Dave Propst's H Frame Hydraulic Press
#10
in this part of the article that I copied explains why the table is not easy to adjust for height

Quoted from his article.

For the uses this press sees, the above two characteristics are of much more value than any of the advantages a slip-fit pin connection provides. But in fact this adjustability with rigidity and strength does come at a price. Changing the lower cross-beam height to new positions it is not performed as rapidly as is the case with a slip-fit pin design. However, when a cross-beam height change is needed, a portable hydraulic lift table actually does the lifting and repositioning. This lift table is used instead of an integral cable winch system because that would interfere with end-load access and ram trolley motion. All that is required of the operator is to run the lift table up to the cross-beams, remove nuts from one end of each of the four shafts and pull the shafts, change the lift table height, then replace the shafts. The heavy work plate and even any workpieces, etc are left in place on the crossbeams The operation can be done by one person in five minutes versus about one minute or slightly less for changing beam height of a well-designed pinned frame with integral cable winch.

To suggest this particular press should have 'rattle-fit' pin connections and be fitted with a cable winch is to misunderstand its intended usage. It is to misunderstand the forces involved at the connections given the open-ended design. It is to be unaware of the other elaborate equipment in the shop and the type of work done with it as presented at the rest of this website. It is to attempt to find a solution to a problem that simply does not exist. This press design causes no disadvantage in our shop since this is not the only press available. This press is not a 'stand-alone' piece of equipment. Rather it is only one tool among many in a commercial fabrication operation. Therefore, when a job is more appropriately performed by a traditional, rapidly adjustable, pinned-frame press, that job is done in just such a press! On those very rare occasions when the job is more appropriately done in a large, high-tonnage press, that job is taken to just such a press at a nearby heavy fabrication shop. This press is not meant to be a one-size fits all, be-all, end-all device. No claim is made to that effect. On the contrary, this press was designed to very efficiently perform tasks that are specific to custom car fabrication as explained at Shop Overview . This press is but one small part of a larger group of tools that work togeth


DA
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Dave Propst's H Frame Hydraulic Press - by Mayhem - 10-28-2013, 09:15 AM
RE: Dave Propst's H Frame Hydraulic Press - by dallen - 10-30-2013, 07:56 AM



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