Need an advice. Press consrtuction.
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
Need an advice. Press consrtuction.
Dear members of this unique web resource,
I am going to produce snowboards in small amount.
Having read a lot of information here I came to the conclusion that I beam press is most popular.
I have attached a few drawings of I beam section and general view of future press.
Also I have some questions for people with experience.
I know that welded I beam is not that good as cast one, so I will use last one. Also I am going to use bolts instead of welded joints for better demolition in future. Is the usage of bolts is suitable?
The main question is about deflection. What do you think about chosen cross-section? Is it reasonable to make it smaller of bigger? The section have to withstand 80 psi. Am I wrong?
I am going to produce snowboards in small amount.
Having read a lot of information here I came to the conclusion that I beam press is most popular.
I have attached a few drawings of I beam section and general view of future press.
Also I have some questions for people with experience.
I know that welded I beam is not that good as cast one, so I will use last one. Also I am going to use bolts instead of welded joints for better demolition in future. Is the usage of bolts is suitable?
The main question is about deflection. What do you think about chosen cross-section? Is it reasonable to make it smaller of bigger? The section have to withstand 80 psi. Am I wrong?
Greeting )
Just need to checked whether you have seen Chrismp's press. Quite possibly the most effective design - just missing a thermal cover )
Enjoy:
And there are a couple of factory video's with this type of press design:
viewtopic.php?t=3173
- Kingswood
- Crisp Custom
- and one of the big boys (they can be seen in the background), I just can't remember which video it is.
Just need to checked whether you have seen Chrismp's press. Quite possibly the most effective design - just missing a thermal cover )
Enjoy:
And there are a couple of factory video's with this type of press design:
viewtopic.php?t=3173
- Kingswood
- Crisp Custom
- and one of the big boys (they can be seen in the background), I just can't remember which video it is.
Who can tell me, what is allowable deflection in the middle of the beam?
The materials in my country are really expensive now. I would like to choose the cheapest way to construct my press.
I have applied the force equal to 80 psi to the bottom and to the upper part of the press. Is it right?
PS all dimensions are in millimiters ( 1 inch = 25.4 mm) (2500 mm = 98.43")
Thank you in advance
The materials in my country are really expensive now. I would like to choose the cheapest way to construct my press.
I have applied the force equal to 80 psi to the bottom and to the upper part of the press. Is it right?
PS all dimensions are in millimiters ( 1 inch = 25.4 mm) (2500 mm = 98.43")
Thank you in advance
Put a fixed center post in the back of your frame and a removable post in the front an re-run your simulation. Those bars on the top of your frame aren't doing anything to prevent deflection.
80 psi might be high, 50-60 is more typical of what most of use.
80 psi might be high, 50-60 is more typical of what most of use.
Fighting gravity on a daily basis
www.Whiteroomcustomskis.com
www.Whiteroomcustomskis.com
Watch the Kingswood video closely at 4:42
Also, Falls' press (minus the locking handle):
www.skibuilders.com/phpBB2/viewtopic.ph ... 1&start=30
I'm glad this was brought up, as I've been meaning to ask, does anyone know what kind of locking mechanism Kingswood used for the handle? At first, I thought it was just mechanical, but if you pause the video at 4:50, it appears the handle may be locked in place pneumatically.
Edit: Upon further review, it appears as though the pneumatic system touching the handle could be some sort of valve that will only allow the bladders to inflate if the handle is locked in place.
Any insight would be appreciated.
Also, Falls' press (minus the locking handle):
www.skibuilders.com/phpBB2/viewtopic.ph ... 1&start=30
I'm glad this was brought up, as I've been meaning to ask, does anyone know what kind of locking mechanism Kingswood used for the handle? At first, I thought it was just mechanical, but if you pause the video at 4:50, it appears the handle may be locked in place pneumatically.
Edit: Upon further review, it appears as though the pneumatic system touching the handle could be some sort of valve that will only allow the bladders to inflate if the handle is locked in place.
Any insight would be appreciated.
My design is very similar.
I used 360UB50.1 universal beam , which is 360mm deep and from memory the web is only 6 or 7mm thick and the flanges approx 175mm wide x 12mm thick. So just a little bit deeper beam than you are proposing.
My press beams are 2.5 metres long. 2 on top 2 on the bottom so its 350mm wide. using small section of UB at each end as the separating section between top and bottom beams.
Bolted together with 32 of 25mm 8.8 HT bolts, 8 per joint.
For curiosity , I tested up to 120psi my full compressor output and the was negligible deflection like 1-2mm I am pretty sure, and that was with the twin air bag hoses laid flat and well packed so they were getting maximum surface area bearing on the profiles. Of course I stood well back while I did this!
