Propblocks.com

Unfortunately due to a lack of suitable blade stock, I am currently not cutting any more prop blocks. When/if I am able to procure more blades, I will start up again.

Instead I have switched to making fiberglass forms to build off of or form props from.

Either Fiberglass molds of my existing blocks or Fiberglass molds with camber for forming sheet props, available in any pitch and a choice of cambers.

In the meantime, FliteTork digital Torque meters are available now.

A couple of new products coming up:

  1. wire-based torque meter meant to measure torque at the end of a flight, or for setting up VP hubs. Will be available soon.

I am no longer selling custom cut prop blocks.

I am also taking over production of the FliteTork digital torque meters. See the tab above for details.

F1D Template sets have arrived and are shipping. See the Misc stuff tab for information.

E-mail me at propblocks@gmail.com in order to place an order.

Pricing including First Class postage to US for Helical forms in Fiberglass:

  • 8″ @ $22
  • 10″ @ $25
  • 12″ @ $27

For non-helical, I typically charge $2 extra for the setup. You will need to contact me with your specifications in order to get it set up. These may take a couple of weeks to make and send.

Treger forms – $27 shipped.

I accept PayPal (at propblocks@gmail.com) or checks: Contact me at propblocks@gmail.com for postal address.

I do ship Internationally and charge only what the post office charges me.

Adding camber to blades

Camber form being tied to block.

Camber form being tied to block.

I wanted to document how I added camber to one of my blocks.

After choosing a blade size, I selected a bit of light A-grain balsa that bent easily around the form. Choosing the right piece of balsa makes life easier.

I cut this piece in a rough rectangle larger than what the blades would be then sanded an arc into the blank. 150 grit sandpaper does wonders on light balsa.

The blank was then soaked in water for around 10 or 20 minutes. A center reference line was drawn on the block and marked at each inch.

I knew I wanted a blade no larger than 14″ diameter, so the blank end was set at 7″ on the block. The bottom edge was aligned with the reference line and I wrapped the blank with thread tightly every 1/4″ or so. In one spot I added a 1/16″ square bit to hold it down more tightly.

The entire bit was popped into the oven and set to ‘Warm’. Once heated, I turn it off and let it dry overnight.

The following day I used thinned Ambroid – A drop every 1/4″ or so on the edge keeps the camber form in place. After the glue dries, the thread is removed and any obvious lumps/bumps are sanded smooth.

Recommendation for model types

F1D – Prop pitches vary from 26″P on the low end up to 35″P on the higher end. Some use washed out tips, others stick with the helical distribution. 27″ to 31″ are good starting points. Diameters can vary from 17.5″ to a bit over 19″.

LPP – 22″ to 26″P seem to be common. Some swear by washed out tips 24″ to 20″ near the tip.

Ministick – 14″ – 16″P seems to be common.

HLS seem to be similar to F1D, maybe average a little higher in pitch. 32″ to 35″ seems common. 18-21.5″ diameter.

Kang Lee recommends:

F1L:  14″ diameter and 26 to 30″ pitch

800 mg EZB: 14 x (26 to 28″P)
600 mg EZB:  13.5 x (24 to 28″P)
400 mg EZB:   13 x  (24 to 28″P)
300 mg EZB:   12 x  (18 to 24″P)
Bill Gowen uses a 28″P block with 2 degree washout at the tips for both F1M and F1L. F1L blades do not reach the washed out portion.

Treger block measurements

Here is some info from #14 in the stock… Measured with a new digital protractor.

Inches Computed Angle Local pitch Measured angle
1 76.41 26.00 75.6
2 64.20 26.00 64.2
3 54.06 26.00 54.2
4 45.97 26.00 45.2
5 39.61 26.00 38.9
6 34.59 26.00 34.1
6.5 32.50 26.02
7 30.10 25.50 29.9
7.5 27.50 24.53
8 25.10 23.55 25.1
8.5 22.80 22.45
9 20.80 21.48 20.7
9.5 18.90 20.44 19.0
10 17.30 19.57 17.6