re:  Pa, we don’t have an excavator was the statement for my middle daughters youngest boy.

https://dutchypatterns.com/

Thank you Jan, The cylinder rams were tricky for sure; the 8mm dowel was 8.15mm diameter. I used a 21/64" drill bit [8.3mm] to give the shaft clearance in the hole. Adding the BumbleChute ShopWax on the shaft and in the hole a smooth action. The tangs on the ends of the cylinders and the shafts are were I used Starbond Medium Thick CA to glue them in place. 
Cheers Peter

PS - I haven't as yet worked out how to "quote" for a reply/answer so just did a copy and paste!