My theory was build it with what I could find locally available, the bolts were $1 each I stumbled accross them, so no brainer use them, maybe I coudl have used smaller but thats what popped up. Same with the steel beams I looked at typical presses and found some similar steel, on the big side so I assumed it was safe. The maths is too complex for me so I just went bigger with my gut feel.
I love my side loader press and wouldn't do much different if I ever built another one.
The "clamshell" upgrade with heavy hinge at one end and locking pin at the other , with air rams to lift/hinge up the top beams, was the key to super easy loading. with this I can quickly and precisely load the ski/board cassette without having to wrestle the gooey layup cassette into a tight slot. Same as the presses with the bottom jacks to liftt he bottom beams its so good to have the clearance when putting the cassette into the press. Some people don;t find they need it but for me as a one man band I find it super helpful. I'll try find a pic to post.
cheers
Rich
I used 360UB50.1 universal beam , which is 360mm deep and from memory the web is only 6 or 7mm thick and the flanges approx 175mm wide x 12mm thick. So just a little bit deeper beam than you are proposing.
My press beams are 2.5 metres long. 2 on top 2 on the bottom so its 350mm wide. using small section of UB at each end as the separating section between top and bottom beams.
Bolted together with 32 of 25mm 8.8 HT bolts, 8 per joint.
For curiosity , I tested up to 120psi my full compressor output and the was negligible deflection like 1-2mm I am pretty sure, and that was with the twin air bag hoses laid flat and well packed so they were getting maximum surface area bearing on the profiles. Of course I stood well back while I did this!
My theory was build it with what I could find locally available, the bolts were $1 each I stumbled accross them, so no brainer use them, maybe I coudl have used smaller but thats what popped up. Same with the steel beams I looked at typical presses and found some similar steel, on the big side so I assumed it was safe. The maths is too complex for me so I just went bigger with my gut feel.
I love my side loader press and wouldn't do much different if I ever built another one.
The "clamshell" upgrade with heavy hinge at one end and locking pin at the other , with air rams to lift/hinge up the top beams, was the key to super easy loading. with this I can quickly and precisely load the ski/board cassette without having to wrestle the gooey layup cassette into a tight slot. Same as the presses with the bottom jacks to liftt he bottom beams its so good to have the clearance when putting the cassette into the press. Some people don;t find they need it but for me as a one man band I find it super helpful. I'll try find a pic to post.
cheers
Rich
MonkeyCAM and SnoCAD - https://github.com/mikemag
Ski binding mounting https://github.com/splitn2/DrillSki
Richard Harcourt | www.splitn2.com | Christchurch New Zealand
rich@splitn2.com | www.facebook.com/splitn2
Ski binding mounting https://github.com/splitn2/DrillSki
Richard Harcourt | www.splitn2.com | Christchurch New Zealand
rich@splitn2.com | www.facebook.com/splitn2
Dude.
Quick, easy and cheap to make aka: Mongo style press.
http://www.skibuilders.com/phpBB2/viewt ... e0ef4a5464
The best example has been built by Chrismp.
You need to look at his press in terms of effective control of the cure cycle. A thermal cover would help this design, as it would retain the heat, reducing costs. Once enough heat has been applied, remove the cover and the lack of physical mass ensures the mold cools quickly and at the required rate. This means you have effective control over the cure cycle.
Deflection of the bottom mold is the only issue you should be concerned about ... subject to safety considerations.
An I-beam press is fine - until the rent goes up, or you need to make another. Do you have the engineering, fabrication skills to make a mongo style press?
Quick, easy and cheap to make aka: Mongo style press.
http://www.skibuilders.com/phpBB2/viewt ... e0ef4a5464
The best example has been built by Chrismp.
You need to look at his press in terms of effective control of the cure cycle. A thermal cover would help this design, as it would retain the heat, reducing costs. Once enough heat has been applied, remove the cover and the lack of physical mass ensures the mold cools quickly and at the required rate. This means you have effective control over the cure cycle.
Deflection of the bottom mold is the only issue you should be concerned about ... subject to safety considerations.
An I-beam press is fine - until the rent goes up, or you need to make another. Do you have the engineering, fabrication skills to make a mongo style press?
The Mongo press was just the starting point (as far as I am aware). I would be cautious with the design - too many issues
Have you're head around this thread:
viewtopic.php?t=2044&postdays=0&postorder=asc&start=15
You want to contain the pressure using an external frame work - per the press shown by Chrismp in his video. Yes - shearing a bolt would be a bad thing. So its a matter of using the right bolts and the correct thickness of steel.
The Mongo press has no safe guard in place for the failure of a weld.
Have you're head around this thread:
viewtopic.php?t=2044&postdays=0&postorder=asc&start=15
You want to contain the pressure using an external frame work - per the press shown by Chrismp in his video. Yes - shearing a bolt would be a bad thing. So its a matter of using the right bolts and the correct thickness of steel.
The Mongo press has no safe guard in place for the failure of a weld.