Note: This is only a tiny part of my AM8 upgrades. You can find the links to the other parts at the bottom of the description.
I wondered why there were no rigid and lightweight h-plates available for the A8/AM8, thus i had to design and manufacture my own. The goal was to increase the stiffness while lowering the wheight of the plate significantly. I achieved both goals and even exceeded my own expectations.
This h-plate constists of three parts (two side plates and the main plate) which are made from 2.5mm thick material. You can choose between aluminium, fiberglass and carbon. I used 2K epoxy to glue the parts together.
This h-plate supports the common 220x220 heatbeds with 209x209mm bore pattern (M3 holes). The bore pattern for the belt mounting is 12x20mm. You can mount SC8UU compatible housings or LM8UU/LM12UU bearings with zipties.
Note: There's also a special "extra wide" middle plate available which you can use for up to 16mm in diameter silicone dampers instead of springs. It's 5mm wider than the normal version (230x220mm instead of 225x220mm).
What to expect (weight + stiffness)
The stock h-plate weighs about 240 grams. My version made from 2.5mm carbon fibre (density 1,5g/cm³) weighs in at just below 70grams. If you fabricate this from fibreglass (density ~1,8g/cm³) you can expect around 85g, and in aluminium it should weight around 125 grams.
In carbon it's by far more rigid than the stock plate. I expect fibreglass and aluminium to behave accordingly.
BOM / materials
You will need 3 pieces of the chosen material. The middle plate is 225 by 220mm in size, while the sides are 220 by 25mm in size. So everything will fit on a plate which is 225x275mm plus a bit of material to allow for cutting.
It's strongly recommended to either use a laser cutter or a milling machine for this.
The files are available as STEP, STL and DXF.
Remix & Sources
There are STEP sources available in the files section. Happy to see improvements and remixes of this plate :)
You might also want to have a look at:
my reinforced Z axis with 12mm linear rods
my Y axis 12mm upgrade
my horizontal Y belt upgrade
my SC8UU compatible 12mm housings for sinter bearings:
The reinforced X tensioner using proper bearings and a motor pulley: