versions.
Although i am a little unsure of how long the seal will last as it was not intended to hold back oil just keep dust out.

the holes its legs are 90x90 box 6mm wall, 25mm solid pins.

Are the pins just Black 25mm something like S275 low carbon steel or something more exotic.
Looks well built, mine will probably be glued together with stick as the mig is only 180a i have just lost the use of 280a as a workshop neighbour has just moved out this week.

That sir is a very nice press, have you considered using a ram and hydraulic powerpack? Can all be had secondhand and probably for less than the cost of a jack, also no need for return spring if you fit a spool valve. Just thoughts.

Bob

I have a old air to hydraulic pump that has been kicking about the workshop for ages ex raf from memory will have to dig it out and have a look.

 

[wookie]

The place I used to work at had a press that we used to get up to 40 tons or more from time to time, the pins were 1 3/4" diameter and the thickness of the uprights was 5/8". A couple of the holes had elongated very slightly. More worryingly was the bed was distorted and slightly bowed and that was made of 3/4" thick by 8" deep flat section on edge.

 

[God mode restorations]

I think with 50 tonne on 6mm wall box the pin holes will start to mushroom.

 

[powderblast]

Are the main uprights 6mm wall thickness where the pins go.

yeah im pretty certain they are 6mm if i think there is going to be a weak link i think it will be the holes i think over time they will become more oval shaped but i made it so the table is has a gap so i could machine up so 10mm washer and weld the at each hole so it will then be 16mm thick hopefully i dont have to do this

 

[powderblast]

I've never used an inverter mig before. The murex is transformer based but it's three phase which from my experience makes for a much smoother weld.

yeah you can tell your welds look great, i unfortunately do not have three phase electric but i would like to have a go on a big machine

 

[powderblast]

This thread has spurred me on to start my build i have been considering a 20t bottle jack inverted was also looking at the air assisted versions.
Although i am a little unsure of how long the seal will last as it was not intended to hold back oil just keep dust out.


Are the pins just Black 25mm something like S275 low carbon steel or something more exotic.
Looks well built, mine will probably be glued together with stick as the mig is only 180a i have just lost the use of 280a as a workshop neighbour has just moved out this week.



I have a old air to hydraulic pump that has been kicking about the workshop for ages ex raf from memory will have to dig it out and have a look.

just standard black round bar just what i had on shelf i welded this with my r tech 180amp welder did it no problem time will tell after use lol but i am thinking of getting there 250 machine as thats the largest they do on single phase

 

[powderblast]

I think with 50 tonne on 6mm wall box the pin holes will start to mushroom.

yeah i think it may be a problem but i made this out of scrap off cuts and to be fair the bottle jack was i think £10 more for the 50 over the 30ton so it made sense as the 50 had a thicker base im not saying it will be used as a 50 tell you the truth i cannot see it getting used lol, but if there is any issues i will machine up some 10mm washer and weld them at each hole so it will then be 16mm thick hopefully i dont have to do this though

 

[WorkshopChris]

just standard black round bar just what i had on shelf i welded this with my r tech 180amp welder did it no problem time will tell after use lol but i am thinking of getting there 250 machine as thats the largest they do on single phase

You can go bigger but they get through lots of electric
https://www.weldingsuppliesdirect.c...rocess-mig-welder-dual-voltage-230v-400v.html
This will go on a 32a supply but they do bigger 230v machines.

 

[balmerchris]

You might need bigger pins. Wiki formula:


To work out the force to shear a 25 mm diameter round steel EN8 bright;

Area of the 25 mm round steel in mm2 = (12.52)(π) ≈ 490.8 mm2
0.8 kN/mm2 × 490.8 mm2 = 392.64 kN ≈ 40 tonne-force
40 tonne-force × 0.6 (to change force from tensile to shear) = 24 tonne-force

 

[balmerchris]

Don't ask me what any of that means I just found it on Wikipedia. It's what I based my decision on to use 38mm en8 pins

 

[powderblast]

You might need bigger pins. Wiki formula:


To work out the force to shear a 25 mm diameter round steel EN8 bright;

Area of the 25 mm round steel in mm2 = (12.52)(π) ≈ 490.8 mm2
0.8 kN/mm2 × 490.8 mm2 = 392.64 kN ≈ 40 tonne-force
40 tonne-force × 0.6 (to change force from tensile to shear) = 24 tonne-force

i would of thought the holes would oval before it shears the bar????

would of thought the thinnest material would go first which is the holes

 

[powderblast]

You can go bigger but they get through lots of electric
https://www.weldingsuppliesdirect.c...rocess-mig-welder-dual-voltage-230v-400v.html
This will go on a 32a supply but they do bigger 230v machines.

to be fair most of my welding is more 3mm box so this welder has done me fine but on the odd occasion i do weld thicker stuff i would love a larger machine

 

[balmerchris]

Perhaps, but I didn't want to chance it, 50ton is a lot.

 

[balmerchris]

to be fair most of my welding is more 3mm box so this welder has done me fine but on the odd occasion i do weld thicker stuff i would love a larger machine

Lorch m Pro 252 control Pro would be my choice for a single phase welder, if I could afford one that is.

 

[powderblast]

Perhaps, but I didn't want to chance it, 50ton is a lot.

i agree and if this wasnt made from odd bits i would of over build it but i just looked and thought theres enough to build a press lets do it lol, but to be honest i would think it would depend on what you are pressing you are not going to be using 50 ton everytime so hope fully on the odd occasion it can cope with that force but automotive stuff i think it will be fine maybe if i was to build some sort of brake the maybe it would start to destroy itself.

i have watched youtube clips of 50-100 ton machines pressing on flat bar and it never cut through the metal only bent it so hopefully the pins will be ok (i hope)

 

[powderblast]

Lorch m Pro 252 control Pro would be my choice for a single phase welder, if I could afford one that is.

thats one nice machine with a decent price tag i would be happy with yours if it was single phase, there has to be a difference also between single and three phase machine because the beads look so much nicer on a three phase unit

i once bought aload of gear from a guy who got it from a collage all three phase (bought as a job lot for the lathe and put a vfd on it) and i sold the rest of the stuff in it was an old Elliott three phase pillar drill and they guy who came and bought it said that there is not comparison in motors three phase are better not sure why again i have never played with three phase gear i wish i never got rid of that pillar drill now

 

[balmerchris]

I have a 3 phase elliot pillar drill in pieces in the spare room just need some free time and dry weather to paint it.