Okay boys,
for all who is interested , I think we just about have the LD grapple figured out, we did some CAD today and plan on cutting tomorrow! Assembly shall begin!
Great to hear Markham is going to produce a LD grapple. Millonzi sold quite a few of them (many dozens) in the past year or two just to folks on TBN so there is clearly a market for an appropriately sized grapple for CUTs. I bought Millonzi's LD48 and have used it successfully for over two years. There are a few tips to pass on that you should consider in getting into this market.
There are two big points I'd try to get across. One has to do with size and the other with adapters.
A major point you skidsteer implement manufacturers need to keep in mind is that CUTs are not nearly as powerful as skidsteers and CUTs are used typically by owners on their property not by construction crews. Bottom line is that the Millonzi LD48 has held up well even on 40+hp CUTs with over 2500lbs lift capacity and that grapple was made of 3/8 inch mild steel and weighed only 280lbs. A more recent version of the LD48 was beefed up just a bit by building just the outer tines of 1/2 inch stock and adding a bit more cylinder and tine tip protection to the upper jaw but it still weighed only 300lbs and small change.
The biggest hassle Millonzi seemed to have in building these grapples was in dealing with the pin specific adapters. I know that WRLong doesn't seem to have any trouble with that issue but Millonzi struggled and usually asked the purchaser to provide the pin specifications. As Markham has always asked the customer to do their own bucket measurements you might want to think about that issue. I imagine that a little research on the major CUT brands would allow you to produce templates that would be far more reliable than getting customers to measure. Besides, I think Millonzi always custom built these pin adapters so never had a tried and true template to cut their own variation and misfit rate. Many of your potential customers will not have standard QA adapters on their CUTs so the pin adapter issue is a major consideration as you produce these things. If you can keep the price at or below what you are selling the 66 inch version you'll have a great market but most of the business will likely be for pin mounts rather than QA so it is important to get this issue front and center in your manufacturing plans.
A couple of smaller points: curving the bottom tines just a bit (see Millonzi photos) is great for getting under roots and rocks. Most manufacturers just have straight tines which seems unnecessary in these days with CAD systems and automated precision cutting. Also, making the upper jaw at about half as wide as the bottom tines seems a good ratio for holding things in place but still allowing a single hydraulic cylinder to contol it. Finally, unlike the clamshell style grapples, you don't need a lot of force on the upper jaw to keep loads in place so don't oversize the ram.
You are a small company so it might be hard to introduce a lot of new things at once but a light duty QA adapter would be another obvious product. I had a heavy duty overbuilt Horst adapter on my first tractor but now have a lighter duty stock Kioti QA adapter which would clearly be easier and cheaper to build and works just as well.
Best of luck with developing a light duty grapple for CUTs. TBN guys will beat a path to your door if you get it right.