12 bladed Ransomes Ajax
With help and guidance from the FAQ section I have restored my mk3 Ajax. Having restored a mk 5 already, I was familiar with obtaining the correct bushes and bearings, As Ajax's are still readily available I had no issues with a slight deviation and making a 12 bladed cylinder from 2 six bladed ones, it was mainly curiosity to see how much better the cut would be.
I found a local powder coasters to ensure the frame handles and fittings last another 75 years, I also found a nickel platers for all the nuts bolts and shafts, it's like Christmas bolting all the bits together. I thoroughly enjoying the project and didn't rush it, over the winter I have a mk 8 certes to restore. pictures to follow once I have read the instructions ( I may need to do this from a PC not my phone )
Hi Woody. Looking forward to seeing your re-stored Ajax especially the 12 blade cutting cylinder! Cheers. Rob
i have inserted the pictures,hopefully they have loaded ok , it was great fun to do. it was my first go at welding so that took some time, i got th ecylinder profesionally sharpened so it was true, it cuts really well but only on short grass :-)
That cutting cylinder along with the rest of the mower looks absolutely fantastic Woody. Well impressed.
I can now strip an Ajax in 15 minutes, they are a joy to work on, it was my Covid project so I had plenty of time, removing the bearings was tricky but I found a carefull application of heat gave different expansions to the steel and aluminium where this was made easier. Replacement of the sintered bushes was tedious and involved careful cutting through but makes a world of difference. It is like a sewing machine now, makes a beautiful noise and I'm delighted with the results. I aim to restore a certes over this winter and will take my time
Crikey, 15 minutes that is very impressive. Completely beyond my skills set!! Out of interest how long did it take you to fabricate the 12 blade cutting cylinder? Looking forward to seeing the Certes when completed.
The cylinder was done in a couple of weeks, I used two cylinders so I had blades that were of the correct size and profile, I carefully cut the blades from the donor cylinder and set them into the other one, using a mig welder for the inside welds and TIG on the outside ( you couldn't get the TIG to fit for the inside ones) this was more straightforward than I thought it would be, the biggest issue was then to ensure the blades were perfectly aligned, this was achieved by getting it professionally sharpened which then ground the blades to a uniform height. Careful masking of the edge and then primer and topcoat gave a nice finish.
Fantastic!! Cheers Woody
Very nice job woody and certainly an engineering challenge well done, however is the cut significantly better?Only saying as the Ransomes Ajax was designed with a 6 blade cutting cylinder in which the rotational speed is determined by a specific gear ratio. When adding more blades to a cutting cylinder is there also a need to up the rotational speed of the cutting cylinder?
I can say the cut is much better, perhaps not twice as good though. It is not possible to change the gearing of the Ajax ( not impossible but perhaps impracticable) so drawing inspiration from other articles on the forum, adding extra blades increases the amount of cuts in a given length of push forward.
a drawback is that you cannot cut longer grass as it will not feed into the cylinder. In practice this means to get a good finish you need to cut at least every 3 days or less.
I did it for fun and to keep busy whilst we were locked down, as soon as my garden machinery shop opened I took the cylinder in, aesthetically it looks great although I'm bias and it does cut better, my only thought is it might put extra wear on the gearing, I have new RL5 bearings and sintered bushes and by using an oil gun every other use I hope it will last another 70 or so years.
Ajaxs are straightforward to strip and repair and machines are easily obtainable, this is why I had no qualms cutting up an old cylinder.
I hope someone else has a go at something unusual and look forward to seeing their efforts
One further point, is that as the article suggests it is harder to push.
it was the article you found that provoked me to add the blades, it was purely an indulgence to see what the benefit would be