AdamG Posted August 11, 2017 Author Share Posted August 11, 2017 Thanks, I have looked at your press. Maybe I should have done something like that, but I tried to start simple (avoid hydraulics). I have been thinking of replacing my jack with a single or two small cylinders and a power pack like this: https://www.princessauto.com/en/detail/2-stage-12v-dc-multifunction-hydraulic-power-unit/A-p8541666e I think the width of my frame is a bit excessive, and there's only the two 2.5 x 0.25" wall tubes for structure, so I'm a bit nervous of putting a hydraulic load on there, even if it's only a single 2" or 2.5" cylinder, or two 1"-1.5" cylinders. Any comments? Sorry, I meant this power pack: https://www.princessauto.com/en/detail/2-hp-ac-2-stage-multifunction-hydraulic-power-unit/A-p8677239e Quote Link to comment Share on other sites More sharing options...
the iron dwarf Posted August 11, 2017 Share Posted August 11, 2017 that sort is ok for a few minutes use, I tested a similar one a while ago and with continuous use the oil boiled in 8 minutes, mine is ok with 8 hours also that is 2 speed which means time to change over, mine is always on full power and mostly it takes less than 1/4 second from the press starting to move until it is fully in contact with the work which would mean for yours to move at high speed and internally change to high pressure would take longer than mine on high pressure all the time. you also need to add a double acting solenoid valve to that pump to control it. will go look at your frame next Quote Link to comment Share on other sites More sharing options...
AdamG Posted August 11, 2017 Author Share Posted August 11, 2017 Hmmm. Good to know. Do you sell yours? Can't find a website etc. Even if you do, could you get something like that across a border? I could look at making one myself, but the point of this thread is that I'd rather get back to forging! Also, I think that power pack has an internal bypass, so it uses the fast flow/low pressure to get the ram moving, and then the slow flow/high pressure once it hits resistance. I was going to use electric foot pedals for up and down, and maybe interrupt the signal with roller switches for the top of the travel. Quote Link to comment Share on other sites More sharing options...
the iron dwarf Posted August 11, 2017 Share Posted August 11, 2017 IF the welding was done perfectly I would still not want to use it for more than a couple of tons and I would test it remotely to double what I was going to use it at and always work out which way things will go for every possible failure point. on something like that I may go up to 1/4" 7018 rods, thicker metal and better design table 1" thick with 4 by 2 box on edge on both sides, some triangulation at the top and when testing it use a dial gauge to see if things move under load 9 minutes ago, AdamG said: Hmmm. Good to know. Do you sell yours? Can't find a website etc. Even if you do, could you get something like that across a border? I could look at making one myself, but the point of this thread is that I'd rather get back to forging! Also, I think that power pack has an internal bypass, so it uses the fast flow/low pressure to get the ram moving, and then the slow flow/high pressure once it hits resistance. I was going to use electric foot pedals for up and down, and maybe interrupt the signal with roller switches for the top of the travel. yes I sell them, yes it can go across a border. yes your power pack with have an internal valve to change speed but that takes time, even if it is a fraction of a second it means it might as well have been on full pressure from the start. you want limit switches for both top and bottom travel settings and make them easy and fast to set, mine I just spin a nut to change it. also for slitting or drifting you need to add a stripper plate or you will have hot metal stuck on the tool and the cylinder getting hot while you struggle to remove the tool Quote Link to comment Share on other sites More sharing options...
AdamG Posted August 11, 2017 Author Share Posted August 11, 2017 Ok, thanks. Please PM me with your website. Also, I just unhooked the pneumatic actuator I had made for the jack's pressure release, and sure enough, when closed right I get more pressure. I think your cautions still apply though. I made a stripping bottom die and I'll make a few different top punching dies but I'll have to be careful and maybe not use this for more than some lighter work. Quote Link to comment Share on other sites More sharing options...
AdamG Posted August 12, 2017 Author Share Posted August 12, 2017 And on a slightly different topic (different machine, also made by me)... Quote Link to comment Share on other sites More sharing options...
