Thank you folks for your kind words - I really appreciate it. All of this was possible because of fantastic job of Maslow - thank you Bar. Maslow gave me possibility to create and broke the mould what is possible and what is not. Another issue is support - when I was building Maslow, I’ve got excellent advice from all over the world. Thanks to Maslow community I solved my mechanical and software problems on the spot. It took me only 2 weeks to assemble and debug my Maslow!.
I think that with current experience I will make a second build of Maslow. There is a slight issue with accuracy - distortion in x-direction, so I need more rigid frame and definitely new sled.
Overall a lot of fun and open possibilities - most important robust workflow from concept to design, machine readable G code, CNC, fabrication. And all of it in my own garage without mortgaging my wife and my dog
Thank you guys
Hey kayaker37 - I logged around 70km so far and boat behaves quite well. Stable, fast and easy to launch from shore or deck. I am using Endomondo to record speed and distance - max speed 12.5km/h; easy to maintain 6.9km/h. I’ve build her too strong - two layers of 400g/m2 so she weights 20kg - should be lighter. Outrigger design was total disaster - too flimsy. After 5 iterations I decided on classical moving seat. Now boat is good 0.5m too short and my position must be moved good 20cm afore. I will do a second build: 5.2m long, about 3cm taller, 5cm narrower. But before I have to rebuild my Maslow: Y-dimension is squashed by 2cm vs my design values. I think that wooden frame, my clumsy sled and Bosh router is to blame. I have to fix it.
Here is fall picture from Warta river
I’ve build second version and it works! I row 150 km in 3 days on Warta river and it was great.
Here is picture of her - she was build using the same method but on my new Maslow Mark II. Because Mark II is much more accurate, I had way less fairing and sanding.
How does Maslow Mark II differ from your first?
I finally mounted the sled, have to get foam material and figure out calibration, and get a permanent computer figured out. It was 28 degrees Fahrenheit in my garage this am, not in rush.
I’m working on a similar project but because I have no Maslow I’ve just been cutting out the hull sections with printed paper templates and a jigsaw. Reading this post has made me wonder though, perhaps a Maslow could be used to directly cut the sections of foam? One would have to use thinner foam sheets and it would create lots of sawdust (or foam dust rather) but could be an interesting possibility.
On a less speculative note, I am wondering if you can help me with a few unsolved problems I still have before I can glass the hull.
First off, did you rough up the foam before glassing or do anything to prevent delamination between the foam and the fiberglass? Have you seen any delamination in your hulls? On your second version, what weight of cloth and how many layers did you use?
Second, how did you secure fittings and such to the hull? It looks like the riggers are bolted right through the gunwale but what about the foot stretcher and slides? Also, for the foot stretcher and slides, did you place any wood under the fiberglass to spread out the force or did you find that the fiberglass could hold the strain?
Finally, did you make the riggers? If not, do you know where I could order a pair?
Thank you so much and congratulations on the incredible work.
Welcome to our community!
I am glad to be of help - I would love to see your design and I will keeping my finger crossed for your success. Here are my answers:
Cutting sections directly - yes, it is possible but you loosing one big advantage of wire cutting. Maslow is 2D and you can cut only the biggest profile: every station of my boat is slightly smaller if you going from midship towards bow or stern. Using both stations patterns for cutting slice of styrofoam I am achieving almost 3D effect (for example you holds a “sandwich”: station 23-styrofoam-station 24 and moving with your hands a sandwich such way that hot wire slides on both edges - believe me, it works and is better than 5 axis robot - cost much less ;-)) ).
Every slight imperfection in shape cost you a lot of fairing and sanding. Maslow cuts 2D and your hull will have steps on every station - you generate a lot - I mean - A LOT of sanding.
Delamination: when I am fairing styrofoam hull I am using long board and 120 sand paper. Surface is rough and absorbs epoxy - I did not experience delamination - keep in mind that I using XPS (closed cells styrofoam). It has good epoxy adhesion, low water absorption and much higher density than ordinary styrofoam - also much easier to work with. What needs to be roughed up are surfaces in between slices as slabs of XPS have shining finish. You do not need any gaps between slices and glue sticks better to sanded surface.
Cloth schedule: my objective was to be as light as possible for easy launching and transport on the roof of my VW Transporter. On my first shell I used 2 x 400 g/m2 (be careful when converting to oz/sq.yard - it depends on twill) and shell was 21- 22kg. I though that it is too heavy and my next shell I did: bottom - 2x200 g/m2; top - combination of 1x100g/m2 of carbon fibre and 1x 200g/m2 glass - plus carbon reinforcement on gunwale and cockpit. And this was a mistake! She weights 20kg and on my trip I made several dents by hitting rocks and walking on her. I never broke anything but she is a little on delicate side. My advise - be rather generous on cloth; more layers of thiner material are better; forget about carbon fibre - if you not vacuum bagging you not gaining weight and cost you more. It is hard to achieve less than 20kg in amateurish workshop.
Double check your design on longitudinal stiffness! At 5m length I see a small flexibility when I am lifting her by bow fully loaded.
Fittings: you’ve nailed problem good question! I thought that drilling a hole, pouring thicken with micro bubbles epoxy and sinking bolts will suffice. Men I was wrong! I ended up with reinforcing screws with SEVERAL layers of heavy cloth - specially foot stretcher which exerts both pulling and pushing forces. Bolting riggers through gunwale is good idea but still I laminated through an aluminum tubes for reinforcement. Under slider there are no big side or up forces as your weight is always down but under stretcher definitively you need reinforcement. Hardwood laminated between layers of cloth will be sufficient but watch potential rot problem in future. Riveting works for bungee cords hooks for holding camping gear but not for carrying handles which I put on the transom and bow - those needs reinforcement as well.
Riggers: At first I wanted to buy it too but it is custom boat build to my hight, arms length, tights length etc. Additionally I wanted her to be easy de-riged for transport. It takes me 30min to put her on the roof, drive to lake, rig her and enjoy rowing. So I designed identical port and starboard outrigger and build a wooden pattern/holder as on the pictures below.
Then I cut pieces and fitted to each other, as my holder kept structure as designed - a lot of elbow grease but with quality files (flat, round and semi round), custom made vice to hold pipes you can do it - clock-master precision is not required as small gaps will be filled during welding.
And here is the most difficult part - find a friendly welder with TIG welding machine for aluminum - my parts are 2mm thick so it is quite delicate job. Fortunately I found THE guy - I took holder and all parts to his shop, we figured out order of welding and piece by piece we put it together. As port and starboard rig are the same we used the same holder. Wood of the holder burnt a little but after several hours and $50 I had everything: rig, stretcher and slider.
I had to add about 3 inches of heavy padding on top of the seat to move my butt up as shoes are a little too high - other option would be to dig my feet down into flor which will require redesign stretcher and a little fibreglass job, well next season
Shoes are typical, from the shelf shoes for … road cyclist ;-o Its waterproof, have two screws at the sole and velcro straps. Rowers supplier wanted from me 180 EURO! Identical one for cyclist in the shop like Sport Check, cost 60 Euros!!! No brainer…
Sculls are Concept 2’s Bentam Compact with medium stiffness Ultralight carbon fiber shaft - it is fantastic for my recreational rowing and I easily maintain avg speed 8.5km/hr on 10km (4.5kn) and I do 500m in calm conditions at 9.6km/hr (5.2kn)
Not bad and I think that she looks pretty