Let's Build a Press

Capt C

Capt C

Saltwater Cowboy
Ginger Viking said:
I do think I will change the bushings for bearings. I know it will run a lot smoother but will add to the cost. It will be worth it. I will probably use metric bearings and shafts because I can get metric bearings cheaper.
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@Ginger thanks for posting the tensile strength of the bolts. Looks like mine are 3/8 bolts so i feel better now. I do not see the need to install the L brackets bolting it to the bench. I am not sure i follow you on the bearings.. Were are they located at? Plus i am not sure i understand this math equation posted by IrocZ. Take your plates (3x5) = 15 square inches x 1000 psi= 15,000 lbs. This is the pressure of the jack needed to hit 1,000 psi. Would this not change when you actually put something in the press like a 2x4 bag. It just seems to me that would change it to 8 sq in.
 
shimz

shimz

vapest
Ginger Viking said:
I do think I will change the bushings for bearings. I know it will run a lot smoother but will add to the cost. It will be worth it. I will probably use metric bearings and shafts because I can get metric bearings cheaper.
Click to expand...
Yes, but you may need to provide for spring return if you go that route.
 
IrocZ

IrocZ

Really Active Member
Capt C said:
I never rely thought about that@IrocZ. I think i will contact Lowtemp plates and see what kind of pressure it would take to shear those threads. I have not seen the need for any pressure over 2500 psi although i have only had 2 pressing sessions. My press did come with 2 very heavy duty L brackets to bolt to each end of the top plate and the other to bolt to the work bench. Not sure what kind of pressure it would take to shear those threads but that is a scary thought. I would have to say that having a good pressure gauge is a must with these open cage presses.
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I wouldn't worry too much about your's Capt, being manufactured and all. Your press is super sweet!

I was looking at it for Ginger's planned build :)
 
IrocZ

IrocZ

Really Active Member
Capt C said:
@Ginger thanks for posting the tensile strength of the bolts. Looks like mine are 3/8 bolts so i feel better now. I do not see the need to install the L brackets bolting it to the bench. I am not sure i follow you on the bearings.. Were are they located at? Plus i am not sure i understand this math equation posted by IrocZ. Take your plates (3x5) = 15 square inches x 1000 psi= 15,000 lbs. This is the pressure of the jack needed to hit 1,000 psi. Would this not change when you actually put something in the press like a 2x4 bag. It just seems to me that would change it to 8 sq in.
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Yes, this would change to 8 sq in when using 2x4 bags. I was looking at theoretical max amount of pressure needed for those plates.
 
Ginger Viking

Ginger Viking

Member
Capt C said:
@Ginger thanks for posting the tensile strength of the bolts. Looks like mine are 3/8 bolts so i feel better now. I do not see the need to install the L brackets bolting it to the bench. I am not sure i follow you on the bearings.. Were are they located at? Plus i am not sure i understand this math equation posted by IrocZ. Take your plates (3x5) = 15 square inches x 1000 psi= 15,000 lbs. This is the pressure of the jack needed to hit 1,000 psi. Would this not change when you actually put something in the press like a 2x4 bag. It just seems to me that would change it to 8 sq in.
Click to expand...
I think it is the sq inches of what you are pressing and not your plate size. Back to the bolt size...on a standard 2 plate cage none of the force is on the bolts. It's all on the plates. A 3 plate cage has the force on the bolts. I don't know your setup.
 
IrocZ

IrocZ

Really Active Member
Ginger, check out the attachment of Capt C's press. He posted it on another thread, and I wanted to link it so you could see it for ideas. It only gave a link to the pics, didn't actually put the pics up. You could check out the whole thread. It is one of the best looking presses I've seen.

I'm definitely watching, hoping you hit a home-run, and I can copy it :)
 
IrocZ

IrocZ

Really Active Member
FWIW, I know of a guy who wrecked his jack from the heat.

It was a standup Harbor Freight press that was used in the shop. He picked up some plates and only got like 3 squishes done before his jack wouldn't give pressure anymore. He said next time he would build the press with insulating washers.

I never saw the press, but only heard of his failure from a buddy after the fact.

It's a completely different setup than yours, so Idk if it relates. Heat does kill jacks tho.

I like that your putting quite a bit of forethought into this (y)
 
Ginger Viking

Ginger Viking

Member
I changed my design again. I made the structure posts into the guide posts. This will save a little on material costs. I have been looking at bearing and shaft costs. I can find cheap metric bearings and cheap standard shaft. Standard bearings are 3-4 times the cost of metric and metric shafting is 2-3 times the cost of standard. The most cost effective size I have found so far is 20mm. Any good sources for cheap linear rail and bearings welcome. I've already looked at VXB, amazon, and walmart. Probably buy vbx thru amazon or walmart and save on shipping.
 

Attachments

Capt C

Capt C

Saltwater Cowboy
Ginger Viking said:
It won't require springs since I'm using bearings instead of bushings. Gravity should take care of the rest.
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Hey Ginger when you do your build can you post a picture of the type of bearing you will be using in that plate. The only thing i know about bearings is axle bearings. Just curious i have never seen the type of bearing that allows a shaft thru the bearing instead of rotating around the shaft or axle.
 
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