Jbradshaw Posted August 12, 2017 Share Posted August 12, 2017 Does anyone have any thoughts on a bolt together version of this style of press? Quote Link to comment Share on other sites More sharing options...
arftist Posted October 15, 2017 Share Posted October 15, 2017 7018 is a code rod, fast fill slow freeze. It runs best uphill works flat too.. 7014 is similar but works in more positions including downhill. Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 15, 2017 Share Posted October 15, 2017 On 8/12/2017 at 12:24 PM, Jbradshaw said: Does anyone have any thoughts on a bolt together version of this style of press? Yes. How much do you know about fabrication and equipment design? A number of us could build a safe enough version of one but it's not something I personally feel comfortable instructing folk online. I'll point out mistakes, especially dangerous ones but if you wish to build one yourself. Buy a proven set of plans and ignore Youtube videos. If you're still unsure, take a basic metal shop class, if you pick it up quickly enough the instructor might give you a hand. Any press is a mechanical bomb and energy being energy is drawn (law of physics) to the path of least resistance, the weak link. A failure under pressure can result in metal in the air and flying metal is shrapnel. Bolts are natural shear points and make fine shrapnel. When I was taking occupational heavy metal shop in High school about the closest acceptable project to a mechanical device like a press was an engine stand. That was an advanced class you couldn't even apply or test for it without having passed metal shop 3. After graduation I certified as a welder fabricator with one tech school class. Nobody is even going to give a high school grad a cert tests without a trade school diploma. I'm not trying to discourage you from building equipment for your shop, I just don't want to read about you, family or friends in the prayers section. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Jbradshaw Posted October 15, 2017 Share Posted October 15, 2017 1 hour ago, Frosty said: Yes. How much do you know about fabrication and equipment design? Frosty I'm not sure how to answer this, which may be a warning sign. But I can layout and drill holes accurately. There are multiple plans available for these presses (all welded versions though) and I do have copies of a couple of them (very similar to each other). And I do plan on welding using flux core wire. But I thought a redundant set of fasteners may add a level of safety, hence the question. What i was thinking is to reinforce the critical joints with a 3/4" grade 8 bolt (shear strength 40200 lb) on each side of the joint. That should distribute the force between the two bolts so there is 20,000 lb. to each bolt (using a 20 ton air over hydraulic jack). With the structure being built from square tube that would give each bolt two shear plains, so 10,000 lb per shear plain. So a safety factor of 4x. When considering that the force would be distributed to two joints (a total of four 3/4" grade 8 bolts), that should cut the numbers each bolt is exposed to in half again. If I were relying solely on the fasteners I would think that I would need at least two on each side of each joint to take any play out of the joint. I am a pharmacist not an engineer. So if the thought process I laid out above is faulty please fire away. I'd rather be dumb than dead. Quote Link to comment Share on other sites More sharing options...
BeaverNZ Posted October 18, 2017 Share Posted October 18, 2017 Structural bolts are often called friction grip bolts meaning when they are tightened correctly the two surfaces they are clamping together have enough friction so the bolt is under no or little shear loading. Often the bolts are done up to a certain light torque and then tightened a set amount of degrees with a strong arm bar or a flogging spanner Cheers Beaver Quote Link to comment Share on other sites More sharing options...
Frosty Posted October 19, 2017 Share Posted October 19, 2017 I asked because I got the impression you wanted to build one without welds. Using bolts to reinforce critical points can be beneficial. I just wasn't clear about what you were asking. Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Jbradshaw Posted October 19, 2017 Share Posted October 19, 2017 I worded it that way intentionally hoping to begin some discussion about the feasibility of doing a bolt together version for people that don't have access to a welder. I ran my thought process above by a mechanical engineer friend that trains at the same Muay Thai gym as me. Unfortunately he did not want to give a firm answer without running some math. Quote Link to comment Share on other sites More sharing options...
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